Kirkland Jared D, Dahlin Brian C, O'Brien William T
Department of Radiology, David Grant Medical Center, Travis AFB, California, USA.
Department of Radiology, UC Davis, Sacramento, California, USA.
BMJ Case Rep. 2016 Jul 13;2016:bcr2016012464. doi: 10.1136/bcr-2016-012464.
During embryological development, primitive anastomoses exist between the carotid and vertebrobasilar arteries. These anastomoses typically regress or are incorporated into the developing vasculature. Persistence beyond fetal development, however, results in vascular anomalies that alter haemodynamic flow with a predisposition for aneurysm formation. The carotid-vertebrobasilar anastomoses mirror the primitive communications and include (from most to least common) the trigeminal, hypoglossal, proatlantal and otic arteries. The hypoglossal and proatlantal variants extend through the hypoglossal canal or foramen magnum, respectively. We present a previously undescribed variant of these persistent fetal anastomoses, the 'transclival artery', which courses through its own transclival skull base canal/foramen.
在胚胎发育过程中，颈动脉与椎基底动脉之间存在原始吻合支。这些吻合支通常会退化或融入发育中的脉管系统。然而，在胎儿发育后持续存在会导致血管异常，改变血流动力学并易形成动脉瘤。颈动脉 - 椎基底动脉吻合支反映了原始交通情况，包括（从最常见到最不常见）三叉动脉、舌下动脉、寰前动脉和耳动脉。舌下动脉和寰前动脉变异分别穿过舌下神经管或枕骨大孔。我们展示了这些持续存在的胎儿吻合支一种此前未描述过的变异，即“经斜坡动脉”，它穿过其自身的经斜坡颅底管/孔。
