Nandoliya Khizar R, Khazanchi Rushmin, Winterhalter Emily J, Youngblood Mark W, Karras Constantine L, Jain Rishi, Sonabend Adam M, Chandler James P, Magill Stephen T
J Neurosurg. 2024 Aug 2;142(1):230-238. doi: 10.3171/2024.4.JNS24157. Print 2025 Jan 1.
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).
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.
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.
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.
为了在前庭神经鞘瘤（VS）显微手术中保留面神经功能，一些人主张如果肿瘤与变薄的面神经紧密粘连则进行次全切除（STR）。本研究的目的是确定残留体积是否与肿瘤进展相关，以及在STR过程中是否存在一个应追求的阈值残留体积以防止复发。本研究的次要目的是确定最后一次随访时的面神经功能是否与切除范围（EOR）相关。
回顾性收集164例接受VS切除术患者的临床和影像学资料。使用Visage测量肿瘤体积，并采用标准统计方法。采用House-Brackmann量表评估术前和最后一次随访时面神经功能的变化。
61例患者（37%）接受了全切除（GTR），103例（63%）接受了STR。临床和影像学的中位随访时间分别为49个月和48个月。STR术后的中位残留体积为0.5 cm³。Kaplan-Meier精算生存分析显示，GTR术后5年无进展生存率（PFS）为96.3%，高于STR术后（84.5%，p = 0.03）。对接受STR的患者进行递归分割分析显示，残留体积为0.60 cm³是复发的最佳阈值。残留体积≥0.60 cm³的患者，无论是否接受辅助立体定向放射治疗（SRS），其5年PFS为76.0%，低于残留体积<0.60 cm³的接受GTR（96.3%）或STR（95.6%）的患者（p < 0.01）。Cox回归分析显示，即使考虑患者年龄、辅助放射外科治疗和术前肿瘤大小，残留体积≥0.60 cm³（HR 14.4，p = 0.01）仍与肿瘤进展独立相关。在112例最后一次治疗后至少随访24个月的患者中，111例（99.1%）患者实现了肿瘤控制，最后一次随访的中位时间为71个月。最后一次随访时较差的面神经功能与既往VS治疗独立相关（校正OR 3.7，p = 0.04），但与残留体积分组或术前肿瘤体积无关。
VS切除术后残留体积 > 0.60 cm³与肿瘤进展独立相关，即使考虑辅助SRS。这些数据支持在VS手术中最大化EOR，即使无法安全实现GTR。
