埃及人群中 Willis 环及其两个部分的结构：一项磁共振血管造影研究。

Zaki S M, Shaaban M H, Abd Al Galeel W A, El Husseiny A A W

Department of Anatomy and Embryology, Faculty of Medicine, Cairo University, Cairo, Egypt.

Fakeeh College for Medical Sciences, Jeddah, Saudi Arabia.

Folia Morphol (Warsz). 2019;78(4):703-709. doi: 10.5603/FM.a2019.0015. Epub 2019 Feb 14.

BACKGROUND

We hypothesized that the collateral circulation differs in different ethnic groups. So, the aim of our work was to study variations of the circle of Willis (COW) among Egyptian and to compare our findings with the findings of other nationalities.

MATERIALS AND METHODS

One hundred patients were studied using magnetic resonance angiography (3D-TOF-MRA). Frequency and morphologic variations in COW were studied. The diameters of the arteries of the anterior and posterior circle were verified. Finally, the differences among the mean diameters of these arteries regarding age and sex were also studied.

RESULTS

Complete, partially complete and incomplete COW were encountered in 28%, 38% and 34% in the studied cases. The incomplete anterior circle was found in 34% (10% isolated incomplete anterior circle and 24% combined incomplete anterior and posterior circles) and the incomplete posterior circle came across in 62% (38% isolated incomplete posterior circle and 24% combined incomplete anterior and posterior circles). Seven anterior circle variations were found. The commonest type was the classical type "a" with a prevalence of 56%, being higher in male (57.1%). The 2nd common type was type "g" (hypoplasia or aplasia of the anterior communicating artery) with a prevalence of 24%, being higher in male (66.7%). Six posterior circle variations were found. The commonest variation was the classic type "a" with a prevalence of 26%, being higher in male (61.5%). Posterior circles types "d, e, h" (18%, 24%, 20%) constituted 62% and were characterised by hypoplasia/absent of the posterior communicating arteries.

CONCLUSIONS

The prevalence of complete COW (classic or textbook type) was encountered only 28% of the studied cases. Variations of COW were found to be more common in the posterior circulation (62%). The incomplete anterior circle was found in 34% and it is mostly caused by hypoplasia or aplasia of the anterior communicating artery which was found to be more common compared to the literature.

背景

我们推测不同种族的侧支循环存在差异。因此，我们研究的目的是探讨埃及人群中 Willis 环（COW）的变异情况，并将我们的研究结果与其他民族的研究结果进行比较。

材料与方法

使用磁共振血管造影（3D-TOF-MRA）对 100 例患者进行研究。研究 COW 的频率和形态变异。测量前后循环动脉的直径。最后，研究这些动脉平均直径在年龄和性别方面的差异。

结果

在所研究的病例中，完整型、部分完整型和不完整型 COW 分别占 28%、38%和 34%。发现 34%的患者前循环不完整（10%为孤立性前循环不完整，24%为前后循环联合不完整），62%的患者后循环不完整（38%为孤立性后循环不完整，24%为前后循环联合不完整）。发现 7 种前循环变异。最常见的类型是经典的“a”型，患病率为 56%，男性患病率更高（57.1%）。第二常见的类型是“g”型（前交通动脉发育不全或缺失），患病率为 24%，男性患病率更高（66.7%）。发现 6 种后循环变异。最常见的变异是经典的“a”型，患病率为 26%，男性患病率更高（61.5%）。后循环的“d、e、h”型（分别为 18%、24%、20%）占 62%，其特征是后交通动脉发育不全/缺失。