Otologic Surgery [4 ed.] 9780323299770

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OTOLOGIC SURGERY

Fourth Edition

Derald E. Brackmann, MD Clinical Professor of Otolaryngology–Head and Neck Surgery and Neurological Surgery University of Southern California School of Medicine; Associate, House Clinic Los Angeles, California

Clough Shelton, MD C. Charles Hetzel Jr., MD, and Alice Barker Hetzel Presidential Endowed Chair in Otolaryngology Professor and Chief, Otolaryngology–Head and Neck Surgery University of Utah School of Medicine Salt Lake City, Utah

Moisés A. Arriaga, MD, MBA Clinical Professor of Otolaryngology and Neurosurgery Director of Otology and Neurotology Department of Otorhinolaryngology–Head and Neck Surgery Louisiana State University Health Science Center New Orleans, Louisiana; Medical Director, Hearing and Balance Center Our Lady of the Lake Regional Medical Center Baton Rouge, Louisiana

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1600 John F. Kennedy Blvd. Ste 1800 Philadelphia, PA 19103-2899 OTOLOGIC SURGERY, FOURTH EDITION Copyright © 2016 by Elsevier, Inc.

ISBN: 978-0-323-29977-0

All rights reserved. No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions. This book and the individual contributions contained in it are protected under copyright by the P ­ ublisher (other than as may be noted herein). Notices Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary. Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility. With respect to any drug or pharmaceutical products identified, readers are advised to check the most current information provided (i) on procedures featured or (ii) by the manufacturer of each product to be administered, to verify the recommended dose or formula, the method and duration of administration, and contraindications. It is the responsibility of practitioners, relying on their own experience and knowledge of their patients, to make diagnoses, to determine dosages and the best treatment for each individual patient, and to take all appropriate safety precautions. To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein. Previous editions copyright © 2010, 2001, 1994, by Saunders, an imprint of Elsevier, Inc. ISBN: 978-0-323-29977-0

Content Strategist: Belinda Kuhn Content Development Specialist: Jen Ehlers Publishing Services Manager: Patricia Tannian Project Manager: Carrie Stetz Design Direction: Margaret Reid

Printed in China Last digit is the print number: 9 8 7 6 5 4 3 2 1

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Dedication This book is dedicated to our mentors and teachers, Drs. Howard P. House, William F. House, and James L. Sheehy. Each of these outstanding physicians had special talents and characteristics that, when melded together, resulted in an outstanding clinical, research, and educational facility, The House Clinic and Institute. Howard House, the founder of our institution, was among the first to concentrate his activities in the field of otology. He devoted his career to the treatment of otosclerosis. In addition to his surgical genius, Howard was recognized as an outstanding statesman and fundraiser. Without him the House Clinic and Institute, which has provided so many opportunities for all of us, would not exist. He died in 2003 at the age of 95. At the time of his death, he was still coming to the office regularly and was active in development work for the Institute.

William F. House joined his brother in practice after completing his residency. A creative genius, Bill recognized that the future of otology lay in the diagnosis and treatment of diseases of the inner ear. He introduced the operating microscope and microsurgical techniques to the field of neurosurgery, and revolutionized the treatment of acoustic neuromas and other neurotologic problems. He is also recognized as instrumental in bringing the cochlear implant to the state of a practical clinical device as it is now widely applied. Bill passed away in December 2012 after a lengthy illness. To the very end, he pursued a number of new innovations in otology and audiology. Bill’s genius improved the quality of life for multitudes of patients. His legacy will live forever.

The final link in the chain that resulted in the success of the House Clinic and Institute was Dr. James L. Sheehy. His special interest was in the field of chronic otitis media. In addition to his outstanding surgical ability, Jim possessed exceptional talent in organizational ability and teaching. Jim was responsible for developing all the patient educational materials as well as serving as the editor for all of the many publications produced by members of the House Clinic. His course development, panel discussions, and slide preparation techniques became standards for our specialty. Jim had been a member of the House Clinic for 48 years and died in 2006. It was our great privilege to be under the personal tutelage of each of these outstanding men. In addition to all the attributes enumerated above, each was first and foremost an outstanding physician. They practiced the art and science of surgery in the finest fashion, making it most appropriate that this book on surgical technique be dedicated to them.

Derald E. Brackmann, MD Clough Shelton, MD Moisés A. Arriaga, MD v

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In Memoriam

On October 19, 1996, the field of otology lost one of its most influential leaders of modern times. Harold Frederick Schuknecht, MD, Professor Emeritus of the Department of Otology and Laryngology at the Harvard Medical School and Chief Emeritus of the Department of Otolaryngology at the Massachusetts Eye and Ear Infirmary, was a world-renowned clinical otologist, otopathologist, teacher, and scholar. His contribution to human otopathology is unparalleled. His book, Pathology of the Ear, which he solely authored, is without question the most complete and comprehensive thesis on the subject. His clinical approach and technical innovations were based on scientific principle, and he unabashedly held others to the same standard. His influence as a teacher and role model is evidenced by the unprecedented number of his students who have followed in his footsteps and have risen as leaders in our specialty. Through his life’s work and through the lives of those he has touched, his influence lives on.

Mendell Robinson, MD, known for his eponymous stapes prosthesis, passed away on September 29, 2007. A sketch on a napkin during an air flight in 1960 led to the development of this popular and successful prosthesis. Dr. Robinson was an internationally renowned otosclerosis surgeon and had a successful otologic practice in Providence, Rhode Island, for almost 50 years. He was so appreciated that the mayor of Providence officially declared “Mendell Robinson Day” on two separate occasions. We have chosen to leave his chapter unchanged from the previous edition.

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IN MEMORIAM

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As the previous edition of Otologic Surgery was going to press, we were saddened by the sudden death of our dear colleague Antonio De la Cruz. He succumbed to a malignant lymphoma after a very brief illness. Antonio was a member of the House Clinic and Institute for 34 years and director of the Institute’s Department of Education. He directed hundreds of temporal bone dissection courses at the Institute and was responsible for teaching otologic surgery to thousands of physicians. His colleagues recognized him by election to the presidency of the American Academy of Otolaryngology–Head and Neck Surgery and the American Otologic Society. Antonio participated in more national and international courses than any physician in the history of our specialty. All of us marveled at his tireless energy, which allowed him to travel at least on a monthly basis to courses around the world. In addition to his teaching activities, Antonio maintained an active otologic and neurotologic practice, benefiting many patients with his expertise. He contributed greatly in many areas, particularly in the surgical correction of congenital atresia of the external auditory canal. A former House Fellow wrote the following: “I am saddened to hear of Antonio’s passing. He had a unique ability to encourage others to perceive the skills of the expert to be achievable by them. His humble style, though, belied a high level of skill and savvy. His focused energy, his keen intellect, and his eagerness to teach all made him a great mentor and colleague, roles that touched so many of us over the last 30+ years. I am sure many, many will miss him but will forever cherish the perspective, skills, and tips he gave so freely. His contributions will live on.”

William E. Hitselberger, a giant in the field of neurosurgery, passed away suddenly on February 13, 2014. Bill joined Dr. William F. House to form the first neurotologic/neurosurgical team, which revolutionized the treatment of acoustic neuromas and other skull base tumors. Bill was criticized by his colleagues for forming this association but persevered. He participated in the removal of more than 5000 acoustic neuromas, a record that is unlikely to ever be broken. He was the first to place an electrode onto the cochlear nucleus to produce auditory sensations. This led to the development of the auditory brainstem implant. Bill was proud that he participated in the training of more than 100 neurotologists, all of whom remember him fondly. Bill’s legacy will be the multitude of patients whose lives he has improved.

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Contributors Ksenia A. Aaron, MD

Medical Resident Department of Otolaryngology–Head and Neck Surgery Keck School of Medicine of the University of Southern California Los Angeles, California

Oliver F. Adunka, MD

Professor and Director Division of Otology, Neurotology, and Cranial Base Surgery Director, OSU Hearing Center Director, Pediatric Otology & Hearing Program at Nationwide Children’s Hospital; Department of Otolaryngology–Head and Neck Surgery The Ohio State University Wexner Medical Center Columbus, Ohio

Sumit K. Agrawal, MD

Associate Professor Department of Otolaryngology–Head and Neck Surgery Western University London, Ontario, Canada

Shane R. Anderson, MBBS, MPhil

Consultant Otologist Department of Otolaryngology–Head and Neck Surgery Institute of Surgery The Townsville Hospital Queensland, Australia

Moisés A. Arriaga, MD, MBA

Clinical Professor of Otolaryngology and Neurosurgery Director of Otology and Neurotology Department of Otorhinolaryngology–Head and Neck Surgery Louisiana State University Health Science Center New Orleans, Louisiana; Medical Director, Hearing and Balance Center Our Lady of the Lake Regional Medical Center Baton Rouge, Louisiana

Joshua Bakhsheshian, MD

Neurological Surgery Resident University of Southern California Medical Center Los Angeles, California

Leonard P. Berenholz, MD

The Lippy Group for Ear, Nose, and Throat Warren, Ohio

K. Paul Boyev, MD

Associate Professor Director, Division of Otology-Neurotology Residency Program Director Department of Otolaryngology–Head and Neck Surgery University of South Florida College of Medicine Tampa, Florida

Derald E. Brackmann, MD

Clinical Professor of Otolaryngology–Head and Neck ­Surgery and Neurological Surgery University of Southern California School of Medicine; Associate, House Clinic Los Angeles, California

Craig A. Buchman, MD

Professor and Vice Chairman for Clinical Affairs Chief, Division of Otology/Neurotology and Skull Base Surgery Director, UNC Ear and Hearing Center Director, UNC Skull Base Center Administrative Director, W. Paul Biggers Carolina ­Children’s Communicative Disorders Program UNC School of Medicine Chapel Hill, North Carolina

Kim Burchiel, MD

John Raaf Professor and Chairman Department of Neurological Surgery Professor Department of Anesthesiology and Perioperative Medicine Oregon Health and Sciences University Portland, Oregon

John P. Carey, MD

Professor, Otolaryngology–Head and Neck Surgery Division Head, Otology, Neurotology, and Skull Base ­Surgery Director, Neurotology Fellowship Johns Hopkins University School of Medicine Baltimore, Maryland

Ricardo L. Carrau, MD

Professor, Department of Otolaryngology–Head and Neck Surgery Director, Comprehensive Skull Base Surgery Program The Ohio State University Medical Center Columbus, Ohio

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CONTRIBUTORS

Stephen P. Cass, MD

Robert D. Cullen, MD

Adam M. Cassis, MD

M. Jennifer Derebery, MD

Professor Department of Otolaryngology University of Colorado School of Medicine, Anschutz ­Medical Campus Denver, Colorado Assistant Professor Department of Otolaryngology West Virginia University Hospital Morgantown, West Virginia

Jon Chan, MD

Fellow Department of Otolaryngology–Head and Neck Surgery The Ohio State University Medical Center Columbus, Ohio

Ray C. Chang, MD

Department of Otolaryngology University of Miami; Department of Otolaryngology Jackson Memorial Hospital Miami, Florida

Wei-Chieh Chao, MD

Department of Otolaryngology–Head and Neck Surgery Chang Gung Memorial Hospital, Keelung Chang Gung University Taoyuan, Taiwan

Douglas A. Chen, MD

Pittsburgh Ear Associates; Director, Division of Neurotology Department of Neurosurgery Allegheny General Hospital Pittsburgh, Pennsylvania

Joseph M. Chen, MD

Chief, Department of Otolaryngology–Head and Neck Surgery Sunnybrook Health Sciences Centre Toronto, Ontario, Canada

Vittorio Colletti, MD

Professor and Director International Center for Performing and Teaching Auditory Brainstem Implants in Children Milan, Italy

Sarah S. Connell, MD

Department of Head and Neck Surgery The Permanente Medical Group Walnut Creek, California

Benjamin T. Crane, MD, PhD

Associate Professor, Department of Otolaryngology University of Rochester Medical Center Rochester, New York

Medical Director Midwest Ear Institute; Associate Otologic Center Kansas City, Missouri

Neurotologist House Clinic; Department of Otolaryngology Keck School of Medicine of the University of Southern California Los Angeles, California

Christine T. Dinh, MD

Assistant Professor of Otolaryngology Department of Otolaryngology University of Miami Miller School of Medicine Miami, Florida

John L. Dornhoffer, MD

Professor and Vice-Chairman Department of Otolaryngology–Head and Neck Surgery University of Arkansas for Medical Sciences Otolaryngologist Arkansas Children’s Hospital Little Rock, Arkansas

Robert W. Eppsteiner, MD

Resident Department of Otolaryngology–Head and Neck Surgery University of Iowa Iowa City, Iowa

Adrien A. Eshraghi, MD, MSc

Professor of Otolaryngology and Biomedical Engineering Director, University of Miami Hearing Research Laboratory Co-Director, University of Miami Ear Institute University of Miami Miller School of Medicine Miami, Florida

Jose N. Fayad, MD

Otolaryngology Unit Head Johns Hopkins Aramco Healthcare Khahran, Saudi Arabia; Clinical Professor of Otolaryngology University of Southern California Los Angeles, California

Rick A. Friedman, MD

Professor of Otolaryngology and Neurosurgery Director of Otology and Neurotology and the USC Acoustic Neuroma Center Caruso Department of Otolaryngology–Head and Neck Surgery Keck School of Medicine of the University of Southern California Los Angeles, California

CONTRIBUTORS

Takanori Fukushima, MD, MMSc

Steven A. Harvey, MD

Bruce J. Gantz, MD

Laura T. Hetzler, MD

Professor of Neurosurgery Duke University Medical Center and Duke Raleigh ­Hospital Durham, North Carolina Professor and Department Head Department of Otolaryngology–Head and Neck Surgery University of Iowa Hospitals and Clinics Iowa City, Iowa

Emilio Garcia-Ibanez, MD

Instituto de Otologia Garcia-Ibanez Barcelona, Spain

Luis Garcia-Ibanez, MD

Instituto de Otologia Garcia-Ibanez Barcelona, Spain

Gale Gardner, MD

Clinical Professor Department of Otolaryngology–Head and Neck Surgery Louisiana State University–Shreveport Shreveport, Louisiana

Michael E. Glasscock III, MD

Adjunct Professor Department of Otolaryngology-Otology Vanderbilt University Medical Center Nashville, Tennessee

John C. Goddard, MD

Otology, Neurotology, and Skull Base Surgery Department of Otolaryngology–Head and Neck Surgery Northwest Permanente PC Portland, Oregon

Samuel P. Gubbels, MD

Associate Professor Department of Otolaryngology University of Colorado, Anschutz Medical Campus Denver, Colorado

Richard K. Gurgel, MD

Assistant Professor Department of Otolaryngology–Head and Neck Surgery University of Utah Salt Lake City, Utah

Ophir Handzel, MD

Director Cochlear Implant Center Department of Otolaryngology/Head, Neck, and ­Maxillofacial Surgery Tel-Aviv Sourasky Medical Center Tel-Aviv University Tel-Aviv, Israel

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Clinical Assistant Professor Department of Otolaryngology Medical College of Wisconsin Milwaukee, Wisconsin Assistant Professor and Program Director Department of Otolaryngology–Head and Neck Surgery Louisiana State University Health Sciences Center New Orleans, Louisiana; Our Lady of the Lake Regional Medical Center Baton Rouge, Louisiana

Todd A. Hillman, MD

Partner Pittsburgh Ear Associates Pittsburgh, Pennsylvania; Clinical Faculty Department of Otolaryngology Temple University Philadelphia, Pennsylvania

Luke Hnenny, MD

Assistant Professor of Neurosurgery Regina Qu’Appelle Health Region University of Saskatchewan Regina, Saskatchewan, Canada

Howard P. House, MD†

Formerly Professor Emeritus, University of Southern ­California; Founder and Chairman Emeritus, House Clinic and Institute St. Vincent’s Medical Center Los Angeles, California

John W. House, MD†

Formerly Clinical Professor, Department of Otolaryngology University of Southern California School of Medicine; President, House Clinic and Institute Los Angeles, California

William F. House, MD†

Formerly at Hoog Hospital Newport Beach, California

Brandon Isaacson, MD

Associate Professor Department of Otolaryngology University of Texas Southwestern Medical Center Dallas, Texas

Robert K. Jackler, MD

Sewall Professor and Chair Department of Otolaryngology–Head and Neck Surgery Stanford University School of Medicine Stanford, California

†Deceased.

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CONTRIBUTORS

C. Gary Jackson, MD

J. Walter Kutz Jr., MD

Neal M. Jackson, MD

Jed A. Kwartler, MD, MBA

Professor (Retired) Department of Otolaryngology/Neurotology Vanderbilt University Medical Center Nashville, Tennessee Resident Physician Department of Otorhinolaryngology–Head and Neck Surgery Louisiana State University Health Science Center–New Orleans New Orleans, Louisiana

Herman A. Jenkins, MD

Associate Professor Department of Otolaryngology University of Texas Southwestern Medical Center Dallas, Texas Director, Ear Specialty Center Summit Medical Group Berkeley Heights, New Jersey; Clinical Associate Professor Department of Otolaryngology Rutgers Medical Network Newark, New Jersey

Professor and Chair Department of Otolaryngology University of Colorado School of Medicine Aurora, Colorado

Gregory P. Lekovic, MD, PhD

Amin B. Kassam, MD

William H. Lippy, MD

David M. Kaylie, MD

Philip D. Littlefield, MD

Andrew Y. Kee, MD

Larry B. Lundy, MD

Bradley W. Kesser, MD

J. Eric Lupo, MD

Andrew Ko, MD

William M. Luxford, MD

Vice President, Neuroscience Clinical System Program Chair of Neurosurgery, Aurora Medical Group Aurora St. Luke’s Medical Center Milwaukee, Wisconsin Associate Professor Division of Otolaryngology Duke University Medical Center Durham, North Carolina Department of Radiation Oncology Legacy Cancer Institute Legacy Health Portland, Oregon Associate Professor Department of Otolaryngology–Head and Neck Surgery University of Virginia Charlottesville, Virginia Assistant Professor Department of Neurological Surgery University of Washington Seattle, Washington

Jafri Kuthubutheen, MBBS

Otolaryngology Fellow Department of Otolaryngology–Head and Neck Surgery Sunnybrook Health Sciences Centre, University of Toronto Toronto, Ontario, Canada; Department of Otolaryngology–Head and Neck Surgery University of Western Australia Perth, Western Australia

Staff Neurosurgeon House Clinic Los Angeles, California

Otologist Founder The Lippy Group for Ear, Nose, and Throat Warren, Ohio Otology and Neurotology Department of Otolaryngology Walter Reed Army Medical Center Washington, DC Associate Professor Department of Otolaryngology–Head and Neck Surgery Mayo Clinic Jacksonville, Florida Clinical Fellow Otology/Neurotology House Clinic Los Angeles, California Neurologist House Clinic; Clinical Professor of Otolaryngology Keck School of Medicine at the University of Southern California; Clinical Associate of Otolaryngology University of California, Irvine School of Medicine Los Angeles, California

John T. McElveen Jr., MD

President, Carolina Ear and Hearing Clinic Director, Carolina Ear Research Institute Raleigh, North Carolina

CONTRIBUTORS

Michael J. McKenna, MD

Steven R. Otto, MA

Theodore R. McRackan, MD

Mark D. Packer, MD

Professor Department of Otology and Laryngology Harvard Medical School Boston, Massachusetts Assistant Professor Department of Otolaryngology–Head and Neck Surgery Division of Neurotology Medical University of South Carolina Charleston, South Carolina

Lloyd B. Minor, MD

Carl and Elizabeth Naumann Dean of the Stanford ­University School of Medicine Professor of Otolaryngology–Head and Neck Surgery Professor of Bioengineering and Neurobiology Stanford, California

Edwin M. Monsell, MD, PhD

Professor Department of Otolaryngology–Head and Neck Surgery Wayne State University School of Medicine Detroit, Michigan

Joseph B. Nadol Jr., MD

Walter Augustus LeCompte Distinguished Professor and Emeritus Chair Department of Otology and Laryngology Harvard University; Emeritus Chief of Otolaryngology Massachusetts Eye and Ear Infirmary Massachusetts General Hospital Boston, Massachusetts

Julian M. Nedzelski, MD

Professor Emeritus, Department of Otolaryngology–Head and Neck Surgery University of Toronto Consultant, Department of Otolaryngology–Head and Neck Surgery Sunnybrook Health Sciences Centre Toronto, Ontario, Canada

J. (John) Gail Neely, MD

Professor of Otology, Neurotology, Base of Skull Surgery Department of Otolaryngology–Head and Neck Surgery Washington University School of Medicine St. Louis, Missouri

James L. Netterville, MD

Professor Department of Otolaryngology Vanderbilt University Medical Center Nashville, Tennessee

Rosemary Ojo, MD

Otolaryngology Resident Department of Otolaryngology University of Miami Miller School of Medicine Miami, Florida

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Chief Audiologist and Coordinator, ABI Program Department of Auditory Implants and Perception House Clinic Los Angeles, California Neurotology Fellow, Otolaryngology The Ohio State University Lieutenant Colonel, United States Air Force Columbus, Ohio

Lorne S. Parnes, MD

Professor Otolaryngology–Head and Neck Surgery and Clinical ­Neurological Sciences Western University London, Ontario, Canada

Brian P. Perry, MD

Clinical Professor Department of Otolaryngology–Head and Neck Surgery University of Texas Health Science Center at San Antonio San Antonio, Texas

Dennis Poe, MD

Associate Professor of Otology and Laryngology Boston Children’s Hospital Boston, Massachusetts

Daniel M. Prevedello, MD

Associate Professor Department of Neurological Surgery Director, Minimally Invasive Cranial Surgery Program The Ohio State University Wexner Medical Center Columbus, Ohio

Tali Rasooly, BA

Clinical Research Assistant P.A.I.N. Research Group Boston Children’s Hospital Boston, Massachusetts

Miriam I. Redleaf, MD

Professor of Otolaryngology Director of Hearing Services University of Illinois Hospital and Health Sciences System Chicago, Illinois

Joseph B. Roberson Jr., MD Chief Executive California Ear Institute CEI Medical Group East Palo Alto, California

Daniel S. Roberts, MD, PhD Clinical Fellow House Clinic Los Angeles, California

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CONTRIBUTORS

Mendell Robinson, MD†

M. Coyle Shea Jr., MD

Joseph P. Roche, MD

James L. Sheehy, MD†

Peter S. Roland, MD

Clough Shelton, MD

Formerly Clinical Associate Professor Brown University School of Medicine Senior Surgeon, Miriam Hospital, Rhode Island Hospital Providence, Rhode Island Neurotology Fellow Department of Otolaryngology–Head and Neck Surgery University of Iowa Hospitals and Clinics Iowa City, Iowa Chairman Department of Otolaryngology–Head and Neck Surgery University of Texas Southwestern Medical Center Dallas, Texas

Jonathan Russin, MD

Assistant Professor of Clinical Neurological Surgery Assistant Surgical Director Center for Neurorestoration Keck School of Medicine of the University of Southern California Los Angeles, California

Leonard P. Rybak, MD, PhD

Clinical Associate Department of Otolaryngology–Head and Neck Surgery University of Tennessee Health Science Center Memphis, Tennessee Formerly Clinical Professor of Surgery and Otolaryngology Keck School of Medicine of the University of Southern California Los Angeles, California C. Charles Hetzel Jr., MD, and Alice Barker Hetzel Presidential Endowed Chair in Otolaryngology Professor and Chief, Otolaryngology–Head and Neck Surgery University of Utah School of Medicine Salt Lake City, Utah

David W. Sim, MBChB, MSc, DLO Honorary Senior Lecturer University of Edinburgh Edinburgh, United Kingdom

William H. Slattery III, MD

Professor of Surgery Division of Otolaryngology Southern Illinois University School of Medicine Springfield, Illinois

Clinical Professor of Otolaryngology Keck School of Medicine of the University of Southern California Head, Department of Clinical Studies, House Institute Los Angeles, California

Peter L. Santa Maria, MBBS, PhD

Robert F. Spetzler, MD

Instructor Department of Otolaryngology Stanford University School of Medicine Stanford, California

Jed Schroeder, MSc

Department of Radiation Oncology Legacy Cancer Institute Legacy Health Portland, Oregon

Harold F. Schuknecht, MD†

Formerly Professor and Chairman Emeritus Department of Otology and Laryngology Harvard Medical School; Emeritus Chief of Otolaryngology Department of Otolaryngology Massachusetts General Hospital Boston, Massachusetts

Marc S. Schwartz, MD

Neurosurgery House Clinic Los Angeles, California

†Deceased.

Director and J.N. Harber Chair of Neurological Surgery Barrow Neurological Institute; Professor Department of Surgery, Section of Neurosurgery University of Arizona College of Medicine Tucson, Arizona

Barry Strasnick, MD

Professor and Chair EVMS Otolaryngology–Head and Neck Surgery Norfolk, Virginia

Christopher A. Sullivan, MD

Assistant Professor, Otolaryngology–Head and Neck ­Surgery Wake Forest University School of Medicine; Staff Surgeon, Otolaryngology–Head and Neck Surgery North Carolina Baptist Hospital; Assistant Professor, Regenerative Medicine Wake Forest Institute for Regenerative Medicine Winston-Salem, North Carolina

Charles J. Syms III, MD

Resident Ear Medical Group; Clinical Professor Department of Otolaryngology University of Texas Health Science Center at San Antonio San Antonio, Texas

CONTRIBUTORS

Mark J. Syms, MD

President Arizona Ear Center Director of Neurotology Barrow Neurological Institute Phoenix, Arizona

Steven A. Telian, MD

John L. Kemink Professor of Neurotology Otolaryngology–Head and Neck Surgery University of Michigan Ann Arbor, Michigan

Fred F. Telischi, MD, MEE

Chairman, Department of Otolaryngology Professor, Departments of Otolaryngology, Neurological Surgery, and Biomedical Engineering University of Miami Miller School of Medicine Miami, Florida

P. Daniel Ward, MD

Assistant Professor of Surgery Department of Otolaryngology–Head and Neck Surgery University of Utah Health Care Salt Lake City, Utah

Frank M. Warren, MD

Neurotologist Providence Health & Services Portland, Oregon

Heather M. Weinreich, MD, MPH Assistant Professor Department of Otolaryngology Johns Hopkins University Baltimore, Maryland

D. Bradley Welling, MD, PhD

Associate Professor Department of Otolaryngology Sahlgrenska University Hospital Göteborg, Sweden

Walter Augustus LeCompte Professor and Chair Department of Otology and Laryngology Harvard University; Chief of Otolaryngology Massachusetts Eye and Ear Infirmary Massachusetts General Hospital Boston, Massachusetts

Debara L. Tucci, MD

Richard J. Wiet, MD

Courtney C.J. Voelker, MD, PhD

Eric P. Wilkinson, MD

Anders Tjellström, MD, PhD, D.Sc.hc

Professor of Surgery Director, Duke Cochlear Implant Program Department of Otolaryngology–Head and Neck Surgery Duke Medicine Durham, North Carolina Assistant Professor Department of Otolaryngology–Head and Neck Surgery Division of Otology/Neurotology–Lateral Skull Base ­Surgery Northwestern University Feinberg School of Medicine Chicago, Illinois

P. Ashley Wackym, MD

Vice President of Research Legacy Research Institute Legacy Health; President, Ear and Skull Base Center Portland, Oregon

Professor, Clinical Otolaryngology and Neurosurgery Northwestern University; Senior Partner Ear Institute of Chicago Chicago, Illinois Associate House Clinic Los Angeles, California

Rasim Yilmazer, MD

Neurotology Fellow Department of Otolaryngology University of Miami Miller School of Medicine Miami, Florida

Yu-Lan Mary Ying, MD

Assistant Professor, Otology/Neurotology Department of Otolaryngology–Head and Neck Surgery Rutgers New Jersey Medical School Newark, New Jersey

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Acknowledgments Publication of a book of this scope requires a tremendous effort on the part of many, all of whom I wish to sincerely thank. First, thanks to my lovely wife, Charlotte, who supports all my efforts and forgave my absence for the time devoted to this project. No less supportive are our four sons, David, Douglas, Mark, and Steven, who provide diversion and pleasure by taking me hunting and fishing. Since the publication of the third edition, one additional grandchild has blessed Charlotte and me. Lauren, Nicholas, Sammy, Kaylie, Daniel, and Megan have a new cousin, Addison. All of them provide immeasurable pleasure to us. What we have been told about the joys of grandparenting was underestimated. Anthony Pazos deserves special recognition. He spent countless hours in the temporal bone laboratory learning firsthand the various operations that he then illustrated. All the authors have appreciated his attention to detail and willingness to work with them until everything was “just right.” The publishers have been extremely supportive throughout the development of this book. From the beginning, they made a major commitment to ensure that this volume would be of only the highest quality. Finally I wish to thank my surgical assistant, Matthew Layner, and my executive secretary, Alyssa Gonzalez. She maintains my focus and orientation on a daily basis and her efforts are greatly appreciated. Derald E. Brackmann, MD

I would like to thank my wife, Kay, and my children, J­ordan and Bill, for their support and encouragement ­during my career as well as their understanding regarding the demands of my profession. I would also like to take this opportunity to thank my teachers, friends, and former associates at the House Clinic and my teachers at Stanford, all of whom gave me the skills necessary to practice otologic surgery. Special recognition goes to the Otolaryngology faculty, residents, and alumni of the University of Utah. Their energy and enthusiasm keep my professional life fresh and vibrant. It is very gratifying to see their success and advancement in career development.

Clough Shelton, MD My family’s patience and support of this book and all my academic projects continue to motivate and encourage me. Special thanks to my wife Rosemary and children (Becca, Moi, and Toby) and my parents Moisés Agusto and Leticia. I particularly want to thank Derald Brackmann for his mentorship and stellar example of skill in otologic surgery and graceful balance of complex competing demands. The physicians and alumni of the House Clinic provide an active network of otologic innovation whose concepts serve as a thread of continuity in this book. My Louisiana State University residents, fellows, and partners have provided insightful questions, innovative techniques, and suggestions that have prompted some of the changes in this edition.

Moisés A. Arriaga, MD, MBA

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Otologic Instrumentation

1

Eric P. Wilkinson  |  Jose N. Fayad  |  J. Eric Lupo

Sophisticated micro-otosurgical techniques mandate that the otologic surgeon and surgical team have an in-depth understanding of the operating room (OR) layout and surgical instrumentation. This chapter describes in detail different surgical procedures and the necessary OR setup and instruments. Appendix 1-1 provides a comprehensive list of instruments and equipment.

OPERATING ROOM The OR for otologic surgery requires features that differ from ORs used for nonotologic surgery. The following sections elaborate on the general environment of the OR designed for ear surgery. A word about the sterile field is in order. Respecting the sterile field is vital during routine otologic surgery and takes on special significance during neurotologic procedures. Maintaining the proper sterile environment means limiting traffic through the OR and keeping the number of visitors to a minimum. It is preferable for observers to be in a remote room watching the procedures on video. Individuals allowed in the OR should be experienced in sterile technique and should wear jackets over scrubs so that all skin surfaces are covered (Fig. 1-1). Before entering the OR, the operative site is confirmed with the patient. The correct ear is marked with a marking pen. As many otologic procedures are performed on awake patients under local anesthesia, an OR environment conducive to their psychological well-being is imperative. Members of the surgical team and visitors must use discretion when making comments during surgery performed under local anesthesia. The first piece of OR equipment to be discussed is the operating table. The surgeon must be comfortable while performing microsurgery. Adequate leg room under the table can be achieved with older OR tables by placing the patient 180 degrees opposite the usual position; in other words, the patient’s head is where the feet would normally be (Fig. 1-2). Newer electric tables easily accommodate the patient and surgeon. Because most otologists spin the OR table 180 degrees after the induction of anesthesia, the new tables allow for spinning the table without unlocking it. Nonetheless, after the patient is properly positioned, the table must be firmly locked in place. All ORs are equipped with wall suction. Standard suction devices are acceptable for otologic surgery. It is preferable, however, to use a multiple-canister suction setup, minimizing the number of times the bottles must be emptied (Fig. 1-3). Suction systems have several locations where the amount of suction can be varied, but the surgeon should

also use a control clamp on the suction tubing on the sterile field (Fig. 1-4). The tubing that is attached to the suction tips and suction-irrigators should be highly flexible. The readily available disposable suction tubing is not flexible enough for microsurgery and places awkward torque on the surgeon’s hands. Suction setup problems are common in every OR. The prudent team troubleshoots the system in advance and has access to backup equipment. Electrocautery equipment should be in a ready-to-use state on all procedures except perhaps stapes surgery. The patient must be properly grounded. It is advantageous to have monopolar and bipolar cautery on the field for all chronic ear and neurotologic procedures. To minimize risk to an implanted device such as a cochlear implant or auditory brainstem implant, monopolar cautery should be avoided after an implant has been placed. Nonadherent tips are available for most cautery devices and are desirable. Surgeons have at their disposal a wide array of safe cautery devices, but they must be thoroughly familiar with these electric instruments before use. The surgical drill is another essential piece of equipment for otologic surgery. The vast array of available drills precludes an in-depth discussion of each system. In general, otologic drills fall into two categories: air driven and electric. There are advantages and disadvantages to each type, and most surgeons have a distinct preference based on training and experience. For surgeons using air-driven drills, it is preferable to use a central source of nitrogen to power the drill instead of tank-supplied gas within the OR. A central source eliminates the need for changing tanks during long procedures. High-speed drills capable of doing most of the bone work in the temporal bone include the Fisch, Medtronic, and Anspach drill systems. These drills generally are unsuitable for work in the middle ear, especially around the stapes footplate. For the latter purposes, a microdrill, such as the Skeeter drill or Bien-Air, is suitable (Fig. 1-5). Whatever drill is used in the middle ear, it must have a variable speed control and a wide array of drill bits. Most larger otologic drills are equipped with straight and angled handpieces. Most surgeons prefer straight handpieces for early gross removal of the mastoid cortex, switching to angled handpieces for working deeper in the temporal bone. The Anspach drill system has a handpiece that can be converted from straight to angled simply by rotating the connection. A full complement of cutting and diamond burrs is mandatory. Figure 1-6 shows the Anspach drill system. Most drill systems have attachments that vary in shape, diameter, and length. It is the surgeon’s responsibility to be

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OTOLOGIC SURGERY

Figure 1-4  Suction tubing with control clamp.

Figure 1-1  Observer in jacket.

Figure 1-5  Medtronic Skeeter microdrill for footplate work.

Figure 1-2  Operating table with patient’s head at foot of bed. Figure 1-6  Anspach drill system.

Figure 1-3  Multiple-canister suction setup.

intimately familiar with the drill system and to have all of the attachments and burrs that might be needed. The otologic drill should be held in the hand like a pencil, with the hand resting comfortably on the sterile field. The side of the burr should be used to provide maximum contact between the bone and the flutes of the burr, affording safer and more efficient drilling (Fig. 1-7). The newer drills are remarkably reliable, but, similar to other tools, may malfunction. Drill systems require proper care and inspection before use. A backup system should be readily available. The introduction of the operating microscope revolutionized otologic surgery. Most otolaryngologists are familiar with the microscope. Several brands of optically superior instruments are available; most are sufficiently similar to share the same general principles.

CHAPTER 1 — Otologic Instrumentation

The otologic surgeon must be familiar with the adjustments on the microscope and must be prepared to troubleshoot the problems that may arise with the scope. The focal length of the objective lens is a matter of personal preference. Most otologists use a 200- or 250-mm objective. If a laser is attached to the microscope, one might consider a 300-mm objective. The objective lens should be selected, confirmed, and properly mounted before draping the microscope. Other adjustments, such as the most comfortable interpupillary distance, also should be performed before the scope is draped. Par focal vision should be established so that the surgeon can change magnification without having to change focus. This is accomplished by first setting the diopter setting of both eyepieces to zero. The 40× magnification (or highest available setting) is selected. The locked microscope is focused on a towel using the focus knob only. Without

Figure 1-7  Proper holding of the drill.

A

3

disturbing any of the settings, the magnification is now set at 6× (or the lowest available setting). The eyepieces are individually adjusted to obtain the sharpest possible image. The diopter readings are recorded for future use. The surgeon should have par focal vision when these appropriately adjusted eyepieces are used. The microscope should move easily. All connections should be adjusted so that the microscope does not wander by itself, yet permit movement to any position with minimal effort. Wrestling with the microscope during microsurgery is an extreme distraction. Proper posture at the operating table is crucial. To perform microsurgical procedures, the first rule is that the surgeon must be comfortable. The surgeon should be seated comfortably in a proper chair with the back support at the correct height. Both feet should be resting comfortably on the floor. Fatigue is avoided by assuming a restful position in the chair, rather than a rigid upright posture (Fig. 1-8). The overall OR setup for routine otologic surgery is shown in Figure 1-9. For neurotologic surgery, more space must be available for additional equipment. Middle cranial fossa procedures require some modifications to the OR setup (Fig. 1-10). The essential modification entails the surgeon and the microscope trading places such that the surgeon is seated at the head of the table. Cooperation and careful orchestration among the surgeon, nursing personnel, and anesthesiologist are required for ­otologic surgery. The needs of the otologist are best served by having the anesthesiologist at the foot of the bed and the scrub nurse opposite the surgeon. Video feed of the ­procedure to the OR team members helps facilitate anticipation of surgical needs. Space for additional equipment, such as the facial nerve monitor and/or laser, and personnel necessary for their operation should be considered.

B Figure 1-8  A, Proper posture for the surgeon. B, Wrong posture for the surgeon.

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OTOLOGIC SURGERY

Back table

Nurse

Bovie

IV stand

Mayo stand

Scope Anesthetist Surgeon

Anesthesia

Figure 1-9  Usual otologic/neurotologic operating room setup.

Anesthetist Anesthesia

Scope

Surgeon IV stands

Mayo stand

Drill

Bovie

Nurse Back table Figure 1-10  Operating room layout for middle fossa surgery.

STAPES SURGERY The following description of the instrumentation and operative setup for stapes surgery also provides information useful for other middle ear procedures. Under most circumstances, it is preferable to perform stapes surgery under local anesthesia, and surgeons who do so usually use some type of preoperative sedation. Numerous regimens are available, and their description is beyond the scope of this text. If sedation is administered by the surgeon or nursing personnel without the assistance of an anesthetist or anesthesiologist, the agents used should be short acting and reversible. It is far safer for the patient to be psychologically prepared for the procedure than to be oversedated. Monitored anesthesia care may also be performed. This approach requires the presence of anesthesia personnel in the OR to sedate

the patient as is required for the operation, and to monitor vital functions. The surgeon is relieved from this duty, allowing total concentration on the microsurgery. About 30 minutes before the operation, the patient is brought to the preoperative holding area. If the surgeon routinely harvests a postauricular graft, this area is now shaved. A plastic aperture drape is applied to the operative site and trimmed so as not to cover the patient’s face (Fig. 1-11). An intravenous line is started, and the patient is now ready to go to the OR. When the patient is on the OR table, the monitors are placed on the patient by the nursing or anesthesia staff. Minimal monitoring includes pulse oximetry, automatic blood pressure cuff, and electrocardiogram electrodes. The ear and plastic drape are scrubbed with an iodine-containing solution, unless the patient is allergic to iodine. A head drape is applied, and the ear is draped with sterile towels so as not to cover the patient’s face; this can

CHAPTER 1 — Otologic Instrumentation

Figure 1-11  Plastic drape applied for stapes surgery.

Figure 1-12  Patient draped in the operating room for stapes surgery. Note opening for the patient’s face opposite the surgeon.

be facilitated by supporting the drapes with a metal bar attached to the OR table, or by fixing the drapes to the scrub nurse’s Mayo stand (Fig. 1-12). The patient’s head is now gently rotated as far away from the ipsilateral shoulder as possible, and the table is placed in slight Trendelenburg and is rotated toward the surgeon. These maneuvers increase the surgeon’s working room and obtain a straight view of the posterior superior aspect of the external auditory canal (EAC). The EAC is irrigated gently with saline heated to body temperature. Vigorous cleaning of the canal is avoided until the ear is anesthetized. The local anesthesia is administered with a plastic Luer-Lok syringe. A 1.5-inch, 27-gauge needle is firmly attached to the syringe. If the ear is injected slowly and strategically, excellent anesthesia and hemostasis can be achieved with a solution of 1% lidocaine with 1:100,000 epinephrine. When using stronger concentrations of epinephrine (e.g., 1:40,000), the patient’s blood pressure and cardiac status must be considered, in addition to the possibility of mixing errors. The canal is injected slowly in four quadrants starting lateral to the bony-cartilaginous junction. The final injection is in the vascular strip. If one routinely harvests fascia or tragal perichondrium, these areas are now injected. Before describing stapes surgical instruments, a few general comments are in order. All microsurgical instruments should be inspected periodically to ensure sharp points and

5

Figure 1-13  Speculum array.

cutting surfaces. The instruments for delicate work should have malleable shanks, enabling the surgeon to bend the instruments to meet the demands of the situation. If the surgeon prefers a total stapedectomy to the small fenestra technique, an oval window seal must be selected. If fascia is used, the tissue is harvested before exposing the middle ear. The tissue is placed on a Teflon block or fascia press to dry. If perichondrium is preferred, this may be harvested immediately before footplate removal. For the small fenestra technique, a small sample of venous blood is obtained when the intravenous line is started. This blood sample is passed to the scrub nurse and placed in a vial on the sterile field. Various ear specula should be available in oval and round configurations. Sizes typically range from 4.5 to 6.5 mm (Fig. 1-13). It is desirable always to work through the largest speculum that the meatus permits without lacerating canal skin. Some surgeons prefer to use a speculum holder for stapes and other middle ear procedures. The tympanomeatal flap is started with incisions made at the 6 and 12 o’clock positions with the No. 1, or sickle, knife. These incisions are united with the No. 2, or lancet, knife. This instrument actually undermines the vascular strip instead of cutting it. The strip is cut with the Bellucci scissors. The defined flap is elevated to the tympanic annulus with the large round knife, known as the large “weapon.” When properly identified, the annulus is elevated superiorly with the Rosen needle and inferiorly with the annulus elevator, or gimmick. Figure 1-14 shows a typical set of stapes instruments, including suction tips. Adequate exposure usually requires removal of the bony ledge in the posterosuperior quadrant. This can be initiated with the Skeeter microdrill and completed with a stapes curette (Fig. 1-15). From this point on, the steps differ depending on the technique preferred by the surgeon. The diagnosis of otosclerosis should be confirmed on entering the middle ear and a measurement should be taken from the long process of the incus to the stapes footplate with a measuring stick. The next step is to make a control hole in the footplate with a sharp pick-needle (Barbara needle) or the laser. The incudostapedial joint is separated with the joint knife or small right angle hook, the tendon is cut with scissors or laser, and the superstructure is fractured inferiorly and extracted. For work on the footplate, the surgeon must have a variety of suitable instruments available. A stapedotomy can be created with a microdrill, laser, or needles and hooks. The

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Figure 1-14  Stapes instruments

Figure 1-15  Stapes curette. Figure 1-16  Crimpers and footplate hook.

0.3-mm obtuse hook is useful for enlarging the fenestra. For total footplate extraction, a right-angle hook or excavator (Hough hoe) is used. If a graft is to be placed over the oval window, it is guided into place with a footplate chisel. The prosthesis is grasped with a smooth alligator or strut forceps and placed on the incus. It is positioned on the graft or into the fenestra with a strut guide. A small right-angle hook may be necessary to fine-tune the position of the prosthesis (Fig. 1-16). The wire is secured onto the incus with a crimper or wire-closing forceps. The McGee crimper is useful, especially if followed by a fine alligator forceps for the last gentle squeeze. Nitinol is a metal alloy of nickel and titanium used in stapes prostheses because of its unique ability to secure itself to the incus upon heating. Once the wire is maneuvered into position on the incus, a pulse of laser energy or a brief pulse of heat from a microheating electrode applied to the wire causes the wire to close around

Figure 1-17  Rosen suction tubes with House adapter; Baron tubes.

CHAPTER 1 — Otologic Instrumentation

7

Figure 1-18  Proper holding of instruments as shown by Dr. William House.

the incus. Nitinol is found in prostheses such as the SMart piston (Olympus) or the Eclipse piston (Grace Medical). Suction tubes for stapes surgery include Nos. 3 to 7 Fr Baron suctions plus Rosen needle suction tips (18 to 24 gauge) with the House adapter (Fig. 1-17). The Rosen tips are useful when working near the oval window with the surgeon’s thumb off the thumb port. Excessive ear packing material after stapes surgery is not necessary. Absorbable gelatin sponge may be placed across the flap incisions to secure the flap in place. Antibiotic ointment may also be placed to hold the flap in place. A piece of cotton suffices as a dressing, unless a postauricular or endaural incision has been made, in which case a mastoid dressing is applied. For all middle ear procedures, the surgeon should hold the instruments properly. The instrument should rest, like a pencil, between the index finger and thumb, allowing easy rotation around the shank. The fingers and hands should always be anchored on the patient or the OR table. The middle and ring fingers should rest on the speculum so that the hand moves as a unit with the patient. Proper hand position and holding of instruments should afford the surgeon an unimpeded view (Fig. 1-18).

TYMPANOPLASTY WITH MASTOIDECTOMY The preparation and draping for tympanoplasty with or without mastoidectomy are much the same as for stapes surgery. The major difference is the amount of hair shaved before draping. Usually, enough hair is shaved to expose about 3 to 4 cm of skin behind the postauricular sulcus. The plastic drape is applied to cover the remaining hair (Fig. 1-11). The patient is positioned on the OR table as described earlier. Whether the procedure is performed under local or general anesthesia depends on the extent of the surgery, the surgeon’s preference, and the desire of the patient. After appropriate sedation or induction of the anesthesia, the ear and plastic drape are scrubbed with the proper solution or soap. Some surgeons place a cotton ball in the meatus if a

Figure 1-19  Chronic ear surgery draping for general anesthesia.

perforation exists, preferring not to allow the preparation solution to enter the middle ear. The field is draped as described earlier, the head is rotated toward the contralateral shoulder, and the table is placed in slight Trendelenburg position (Fig. 1-19). The postauricular area, canal, and tragus (if necessary) are injected with 1% lidocaine with 1:100,000 epinephrine for local and general anesthesia cases. Most chronic ear procedures begin in a similar fashion. Through an ear speculum, vascular strip incisions are made with the sickle or Robinson knife and united along the annulus with the lancet knife. The vascular strip incisions are completed with a No. 64 or 67 Beaver blade. This same blade can be used to transect the anterior canal skin just medial to the bony-cartilaginous junction. The postauricular incision is made with a No. 15 Bard-Parker blade behind the sulcus. The level of the temporalis fascia is identified, and a small self-retaining (Weitlaner) retractor is inserted. The fascia is cleared of areolar tissue and incised. A generous area of fascia is undermined and removed with Metzenbaum scissors. The scrub nurse can assist by using a Senn retractor to elevate skin and soft tissues away from the fascia. The fascia is thinned on the Teflon block and dehydrated by placing it under an incandescent bulb, carefully monitoring

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OTOLOGIC SURGERY

its progress. The fascia may also be dehydrated by placing it on a large piece of Gelfoam and compressing this complex in a fascia press. Figure 1-20 shows the instruments used in the initial stages of chronic ear surgery. Continued postauricular exposure is obtained by incising along the linea temporalis with a knife or with the electrocautery. A perpendicular incision is made down to the mastoid tip. Soft tissues and periosteum are elevated with a Lempert elevator (Fig. 1-21), the vascular strip is identified, and a large self-retaining retractor is inserted. A very large

retractor, such as an Adson cerebellar retractor with sharp prongs, is preferred. Next, under the microscope, the remaining anterior and inferior canal skin is removed down to the level of the annulus with the large weapon. The plane between the fibrous layer of the drum remnant and the epithelium is developed with a sickle knife, and the skin is pulled free with a cup forceps. The canal skin is placed in saline for later use as a free graft. The ear canal is enlarged with the drill and suction-­ irrigators. An angled handpiece and medium to

A

B Figure 1-20  A, Instruments for making a canal incision. B, Instruments for handling fascia.

Figure 1-21  Periosteal elevators.

CHAPTER 1 — Otologic Instrumentation

small cutting burr are used. Irrigation through the suctionirrigators is done with a physiologic solution such as Tis-USol, lactated Ringer, or saline. Two large (3000 mL) bags of irrigant are hung and connected by way of a three-way stopcock to the delivery system (Fig. 1-22). For mastoidectomy surgery, the surgeon must have a full array of cutting and diamond burrs, and a complete set of suction-irrigators. It is advisable to have bone wax and absorbable knitted fabric (Surgicel) readily available. Cholesteatoma removal can be accomplished with middle ear instruments such as the gimmick, weapon, and fine scissors. Although the setup for closing and packing after chronic ear surgery varies with the specifics of the situation, a few generalities should cover most situations encountered by the otologist. To maintain the middle ear space, silicone elastomer (Silastic) sheeting works well and is readily available. This sheeting comes in various thicknesses, with and

9

without reinforcement. For middle ear packing, absorbable gelatin sponge (Surgifoam) is the usual choice, soaked in saline or an antibiotic otic preparation. Surgifoam is also used to pack the EAC, although some surgeons prefer an antibiotic ointment, as described in the section on stapes surgery. For meatoplasty packing, 1-inch nonadhesive Curity packing strip or nasal packing gauze is saturated with an antibiotic ointment and rolled around the tip of a bayonet forceps; this creates a plug that conforms to the new meatus and is easily removed (Fig. 1-23). Wound closure is accomplished by closing the periosteal layer and placing deep dermal interrupted absorbable sutures. The skin does not typically require a separate suture closure as Steri-Strips provide adequate approximation for healing. The wound is finally covered with a standard mastoid dressing. Some additional instruments that prove to be handy in many chronic ear procedures include an ossicles holder, Crabtree dissectors, Zini mirror, right-angle hooks, and the House-Dieter malleus nipper. It is impossible to describe instruments for every conceivable situation, but the foregoing should cover most of the needs of the otologist.

ENDOSCOPIC MIDDLE EAR SURGERY Endoscopic tympanoplasty is a novel technique for surgically addressing tympanic membrane perforations, cholesteatomas, and other middle ear issues. The transcanal endoscopic

Figure 1-24  Assorted endoscopes for endoscopic-assisted surgery. Figure 1-22  Suction irrigation setup.

A

B Figure 1-23  A, Surgifoam packing. B, Meatoplasty packing.

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OTOLOGIC SURGERY

view may afford a wide view of the middle ear, encompassing areas that are not possible to visualize with the traditional operating microscope. Specialized endoscopes (Fig. 1-24) and instrumentation have been developed for the purpose of endoscopic middle ear surgery. Many of the same instruments used in standard otologic tympanoplasty may be used; however, instruments with single and double curvature and microtips have been found to be useful. An endoscopic tower with monitor, camera input, and light source is positioned across the operating table from the surgeon for ergonomic viewing by the surgical team. Apart from these aspects, the patient is positioned in the room as in traditional otologic surgery and is prepared and draped in a similar fashion.

ENDOLYMPHATIC SAC SURGERY There are many well-described procedures on the endolymphatic sac. The purpose of this chapter is not to outline the surgical options, but rather to discuss the methodology for performing sac surgery. The preparation and draping of the patient for endolymphatic sac surgery are essentially the same as for tympanoplasty with mastoidectomy surgery. In the preoperative holding area, the postauricular area is shaved, exposing at least 4 cm of skin behind the sulcus. Plastic adhesive drapes are applied, and the patient is transported to the OR. Endolymphatic sac surgery is performed with the patient under general anesthesia. The field is scrubbed in the usual manner, and the patient is positioned as described for chronic ear surgery. This is a good time to mention briefly the use of intraoperative facial nerve monitoring and other forms of physiologic monitoring, including eighth cranial nerve and cochlear potentials. Many surgeons use facial nerve monitoring whenever the facial nerve might be in jeopardy. Electrodes for facial nerve monitoring or other forms of monitoring should be positioned before the preparation. After the preparation for endolymphatic sac surgery, the planned incision is injected with 1% lidocaine with 1:100,000 epinephrine. The incision is made 2 to 3 cm behind the sulcus. Periosteal incisions are made sharply or with the electrocautery. A Lempert elevator elevates soft tissues and periosteum up to the level of the spine of Henle. A House narrow (canal) elevator is used to delineate the EAC, and a large self-retaining retractor is inserted. With drill and suction-irrigator, a complete mastoidectomy is performed. The antrum is not widely opened, but is instead blocked with a large piece of absorbable gelatin sponge (Gelfoam) to prevent bone debris from entering the middle ear. Bone over the sigmoid sinus and posterior fossa dura is thinned with diamond burrs. The retrofacial air tract is opened widely to locate the endolymphatic sac. The sac is decompressed with a diamond burr. A stapes curette can be used to remove bone over the proximal sac. The occasional bleeding that occurs over the surface of the sac or surrounding dura is best controlled with bipolar cautery. Alternatively, monopolar cautery at a very low setting can be used. The cautery tip is touched to an insulated Rosen or gimmick that is in contact with the offending vessel (Fig. 1-25). Another method used to control small areas of bleeding in endolymphatic sac and chronic ear surgery is to cover the area with pledgets of Gelfoam that have been soaked in topical thrombin.

Figure 1-25  Insulated gimmick (top) and Rosen (bottom).

Figure 1-26  Endolymphatic sac instruments and materials.

Before opening the sac, the wound is irrigated copiously with saline or bacitracin solution. Fresh towels are placed around the field. The sac is opened with a disposable Beaver ophthalmic blade (No. 59S, 5910, or 5920). The lumen is probed with a blunt hook or gimmick. The shunt tube preferred by the surgeon is now inserted. Thin Silastic sheeting (0.005 inch) can be used to fashion a shunt. Figure 1-26 shows the materials for the latter steps of endolymphatic sac surgery. As with chronic ear procedures, the wound is closed in layers, usually beginning with 2-0 chromic and finishing with 4-0 Vicryl or Dexon. A standard mastoid dressing is applied. This dressing either is prepared in the OR or is obtained as a prepackaged dressing (e.g., Glasscock dressing).

NEUROTOLOGIC PROCEDURES This section describes the OR layout for neurotologic procedures, the only exception being middle fossa surgery, which is discussed separately. For procedures involving intracranial structures, extraordinarily meticulous attention to detail is mandatory. The preparation for neurotologic surgery may

CHAPTER 1 — Otologic Instrumentation

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A Figure 1-27  Drapes (3M 1000) applied for neurotologic surgery.

begin the evening before surgery by having the patient wash his or her hair and scalp with an antiseptic shampoo. The day of surgery, the surgeon sees the patient in the holding area so that the ear to be operated on is positively identified. The surgical site is shaved so that at least 6 cm of postauricular scalp is exposed. An adhesive is applied to the area and the plastic drapes are applied (Fig. 1-27). At the same time, the abdomen is shaved from below the umbilicus to the inguinal ligaments in preparation for harvesting a fat graft from the left lower quadrant. The fat donor site is prepped and surrounded by drapes and covered with a plastic adhesive drape. After anesthetic induction, a urinary catheter is inserted and arterial and central venous lines are placed when indicated. Electrodes for monitoring CN VII and VIII (and possibly other nerves) are positioned. The patient’s head is supported on towels or a “donut” as needed and rotated toward the contralateral shoulder. The surgical sites are scrubbed and then blotted dry with a sterile towel. The areas are draped off with towels and then covered with plastic adhesive drapes (e.g., Steri-Drape, Ioban, Cranial-Incise). Some surgeons prefer to include another layer of towels around the cranial site, followed by either sheets or a disposable split sheet. It is important to have several layers of draping to prevent saturation of the drapes with fluids down to the level of the patient (Fig. 1-28). Because the scrub nurse must handle numerous items attached to tubes and cords, it is helpful to have a plastic pouch fastened to the field into which the drill, suction, and cautery tips can be placed (Fig. 1-29). Two Mayo stands are kept near the field: one for the neurotologic instruments and the other for the fat-harvesting tools (Fig. 1-30). The postauricular area is injected with the usual local anesthetic, and the plastic drape is cut away with scissors to expose the mastoid and lateral subocciput. As with other procedures, a skin incision is made, hemostasis is obtained, soft tissues and periosteum are elevated, and a large self-retaining retractor is inserted. Bone removal is accomplished using a drill and suction-irrigation. For neurotologic cases, bone removal is more extensive, exposing the sigmoid sinus and a considerable amount of posterior fossa dura behind the sigmoid. It is imperative that the surgeon has immediate access to bone wax and Surgicel. Many surgeons also insist on having immediate access to hemoclips and thrombin-soaked Gelfoam.

B

C Figure 1-28  A to C, Draping sequence for neurotologic surgery.

Figure 1-29  SK-100 Surgi-kit for holding instruments.

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OTOLOGIC SURGERY

A

B Figure 1-30  A, Mayo stand setup for tumor. B, Mayo stand setup for fat graft.

The extent of bone removal varies depending on the surgeon’s preference and the nature of the procedure. Some surgeons decompress the sigmoid completely, whereas others leave a thin shell of bone over the sinus (Bill’s island). After appropriate bone removal, the retractor is removed, and the field is irrigated vigorously with bacitracin solution. Bacitracin solution can be prepared by dissolving 50,000 U of bacitracin in 1 L of normal saline. After wound irrigation, fresh towels are placed around the field. With a wound free of bone dust and debris, the dura can now be opened with a No. 11 Bard-Parker scalpel blade or with the tips of Jacobson scissors. The dura can be pulled away from underlying structures by using a corkscrew-like instrument included in some neurotologic instrument sets (Fig. 1-31). The subdural space is entered, taking care not to violate the arachnoid; this helps to avoid injury to vessels before adequate exposure. The dural flap is carefully developed with Jacobson scissors. Hemostasis is controlled with bipolar cautery. The arachnoid is opened carefully with a sharp hook or the tips of the scissors, allowing the egress of cerebrospinal fluid. After opening the arachnoid, one should switch to fenestrated (Brackmann) suction tips (Fig. 1-32). The cerebellum and other intracranial structures should be protected with moist neurosurgical cottonoids. A variety of cottonoids should always be on the stand. For vestibular neurectomy procedures, the plane between the cochlear and vestibular nerves can be developed with a blunt hook, or the gimmick. The nerve section itself can be completed with a sharp hook or microscissors (Fig. 1-33). The same instruments can be used to define the plane between an acoustic neuroma and the facial nerve. A sharp

Figure 1-31  Brackmann neurotologic instruments.

Figure 1-32  Brackmann fenestrated suction-irrigators.

right-angle hook palpates Bill’s bar and sections the superior vestibular nerve fibers along with the vestibulofacial fibers. After establishing the proper plane between the tumor and facial nerve, a blunt hook is used to continue the dissection, avoiding stretching of the facial nerve. Facial nerve monitoring has greatly assisted this part of the dissection. For small tumors, the previously mentioned technique might suffice for total tumor removal. Larger tumors are removed by extensive intratumoral debulking, mobilization of the capsule, and removing the capsule in a piecemeal fashion. Debulking is typically performed with the ultrasonic aspirator or with morcellation using large crushing forceps. Intratumoral hemostasis is achieved with bipolar or thrombin-Gelfoam pledgets as necessary. As the tumor is debulked, the capsule collapses and can be dissected from the brainstem. Portions of the capsule may then be resected with a CO2 laser or sharply with microscissors. The CUSA Excel+ Ultrasonic Aspiration System (Fig. 1-34) is a valuable instrument for intratumoral debulking of the tumor. The system generates ultrasonic energy, which fragments tissue in a precise manner limiting damage to neighboring tissue. Whatever tool is used, proper use of these sophisticated, potentially dangerous instruments must be learned from user manuals and appropriate training and courses. Hemostasis is vital during neurotologic surgery, and the surgeon must have immediate access to all possible items necessary to control bleeding from whatever the source. In addition to unipolar and bipolar cautery, bone wax and precut pieces of Surgicel should be on the Mayo stand. Microfibrillar collagen (Avitene) is another preferred hemostatic agent to have available. Pledgets of Gelfoam soaked in topical thrombin are quite useful. Vascular clips and a reliable clip applicator are useful for controlling bleeding from the petrosal vein and its tributaries (Fig. 1-35).

CHAPTER 1 — Otologic Instrumentation

13

Figure 1-33  Hooks for neurectomy and tumor dissection.

Figure 1-34  CUSA Excel+ Ultrasonic Aspirator System for rapid tumor debulking.

Figure 1-35  Clips and clip applicators.

Infratemporal fossa and other approaches to the skull base are set up in much the same manner as has already been discussed. Incisions are generally long and may extend into the upper cervical region to access major neurovascular structures. Silastic vessel loops should be placed around these structures for control and easy identification. Ligatures of 0 silk and transfixion sutures of 2-0 silk need to be available for jugular vein ligation. Cardiovascular sutures (e.g., 5-0 and 6-0 polypropylene [Prolene]) should also be close by. The self-retaining retractors described earlier are usually insufficient for skull base surgery. The Fisch infratemporal retractor or pediatric rib retractor is better suited to these

tasks, which often include anterior displacement of the mandible. If mandibulotomy is indicated, the appropriate oscillating saw needs to be available. Some instruments facilitate work on or near the facial nerve. For rerouting the facial nerve, bone is removed with a drill until an eggshell thickness remains. The remaining bone is removed gently with a stapes curette. The nerve can be mobilized with a dental excavator or microraspatory. If a segment of the nerve is to be excised, as in a facial neuroma, this should be done sharply with a fresh knife blade. Likewise, before any neurorrhaphy, the ends of the nerve and graft should be freshened. A 9-0 monofilament suture is used for nerve anastomosis. Appropriate needle holders and forceps must be available (Fig. 1-36). An alternative or adjunct to suturing is to use NeuraGen nerve guides. Before closing neurotologic and skull base wounds, abdominal fat is removed from the left lower quadrant, most of the dissection being done with electrocautery. The abdominal wound is closed (over a drain if necessary) in layers, with the skin being approximated with a running intradermal 4-0 Vicryl or Dexon suture. The fat is cut into strips and insinuated into the dural defect. Continuous lumbar drainage is rarely necessary to prevent cerebrospinal fluid leakage except in extensive intracranial-extracranial resections. If the neck is opened, a suction drain is inserted into the depths of the wound before closure. Wounds are closed as in other otologic procedures and dressed with a standard mastoid dressing. Also under the rubric of neurotologic surgery is cochlear implant surgery. Each presently available cochlear implant device has its own unique set of requirements and, possibly, instruments. The surgeon must have proper training and experience to perform cochlear implant procedures. He or she must have all of the necessary special equipment for electrode placement and internal receiver fixation (Fig. 1-37).

MIDDLE FOSSA SURGERY Middle fossa procedures are discussed separately from other neurotologic procedures because they involve a different OR setup and some different instruments. The most obvious deviation from other procedures is the position from

14

OTOLOGIC SURGERY

Figure 1-36  Nerve anastomosis equipment.

Figure 1-38  Patient draped for middle fossa surgery. Figure 1-37  Cochlear implant tools.

which the surgeon operates. The surgeon and the microscope trade locations, so that the surgeon operates from the head of the bed facing caudally (Fig. 1-10). As with other neurotologic procedures, middle fossa surgery is performed with the patient under general anesthesia. The ipsilateral scalp is shaved to accommodate the middle fossa incision taken a distance of 6 cm superiorly and anterior from 2 cm postauricularly or a strip-shave encompassing the incision may be used. Plastic adhesive drapes are then applied. The surgical site and plastic drapes are scrubbed and blotted dry. The area is covered with another plastic adhesive drape. Towels are positioned to block off the entire temporoparietal scalp, including the auricle and zygomatic arch. Sterile sheets complete the draping (Fig. 1-38). The abdomen is usually prepared as in other neurotologic surgeries. The incision is planned so that it begins in the preauricular incisura below the root of the zygoma. It extends cephalad to the area just above the superficial temporal line. A gentle curve facilitates exposure. Before the incision, as in other cases, the area is infiltrated with local anesthesia. The plastic drape is cut away to expose the skin. After the skin incision is made, the temporalis fascia is identified; it is

recommended that an inferiorly based temporalis muscle flap be created instead of splitting the muscle. This flap is centered over the zygoma, is elevated from the calvaria, and is reflected caudally by suturing the end of the flap to the drapes. Preserving the muscle with its neurovascular bundle does not limit the surgeon’s exposure, and allows the use of this muscle if facial reanimation surgery should ever be necessary. The remaining temporalis muscle is reflected laterally, and a selfretaining retractor is inserted. A craniotomy is performed. The size of the bone flap removed is typically 5 cm2; however, the size may be dictated by the amount of exposure necessary. For tumor removal, it is wise to err on the large side. The bone flap is removed carefully from the dura with an Adson periosteal elevator, or “joker.” The bone flap is placed in bacitracin solution. The craniotomy edges are smoothed with a rongeur, and bleeding is controlled with bone wax. The joker is used to dissect the dura from the floor of the middle fossa. The surgeon is now ready to insert the House-Urban middle fossa retractor. The surgeon must be familiar with the mechanical workings of this device (Fig. 1-39). The retractor is locked under the bony edges of the craniotomy. The blade housing is positioned so that

CHAPTER 1 — Otologic Instrumentation

15

Figure 1-39  House-Urban middle fossa retractor.

Figure 1-40  Plating system for cranioplasty after tumor resection.

it allows good visualization of the field without placing excessive traction on the temporal lobe. This usually requires repositioning the retractor several times during the early stages of the dissection. Next, the retractor blade is inserted, and the extradural dissection proceeds. The blade can be tilted with the hand and advanced with the thumb, leaving the other hand free for suctioning. Bleeding can be troublesome from the floor of the middle fossa, especially near the middle meningeal artery. Bipolar cautery, bone wax, Surgicel, and other hemostatic agents should be readily available. The surgeon elevates the dura and temporal lobe until the arcuate eminence, superior petrosal sinus, and greater superficial petrosal nerve are visible. Bone over the internal auditory canal (IAC) and geniculate ganglion is removed with a large diamond burr. When the dura over the IAC has been skeletonized completely as far medially as the porus, the wound is irrigated with bacitracin solution, and fresh towels are placed around the field. The dura over the IAC is opened posteriorly (away from the facial nerve) with a sharp hook. For vestibular neurectomy, Bill’s bar is palpated with the same sharp hook that then transects the superior vestibular nerve. Fine microscissors (e.g., Malis, Jacobson) are used to remove a segment of the nerve in continuity with Scarpa’s ganglion. In a likewise fashion, the inferior vestibular and singular nerves are sectioned. For acoustic tumor removal, significantly more bone removal is required. Having established adequate exposure, the plane between the facial nerve and tumor is developed as in the translabyrinthine approach. At the conclusion of the procedure, the defect over the IAC can be reconstructed by filling it with small pieces of abdominal fat. The field is inspected for hemostasis, and the middle fossa retractor is removed, allowing the brain to reexpand. The wound is irrigated again with bacitracin. Microplates are used to secure the bone flap in place (Fig. 1-40), and the wound is closed in layers, suturing the temporalis flap back to normal anatomic position. Some surgeons close the skin over a Penrose drain, which is removed the day after surgery. A mastoid dressing completes the closure.

that the otologist is likely to encounter. Although these descriptions do not exhaust all possibilities, they have proved to be satisfactory for many otologists. Appendix 1-1 lists instruments and equipment that have been presented in the text.

CONCLUSION This chapter has provided a detailed description of the OR environment and instrumentation for most procedures

APPENDIX 1-1.  INSTRUMENTS AND EQUIPMENT FOR OTOLOGIC SURGERY GENERAL OPERATING ROOM EQUIPMENT • 3M 1000 plastic aperture drapes • 3M 1020 aperture drapes • 3M Ioban drape, Steri-Drape, Ioban drape, or CranialIncise drape • Preoperative skin preparation tray • Suction irrigation setup • Suction canisters • Electrocautery unit • Skytron operating table

STAPES SURGERY • Assorted Farrior specula • Finger-control Luer-Lok syringe • Needle, 1½ inch, 25 or 27 gauge • Small Weitlaner retractor • Sheehy fascia press • House cutting block • Scalpel, No. 15 Bard-Parker blade • Adson tissue forceps • Iris scissors • House-Baron suction tubes, 3 to 7 Fr • House suction tube adapter • Rosen suction tubes, 18 to 24 gauge • Sickle knife (No. 1 knife) • Lancet knife (No. 2 knife) • Robinson knife • Sheehy-House weapon (large and small) • Rosen needle • House elevator • Gimmick annulus elevator • House stapes curette

16

OTOLOGIC SURGERY

• Incudostapedial joint knife • Bellucci scissors • Straight Barbara needle pick • Measuring struts, 4.0 to 5.0 mm • Measuring disk, 0.6 mm • Hough hoe • Hook, obtuse, 30 degree, 0.25 mm • Pick, 0.3 mm, 90 degree • Strut guide • Footplate chisel • Skeeter drill; 1.0, 0.7, and 0.6 mm burrs • House strut forceps (nonserrated) • McGee wire closing forceps (crimper) • Antibiotic ointment • Cotton balls, adhesive bandages, mastoid dressing • Speculum holder

CHRONIC EAR SURGERY • Assorted Farrior specula • Finger-control syringe • Needle, 1½ inch, 25 or 27 gauge • Small Weitlaner retractor •  Large self-retaining retractor (Weitlaner, Adson cerebellar) • Scalpel, No. 15 Bard-Parker blade • Beaver blade, No. 64 or 67 • House cutting block • Sheehy fascia press • House-Baron suction tubes, 3 to 7 Fr • Adson forceps • Iris scissors • Small Metzenbaum scissors • Sickle knife • Lancet knife • Robinson knife • Sheehy-House weapon, 2.5 mm and 2.0 mm • Rosen needle • Gimmick • Crabtree dissector (large and small) • Lempert elevator • House narrow elevator • Pick, right angle, 0.6 mm • Pick, right angle, 1.5 mm • Pick, right angle, 3 mm • Bellucci scissors • Hartmann forceps • House alligator forceps • House cup forceps • House-Dieter malleus nipper • Zini mirrors • Sheehy ossicles holder • Speculum, endaural (or nasal) • Drill with cutting and diamond burrs • House suction-irrigators, 2.5 × 4 Fr through 8 × 12 Fr • Needle holder, Webster • Suture scissors • Suture, 2-0 chromic and 4-0 Vicryl (or Dexon) • Surgifoam (saline soaked and antibiotic soaked) • Curity Packing strip gauze • Silastic sheeting, 0.005 • Gelfilm

• Steri-Strips • Mastoid dressing • Bone wax • Surgicel • Sheehy bone dust collector

ENDOLYMPHATIC SAC SURGERY • Finger-control syringe • Needle, 1½ inch, 25 or 27 gauge • Scalpel, No. 15 Bard-Parker blade • Large self-retaining retractor • Lempert elevator • House narrow elevator • Drill and burrs • House suction-irrigators (assortment) • Brackmann suction-irrigators, 4 × 5 Fr and 5 × 7 Fr • Stapes curette • Gimmick • Insulated gimmick • Bone wax • Surgicel • Bipolar cautery • Bacitracin irrigation solution • Beaver ophthalmic blade (No. 59S, 5910, 5920) • Pick, right angle, 1.5 mm • Hook, right angle, blunt • Rosen needle • House alligator forceps • Silastic shunt material, 0.005 • Suture, 2-0 chromic and 4-0 Vicryl (or Dexon) • Steri-Strips • Mastoid dressing • Cranial nerve monitoring equipment

NEUROTOLOGIC SURGERY • Finger-control syringe • Needle, 1½ inch, 25 or 27 gauge • Scalpel, No. 15 Bard-Parker blade • Large self-retaining retractor • Lempert elevator • House narrow elevator • Drill and burrs • Assorted House suction-irrigators • Assorted Brackmann suction-irrigators • Stapes curette • Gimmick • Insulated gimmick • Bone wax • Surgicel • Bipolar cautery • Bacitracin irrigation • SK-100 Surgi-Kit • Suture scissors • House-Urban dissector • Pick, right angle, 1 mm • Pick, right angle, 1.5 mm • Hook, right angle, blunt, 1.5 mm • Bellucci scissors • House cup forceps • Blakesley nasal forceps (No. 1)

CHAPTER 1 — Otologic Instrumentation

• House alligator forceps • Myringoplasty knife • Jacobson scissors • Malis scissors • Allis forceps • Bayonet forceps • Adson tissue forceps • Microclip applicator • Assorted hemostats • Metzenbaum scissors • Senn retractor • U.S. Army retractor • CUSA Excel Ultrasonic Aspiration System • Fisch infratemporal fossa retractor • Woodson elevator • Fisch microraspatory • Sagittal saw • Needle holder, Castroviejo • Needle holder, Crile-Wood • Needle holder, Webster • Fisch microscissors • Titanium needle holders, smooth (2) • Janetta forceps • Gerald forceps, with and without teeth • Avitene • Drains, Penrose and Jackson-Pratt • Vessel loops • Suture, 5-0 and 6-0 vascular Prolene • Suture, 0 and 2-0 chromic • Suture, 0 and 2-0 silk • Suture, 9-0 nylon or Prolene • Suture, 4-0 Dexon or Vicryl • Neurosurgical cottonoids • NeuraGen nerve guide • Steri-Strips • Mastoid dressing • Topical thrombin • Surgifoam •  Special neurotologic instrument sets (e.g., Kartush, Benecke) • Cranial nerve monitoring equipment

MIDDLE CRANIAL FOSSA SURGERY • Finger-control syringe • Needle, 1½ inch, 25 or 27 gauge • Scalpel, No. 15 Bard-Parker blade • Large self-retaining retractor • Lempert elevator • House narrow elevator • Adson periosteal elevator “joker” • Drill and burrs • Assorted House suction-irrigators • Brackmann suction-irrigators • Stapes curette • Gimmick • Insulated gimmick • Bone wax • Surgicel • Bipolar cautery • Bacitracin irrigation • SK-100 Surgi-Kit • Pick, right angle, 1 mm • Pick, right angle, 1.5 mm • Hook, right angle, blunt, 1.5 mm • Bellucci scissors • Fisch microscissors • House cup forceps • Metzenbaum scissors • House-Urban middle fossa retractor • Rongeur, Leksell • Adson tissue forceps • Microclip applicator • Assorted hemostats • Avitene • Cottonoids • Gelfoam • Suture, 0 and 2-0 chromic • Suture, 4-0 Vicryl (or Dexon) • Topical thrombin • Mastoid dressing • Special neurotologic instrument sets • Cranial nerve monitoring equipment

17

2

Canalplasty for Exostoses of the External Auditory Canal and Miscellaneous Auditory Canal Problems Joseph B. Roberson Jr.

Please access ExpertConsult.com to view the corresponding videos for this chapter. Although clinical disease caused by exostoses of the external auditory canal (EAC) is infrequent, it occurs often enough that a method of surgical management should be in the armamentarium of the otologic surgeon. Because it is not a high-incidence problem or one that is life threatening, many otolaryngologists use various independent approaches, which frequently result in elimination of, or damage to, the canal skin. These procedures frequently produce suboptimal results. A well-conceived approach addresses the problem of removal of exostoses, while maintaining the valuable residual skin of the EAC. This chapter begins with clinical observations regarding this condition and then describes an operative procedure that has been very successful in its management. The etiology of these benign growths of the tympanic bone is strongly associated with the frequency and severity of exposure to cold water.1,2 Frequently, these lesions are found in surfers, swimmers, kayakers, or other individuals with frequent cold-water exposure over several years. A widely held belief based on clinical information is that exostoses occur primarily during the years of growth, with their proliferation being enhanced or perhaps even caused by exposure to cold water during this period. This belief tends to be supported by historical information from patients with exostoses, who almost always indicate that they swam in cold water during their youth.3-5 This historical information is strongly corroborated by the high incidence of exostoses in avid surfers who spend hours in the water almost daily. In our clinical experience, this problem occurs almost exclusively in men, who are more likely than women of the same age to have had frequent cold-water exposure during their youth. Most exostoses do not develop to a degree sufficient to cause clinical symptoms. Patients are frequently referred to otologists because the growths are observed, and not understood, by primary care physicians. This is particularly true with exostoses that have a more pedunculated form than the more subtle sessile configuration. When exostoses become more marked, however, they obstruct the natural elimination of desquamated epithelium from the ear canal, and patients usually present with recurrent episodes of external otitis. In their most prolific expression, exostoses can lead to

18

hearing impairment by causing the collection of epithelial debris that tamponades tympanic membrane movement, by impinging on and limiting the mobility of the malleus, or by markedly narrowing the aperture of the canal. These conditions may manifest as a conductive hearing impairment on audiometric examination. The EAC is part of the hearing pathway. Essentially, the EAC is a tube with resonant characteristics that amplify the incoming sound. The degree of amplification and the frequency at which it occurs are a function of the diameter and the length of the canal. When the diameter becomes small, it can interfere with the passage of sound and cause a hearing impairment. This effect does not become significant, however, until the aperture becomes very small. With apertures less than 3 mm, high-frequency sounds begin to diminish, and further compromise of the channel diameter results in increased impairment and lower frequency loss.

EXOSTOSES OF THE EXTERNAL AUDITORY CANAL SURGICAL INDICATIONS Surgery is indicated when chronic or recurrent external otitis exists with or without debris entrapment, or a conductive hearing impairment develops. The presence of chronic and recurrent infection over an extended period seems to debilitate the canal skin and can compromise the skin’s ability to reepithelialize in a robust and healthy manner in the postoperative period. For this reason, surgical therapy should be considered when a pattern of recurrent external otitis has been established in these patients. Patients who have significant external canal exostoses without recurrent infection or hearing impairment should be observed periodically, and surgery should be avoided until these symptoms occur.

PREOPERATIVE PREPARATION PATIENT PREPARATION There are two components of patient preparation for otologic surgery performed under local anesthesia: psychological and pharmacologic.

CHAPTER 2 — CANALPLASTY FOR EXOSTOSES OF THE EXTERNAL AUDITORY CANAL

Psychological Preparation

To reduce anxiety and create rapport, the surgeon should provide the patient with a full explanation of the procedure and its objectives, benefits, and risks. In addition, a surgical nurse or medical assistant should explain what will happen to the patient in the operating room and describe such things as the operating room environment, use of an intravenous line for medication delivery, placement of monitor electrodes, and draping. By informing the patient of these things and making him or her part of the process, the clinician reduces the patient’s anxiety, encourages cooperation, and may reduce bleeding. Beyond the technical advantages achieved by such preparation, there is an ethical responsibility to inform the patient. In addition, the likelihood of the patient becoming litigious because of a poor result is markedly reduced if he or she has been informed about the procedure and its risks and benefits and has had an opportunity to discuss the risks and benefits with the surgeon before the surgery. Both oral and written communication of risks and benefits is suggested. Pharmacologic Preparation

The pharmacologic preparation of the patient can be achieved in many ways. In the average adult who selects intravenous sedation with local anesthesia, we give fentanyl, 50 to 100 μg, and midazolam (Versed), 5 to 10 mg intramuscularly 1 hour before the surgical incision. An intravenous catheter is started in the arm opposite the ear to be operated on before the patient arrives in the operating room, and 5% dextrose in Ringer solution is started with a volutrol. Unless the patient appears very sedated, an additional 50- to 100-μg dose of fentanyl is placed in the volutrol and infused slowly over 30 to 45 minutes. As the surgery proceeds, alternating supplements of intravenous midazolam and fentanyl are infused as needed to maintain sedation. In selected cases, general anesthesia is selected by either the surgeon or the patient. Patients with a history of claustrophobia, patients with poor language skills in the surgeon’s native tongue, and patients with difficult neck mobility are best approached under general endotracheal anesthesia. One advantage of use of general anesthesia is the ability to use facial nerve monitoring during the procedure. Intravenous or oral antibiotics are not required unless age, disease state, or immune compromise indicates a higher than acceptable risk of infection postoperatively as long as antibiotics are placed in the ear canal packing following surgery. SITE PREPARATION The hair is shaved behind the ear to a distance of approximately 1.5 inches posterior to the postauricular fold. The auricle and the periauricular and postauricular areas are scrubbed with povidone-iodine (Betadine) solution or chlorhexidine gluconate (Hibiclens) for iodine-allergic patients. A plastic drape is placed over the area with the auricle and the postauricular area exteriorized through the opening in the drape. This drape is placed over an L-shaped bar that is fixed in the rail attachment of the operating table (Fig. 2-1). For patients under local anesthesia with sedation, a small, low-volume office fan is attached to the bar to provide a gentle cooling breeze to the patient’s face during the procedure. The plastic drape forms a canopy, allowing the patient to see from under the drape, thus reducing the

19

feeling of claustrophobia. In addition, a foam earpiece from an insert speaker is put into the opposite ear. The earpiece is connected to a compact disk player and input microphone that allows the patient to listen to relaxing music and provides a pathway to converse with the patient, if desired.

ANALGESIA It is important not only to achieve analgesia, but also to maximize canal hemostasis with injections into the external auditory meatus., A classic quadratic injection with 2% lidocaine (Xylocaine) with 1:20,000 epinephrine solution in a ringed syringe with a 27-gauge needle is made such that each injection falls within the wheal of the previous injection. Another useful injection is an anterior canal injection, which is made with the bevel of the needle parallel to the bony wall of the external meatus (Fig. 2-2). In a patient with extensive exostoses, this injection is usually made into the lateral base of a large anterior sessile osteoma. After insinuation of the needle, it is advanced a few millimeters, and a few drops are injected extremely slowly. The solution infiltrates medially along the anterior canal wall and provides some analgesia to the auriculotemporal branch of the fifth cranial nerve (CN V), which is usually unaffected by the quadratic injection and adds to the hemostasis anteriorly. The postauricular area is infiltrated with 2% lidocaine with 1:100,000 epinephrine solution mixed with equal parts of 0.5% bupivacaine.

SURGICAL TECHNIQUE Most surgical approaches for removal of EAC exostoses are through the transmeatal route.6-8 This approach has two disadvantages. It usually results in significant loss of the remaining canal wall skin through damage by the drill, and it does not allow adequate visibility or instrument and drill access to remove the medial portion of the exostotic mass near the tympanic membrane safely. A large sessile anterior exostosis is almost uniformly present in these patients (Fig. 2-3). The approach described here is primarily postauricular and one that maximizes conservation of the canal wall skin and facilitates careful removal of the anterior exostosis, which is usually extremely close to the tympanic membrane. A curvilinear postauricular incision is made approximately 1 cm behind the postauricular fold (Fig. 2-4). The skin and subcutaneous tissues are elevated anteriorly to the area of the spine of Henle and the bony posterior canal, and a toothed, self-retaining retractor is placed (Fig. 2-5). Locating this area is facilitated by finding the plane of the lateral surface of the inferior border of the temporalis muscle and dissecting in this plane anteriorly to reach the meatus. When this area is reached, the skin overlying the lateral slope of the posterior exostosis is elevated from its surface, and a bladed tympanoplasty retractor is inserted to hold the elevated skin off the surface of the lateral portion of the bony mass (Fig. 2-6). Although there may be more than one posterior and anterior exostosis, predominant anterior and posterior exostoses are usually present along with others of lesser mass. These secondary masses may be handled similarly to the primary exostoses, or may be removed directly. In the large majo­ rity of cases, the vascular strip area is spared by exostosis.

20

OTOLOGIC SURGERY Drape bar Anterior canal injection

Face fan

Figure 2-2 

Figure 2-1 

A Anterior exostoses

Retractor in place

Posterior exostoses Postauricular incision

B Figure 2-3 

To simplify the description here, this operation is divided into two major segments: removal of the posterior exostosis and removal of the anterior exostosis. REMOVAL OF POSTERIOR EXOSTOSIS With a medium-sized cutting burr and an appropriately scaled suction-irrigator, the posterior exostosis is entered along its lateral sloping edge, and the bony removal is progressed medially, keeping a shell of bone over the area being

Figure 2-4 

burred anteriorly (Fig. 2-7). The remaining skin over the exostosis medial to the skin elevated earlier is protected from the burr. As this shell becomes thinner, it is advisable to switch to a diamond burr to prevent a sudden breakthrough to the skin, which might occur if one continues with the cutting burr on the excessively thinned bone. The bone removal is continued medially and posteriorly until the estimated normal posterior canal contour and dimension are achieved. As one approaches a medial depth consistent with the posterior

CHAPTER 2 — CANALPLASTY FOR EXOSTOSES OF THE EXTERNAL AUDITORY CANAL

Perkins retractor holds skin off exostoses

Postauricular tissues elevated and held in retractor

Figure 2-6 

Figure 2-5 

Bone shell protects skin

Flat elevator

Figure 2-7 

Figure 2-8 

21

22

OTOLOGIC SURGERY

annulus of the tympanic membrane (which usually cannot be seen directly at this point), care must be taken to avoid damage to the chorda tympani nerve and the posterior aspect of the tympanic membrane. The surgeon should also keep in mind that some patients’ facial nerves exist lateral to the tympanic annulus at its posteroinferior border. Facial nerve monitoring reduces the possibility of injury to the nerve in a patient unable to tolerate local anesthesia. The thinned bony shell is collapsed, and a small elevator reveals the inside surface of the posterior canal skin that was over the exostosis (Fig. 2-8). An incision is made midway along the posterior canal skin perpendicular to the long axis of the EAC (Fig. 2-9). The posterior canal skin medial to this incision is positioned onto the new contour of the posterior canal wall (Fig. 2-10). The transmeatal approach is then taken, and incisions are made with a sickle knife superiorly and inferiorly in the canal, extending from the ends of this previous incision laterally to the meatus, and creating a laterally based posterior canal skin flap. This flap is involuted back into the meatal portion of the canal and held there with the retractor (Fig. 2-11). Attention is turned to the anterior exostosis, which has now been revealed. REMOVAL OF ANTERIOR EXOSTOSIS With a round knife, an incision is made in the skin overlying the anterior exostosis from superior to inferior over the dome of the exostosis and as far medially as can be seen. This incision is connected to the incisions previously made

Incision in posterior canal skin

superiorly and inferiorly in the canal that defined the posterior canal skin flap, and this anterior canal flap is elevated laterally (Fig. 2-12). Frequently, the skin of the vascular strip can be left intact if the exostoses do not involve this portion of the canal. With a back-angled Perkins tympanoplasty elevator, this laterally based anterior canal skin flap is elevated further to the cartilaginous portion of the anterior canal and is smoothed so as to lie laterally near the posterior canal flap under the retractor (Fig. 2-13). With a cutting burr and small suction-irrigator, the anterior exostosis is removed in a manner similar to that of the posterior one, and a thin shell of bone that protects the canal skin is left over the anteromedial portion of the exostosis from the burr (Fig. 2-14). This bone removal is continued to the area of the anterior annulus of the tympanic membrane. The bony shell is collapsed and removed, leaving the intact anterior canal skin (Fig. 2-15). Usually, it is necessary to finish up and smooth an edge of bone that remains at the anterior extent of this dissection to have a smooth contour near the annulus area. To protect the elevated anterior sulcus skin from the burr, a small tympanic membrane-sized piece of silicone elastomer (Silastic) or suture packet foil is placed on the inside surface of the anterior canal skin to hold it against the tympanic membrane during drilling. This prevents the skin flap from getting involved with the burr and prevents damage to the tympanic membrane that might occur with the burr being used in such close proximity to the membrane. Subsequently, the Silastic is removed, the medial anterior canal skin is placed on the bone, and all

Medial posterior canal skin on new contour

Figure 2-9 

Figure 2-10 

CHAPTER 2 — CANALPLASTY FOR EXOSTOSES OF THE EXTERNAL AUDITORY CANAL

Posterior canal flap involuted into meatus

23

Laterally based anterior canal skin flap is elevated

Figure 2-11  Figure 2-12 

Anterior skin flap folded laterally

Anterior exostoses removed, leaving shell

Figure 2-13 

Figure 2-14 

24

OTOLOGIC SURGERY

Skin flaps placed back on new contours of bony canal Remove shell of bone

Figure 2-16  Figure 2-15 

skin flaps are folded back into position on the new contours of the bony canal (Fig. 2-16). The medial flaps are packed into place with chloramphenicol (Chloromycetin) or ofloxacin (Floxin)-soaked absorbable gelatin sponge (Gelfoam) pledgets, and the postauricular incision is closed with interrupted subcuticular 4-0 polyglactin 910 (Vicryl) suture. Through the transmeatal route, the laterally based canal skin flaps are packed into place with Gelfoam pledgets. A cotton ball is placed in the meatus, and a mastoid dressing is applied. The patient is returned to the outpatient recovery area and discharged after appropriate recovery.

POSTOPERATIVE CARE The patient is instructed to remove the mastoid dressing the next morning. The Gelfoam packing is removed using the stereomicroscope on the first office visit 1 week later. Antibiotic-steroid eardrops are prescribed for use twice daily for 1 week and once every 3 days for another 2 to 3 weeks. The second postoperative visit is at 1 month. If there is no evidence of infection, no additional eardrops are recommended. Because most of the patients in whom this procedure is done have had recurrent external otitis, and because time is needed for epithelialization of uncovered bone, the ear canal may remain moist for a longer time than in a typical tympanoplasty. Until the ear canal is completely dry and healed, the patient should be seen every few weeks to inspect and clean debris from the canal as needed.

The canal skin has usually been exposed to numerous infections and has been stretched over the exostoses; as a result, it may not be as resilient as normal canal skin. Return to water exposure should be avoided until after complete healing has occurred—usually between 3 and 8 weeks. Frequently, avid surfers return to the water much sooner than instructed, however. Antibiotic drops given after water exposure reduce the risk of early postoperative infection. If the patient is still in the growth years, further repeated exposure of the ear to cold water should be moderated. The bone may reproliferate under these conditions, and further surgery may become necessary.9 In patients who want to return to frequent surfing or similar water exposure, earplugs should be worn to prevent water entrance. This problem lessens in older surfers because they may be beyond their rapid growth phase, and the economic exigencies of life tend to decrease their frequency of exposure. It is advisable to see the patient annually for 2 years to assess the tendency for the problem to recur, although recurrence is infrequent.

PROBLEMS AND COMPLICATIONS Although this procedure is not fraught with serious complications, complications can occur during several aspects of the operation. As the medial extent of the canal is approached in the removal of the posterior exostosis, the course of the chorda tympani nerve must be kept in mind. This portion of the bone removal is done largely without definite landmarks: the surgeon must rely on mental estimation of the distances

CHAPTER 2 — CANALPLASTY FOR EXOSTOSES OF THE EXTERNAL AUDITORY CANAL

25

Tympanic membrane and malleus Fibrosis

Canal incision

Noninvolved canal skin

M I S Figure 2-17 

in arriving at the posterior annulus. Mentally extending the plane indicated within the vascular strip area of the EAC may assist positioning of the lower portion of the bone removal. The chorda tympani nerve is beneath the bone near this field of dissection and could sustain damage. Also, it is important to remember the course of the facial nerve, which passes posterior and inferior to the canal, although this area is farther from the immediate area of dissection than the chorda tympani nerve. When a burr is used very near the tympanic membrane and the malleus, a diamond burr should be used because it is less likely than the cutting burr to run erratically.

SUMMARY Exostoses of the EAC usually manifest without attendant compromise in function or clinical disease. When recurrent external otitis or hearing impairment results, however, surgical removal is indicated. Canalplasty has significant advantages over commonly used transmeatal approaches by maximizing conservation of canal skin and providing surgical access to the anterior medial zone of the canal. Complications are infrequent, but attention to the anatomy of the chorda tympani and facial nerve pathways and careful drill technique in the area of the tympanic membrane are important. Although surgical techniques involving the EAC have had little attention compared with other reconstructive procedures, they should be in the armamentarium of all otologic surgeons. This technique has proved to be effective for the management of exostoses of the EAC.

MISCELLANEOUS EXTERNAL AUDITORY CANAL CONDITIONS MEDIAL THIRD STENOSIS For unknown reasons, some patients develop weeping epitheliitis over the medial third of the EAC. Treatment consists of antibiotic-steroid eardrops that supply broad-spectrum bacterial coverage. Intense treatment, including debridement and the use of topical agents, is usually necessary to

bring the process under control. Despite attempts at treatment, progression of the condition may follow a relentless course, resulting in dense fibrosis of the medial segment of the EAC with conductive hearing loss. The mesotympanum and ossicular chain are characteristically spared. Surgical repair may be necessary when conductive hearing loss produces a functionally significant deficit for the patient. Successful repair is frequently possible, although restenosis may occur; this possibility should be included in the informed consent. Technically, a postauricular approach is used to allow complete resection of the fibrotic segment medial to noninvolved EAC skin where an incision has been previously created working through a transcanal route (Fig. 2-17). Removal of most of the fibrous layer of the tympanic membrane seems to reduce the chance of postoperative restenosis. Tympanoplasty is performed with a lateral graft technique. Coverage of the resultant exposed bone is mandatory and is provided with a free split-thickness skin graft. The posterior surface of the pinna provides skin of appropriate character within the operative field and can be taken with a No. 10 blade. Skin grafts should overlap the fascia used for tympanic membrane replacement but should not extend to cover the lateral surface of the reconstructed drum. Antibiotic-containing absorbable packing is removed 7 to 14 days later, and antibiotic-steroid eardrops are continued for 2 weeks beyond healing to be tapered over time. Close observation postoperatively is necessary to intervene with any signs of restenosis. Recurrent epitheliitis may occur months or years after successful repair.

COLL APSING CANAL Stenosis of the cartilaginous portion of the lateral EAC may produce symptoms for some patients. In severe cases, conductive hearing loss may result when closure to less than 2 mm occurs. More commonly, accumulation of debris and a warm, moist environment lead to recurrent external otitis. Although this condition occurs naturally, an iatrogenic component is frequently present. After a postauricular incision, the natural tension of the cartilaginous canal may be unopposed by inadequately reapproximated deep layers such as the mastoid

26

OTOLOGIC SURGERY Elevated skin and tympanic membrane

Cartilage and attached perichondrium

Cartilage and attached perichondrium

Lateral

M TM M S I Canal skin

Medial Figure 2-18 

periosteum. Gradual stenosis may occur until symptoms become evident many years after the surgical procedure. Operative repair includes removal of cartilage from the anterior concha and posterior cartilaginous canal from the postauricular area with imbrication of the deep tissue layers overlying the mastoid cortex, similar to imbrication of the subcutaneous musculoaponeurotic system in a facelift. The skin of the ear canal need not be violated in such a procedure. Postoperative stenting for 2 weeks also is helpful in restoring a normal contour to the canal. In some patients with only lateral soft tissue and cartilage involvement, the stenosis may be addressed via a transcanal route, avoiding a postauricular incision.

KERATOSIS OBTURANS Exuberant accumulation of desquamated skin may produce bony erosion and gradual expansion of the bony EAC.10 The process may progress to the point of erosion into structures adjacent to the canal, such as the temporomandibular joint or mastoid. Erosion lateral to the eardrum may cause loss of support of the fibrous annulus of the tympanic membrane and a characteristic “jump rope sign” inferiorly (which can also be seen after curetting for a stapes procedure more superiorly). Poor epithelial migration has been proposed as the cause of the disorder. Frequent cleaning may retard the process. Cleaning may be much easier if the typically inspissated and adherent material is softened with mineral oil for several days before the clinical appointment. Surgical intervention is rarely indicated unless severe erosion exposes vital structures.

OSTEONECROSIS AND OSTEORADIONECROSIS OF THE TYMPANIC BONE Radiation and occasionally chronic vasculitis devascularize a portion of the tympanic bone, producing skin loss and bone exposure. The low-grade osteomyelitis can be managed

conservatively with topical antimicrobials and mild debridement. Addition of oral antibiotics may improve the chance of healing lesions in the early phases. Frequently, bone involvement progresses, however, and can lead to further skin loss. A culture and sensitivity test is indicated before institution of topicals, and later with deterioration of healing, to look for resistant organisms. One must always consider malignancy in such a clinical situation, and biopsy is prudent in many cases. Operative repair is indicated for progression of bone exposure or associated cellulitis or both. Removal of all devitalized bone with the postauricular approach is necessary. The margins of the canal skin are freshened similar to what is performed in a tympanoplasty. Autogenous fascia is placed directly on the freshly drilled bone, and the skin is returned to anatomic position overlying it. The external canal is packed with antibiotic-containing absorbable sponge to be removed in 7 to 10 days when antibiotic drops are initiated and continued until complete healing occurs.

SCUTUM DEFECTS Cholesteatoma of the pars flaccida produces bone erosion in many patients. Repair of the EAC is necessary to prevent reretraction and cholesteatoma formation through the canal defect. Small defects (5 years) with CAA, the most crucial elements remain the functional and anatomical integrity of the inner ear as documented by boneconduction audiometry, and middle and inner ear anatomy as viewed on high-resolution thin-section (≤1 mm) axial and coronal CT scans. Prognosis for hearing improvement with surgery is correlated with the degree of malformation and other anatomical structures including middle ear volume and incudostapedial joint angle.43,59,60

TIMING OF SURGICAL REPAIR The timing of atresia surgery very much depends on the family’s decision for auricular reconstruction. Regardless of microtia repair, atresia repair is not recommended until the child is 5 to 6 years of age. Before this age, there may be a tendency to scar and stenose the new canal, or form exostosis-like bony growths that may occlude the EAC.

CHAPTER 4 — Congenital Malformation of the External Auditory Canal and Middle Ear

The mastoid and middle ear are better pneumatized in older children. In addition, younger children tend to be less cooperative in the office for the important postoperative care: packing removal and debridement. Failure to remove packing or clean the ear well could jeopardize an otherwise successful surgery. Finally, younger children tend to be more prone to the vagaries of the eustachian tube, and waiting until the child is 5 to 6 years old allows maturation of eustachian tube function with less risk of middle ear effusion. Options for microtia repair, other than observation, include a prosthetic ear applied either with medical tape or osseointegrated titanium implants (e.g., Vistafix, Cochlear Corp.), Medpor porous polyethylene implant (Stryker Corp.), or autologous rib cartilage.67-70 Each method has its own risks, benefits, and cosmetic outcomes, which are beyond the scope of this chapter. For the purposes of atresia repair, however, the Medpor implant can be placed after atresia surgery (this method has been reported by one group71), whereas the rib cartilage microtia reconstruction is placed before atresia surgery. Rib graft microtia repair is recommended at age 5 to 6 years, when the costal cartilage has developed sufficiently to allow for reconstruction of the auricle. If the family chooses the osseointegrated bone-conduction device for hearing habilitation (see Chapter 33), the otologic surgeon must communicate with the microtia surgeon regarding the timing and, more importantly, the placement of the device so it does not interfere with future microtia reconstruction. Placement must allow for the possibility of transplanting costal cartilage or implanting the Medpor framework to an area with unscarred tissue for future microtia repair. Many times the device must go a bit more posterior than if placed with a normal auricle. If positioned posterior enough, the implant can be placed at any time (after age 5, per Food and Drug Administration [FDA] regulations) regardless of the microtia repair. Most microtia surgeons, however, prefer to place the framework (cartilage or polyethylene) before implantation of the bone-conduction device. Rib graft auricular reconstruction must be performed before atresia surgery to avoid interfering with the critical blood supply to the surrounding soft tissue. However, Medpor reconstruction should be performed after atresia surgery because the atresia operation risks exposure of the implant, in which case it will not heal because of a lack of blood supply to the implant and the attendant risk of infection or extrusion. The child with a congenital ear canal cholesteatoma in the setting of congenital aural stenosis (CAS) demands more immediate surgical intervention. Such patients may present with an infected or draining ear or acute facial palsy. The estimated prevalence of cholesteatoma in CAS ranges from 19% to 48%, with females more likely than males to harbor cholesteatoma, and more likely in the left ear.72,73 Children with hemifacial microsomia (Goldenhar syndrome) or Treacher Collins syndrome tend not to acquire these cholesteatomas.73 Diagnosis is suspected based on high-resolution CT imaging (see later). Infection, otorrhea, or otalgia in any child with CAS, regardless of age, should prompt urgent high-resolution CT imaging. In the child with ear canal cholesteatoma, imaging

45

will show a rounded density lateral to the atretic plate with smooth, bony remodeling (Fig. 4-1). The priority in these patients is removal of the cholesteatoma and all epithelial elements and resolution of the infection. With middle ear involvement, the operation should be staged for the purposes of hearing improvement.

PREOPERATIVE EVALUATION AND PATIENT COUNSELING The preoperative evaluation of the patient desiring atresiaplasty rests on audiometric and radiographic data. Audiometrically, the patient must have normal bone-conduction thresholds in the atretic ear, indicating normal inner ear function. In patients with bilateral CAA, the masking dilemma can be overcome, and bone-conduction thresholds for each individual ear can be obtained through sensorineural acuity level (SAL) testing.74 Obtaining more reliable and accurate audiometric thresholds before surgery, especially in patients with bilateral CAA, is another reason to wait until the child is 5 to 6 years old to recommend atresia surgery. Because of this age recommendation, CT imaging is also not recommended until the child is 5 to 6 years old. CT imaging in younger children delivers a higher total body radiation dose and increases the estimated lifetime attributable cancer mortality risk.75 CT imaging in younger children may also show middle ear fluid that the child will eventually outgrow. Opacification of the middle ear is a contraindication to atresia surgery, and the scan will have to be repeated to demonstrate a clear middle ear space before surgery. Finally, the middle ear and mastoid are still developing in younger children, and waiting until the child is age 5 or 6 to image the ear will capture a more developed middle ear and mastoid. Thin (≤1 mm) section, high-resolution CT imaging in the axial and coronal planes must demonstrate favorable anatomy (Fig. 4-2). The Jahrsdoerfer classification system (Table 4-1) can prognosticate hearing results 1 month after surgery: patients who score 7 or higher have an 80% to 90% chance of achieving normal or near-normal hearing (speech-reception threshold [SRT] ≤30 dB HL); patients with scores less than 7 have only a 40% to 50% chance of achieving normal or near-normal hearing.59 Middle ear volume was found to be the single best predictor of hearing outcome in this and other studies on middle ear anatomy and hearing outcomes.43,59 Alternatively, the otologic surgeon may inspect the four most important imaging elements helpful in planning reconstruction of a congenitally malformed ear: (1) the degree of pneumatization of the temporal bone; (2) the course of the facial nerve, including the relationship of the horizontal portion to the footplate and the location of the vertical segment; (3) the presence of the oval window and stapes footplate; and (4) the status of the inner ear.5,6,76 CT also provides information on thickness and form of the atretic bone, size and status of the middle ear cavity, distance between atretic bone and ossicles, attachment of malleus neck to atretic plate, and soft tissue contribution to the atretic ear canal, all of which are important factors for surgical planning.

46

OTOLOGIC SURGERY

A

B

C Figure 4-1  High-resolution computed tomography in the coronal plane (A) and axial plane (B) of an acquired ear canal cholesteatoma in the right ear. Note the rounded, expansile lesion with smooth bony remodeling lateral to the atretic plate and middle ear space. C, Axial diffusion-weighted magnetic resonance image of the same patient with a right ear canal cholesteatoma. Note the bright signal in the lateral temporal bone on the right.

Figure 4-2  Congenital aural atresia, right ear. Coronal high-resolution computed tomography shows atretic external auditory canal and normally developed mastoid air cell system, with normal inner ear.

Lack of pneumatization of the middle ear space is the major cause of inoperability in CAA.6,33 In addition, obstruction of the oval window by an overhanging facial nerve will prevent ossiculoplasty and hearing improvement. If the oval window or footplate is absent, surgery is not recommended because long-term hearing outcomes of the oval window drill-out procedure are marginal with significantly higher risk.77 In such patients, the osseointegrated bone-conduction system is an extremely useful alternative. Patients and surgeons alike must understand the risk of facial nerve injury in CAA surgery. This risk stems from the more acute angle the nerve takes at the mastoid genu compared with its typical 90- to 120-degree take-off angle. The nerve often lies more lateral and anterior than usual as well (Fig. 4-3).78 On high-resolution CT, it is important not to mistakenly “identify” the vertical course of the facial nerve in the marrow bone leading to the styloid process and the

CHAPTER 4 — Congenital Malformation of the External Auditory Canal and Middle Ear

Oval window

Fused malleus-incus

47

stenosis (10% to 15%), loss of skin graft with resultant mucosalization of the ear canal and moisture or drainage (10% to 15%), and loss of early hearing gains secondary to tympanic membrane graft lateralization or refixation of the ossicular chain (10% to 15%) are discussed with the family.81-83

SURGICAL TECHNIQUE 60°

A

Normal 95° to 120°

B Figure 4-3  Facial nerve in congenital atresia surgery. A, Normal intratemporal facial nerve anatomy. B, Intratemporal facial nerve anatomy in congenital aural atresia.

The keys to successful atresia repair are careful selection of patients for surgery and meticulous technique and attention to detail at each step. The operation is made more difficult by fatigue and poor ergonomics, which may cause back pain or discomfort. Early atresiaplasty operations failed because the surgeon opened the mastoid and used the antrum and horizontal semicircular canal as landmarks to the middle ear. This posterior technique often led to draining ears and wet cavities. Poor tympanoplasty and skin grafting techniques also contributed.18 Jahrsdoerfer pioneered the anterior approach— using the tegmen and bone overlying the TMJ to follow the most direct path into the epitympanum of the middle ear and opening as few mastoid air cells as possible—the preferred technique today.8

PATIENT POSITIONING AND PREPARATION

Figure 4-4  Pitfalls in congenital aural atresia surgery: facial nerve on coronal high-resolution computed tomography. Arrows point to the vertical (mastoid) segment of the facial nerve in a left ear.

hypoplastic mastoid process (Fig. 4-4).79 Even in atretic ears in which the facial nerve does not have an abnormal course, a significantly reduced distance is found between the facial canal and the TMJ, and the facial canal and the posterior wall of the new canal.41,48 Nevertheless, in experienced hands, facial nerve injury in atresia surgery is low, especially with intraoperative monitoring, and has been estimated at less than 1%.80 The goal of atresia surgery is the creation of a clean, dry, skin-lined ear canal and eardrum with normal to near-normal hearing. The patient and parents are counseled regarding the success of atresiaplasty repair and the chances of successful hearing improvement based on the anatomy noted previously. Patients are informed that a split-thickness skin graft (STSG) from the upper arm (or lower abdomen) is used to line the new EAC. Initially, frequent postoperative visits are necessary for cleaning the desquamated epithelium from the skin graft. The possibilities of a facial nerve paresis or paralysis (