Manninen Hannu, Tulla Harri, Vanninen Ritva, Ronkainen Antti
Department of Radiology, Diagnostic Medical Imaging Centre, Kuopio University Hospital and Kuopio University, Kuopio, Finland.
Ann Thorac Surg. 2008 Jan;85(1):120-5. doi: 10.1016/j.athoracsur.2007.08.035.
The aim of this study was to assess hemodynamic consequences of increasingly common coverage of the left subclavian artery (LSA) during endovascular stent-graft repair for thoracic aortic disease without surgical revascularization. We considered that critical arteries to examine are the right vertebral artery and posterior communicating arteries (PComA) because their simultaneous insufficiency would drastically endanger posterior cerebral circulation. The existence and the diameters of these arteries were studied in a postmortem anatomic study with review of clinical craniocervical computed tomographic (CT) and magnetic resonance (MR) angiographies.
The anatomic material was collected as a part of forensic medicine autopsies. The anatomy of the cerebral arteries of 92 deceased was assessed by angiography and permanent silicone casts.
In five individuals (5.4%) the risk for acute neurological complication after "unprotected" closure of the LSA was estimated to be "substantial" because the diameter of the right vertebral artery above the posterior inferior cerebellar artery was less than 2 mm and was associated with incomplete PComA and in three additional cases (3.3%) with only hypoplastic right vertebral artery, as "possible." Review of a clinical teaching file of MR and CT angiographies with anatomic variations and abnormalities of the circle of Willis identified, also, other variants with increased risk.
When the LSA is closed, insufficient posterior cerebral circulation due to anatomic reasons occurs relatively infrequently, but in order to avoid the debilitating complications in these cases, careful imaging of the right vertebral artery up to the basilar artery is mandatory, and if proven hypoplastic, imaging of PComAs is necessary.
本研究的目的是评估在胸主动脉疾病的血管内支架植入修复术中，在不进行外科血管重建的情况下，越来越常见的左锁骨下动脉（LSA）覆盖的血流动力学后果。我们认为需要检查的关键动脉是右椎动脉和后交通动脉（PComA），因为它们同时供血不足会严重危及大脑后循环。通过尸体解剖研究，并回顾临床颅颈计算机断层扫描（CT）和磁共振（MR）血管造影，对这些动脉的存在情况和直径进行了研究。
解剖材料是作为法医学尸检的一部分收集的。通过血管造影和永久性硅胶铸型对92例死者的脑动脉解剖结构进行了评估。
在5例个体（5.4%）中，“无保护”封闭LSA后发生急性神经并发症的风险被估计为“高”，因为小脑后下动脉上方的右椎动脉直径小于2mm，且伴有PComA不完整；另外3例（3.3%）仅右椎动脉发育不全，被视为“可能”存在高风险。回顾一份包含Willis环解剖变异和异常的MR和CT血管造影临床教学资料，也发现了其他风险增加的变异情况。
当LSA被封闭时，因解剖学原因导致大脑后循环不足的情况相对少见，但为了避免这些病例中出现使人衰弱的并发症，必须对直至基底动脉的右椎动脉进行仔细成像，如果证实发育不全，则有必要对PComA进行成像。
