Esposito Felice, Becker Donald P, Villablanca Juan Pablo, Kelly Daniel F
Division of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles, Los Angeles, California, USA.
Neurosurgery. 2005 Apr;56(2 Suppl):E443; discussion E443. doi: 10.1227/01.neu.0000157023.12468.6a.
Prepontine retroclival tumors have typically been removed through a variety of anterolateral, lateral, and posterolateral cranial base approaches. Here, we describe an endonasal transclival cranial base approach for removal of prepontine epidermoid tumors.
Two men, 40 and 52 years old, each presented with a history of headaches and cranial nerve deficits. In each patient, magnetic resonance imaging showed a large T1 hypointense/T2 hyperintense mass occupying the posterior suprasellar, premesencephalic, and prepontine cisterns, with significant mass effect on the brainstem. Both patients underwent an endonasal transsphenoidal transclival cranial base tumor removal with the operating microscope and endoscopic assistance. The dural and bony defects were repaired with abdominal fat grafts, collagen sponge, titanium mesh, and cerebrospinal fluid diversion. One patient developed a postoperative cerebrospinal fluid leak and meningitis requiring two reoperations to repair, ultimately with fat and fascia lata grafts.
At 1 year after surgery, both patients have improved compared with their preoperative neurological state, and volume analysis of preoperative and 1-year postoperative magnetic resonance imaging scans confirm a marked reduction in mass effect on the brainstem, with a 78% tumor removal in one patient and 76% removal in the other. Both patients have normal endocrine function.
The endonasal approach offers a minimally invasive, anatomically direct route for removing prepontine epidermoid tumors that obviates brain retraction. The use of angled endoscopes is essential for gaining lateral, cephalad, and caudal visualization to augment the limited microscope view. Inadequate repair of clival dural defects remains the greatest potential pitfall in attempting transsphenoidal transclival tumor removal.
桥前斜坡后肿瘤通常通过各种前外侧、外侧和后外侧颅底入路进行切除。在此，我们描述一种经鼻经斜坡颅底入路切除桥前表皮样囊肿。
两名男性患者，年龄分别为40岁和52岁，均有头痛和颅神经功能缺损病史。每位患者的磁共振成像显示一个大的T1低信号/T2高信号肿块，占据鞍上后部、中脑前和桥前脑池，对脑干有明显的占位效应。两名患者均在手术显微镜和内镜辅助下接受经鼻经蝶窦经斜坡颅底肿瘤切除术。硬脑膜和骨缺损用腹部脂肪移植、胶原海绵、钛网修复，并进行脑脊液分流。一名患者术后发生脑脊液漏和脑膜炎，需要两次再次手术修复，最终采用脂肪和阔筋膜移植。
术后1年，两名患者的神经功能状态均较术前有所改善，术前和术后1年磁共振成像扫描的体积分析证实脑干的占位效应明显减轻，一名患者肿瘤切除率为78%，另一名患者为76%。两名患者的内分泌功能均正常。
经鼻入路为切除桥前表皮样囊肿提供了一种微创、解剖学上直接的途径，避免了脑牵拉。使用角度内镜对于获得外侧、头侧和尾侧视野以扩大有限的显微镜视野至关重要。斜坡硬脑膜缺损修复不当仍然是经蝶窦经斜坡肿瘤切除术中最大的潜在陷阱。
