Lazaro Tyler T, Srinivasan Visish M, Cotton Patrick C, Cherian Jacob, Johnson Jeremiah N
Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA.
Department of Neurosurgery, Barrow Neurological Institute, Phoenix, Arizona, USA.
Oper Neurosurg. 2021 Nov 15;21(6):E539-E540. doi: 10.1093/ons/opab338.
Aneurysms of the posterior inferior cerebellar artery (PICA) represent the second most common posterior circulation aneurysm and commonly have complex morphology. Various bypass options exist for PICA aneurysms,1-6 depending on their location relative to brainstem perforators and the vertebral artery, and the presence of nearby donor arteries. We present a case of a man in his late 40s who presented with 3 d of severe headache. He was found to have a fusiform right P2-segment PICA aneurysm. Preoperative angiogram demonstrated the aneurysm and a redundant P3 caudal loop that came in close proximity to the healthy P2 segment proximal to the aneurysm. The risks and benefits of the procedure were discussed with the patient, and they consented for a right far lateral approach craniotomy with partial condylectomy for trapping of the aneurysm with bypass. The aneurysm was trapped proximally and distally. The P3 was transected just distal to the aneurysm and brought toward the proximal P2 segment, facilitated by a lack of perforators on this redundant distal artery. An end-to-side anastomosis was performed. Postoperative angiogram demonstrated exclusion of the aneurysm and patent bypass. The patient recovered well and remained without any neurological deficit at 6-mo follow-up. This case demonstrates the use of a "fourth-generation"5,7,8 bypass technique. These techniques represent the next innovation beyond third-generation intracranial-intracranial bypass. In this type 4B reanastomosis bypass, an unconventional orientation of the arteries was used. Whereas reanastomosis is typically performed end-to-end, the natural course of these arteries and the relatively less-mobile proximal P2 segment made end-to-side the preferred option in this case. Fourth-generation bypass techniques open up more configurations for reanastomosis, using the local anatomy to the surgeon's advantage. The patient consented to the described procedure and consented to the publication of their image.
小脑后下动脉（PICA）动脉瘤是后循环动脉瘤中第二常见的类型，通常具有复杂的形态。根据PICA动脉瘤相对于脑干穿支和椎动脉的位置以及附近供血动脉的情况，存在多种搭桥选择。我们报告一例40多岁男性，因严重头痛3天就诊。发现其患有右侧P2段梭形PICA动脉瘤。术前血管造影显示了动脉瘤以及一个多余的P3尾袢，该尾袢紧邻动脉瘤近端的健康P2段。与患者讨论了手术的风险和益处，患者同意采用右侧远外侧入路开颅并部分髁突切除术，通过搭桥来夹闭动脉瘤。动脉瘤在近端和远端被夹闭。P3在动脉瘤远端被横断并向近端P2段牵拉，由于这条多余的远端动脉上缺乏穿支，使得操作更为便利。进行了端侧吻合。术后血管造影显示动脉瘤被排除且搭桥通畅。患者恢复良好，6个月随访时无任何神经功能缺损。 该病例展示了“第四代”5,7,8搭桥技术的应用。这些技术代表了第三代颅-颅内搭桥技术之后的又一创新。在这种4B型再吻合搭桥中，采用了非常规的动脉走向。虽然再吻合通常是端端进行，但这些动脉的自然走行以及相对活动度较小的近端P2段使得在该病例中端侧吻合成为首选。第四代搭桥技术利用局部解剖结构为外科医生提供了更多再吻合的构型选择。 患者同意了所述手术并同意发表其影像资料。
