Department of Neurosurgery, Osaka City University Graduate School of Medicine, Osaka, Japan.
Division of Neurosurgery, Department of Surgery, Faculty of Medicine, Thammasat University, Pathumthani, Thailand.
Acta Neurochir Suppl. 2023;130:25-36. doi: 10.1007/978-3-030-12887-6_4.
The transpetrosal approach is a complex skull base procedure with a high risk of complications, particularly caused by injury of the venous system. It is in part related to variability of blood outflow pathways and their distinctive patterns in each individual patient.
To evaluate outcomes and complications after skull base surgery with use of the petrosal approach modifications, which selection was based on the detailed preoperative assessment of venous drainage patterns.
Overall, 74 patients, who underwent surgery via the transpetrosal approach at our institution between 2000 and 2017, were included in this study. In all cases, the venous drainage pattern was assessed preoperatively and categorized according to the predominant blood outflow pathway into four types as previously suggested by Hacker: (1) sphenoparietal sinus (SpPrt), (2) sphenobasal vein (SpB), (3) sphenopetrosal sinus (SpPS), and (4) cortical. The blood outflow through the bridging petrosal vein and the vein of Labbé was also taken into consideration. In patients with SpPrt- and a cortical-type venous drainage, the transpetrosal approach was used in a standard way. In patients with SpB-type venous drainage, limited extradural anterior petrosectomy was combined with intradural anterior petrosectomy after dural opening, superior petrosal sinus transection, tentorial cutting, Meckel's cave opening, and trigeminal nerve mobilization. In patients with SpPS-type venous drainage, after standard petrosectomy, dural opening, and tentorial cutting, SpPS ligation was done followed by 2-week interval before staged definitive tumor resection.
Gross total, near-total, and subtotal resection of the lesion (meningioma, 48 cases; retrochiasmatic craniopharyngioma, 11 cases; brain stem cavernoma, 7 cases; other tumors, 8 cases) was achieved in 30 (40.5%), 24 (32.4%), and 20 (27.0%) patients, respectively. Postoperative complications that were possibly related to venous compromise were noted in 18 patients (24.3%), but neither one was major. Of these 18 patients, 9 were symptomatic, but all symptoms-aphasia (4 cases), seizures (2 cases), and confusion (3 cases)-fully resolved after conservative treatment. Overall, 13 patients, including 4 symptomatic, had signal changes on T2-weighted brain MRI, which were permanent only in 3 cases (all asymptomatic).
Our suggested surgical strategy can be applied to any type of the venous drainage pattern. Preoperative evaluation and intraoperative preservation of the blood outflow pathways are crucial means for safe and effective application of the transpetrosal approach.
岩骨乙状窦后入路是一种复杂的颅底手术，并发症风险高，特别是由于静脉系统损伤引起的并发症。这在一定程度上与血液流出途径的可变性及其在每个患者中的独特模式有关。
评估使用岩骨乙状窦后入路改良术式进行颅底手术后的结果和并发症，该术式的选择基于对静脉引流模式的详细术前评估。
本研究共纳入 2000 年至 2017 年间在我院接受岩骨乙状窦后入路手术的 74 例患者。所有患者均在术前评估静脉引流模式，并根据主要血流流出途径分为四类，如 Hacker 先前提出的：（1）蝶顶窦（SpPrt），（2）蝶基底静脉（SpB），（3）蝶岩窦（SpPS）和（4）皮质。还考虑了桥静脉和 Labbe 静脉的血流。在 SpPrt 和皮质型静脉引流的患者中，采用标准的岩骨乙状窦后入路。在 SpB 型静脉引流的患者中，在硬脑膜开放、上岩窦切开、天幕切开、 Meckel 窝开放和三叉神经松解后，行有限的硬膜外前岩骨切除术联合硬膜内前岩骨切除术。在 SpPS 型静脉引流的患者中，在标准的岩骨切除、硬脑膜开放和天幕切开后，进行 SpPS 结扎，然后间隔 2 周进行分期肿瘤切除术。
肿瘤（脑膜瘤 48 例；视交叉后颅咽管瘤 11 例；脑干海绵状血管瘤 7 例；其他肿瘤 8 例）的大体全切除、近全切除和次全切除分别在 30 例（40.5%）、24 例（32.4%）和 20 例（27.0%）患者中实现。18 例（24.3%）患者出现可能与静脉受压有关的术后并发症，但均无严重并发症。在这 18 例患者中，9 例有症状，但所有症状（4 例失语症、2 例癫痫发作和 3 例意识模糊）均在保守治疗后完全缓解。总体而言，13 例患者（包括 4 例有症状）在 T2 加权脑 MRI 上出现信号改变，仅在 3 例（均无症状）中为永久性改变。
我们建议的手术策略可应用于任何类型的静脉引流模式。术前评估和术中保护血液流出途径是安全有效地应用岩骨乙状窦后入路的关键手段。
