Vestibular schwannoma: predictive factors of long-term postoperative neurological outcome

Abstract

Introduction: Vestibular schwannoma (VS) is a slow-growing, benign tumor that is usually diagnosed when symptoms develop. Surgical management aims to reduce long-term sequelae (LTS) associated with late diagnosis.

Objective: Identify predictive factors of LTS after VS surgery and clinical outcome measured by modified Rankin scale (mRS).

Methods: This cohort study included patients submitted to VS surgery from 1999 to 2014, with a mean follow-up of 6.4 ± 4.5 years. Disability was assessed across the mRS the primary outcome was defined by scores 3 to 6, which implied poor outcome in neurological recovery. Predictive factors were identified through multivariate logistic regression.

Results: A total of 101 patients were included in this study. Fifty-one (50.49%) presented mRS ≥ 3 on the late postoperative period. Men comprise 22.8%, and the mean age was 47.1 ± 16.0 years (range19–80). Patients with mRS ≥ 3 presented larger tumors (3.7 ± 1.1 cm vs. 3.2 ± 1.0 cm, p < .001), less total resection (50% vs. 76.7%, p < .010) and more neurofibromatosis II(NFII) (84.9% vs. 64.3%, p = .023). On multivariate analysis NFII, tumor size and type resection were predictive of degree of autonomy (mRS ≥3: NF II (OR 3.5, 95% CI 1.08–11.36, p = .036) and tumor size (each 1 cm, OR1.51, 95% CI 0.96–2.38, p = .050).

Conclusion: Tumor size, presence of NFT II, type of surgical approach and number of surgeries were identified as predictive factors of functional sequelae in long-term follow-up after VS surgery.

Highlights

• One-third of our patients presented some degree of disability that impact in autonomy (mRS ≥ 3) in the late postoperative period.

• Tumor size, NFII, surgical approach were predictive to comprise independency.

• Considering the cranial nerve monitoring and late diagnosis, our results can give some contribution to understanding the Brazilian profile of VS surgery.

• Our findings suggests the need to look over what it is well recognized and identify aspects that affect the prognosis such as functional disabilities in VS surgery.

Chinese abstract

介绍：前庭神经鞘瘤是一种生长缓慢的良性肿瘤, 通常在症状出现时被诊断。手术治疗旨在减少与晚期诊断相关的长期后遗症（LTS）。

目的：探讨用改进的Rankin量表（mRS）测定的VS术后LTS的预测因素及临床疗效。

方法：该队列研究包括1999-2014年接受VS手术的患者, 平均随访6.4±4.5 年。通过mRS评估残疾情况, 主要结果定义为3到6分, 这样的分值意味着神经恢复不良。通过多因素逻辑回归分析确定预测因素。

结果：本研究共纳入101例患者。术后晚期51例（50.49%）表现出mRS≥3。男性占22.8%, 平均年龄47.1±16.0岁（19-80岁）。mRS≥3的患者表现为较大的肿瘤（3.7±1.1 cm 相对于3.2±1.0 cm, p<0.001）。全切除较少（50%相对于76.7%, p<0.010）；神经纤维瘤病II较多（84.9%相对于64.3%, p<0.023）。在多变量分析中, NFII、肿瘤大小和肿瘤类型可预测自主程度（mRS≥3:NFII（OR为3.5,95%CI1.08-11.36, p = 0.036）和肿瘤大小（每1 cm, OR为1.51,　95%CI0.96-2.38, p = 0.050）。

结论：在VS术后长期随访中, 肿瘤大小、NFT-II的存在、手术方式和手术次数是功能性后遗症的预测因素。

Keywords:

• Neurologic disorders
• vestibular schwannoma
• outcome and complications

Disclosure statement

The authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.