Primitive lateral basilovertebral anastomosis（PLBA）から考える椎骨動脈・後下小脳動脈のバリエーション

Anatomical Variations to the Vertebral Artery and Posterior Inferior Cerebellar Artery are Associated with the Partial Persistence of Primitive Lateral Basirovertebral Anastomosis

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・脳幹の動脈解剖は，縦方向と横方向の構造が基本である．

・発生の一時期に存在するprimitive lateral basilovertebral anastomosis（PLBA）に着目すると，小脳動脈のanatomical variationの形成過程が説明可能となる．

・椎骨動脈，前脊髄動脈から脳幹への穿通枝分布にはバリエーションが多いため，塞栓術を行う際には注意が必要となる．

　The angioarchitecture of the hindbrain is homologous to that of the spinal cord, and its vascular system can be analyzed at the longitudinal and axial structures. During embryonic development, there are two main longitudinal arteries: the longitudinal neural artery and the primitive lateral basilovertebral anastomosis.

　Commonly observed variations are formed by the fenestration and duplication of either the vertebrobasilar artery, or cerebellar artery, which can be observed when the primitive lateral basilovertebral anastomosis partially persists. Understanding the pattern and development of blood supply to the hindbrain provides useful information of various anomalies in the vertebrobasilar junction and cerebellar arteries.