INDICATIONS CORRIDOR AND LIMITS OF EXPOSURE The expanded retrosigmoid approach with splitting of the horizontal cerebellar fissure provides a more direct and shorter route for central and dorsolateral pontine lesions while minimizing retraction of tracts, nuclei, and cerebellum.1-4. ANATOMIC ESSENTIALS NEED FOR PREOPERATIVE PLANNING AND ASSESSMENT The middle cerebellar peduncle is partially covered by the petrosal surface of the cerebellum. The horizontal cerebellar fissure (petrosal fissure) divides the petrosal surface of the cerebellar hemisphere into superior and inferior parts. Splitting the petrosal fissure separates the superior and inferior petrosal surfaces and exposes the posterolateral middle cerebellar peduncle (posterior and lateral to the root entry zone of CN5).1-4. ESSENTIALS STEPS OF THE PROCEDURE Expanded retrosigmoid craniotomy is performed, including unroofing of the sigmoid sinus; petrosal fissure is split to expose the posterolateral middle cerebellar peduncle; entry point for resection of the cavernoma is identified; nims stimulator stimulator is used to confirm the absence of tracts and nuclei; myelotomy is performed; and cavernoma and its draining vein (but not the developmental venous anomaly) are removed using a combination of traction and countertraction against gliotic plane. PITFALLS/AVOIDANCE OF COMPLICATIONS Wide splitting of the horizontal cerebellar fissure minimizes retraction or resection of the cerebellum and offers the best angle of attack. Knowledge of brainstem anatomy and use of intraoperative navigation are critical to avoid complications. VARIANTS AND INDICATIONS FOR THEIR USE Far lateral through the middle cerebellar peduncle is a variant that can be used to resect pontine cavernomas if a caudocranial trajectory is preferred.The patient consented to the procedure and to the publication of her image.

中文翻译：

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切除脑桥海绵状血管瘤的小脑中脚入路。

适应症 走廊和暴露限制 扩大乙状结肠后入路，劈开小脑水平裂，为脑桥中央和背外侧病变提供更直接、更短的路径，同时最大限度地减少束、核和小脑的牵拉。1-4。术前计划和评估所需的解剖要点 小脑中脚部分被小脑岩骨表面覆盖。小脑水平裂（岩骨裂）将小脑半球的岩骨面分为上、下两部分。劈开岩骨裂将岩骨上表面和下岩表面分开，并暴露后外侧小脑中脚（CN5 根部入口区的后侧和外侧）。1-4。手术的基本步骤 进行扩大乙状窦后开颅手术，包括去除乙状窦顶；劈开岩裂，暴露小脑中脚后外侧；确定海绵体瘤切除的切入点；nims 刺激器刺激器用于确认束和细胞核的不存在；进行骨髓切开术；使用针对胶质平面的牵引和反牵引相结合的方式去除海绵体瘤及其引流静脉（但不是发育性静脉异常）。陷阱/避免并发症 小脑水平裂的广泛分裂最大限度地减少了小脑的回缩或切除，并提供了最佳的攻击角度。脑干解剖知识和术中导航的使用对于避免并发症至关重要。变体及其使用适应症 如果首选尾颅轨迹，则通过小脑中脚远外侧切除是一种可用于切除脑桥海绵状血管瘤的变体。患者同意该手术并同意发布其图像。