脑干海绵状瘤（CMs）的外科治疗具有挑战性。据报道，采用经鼻腔经蝶骨途径（eTSTCA）的手术是治疗腹侧脑干CMs的有效替代方法。然而，位于脑干腹侧中线的CMs罕见，目前只有少数个案报告提到了采用eTSTCA治疗这些CMs的情况。eTSTCA的疗效和安全性尚未完全研究。本研究回顾性分析了连续5例接受eTSTCA手术治疗腹侧脑桥性CMs的患者。平均CM最大直径为26.0毫米（18-38毫米）。所有患者均接受MR扩散张量成像，确认皮质脊髓束（CST）向后或向侧方偏离CM。在进行皮质切口前进行了直接脑干皮质刺激以确定CST的位置。切除CM后，用人工脑脊液填充腔体，以形成水性手术场（湿场技术），观察肿瘤腔体，并确认完全止血和切除。所有患者均达到了完全切除。术前改良Rankin量表分数为3的患者有3例，为4的患者有2例，而术后3个月，分别有2例患者的分数为1和3例患者的分数为0。术后发现1例脑脊液漏，1例患者出现暂时性展神经麻痹。未观察到其他术中或术后并发症。MR扩散张量成像和直接脑干皮质刺激对确定CST与CM的接近度有用。内窥镜即使在水下也可以清晰视野，并且观察整个CM腔体并确认完全止血而无需额外牵拉脑干实质，包括CST，是安全有效的。eTSTCA为病变提供了直接进入点，并可能是CST向侧面或后方偏移的CM的一种较安全的替代治疗方法。

Surgical treatment of brainstem cavernous malformations (CMs) is challenging. Surgery using the endoscopic transsphenoidal transclival approach (eTSTCA) is reported as a useful alternative for ventral brainstem CMs. However, CMs located in the ventral midline of the brainstem are rare, and only a small number of case reports on these CMs treated with the eTSTCA exist. The efficacy and safety of the eTSTCA have not yet been fully examined.A retrospective analysis was performed for 5 consecutive patients who underwent surgery via the eTSTCA for treating ventral pontine CMs.The average maximum CM diameter was 26.0 mm (18-38 mm). All patients underwent MR-diffusion tensor imaging, which confirmed that the corticospinal tract (CST) deviated posteriorly or laterally to the CM. Direct brainstem cortical stimulation was performed to localize the CST before making the cortical incision. After the excision of the CM, the cavity was filled with artificial CSF to make an aqueous surgical field (wet-field technique) for observing the tumor cavity and confirming complete hemostasis and resection. Total removal was achieved in all patients. The preoperative modified Rankin Scale score was 3 in 3 patients and 4 in 2 patients, whereas it was 1 in 2 patients and 0 in 3 patients 3 months after surgery. Postoperative CSF leakage was observed in 1 patient, and transient abducens nerve palsy was observed in 1 patient. No other intra- or postoperative complications were observed.MR-diffusion tensor imaging and direct brainstem cortical stimulation were useful to ascertain the proximity of the CST to the CM. The endoscope provides a clear view even underwater, and it was safe and effective to observe the entire CM cavity and confirm complete hemostasis without additional retraction of the brainstem parenchyma, including the CST. The eTSTCA provides a direct access point to the lesion and may be a safer alternative treatment for patients whose CST deviates laterally or posteriorly to the CM.