Department of Neurosurgery, J. J. Group of Hospitals and Grant Medical College, Mumbai, India.
Department of Radiology, Tata Memorial Centre, Mumbai, India.
Br J Neurosurg. 2022 Apr;36(2):203-212. doi: 10.1080/02688697.2020.1867058. Epub 2021 Jan 7.
Cerebellopontine angle (CPA) epidermoids, although of benign nature, are of considerable neurosurgical interest because of their close proximity and adherence to the cranial nerves and brain stem. In this paper, we describe our experience and attempt to correlate the final outcomes with the extent of surgical removal. The main objectives were to study various modes of surgical management of CPA epidermoids with regard to removal and preservation of the cranial nerves and also to evaluate the role of endoscopic assisted microsurgical excision thereby minimizing recurrences. This case series is one of the largest series reported so far worldwide.
From 2006 to 2016, 139 patients with CPA epidermoids were operated at Grant Medical College and J. J. Hospital, Mumbai. All patients underwent detailed magnetic resonance imaging (MRI) of brain. Lesions were classified according Rogelio Revuelta-Gutiérrez with respect to their anatomic extent: grade I- within the boundaries of the CPA, grade II- extension to the suprasellar and perimesencephalic cisterns, and grade III-parasellar and temporomesial region involvement. Retrosigmoidal and sub temporal approaches were taken to excise the lesions. Endoscopic assisted microsurgical excision was done in cases with extensions beyond the CPA. Patient follow-up was based on outpatient repeated brain MRI studies.
The mean duration of symptoms before surgery was 42 months (range, 2 months to 6 years). The mean follow-up period was 27 months (range, 2-60 months). The main presenting sympt om was headache in 69% (96/139) of the cases and trigeminal neuralgia in 30% cases was the second most common cause of consultation. Seventy-five percent of patients had some degree of cranial nerve (CN) involvement. Retrosigmoid approach was taken in 92% patients and 7 patients with supratentorial extension were operated by combined retrosigmoidal and subtemporal approach. Endoscopic assisted microsurgical excision was done in 40% cases. Use of angled views by an endoscope helped to excise residual tumor in 47 (83%) patients. Complete excision was achieved in 67% of cases. In 33% patients, small capsular remnants could not be removed completely because of their adherence to vessels, brainstem and cranial nerves. Compared with their preoperative clinical status, 74% improved and 20% had persistent cranial nerve deficits in the first year of follow up.
Epidermoid cysts are challenging entities in current neurosurgery practice due to tumor adhesions to neurovascular structures. Meticulous surgical technique with the aid of neurophysiological monitoring is crucial to achieve safe and effective total or subtotal removal of these lesions. A conservative approach is indicated for patients in whom the fragments of capsule is adhered closely to blood vessels, nerves, or the brainstem, in order to avoid risk of serious neurological deficits related to an inadvertent damage of these structures. Use of angled views by endoscope at the conclusion of the surgery may assure the surgeon of total removal of the tumor.
桥小脑角（CPA）表皮样囊肿，尽管性质为良性，但由于其与颅神经和脑干的紧密接近和粘连，具有相当大的神经外科意义。在本文中，我们描述了我们的经验，并尝试将最终结果与手术切除范围相关联。主要目的是研究各种模式的 CPA 表皮样囊肿的手术治疗，以达到切除和保留颅神经的目的，并评估内镜辅助显微切除术的作用，从而最大限度地减少复发。该病例系列是迄今为止全球报告的最大系列之一。
从 2006 年到 2016 年，孟买格兰特医学院和 JJ 医院对 139 例 CPA 表皮样囊肿患者进行了手术。所有患者均接受了详细的脑磁共振成像（MRI）检查。根据罗赫略·雷韦尔塔-古铁雷斯（Rogelio Revuelta-Gutiérrez）的分类，根据其解剖范围对病变进行分类：I 级-在 CPA 边界内，II 级-延伸至鞍上和间脑池，III 级-累及蝶鞍旁和颞内侧区域。采用乙状窦后和颞下入路切除病变。对于超出 CPA 范围的病例，采用内镜辅助显微切除术。根据门诊重复脑 MRI 研究对患者进行随访。
术前症状平均持续时间为 42 个月（范围 2 个月至 6 年）。平均随访时间为 27 个月（范围 2-60 个月）。主要表现症状为头痛占 69%（96/139），三叉神经痛占 30%，是第二常见的就诊原因。75%的患者有一定程度的颅神经（CN）受累。92%的患者采用乙状窦后入路，7 例天幕上延伸的患者采用乙状窦后联合颞下入路。40%的病例采用内镜辅助显微切除术。内镜使用斜视图有助于切除 47 例（83%）患者的残留肿瘤。67%的病例达到完全切除。33%的患者由于肿瘤与血管、脑干和颅神经粘连，无法完全切除小的囊膜残片。与术前临床状况相比，74%的患者在随访的第一年得到改善，20%的患者持续存在颅神经缺陷。
表皮样囊肿是当前神经外科实践中的具有挑战性的实体，因为肿瘤与神经血管结构粘连。精细的手术技术辅以神经生理监测对于实现这些病变的安全有效全切除或次全切除至关重要。对于那些囊膜碎片与血管、神经或脑干紧密粘连的患者，应采用保守的方法，以避免因无意损伤这些结构而导致严重的神经功能缺损的风险。手术结束时使用内镜的斜视图可以让外科医生确信肿瘤已被完全切除。
