Supplementary Material for: Basilar Artery Dissection: Series of 12 Consecutive Cases and Review of the Literature

<i>Background:</i> Current knowledge on primary or isolated basilar artery dissection (IBAD) is limited to case vignettes and small patient series. <i>Objective:</i> To delineate the frequency and clinical presentations of IBAD along with short-term outcome, specific prognosis and targeted management. <i>Methods:</i> Data were derived from a series of 12 consecutive patients and a review of 88 cases reported in the literature. In all the cases, the dissection was confined to the basilar artery. <i>Results:</i> Disease incidence was estimated at 0.25 per 100,000 person-years. IBAD accounted for roughly 1.0% of all subarachnoid hemorrhage events and for no less than 10.5 and 4.5% of posterior circulation and brain-supplying artery dissections, respectively. The main clinical presentations were subarachnoid hemorrhage (46%) and posterior circulation brain ischemia (42%). Subarachnoid hemorrhage typically manifested at a higher age than brain ischemia (mean age, 48.9 vs. 41.4 years) and was more prevalent among women. Rebleedings related to pseudoaneurysm formation in patients with subarachnoid hemorrhage and recurrent ischemia in stroke patients were common in the acute phase (26.1 and 33.3%, respectively) but were rare in the long term. The outcome was generally favorable in stroke patients but variable in subarachnoid hemorrhage (case fatality rate, 21.7%). The mainstay of therapy for subarachnoid hemorrhage related to IBAD was endovascular occlusion of the aneurysm pouch whereas stroke patients were usually put on anticoagulants. <i>Conclusions:</i> IBAD is probably an underrecognized disease with heterogeneous clinical presentation and prognosis. It should be considered as a differential diagnosis in peritruncal subarachnoid hemorrhage, classic subarachnoid hemorrhage and posterior circulation stroke, especially in young individuals. Case management is challenging and has to be tailored to each patient.

<i>背景:</i> 目前针对原发性或孤立性基底动脉夹层（primary or isolated basilar artery dissection, IBAD）的认知仅局限于个案报道与小样本病例系列研究。<i>目的:</i> 本研究旨在明确原发性或孤立性基底动脉夹层的发病频率、临床表现，以及短期预后、特异性转归与针对性诊疗方案。<i>方法:</i> 研究数据涵盖12例连续入组患者的临床资料，并纳入了文献报道的88例相关病例，所有纳入病例的夹层病变均严格局限于基底动脉。<i>结果:</i> 经估算，本病的发病率为0.25例/10万人年。原发性或孤立性基底动脉夹层约占所有蛛网膜下腔出血事件的1.0%，分别占后循环动脉夹层与脑供血动脉夹层总例数的比例不低于10.5%与4.5%。患者主要临床表现为蛛网膜下腔出血（46%）与后循环脑缺血（42%）。伴蛛网膜下腔出血的患者发病年龄显著高于脑缺血患者（平均年龄分别为48.9岁与41.4岁），且女性患者占比更高。蛛网膜下腔出血患者中因假性动脉瘤形成所致的再出血，以及卒中患者的复发性缺血在急性期较为常见（占比分别为26.1%与33.3%），但长期随访中发生率极低。卒中患者的预后整体良好，而蛛网膜下腔出血患者的预后差异较大，其病例病死率为21.7%。针对伴蛛网膜下腔出血的原发性或孤立性基底动脉夹层患者，核心治疗手段为动脉瘤囊腔内血管闭塞术；卒中患者则通常接受抗凝治疗。<i>结论:</i> 原发性或孤立性基底动脉夹层或为一种被低估的疾病，其临床表现与预后均存在显著异质性。对于椎旁蛛网膜下腔出血、典型蛛网膜下腔出血及后循环卒中患者，尤其是年轻群体，应将本病纳入鉴别诊断范畴。本病的临床诊疗颇具挑战性，需根据患者个体情况制定个体化治疗方案。