Early Translabyrinthine Surgery for Small- and Medium-Sized Vestibular Schwannomas: Consecutive Cohort Analysis of Outcomes

Abstract

Objective: Reappraisal of the role of translabyrinthine (TLAB) surgery in small-and medium-sized vestibular schwannomas (VSs). Study Design: Retrospective study. Setting: Tertiary referral center. Patients: A total of 330 consecutive patients diagnosed between 1973 and 2019 with small-and medium-sized VS up to 20 mm in the extrameatal portion submitted to surgical treatment. Interventions: VS removal through microscopic TLAB approach. Main Outcome Measures: Facial nerve function according to the House-Brackmann scale at 12-month follow-up, postoperative complications and entity of tumor resection assessed with postoperative MRI. A comparative analysis of outcomes between two groups of patients was further conducted, according to tumor size: Group A, small-sized (intrameatal or ≤10 mm extrameatal tumors) and Group B, medium-sized VSs (extrameatal between 11 and 20 mm). Results: Complete tumor removal was achieved in all cases. The overall complication rate was 5.5%, being cerebrospinal fluid leak the most frequent. Patients with small-sized VS (n = 121) presented a significantly better facial nerve function than patients with medium-sized tumors (n = 209), showing House-Brackmann Grades I to II in 92.6% versus 73.6% of cases, respectively ( p < 0.001). A nearly 4.5-fold higher risk of poor facial nerve function at 12 months affects patients with medium-sized tumors (odds ratio, 4.473; 95% confidence interval, 2.122-9.430; p < 0.001). Conclusion:In the current scenario of multioptional VS management, when hearing preservation is not feasible, early TLAB approach as first-line treatment for small-sized VSs showed favorable results. Factors supporting such proactive surgical treatment include long-term definitive cure, no major complications, good facial nerve outcomes, and the possibility of simultaneous hearing rehabilitation with a cochlear implant.

Early surgery and definitive cure in small sporadic vestibular schwannoma

“…The benefits of early surgery on small (< 1 cm) vs mediumsized tumours (between 1 and 2 cm) was also evident in our experience 15 when facial nerve outcomes were compared between the two groups wherein surgery on small tumours offered excellent rates of functional preservation. Our conclusion was that early surgery on a small, growing tumour was a viable alternative to observation.…”

“…Over 50 years of microsurgery as well the long experience with radiotherapy and observation are expected to offer sufficient data to indicate the most appropriate treatment for small vestibular schwannoma 4,6,7 . The surgical outcome has been known for decades 20 and recently improved to the present levels 14,15 . The outcome of observation and radiotherapy took more time to assess mid-to long-term growth as it was to include the result of the full course of therapy, that is of secondary surgery in failures due to growth of the observed or radiated tumour [10][11][12] .…”

“…A more accurate volumetric measurement of tumour size showed a 65% growth rate 22 and changed our view on the natural history of small vestibular schwannoma. Moreover, the results of surgery on small tumours are superior to those of medium-large tumours 5,14,15,20 argument against the observational strategy is that growth during observation leads to surgery on a larger tumour and worse facial nerve outcomes 13 . Facial nerve outcomes were compared based on initial treatment strategy, so that patients operated on at diagnosis with primary surgery were compared with patients allocated to conservative management and operated on after established tumour growth.…”

“…This radically changed the authors' previous indication to wait and see protocols. The recent literature 14,15 points to the fact that 1 cm in the CPA is the critical size allowing good preservation of the facial nerve. Allocating a 1 cm tumour to observation involves a higher risk of impaired facial function in the case of delayed surgery.…”

“…The short and mid-term outcomes favour both observation and radiotherapy, but it gradually emerged that the outcome must include both the long-term 8,9 and the full course of therapy, including surgery, in failures [10][11][12] . As additional data on non-surgical therapies is being made available, a change in the current trends is emerging [13][14][15] . The aim of this study was to present a consecutive series of patients treated for small VS with a translabyrinthine (TLAB) approach or hearing preservation surgery (HPS).…”