TY - JOUR
T1 - Maximizing Exposure of the Internal Auditory Canal Via the Retrosigmoid Approach
T2 - An Anatomical, Radiological, and Surgical Study
AU - Cueva, Roberto A.
AU - Chole, Richard A.
N1 - Publisher Copyright:
© 2018, Otology & Neurotology, Inc.
PY - 2018/8/1
Y1 - 2018/8/1
N2 - Objective: The purpose of this study was to identify anatomic landmarks and surgical techniques that maximize bone removal for exposure of the distal internal auditory canal (IAC) to avoid labyrinthine injury during retrosigmoid removal of tumors within the IAC. Study Design: Anatomic dissection, radiological assessment and retrospective case series. Setting: Tertiary referral center. Methods: On the basis of previously conducted temporal bone anatomic dissections of the temporal bone, the authors performed intraoperative measurement of the undissected distal IAC, performed pre-and postoperative radiological assessment of vestibular schwannoma (VS) patients. The surgical and anatomic information was used to determine the anatomic limits of labyrinth sparing bone dissection and the landmarks most critical to maximal IAC exposure. The authors describe surgical techniques using these data. An edited video of representative surgery highlights important principles. Review of 251 patients requiring IAC bony dissection for tumor removal from January 2005 through October 2017 is described. Results: Achieving complete exposure of the IAC fundus is not possible, without labyrinthine injury, via retrosigmoid approach. Anatomic dissection, intraoperative photography, and postoperative radiographs demonstrate that bone removal within 2 to 3 mm of the fundus is routinely possible. The endolymphatic sac and duct is the optimal landmark for optimizing IAC exposure. Conclusion: The course of the endolymphatic sac and duct in the posterior petrous bone is the most important landmark determining the lateral limit of bony removal during IAC exposure for tumor resection. Surgical techniques based on these anatomic findings facilitate tumor resection while preserving the labyrinth.
AB - Objective: The purpose of this study was to identify anatomic landmarks and surgical techniques that maximize bone removal for exposure of the distal internal auditory canal (IAC) to avoid labyrinthine injury during retrosigmoid removal of tumors within the IAC. Study Design: Anatomic dissection, radiological assessment and retrospective case series. Setting: Tertiary referral center. Methods: On the basis of previously conducted temporal bone anatomic dissections of the temporal bone, the authors performed intraoperative measurement of the undissected distal IAC, performed pre-and postoperative radiological assessment of vestibular schwannoma (VS) patients. The surgical and anatomic information was used to determine the anatomic limits of labyrinth sparing bone dissection and the landmarks most critical to maximal IAC exposure. The authors describe surgical techniques using these data. An edited video of representative surgery highlights important principles. Review of 251 patients requiring IAC bony dissection for tumor removal from January 2005 through October 2017 is described. Results: Achieving complete exposure of the IAC fundus is not possible, without labyrinthine injury, via retrosigmoid approach. Anatomic dissection, intraoperative photography, and postoperative radiographs demonstrate that bone removal within 2 to 3 mm of the fundus is routinely possible. The endolymphatic sac and duct is the optimal landmark for optimizing IAC exposure. Conclusion: The course of the endolymphatic sac and duct in the posterior petrous bone is the most important landmark determining the lateral limit of bony removal during IAC exposure for tumor resection. Surgical techniques based on these anatomic findings facilitate tumor resection while preserving the labyrinth.
KW - Internal auditory canal
KW - Retrosigmoid approach
KW - Vestibular schwannoma
UR - http://www.scopus.com/inward/record.url?scp=85050105051&partnerID=8YFLogxK
U2 - 10.1097/MAO.0000000000001866
DO - 10.1097/MAO.0000000000001866
M3 - Article
C2 - 29995012
AN - SCOPUS:85050105051
SN - 1531-7129
VL - 39
SP - 916
EP - 921
JO - Otology and Neurotology
JF - Otology and Neurotology
IS - 7
ER -