Department Anatomy Digital Imaging and 3D Modeling Laboratory, Ege University, Izmir, Turkey.
Department of Radiology, Faculty of Medicine, Ege University, Izmir, Turkey.
Surg Radiol Anat. 2021 Oct;43(10):1735-1743. doi: 10.1007/s00276-021-02748-z. Epub 2021 Apr 22.
Standart interventional procedures such as screw instrumentation, aortic arch endovascular surgery and cervical nerve blockade may be of fatal risk due to anatomic reason of variations in the proximal part of the vertebral artery (VA). The aim of this study is to study the VA variations of the extracranial segments to evaluate the frequency of the incident to demonstrate the importance of clinical condition strategy.
The prevalence of variations and morphometric measurements of the VA in three-dimensional computed tomographic angiography (3D-CTA) scans were studied. Total 400 VA was investigated for the aortic arch origin of the VA, diameter of the VA, its level of entry into the transverse foramen, the dominance sides, and related basilar artery course.
3D-CTA radiographs of 200 Anatolian patients (120 men and 80 women with age range 17-90 years). In most cases (approximately 94%), both sides of VA were the first branch of subclavian artery. While all the right VAs was branched from the subclavian artery, 6% of the left VAs were branched from the aortic arch. 2/3 of them originated from the proximal of the subclavian artery and 1/3 from the distal. The VA which were originating from the proximal of the classical anatomic pattern tended to enter the transverse foramen more distally than C6 level. VAs with a different level of entry than C6 are left-sided and aortic arch originated (out of 8 cases 3 had a level of entry at C5 and 2 at C4). The outer diameter ranges of the prevertebral part of the VA of subclavian origin and left VA of aortic arch origin were 3.2-3.6 mm and 3.2-3.6 mm, respectively. While the diameters of the right and left VAs were almost the same in approximately 20% cases, the left VA was dominant in up to 60% of cases. A significant relationship was found between the side of the dominant VA and in the course of the basilar artery.
The relationship between the dominant side of VA and the course of the basilar artery of its own vessel has never been reported elsewhere. Such anatomical variations, routine preoperative 3D-CTA evaluation is mandatory to prevent the VA injury when C5-C2 instrumentation, anterior cervical decompression, cervical nerve blockade and aortic arch surgery are planned.
由于椎动脉（VA）近端解剖结构的变异，标准的介入手术如螺钉器械、主动脉弓血管内手术和颈神经阻滞可能存在致命风险。本研究的目的是研究颅外段 VA 的变异情况，以评估其发生率，从而证明临床情况策略的重要性。
在三维 CT 血管造影（3D-CTA）扫描中研究了 VA 变异的流行率和形态测量。共对 400 支 VA 进行了研究，包括 VA 在主动脉弓的起源、VA 的直径、其进入横突孔的水平、优势侧以及相关基底动脉的走行。
对 200 名安纳托利亚患者（120 名男性和 80 名女性，年龄 17-90 岁）的 3D-CTA 射线照片进行了研究。在大多数情况下（约 94%），VA 的两侧均为锁骨下动脉的第一分支。虽然所有右侧 VA 均发自锁骨下动脉，但6%的左侧 VA 发自主动脉弓。其中 2/3 发自锁骨下动脉近端，1/3 发自锁骨下动脉远端。起源于经典解剖模式近端的 VA 倾向于比 C6 水平更靠后进入横突孔。与 C6 水平不同的 VA 进入水平为左侧和主动脉弓起源（8 例中有 3 例位于 C5，2 例位于 C4）。发自锁骨下动脉的 VA 颈椎前部分的外径范围为 3.2-3.6mm，发自主动脉弓的左侧 VA 外径范围也为 3.2-3.6mm。虽然右侧和左侧 VA 的直径在大约 20%的病例中几乎相同，但左侧 VA 在多达 60%的病例中占优势。优势 VA 的侧与基底动脉的走行之间存在显著的相关性。
VA 优势侧与基底动脉自身血管走行之间的关系从未在其他地方报道过。在计划进行 C5-C2 器械、前路颈椎减压、颈神经阻滞和主动脉弓手术时，需要进行常规的术前 3D-CTA 评估，以防止 VA 损伤。
