永存颈内-基底动脉吻合的CTA诊断

摘要

目的:探讨16层螺旋CT血管成像(CTA)在永存颈内-基底动脉吻合诊断中的价值,提高对此类血管变异的认识.方法:回顾性分析1951例行颅脑及颅颈联合CTA检查发现的的10例永存动脉[永存三叉动脉(PTA)8例,永存舌下动脉(PHA)2例]患者的影像学资料,分析永存动脉的发生率、CTA表现及合并其他脑血管异常的情况.结果:PTA的发生率为0.41%(8/1951).PHA的发生率为0.10%(2/1951).PTA均起自颈内动脉海绵窦段,按Saltzman分型显示后循环供血情况:Ⅰ型4例,Ⅱ型3例,Ⅲ型1例.2例PHA分别于C1、C2水平从颈内动脉发出,均向后内弯曲穿过扩大的同侧舌下神经管,与基底动脉形成吻合,吻合处下方的基底动脉萎缩,后交通动脉缺如.PTA吻合口下方基底动脉和(或)椎动脉发育不良2例;PTA合并同侧颈内动脉发育不良、同侧大脑前动脉交通前段发育不良1例;PTA合并烟雾病及其侧枝血管动脉瘤形成1例.PHA合并基底动脉末端动脉瘤1例.结论:16层螺旋CTA能清晰显示永存颈内-基底动脉吻合及其合并的脑血管异常情况,并可根据动脉结构与形态间接评估其血流动力学特征,对外科手术及介入治疗有一定的指导作用.%Objective:To discuss the value of 16 slice spiral CT angiography (CTA) in the diagnosis of persistent ca rotid basilar artery anastomoses,in an effort to improve the understanding of this vascular variation. Methods:The CTA ma terials of 1951 cases having cerebral and neck CTA were reviewed. Of them,10 patients had persistent carotid basilar artery anastomoses [8 patients with persistent trigeminal artery (PTA) ,2 patients with persistent hypoglossar artery (PHA)]. The incidence rate,CTA findings and the complication with other cerebral vascular abnormalities were analyzed retrospec tively. Results:The incidence of PTA was 0.41% (8/1951),of PHA was 0.10% (2/1951). All of the PTA originated from the cavernous segment of internal carotid artery. According to Saltzman classification about the blood supply in posterior circulation;there were Saltzman type Ⅰ (4 cases) ,type Ⅱ (3 cases) ,and type Ⅲ (1 case). Two cases of PHA originated from internal carotid artery at the level of C1/C2 respectively,curved backwards passing through the ipsilateral hypoglossal canal, anastomosed with the basilar artery, the segment of basilar artery below the anastomosis was atrophied, posterior communicated artery was absent. Two patients with PTA had basilar artery and (or) vertebral artery hypoplasia at the point proximal to the anastomosis; one case complicated with ipsilateral internal carotid artery hypoplasia and ipsilateral an terior cerebral artery Al hypoplasia;one case complicated with moyamoya disease and an aneurysm formation of collateral vessels. One patient with PHA complicated with an aneurysm at the end of basilar artery. Conclusion:Persistent carotid bas ilar artery anastomoses and their complicating cerebral artery abnormalities could be clearly displayed on 16 slice spiral CTA. On the basis of CTA manifestations of arterial structure and morphology,hemodynamic characteristics could be evalu ated, which could provide a reference for the guidance of surgery and interventional treatment.