Nisson Peyton L, Ding Xinmin, Tayebi Meybodi Ali, Palsma Ryan, Benet Arnau, Lawton Michael T
Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona.
Department of Neurosurgery, Cedar Sinai, Beverly Hills, California.
Oper Neurosurg (Hagerstown). 2020 Aug 1;19(2):E122-E129. doi: 10.1093/ons/opaa023.
Revascularization of the posterior inferior cerebellar artery (PICA) is typically performed with the occipital artery (OA) as an extracranial donor. The p3 segment is the most accessible recipient site for OA-PICA bypass at its caudal loop inferior to the cerebellar tonsil, but this site may be absent or hidden due to a high-riding location.
To test our hypothesis that freeing p1 PICA from its origin, transposing the recipient into a shallower position, and performing OA-p1 PICA bypass with an end-to-end anastomosis would facilitate this bypass.
The OA was harvested, and a far lateral craniotomy was performed in 16 cadaveric specimens. PICA caliber and number of perforators were measured at p1 and p3 segments. OA-p3 PICA end-to-side and OA-p1 PICA end-to-end bypasses were compared.
OA-p1 PICA bypass with end-to-end anastomosis was performed in 16 specimens; whereas, OA-p3 PICA bypass with end-to-side anastomosis was performed in 11. Mean distance from OA at the occipital groove to the anastomosis site was shorter for p1 than p3 segments (30.2 vs 48.5 mm; P < .001). Median number of perforators on p1 was 1, and on p3, it was 4 (P < .001).
Although most OA-PICA bypasses can be performed using the p3 segment as the recipient site for an end-to-side anastomosis, a more feasible alternative to conventional OA-p3 PICA bypass in cases of high-riding caudal loops or aberrant anatomy is to free the p1 PICA, transpose it away from the lower cranial nerves, and perform an end-to-end OA-p1 PICA bypass instead.
小脑后下动脉（PICA）的血管重建通常采用枕动脉（OA）作为颅外供血动脉。p3段是在小脑扁桃体下方的尾袢处进行枕动脉-小脑后下动脉（OA-PICA）搭桥术最容易到达的受血部位，但由于位置较高，该部位可能不存在或隐藏。
验证我们的假设，即游离PICA的p1段起始部，将受血部位转移到较浅位置，并进行端到端吻合的枕动脉-p1段小脑后下动脉（OA-p1 PICA）搭桥术将有助于该搭桥手术。
在16个尸体标本上采集枕动脉，并进行远外侧开颅手术。测量p1和p3段的小脑后下动脉管径和穿支数量。比较枕动脉-p3段小脑后下动脉端侧吻合和枕动脉-p1段小脑后下动脉端到端吻合。
16个标本进行了端到端吻合的枕动脉-p1段小脑后下动脉搭桥术；而11个标本进行了端侧吻合的枕动脉-p3段小脑后下动脉搭桥术。p1段从枕沟处的枕动脉到吻合部位的平均距离比p3段短（30.2对48.5mm；P<0.001）。p1段穿支的中位数为1，p3段为4（P<0.001）。
尽管大多数枕动脉-小脑后下动脉搭桥术可采用p3段作为端侧吻合的受血部位，但在尾袢位置较高或解剖结构异常的情况下，传统枕动脉-p3段小脑后下动脉搭桥术更可行的替代方法是游离p1段小脑后下动脉，将其从下颅神经处移开，并进行端到端的枕动脉-p1段小脑后下动脉搭桥术。
