ABSTRACT
OBJECTIVE: To preserve facial nerve function in vestibular schwannoma (VS) microsurgery, some have advocated subtotal resection (STR) if the tumor is densely adherent to a thinned facial nerve. The objective of this study was to determine if residual volume is associated with progression and whether there is a threshold residual volume that should be pursued during STR to prevent recurrence. A secondary objective of this study was to determine whether facial nerve function at last follow-up was associated with extent of resection (EOR). METHODS: Clinical and radiographic data were retrospectively collected from the records of 164 patients with VS who underwent resection. Tumor volumes were measured using Visage, and standard statistical methods were used. The House-Brackmann scale was used to assess changes in facial nerve function before surgery and at last follow-up. RESULTS: Sixty-one patients (37%) received gross-total resection (GTR) and 103 (63%) received STR. The median clinical and radiographic follow-ups were 49 and 48 months, respectively. The median residual volume was 0.5 cm3 after STR. Kaplan-Meier actuarial survival analysis revealed a 96.3% 5-year progression-free survival (PFS) rate after GTR, which was greater than that after STR (84.5%, p = 0.03). Recursive partitioning analysis of patients receiving STR revealed a residual volume of 0.60 cm3 as the optimal threshold for recurrence. Patients with residual volume ≥ 0.60 cm3 had a 76.0% 5-year PFS, regardless of adjuvant SRS, which was lower than that for patients undergoing GTR (96.3%) or STR (95.6%) with residual volumes < 0.60 cm3 (p < 0.01). On Cox regression analysis, residual volume ≥ 0.60 cm3 (HR 14.4, p = 0.01) was independently associated with progression, even when accounting for patient age, adjuvant radiosurgery, and preoperative tumor size. In 112 patients with at least 24 months of follow-up after their last treatment, tumor control was achieved in 111 (99.1%) patients at a median last follow-up of 71 months. Worse facial nerve function at the last follow-up was independently associated with prior treatment for VS (adjusted OR 3.7, p = 0.04), but not residual volume cohort or preoperative tumor volume. CONCLUSIONS: Residual volume > 0.60 cm3 after VS resection was independently associated with tumor progression, even accounting for adjuvant SRS. These data support maximizing the EOR during VS surgery, even if GTR cannot be safely achieved.
ABSTRACT
Introduction Vestibular schwannomas (VSs) are treated with microsurgery and/or radiosurgery. Repeat resection is rare, and few studies have reported postoperative outcomes. The objective of this study was to describe clinical characteristics and outcomes in patients undergoing repeat surgery for VS. Methods All adult (≥ 18 years) patients undergoing VS resection between 2003 and 2022 at our institution were retrospectively reviewed to identify patients who underwent repeat surgery of an ipsilateral VS following prior gross-total (GTR) or subtotal resection. Patient, radiographic, and clinical characteristics were reviewed. Primary outcomes were postoperative tumor volume, extent of resection, postoperative cranial nerve deficits, and time to further tumor progression. Results Of 102 patients undergoing VS resection, 6 (5.9%) had undergone repeat surgery. Median (range) follow-up was 20 (5-117) months. Three patients were female. Median age was 56 (36-60) years. Median pre- and postoperative tumor volumes were 8.2 (1.8-28.2) cm 3 and 0.4 (0-3.8) cm 3 . GTR was achieved in two patients. Four patients had higher House-Brackmann scores at last follow-up, but none had tumor progression. Conclusion In this small cohort of patients, repeat resection of recurrent or progressive VS can effectively reduce tumor volume with acceptable perioperative outcomes.
ABSTRACT
BACKGROUND: The VS-5 index was recently proposed to predict complications, nonroutine discharge, length of stay (LOS), and cost after vestibular schwannoma (VS) resection. The VS-5 ranges from 0-17.86, and a score ≥2 was proposed as being predictive of postoperative adverse events. We sought to determine whether the VS-5 is predictive of nonroutine discharge and length of stay in an institutional cohort. METHODS: This is a retrospective study of 100 patients undergoing VS resection. For each patient, a VS-5 score was calculated. Bivariate analyses were conducted to determine differences in postoperative outcomes between high- and low-risk subgroups. Area under the receiver operating characteristic curve sensitivity/specificity analysis using Youden's Index was conducted to evaluate the optimal cutoff. RESULTS: Fifty-one (51%) patients were classified as high risk (VS-5 ≥ 2). Patients with VS-5 ≥ 2 had higher frequency of nonroutine discharge (22% vs. 4%, P = 0.0150) and no significant difference in postoperative LOS. The area under the receiver operating characteristic curve for predicting nonroutine discharge was 0.78 ± 0.15 (P < 0.0001). The optimal cutoff for nonroutine discharge was ≥6, higher than the published cutoff of ≥ 2. The new cutoff was predictive of nonroutine discharge (47% vs. 6%, P = 0 < 0.0001) and LOS (6 [3-11] days vs. 3 [1-28] days, P = 0.0001). CONCLUSIONS: The VS-5 frailty index predicted nonroutine discharge but not LOS. Youden's index indicates that a cutoff of 6, not 2, is optimal for predicting nonroutine discharge and LOS.