Liu Kai, Liu Xinli, Song Huixiao, Gao Xiujuan, Zhang Menglong, Qi Yuangang
Department of Medical Imaging, Ganzhou People's Hospital, The Affiliated Ganzhou Hospital of Nanchang University, Ganzhou, China.
Department of Radiology, The Forth People's Hospital of Jinan, Jinan, China.
Quant Imaging Med Surg. 2021 Apr;11(4):1284-1291. doi: 10.21037/qims-20-725.
The frequency and arrangement of the subsegmental branches of the third portion of the vertebral artery (V3) have been assessed in small samples by autopsy, but they have not been assessed by computed tomography angiography (CTA). To determine the frequency and arrangement of subsegmental branches of V3 by CTA and to analyze the interrelationships among frequency, arrangement, sex, and side-to-side.
First, the radiology records of 668 consecutive patients who underwent cervical or craniocervical CTA scans from October 1, 2017 to October 31, 2019 were retrospectively retrieved. Second, the four demarcation points were ascertained to define the three subsegments by reviewing the resource images, namely, the vertical portion of V3(V3v), horizontal portion of V3(V3h), and extradural portion of V3(V3e). Then, the numerical value and the location of the bifurcating branch in each subsegment of V3 were recorded. Third, the frequency and arrangement of the branches was assessed, and the relationships between sex, laterality and frequency and arrangement were analyzed as well as the interobserver performance.
On the left, 25%, 20.21%, and 6.59% were the frequencies of one branch in the V3v, V3h, and V3e, and 1.05%, 0.00%, and 0.45% were the frequencies of two branches, respectively. On the right, 25.04%, 17.07%, and 6.44% were the frequencies of one branch in the V3v, V3h, and V3e, and 1.04%, 0.3%, and 0.15% were the frequencies of two branches, respectively. There were no differences between the side-to-side and numerical values of the branches according to the t-test (P=0.4341, P=0.7968), and there were no differences between the side-to-side variable, sex variable and number of branches according to the -test (P=0.4474, P=0.3593). There were no differences between the side-to-side and eight arrangements (permutation of 000; 100; 110; 111; 010; 011; 001; 101) by using the two-sample KS test (P=0.942), and there were no differences between sex and the eight arrangements according to the two-sample KS test (P=0.9973, P=0.8519). The interobserver reliability was excellent (Spearman's ranked correlation: 0.9927).
The frequency and arrangement of V3 subsegmental branches could be displayed by source imaging with CTA, and there were no significant differences according to the sex or side of the individual. It was imperative to acquaint the subsegmental branches before the operation involving V3 in the craniocervical junction to determine the surgical approach and reduce bleeding during the surgical procedures.
椎动脉第三段（V3）亚段分支的频率和排列已通过尸检在小样本中进行了评估，但尚未通过计算机断层血管造影（CTA）进行评估。目的是通过CTA确定V3亚段分支的频率和排列，并分析频率、排列、性别和左右侧之间的相互关系。
首先，回顾性检索2017年10月1日至2019年10月31日期间连续668例行颈部或颅颈CTA扫描患者的放射学记录。其次，通过回顾源图像确定四个分界点以定义三个亚段，即V3的垂直段（V3v）、水平段（V3h）和硬膜外段（V3e）。然后，记录V3各亚段分叉分支的数值和位置。第三，评估分支的频率和排列，并分析性别、侧别与频率和排列之间的关系以及观察者间的一致性。
在左侧，V3v、V3h和V3e中一个分支的频率分别为25%、20.21%和6.59%，两个分支的频率分别为1.05%、0.00%和0.45%。在右侧，V3v、V3h和V3e中一个分支的频率分别为25.04%、17.07%和6.44%，两个分支的频率分别为1.04%、0.3%和0.15%。根据t检验，分支的左右侧和数值之间无差异（P=0.4341，P=0.796），根据χ检验，左右侧变量、性别变量与分支数量之间无差异（P=0.4474，P=0.3593）。使用两样本KS检验，左右侧与八种排列（000；100；110；111；010；011；001；101）之间无差异（P=0.942），根据两样本KS检验，性别与八种排列之间无差异（P=0.9973，P=0.8519）。观察者间可靠性极佳（Spearman等级相关性：0.9927）。
CTA源图像可显示V3亚段分支的频率和排列，个体的性别或侧别无显著差异。在涉及颅颈交界区V3的手术前，必须了解亚段分支情况，以确定手术入路并减少手术过程中的出血。
