Lillian S. Wells Department of Neuro-logical Surgery, University of Florida, Gainesville, Florida.
Department of Neurosurgery, Tokyo Medical University, Tokyo, Japan.
Oper Neurosurg (Hagerstown). 2018 May 1;14(5):563-571. doi: 10.1093/ons/opx152.
Advances in diagnosis of posterior inferior cerebellar artery (PICA) aneurysms have revealed the high frequency of distal and/or dissecting PICA aneurysms. Surgical treatment of such aneurysms often requires revascularization of the PICA including but not limited to its caudal loop.
To examine the microsurgical anatomy involved in occipital artery (OA)-PICA anastomosis at various anatomic segments of the PICA.
Twenty-eight PICAs in 15 cadaveric heads were examined with the operating microscope to take morphometric measurements and explore the specific anatomy of bypass procedures.
OA bypass to the p2, p3, p4, or p5 segment was feasible with a recipient vessel of sufficient diameter. The loop wandering near the jugular foramen in the p2 segment provided sufficient length without requiring cauterization of any perforating arteries to the brainstem. Wide dissection of the cerebellomedullary fissure provided sufficient exposure for the examination of some p3 segments and all p4 segments hidden by the tonsil. OA-p5 bypass was placed at the main trunk before the bifurcation in 5 hemispheres and at the larger hemispheric trunk in others.
Understanding the possible variations of OA-PICA bypass may enable revascularization of the appropriate portion of the PICA when the parent artery must be occluded. A detailed anatomic understanding of each segment clarifies important technical nuances for the bypass on each segment. Dissection of the cerebellomedullary fissure helps to achieve sufficient exposure for the bypass procedures on most of the segments.
对后下小脑动脉（PICA）动脉瘤的诊断进展揭示了远端和/或夹层 PICA 动脉瘤的高频率。此类动脉瘤的手术治疗通常需要对 PICA 进行血运重建，包括但不限于其尾环。
研究 PICA 不同解剖节段的枕动脉（OA）-PICA 吻合术涉及的显微解剖结构。
在 15 具尸体头颅的 28 条 PICA 中，使用手术显微镜进行形态测量并探索旁路手术的具体解剖结构。
OA 旁路至 p2、p3、p4 或 p5 段是可行的，只要有足够直径的受体血管。在 p2 段靠近颈静脉孔的环段提供了足够的长度，而无需烧灼任何通往脑干的穿支动脉。小脑延髓裂的广泛解剖为检查一些被扁桃体隐藏的 p3 段和所有 p4 段提供了足够的暴露。OA-p5 旁路在 5 个半球中放置在主干分叉前，在其他半球中放置在较大的半球主干上。
了解 OA-PICA 旁路的可能变异可能使在必须闭塞母动脉时能够对 PICA 的适当部分进行血运重建。对每个节段的详细解剖学理解阐明了每个节段旁路的重要技术细节。小脑延髓裂的解剖有助于实现大多数节段旁路手术的充分暴露。
