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目的:探讨弓下血管襻及其解剖变异在听神经瘤术中的处理策略。方法:2017年1月至2020年12月复旦大学附属华山医院神经外科采用枕下乙状窦后入路切除听神经瘤504例，术中发现并处理弓下血管襻及其解剖变异12例(2.4%)，回顾性分析此12例患者的临床资料。所有患者术后1周评估面神经功能House-Brackmann(H-B)分级以及美国耳鼻咽喉头颈外科学会听力分级。术后3个月以及之后每年门诊复查头颅增强MRI，并评估面、听神经功能。结果:12例患者中，5例正常弓下血管襻黏附在肿瘤后表面，将其向内侧移位后再行肿瘤切除；3例异常弓下血管襻顶端包埋在弓下窝硬膜中，将血管襻连同顶端的硬膜袖套一起游离并向内侧移位后再行肿瘤切除；另4例异常弓下血管襻顶端包埋在弓下窝骨质中，其中1例适度磨除周边骨质将血管襻顶端移出后再行肿瘤切除，3例经血管周围间隙行肿瘤切除。12例肿瘤均完全切除，血管襻主干均保持血流通畅。无一例死亡或合并脑脊液漏。1例术中血管襻分支破裂出血的患者术后出现小脑外侧局灶性梗死，导致共济失调。12例患者术后听力均为D级。12例患者的中位随访时间为13个月(10~53个月)。术后3个月，头颅增强MRI证实12例肿瘤均完全切除。至末次随访，面神经功能H-B分级Ⅰ级5例，Ⅱ级4例，Ⅲ级2例，Ⅳ级1例。12例患者均未见肿瘤复发。结论:听神经瘤术中遇到弓下血管襻及其解剖变异时，需尝试将其充分游离并向内侧移位后再行肿瘤切除；当血管襻顶端深埋在弓下窝骨质中，且有足够空间显露肿瘤和内听道时，可以经血管周围间隙切除肿瘤。“,”Objective:To explore the management strategy of subarcuate loop and its anatomic variations identified during vestibular schwannoma surgery.Methods:From January 2017 to December 2020, 504 cases of vestibular schwannomas were resected through the suboccipital retrosigmoid approach at the Department of Neurosurgery, Huashan Hospital, Fudan University, and 12 cases (2.4%) with a subarcuate loop or its anatomic variation were found and treated during the operation. The clinical data of the 12 patients were retrospectively analyzed. All patients were evaluated by House-Brackmann (H-B) classification of facial nerve function and American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS) hearing classification guidelines at 1 week after operation. Contrast-enhanced MRI was performed in outpatient clinic 3 months after operation and every year thereafter, and facial nerve function and hearing were evaluated.Results:Among 12 patients, 5 cases had a normal subarcuate loop adhering to the dorsal surface of the tumor, tumor resection was accomplished after the loop was displaced medially; in 3 cases, the apex of the anomalous subarcuate loop was embedded in the dura surrounding the subarcuate fossa, and tumor resection was accomplished after the loop was freed and mobilized medially with a sleeve of dura; in 4 cases, the apex of the anomalous subarcuate loop was embedded in the bone surrounding the subarcuate fossa, and tumor resection was accomplished after drilling the subarcuate fossa and releasing the loop in 1 patient, and tumor resection was performed from the perivascular space in 3 patients. Tumors were completely resected in 12 cases, and the main vascular loops remained unobstructed. There was no death or cerebrospinal fluid leakage. One patient with intraoperative vascular loop branch rupture and hemorrhage developed postoperative focal infarction of the lateral cerebellum, resulting in ataxia. All 12 patients had grade D hearing after operation. The median follow-up time of the 12 patients was 13 months (range: 10-53 months). AT 3 months after the operation, enhanced brain MRI confirmed that the tumors were completely resected in all 12 cases. By the last follow-up, facial nerve function H-B classification showed that 5 cases were grade Ⅰ, 4 cases were grade Ⅱ, 2 cases were grade Ⅲ, and 1 case was grade Ⅳ. No tumor recurrence was found in 12 patients.Conclusions:When a subarcuate loop or its anatomic variation is encountered during vestibular schwannoma surgery, an attempt should be made to free and displace it medially before tumor resection. If the apex of the loop is deeply embedded in the bone surrounding the subarcuate fossa and there is enough space to expose the tumor and the internal auditory canal, tumor resection can also be performed from the perivascular space.