Bram Richard, Choi Jason L, See Alfred P, Atwal Gursant S
Department of Neurosurgery, University of Illinois at Chicago, Chicago, United States.
Department of Neurosurgery, Cerebrovascular Surgery and Interventions Center, Boston Children's Hospital, Harvard Medical School, Boston, United States.
Surg Neurol Int. 2023 Feb 3;14:40. doi: 10.25259/SNI_950_2022. eCollection 2023.
Cerebrovascular embryologic development is characterized by the presence of four well-described carotid-vertebrobasilar (VB) anastomoses. As the fetal hindbrain matures and the VB system develops, these connections involute, yet some may persist into adulthood. The persistent primitive trigeminal artery (PPTA) is the most common of these anastomoses. In this report, we describe a unique variant of the PPTA and a four-way division of the VB circulation.
A female in her 70s presented with a Fisher Grade 4 subarachnoid hemorrhage. Catheter angiography revealed a fetal origin of the left posterior cerebral artery (PCA) giving rise to a left P2 aneurysm which was coiled. A PPTA arose from the left internal carotid artery and supplied the distal basilar artery (BA) including the superior cerebellar arteries bilaterally and the right but not left PCA. The mid-BA was atretic and the anterior inferior cerebellar artery-posterior inferior cerebellar artery complexes were fed solely from the right vertebral artery.
Our patient's cerebrovascular anatomy represents a unique variant of the PPTA not well described in the literature. This demonstrates how hemodynamic capture of the distal VB territory by a PPTA is sufficient to prevent fusion of the BA.
脑血管胚胎发育的特征是存在四种已被充分描述的颈动脉 - 椎基底动脉（VB）吻合。随着胎儿后脑成熟和VB系统发育，这些连接逐渐退化，但有些可能持续到成年期。持续性原始三叉动脉（PPTA）是这些吻合中最常见的。在本报告中，我们描述了PPTA的一种独特变体以及VB循环的四分法。
一名70多岁女性出现Fisher 4级蛛网膜下腔出血。导管血管造影显示左大脑后动脉（PCA）起源于胎儿期，导致左P2动脉瘤，已进行了弹簧圈栓塞。一条PPTA起源于左颈内动脉，供应双侧小脑上动脉及右侧而非左侧的PCA的远端基底动脉（BA）。BA中段闭锁，小脑前下动脉 - 小脑后下动脉复合体仅由右侧椎动脉供血。
我们患者的脑血管解剖结构代表了一种在文献中未得到充分描述的PPTA独特变体。这表明PPTA对远端VB区域的血流动力学捕获足以防止BA融合。
