Lindsay A Irwin, Lawrance Lee, Joshua Mitchell, Frank D Corwin, Daniel H Coelho, Nauman F Manzoor
{"title":"Endoscopic-Assisted Presigmoid Approach to the Internal Auditory Canal. A Feasibility Study.","authors":"Lindsay A Irwin, Lawrance Lee, Joshua Mitchell, Frank D Corwin, Daniel H Coelho, Nauman F Manzoor","doi":"10.1097/MAO.0000000000004248","DOIUrl":null,"url":null,"abstract":"<p><strong>Hypothesis: </strong>The retrolabyrinthine (presigmoid) approach has been utilized in various skull base surgeries but has not been fully utilized in the management of internal auditory canal (IAC) lesions, such as vestibular schwannoma (VS). Microsurgical retrolabyrinthine approach provides limited visualization of the IAC, while endoscopic-assisted techniques allow for further lateral exposure with labyrinthine preservation.</p><p><strong>Background: </strong>Traditional approaches to the IAC have the disadvantage of hearing sacrifice or retraction of brain tissue. With the introduction of endoscopic techniques and enhanced visualization, access to this region of complex anatomy is possible.</p><p><strong>Methods: </strong>Radiomorphometric and anatomical dissection was performed on two cadaveric temporal bones. High-resolution computed tomography was used to segment and delineate the volume of the IAC. Projected accessible IAC was compared to actual postdissection data with preservation of the posterior semicircular canal (PSCC) via the retrolabyrinthine corridor.</p><p><strong>Results: </strong>While preserving the PSCC, the 0° and 30° endoscopes visualized 57.1% and 78.6% of the IAC for cadaver 1, and 64.0% and 76.0% of the IAC for cadaver 2, respectively. Sacrificing the PSCC, the 0° and 30° endoscopes provided visualization of 78.6% 85.7% of the IAC for cadaver 1, and 88.0% and 95.1% of the IAC for cadaver 2, respectively.</p><p><strong>Conclusions: </strong>Retrolabyrinthine approach to resection of VS is a potentially viable hearing-preserving alternative to traditional approaches. This approach provides access to the majority of the IAC, while angled endoscopes or sacrifice of the PSCC can provide additional access toward the fundus. Further studies are needed to determine the clinical feasibility of this approach.</p>","PeriodicalId":19732,"journal":{"name":"Otology & Neurotology","volume":null,"pages":null},"PeriodicalIF":1.9000,"publicationDate":"2024-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Otology & Neurotology","FirstCategoryId":"3","ListUrlMain":"https://doi.org/10.1097/MAO.0000000000004248","RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/7/2 0:00:00","PubModel":"Epub","JCR":"Q3","JCRName":"CLINICAL NEUROLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Hypothesis: The retrolabyrinthine (presigmoid) approach has been utilized in various skull base surgeries but has not been fully utilized in the management of internal auditory canal (IAC) lesions, such as vestibular schwannoma (VS). Microsurgical retrolabyrinthine approach provides limited visualization of the IAC, while endoscopic-assisted techniques allow for further lateral exposure with labyrinthine preservation.
Background: Traditional approaches to the IAC have the disadvantage of hearing sacrifice or retraction of brain tissue. With the introduction of endoscopic techniques and enhanced visualization, access to this region of complex anatomy is possible.
Methods: Radiomorphometric and anatomical dissection was performed on two cadaveric temporal bones. High-resolution computed tomography was used to segment and delineate the volume of the IAC. Projected accessible IAC was compared to actual postdissection data with preservation of the posterior semicircular canal (PSCC) via the retrolabyrinthine corridor.
Results: While preserving the PSCC, the 0° and 30° endoscopes visualized 57.1% and 78.6% of the IAC for cadaver 1, and 64.0% and 76.0% of the IAC for cadaver 2, respectively. Sacrificing the PSCC, the 0° and 30° endoscopes provided visualization of 78.6% 85.7% of the IAC for cadaver 1, and 88.0% and 95.1% of the IAC for cadaver 2, respectively.
Conclusions: Retrolabyrinthine approach to resection of VS is a potentially viable hearing-preserving alternative to traditional approaches. This approach provides access to the majority of the IAC, while angled endoscopes or sacrifice of the PSCC can provide additional access toward the fundus. Further studies are needed to determine the clinical feasibility of this approach.
期刊介绍:
Otology & Neurotology publishes original articles relating to both clinical and basic science aspects of otology, neurotology, and cranial base surgery. As the foremost journal in its field, it has become the favored place for publishing the best of new science relating to the human ear and its diseases. The broadly international character of its contributing authors, editorial board, and readership provides the Journal its decidedly global perspective.