Retrosigmoid versus Translabyrinthine Approach for Vestibular Schwannoma Resection: A Retrospective Review of 270 Cases

Objective: Vestibular schwannoma, also known as acoustic neuroma, is a rare pathology with an estimated incidence of 1 in 100,000 people. Vestibular schwannomas may be minimally symptomatic until they grow large in size, with cisternal extension or brainstem compression often seen at initial presentation. Large tumors typically require surgical intervention which can be associated with differing risk profiles depending on the approach. We aim to identify differences in outcomes based on surgical approach for vestibular schwannoma resection.

Methods: A retrospective review was conducted to identify patients undergoing surgical resection of vestibular schwannoma between 2008 and 2023 at our institution. Chart review was conducted to identify demographic data, clinical presentation including hearing assessments, and surgical data such as approach and need for cerebrospinal fluid (CSF) diversion. Data regarding tumor size was collected from radiology reports and Koos grade was documented based on imaging review. Outcomes data collected included length of stay, readmission, clinical examination at follow-up, and CSF leak. Statistical analysis was completed using chi-square test and Student’s t-test where appropriate.

Results: A total of 268 patients were identified with 109 undergoing retrosigmoid approach craniotomy (RS), 146 undergoing translabyrinthine approach craniotomy (TL), and 13 undergoing other or combined approaches. Baseline characteristics including age [52.2 ±13.0 versus 53.6 ± 12.9 years, respectively] and major medical comorbidities for patients undergoing TL versus RS approaches were not significantly different. Patients undergoing RS approach had significantly higher probability of functional hearing preoperatively compared to TL [35% functional hearing RS, 22% functional hearing TL, p < 0.03]. Average Koos grade of the tumor was higher in the RS group [3.43 for RS versus 2.85 for TL, p < 0.01]. Tumors undergoing RS approach were more commonly cystic in nature and larger in size compared to those undergoing TL [RS average size 26.9 ± 11.0 mm, TL average size 20.2 ± 8.0 mm, p < 0.01].

Average length of stay for patients after RS was 5.3 ± 5.7 days compared to TL average 4.2 ± 3.1 days [p < 0.05]. Functional hearing was preserved in 9 patients after RS approach (24%) as opposed to 1 patient undergoing TL approach (3%), [p < 0.01]. Rates of pseudomeningocele and need for permanent CSF diversion were significantly higher in the RS group. There was no difference in mortality rate or days to ambulation after surgery between the groups.

Conclusion: The majority of tumors in our cohort were large with an overall average size of 23 mm and a median Koos grade of 4, with brainstem compression. Patients undergoing RS approach had larger tumors and higher rates of serviceable hearing than patients undergoing TL. Average length of stay was longer for retrosigmoid craniotomy with higher rates of pseudomeningocele and permanent CSF diversion. In patients with large acoustic neuromas, the advantages and disadvantages of surgical approach should be evaluated on a case-by-case basis.

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Artikel online veröffentlicht:
07. Februar 2025