Kawamura Yoichiro, Narumi Osamu, Chin Masaki, Yamagata Sen
Department of Neurosurgery, Kurashiki Central Hospital, Kurashiki, Okayama, Japan.
Neurol Med Chir (Tokyo). 2011;51(2):97-100. doi: 10.2176/nmc.51.97.
Variant deep cerebral venous drainage, primarily involving the basal vein of Rosenthal (BVR), may be a cause of idiopathic subarachnoid hemorrhage (SAH). In this study, deep venous drainage was compared between 13 patients with idiopathic SAH and 35 control patients with aneurysmal SAH diagnosed by digital subtraction angiography (DSA). Venous return was evaluated by DSA on 25 sides in patients with idiopathic SAH and 67 sides in patients with aneurysmal SAH, and the relationship between the BVR and the vein of Galen was classified into 3 categories: types A (normal continuous), B (normal discontinuous), and C (primitive variant). The occurrence rates of the three categories were: idiopathic SAH, type A 24%, type C 40%; and aneurysmal SAH, type A 49.3%, type C 10.4% (p = 0.003). Combined bilateral venous drainage was classified as normal combination (AA), discontinuous combination (AB, BB), and primitive combination (AC, BC, CC), with rates: idiopathic SAH, normal 0%, primitive 58.3%; and aneurysmal SAH, normal 42.4%, primitive 21.2%. Venous drainage on either the left or right side was more commonly type C (primitive) in idiopathic SAH (p = 0.006). Three patients with left-right differences in hematoma distribution on brain computed tomography had types A, B, and C on the SAH dominant side in one patient each. No clear trend was observed between hematoma distribution and primitive variant side. Some patients with idiopathic SAH had thick hematoma in the basal cistern. Further, 3 patients with idiopathic SAH had an aneurysmal pattern, rather than a perimesencephalic pattern. All these patients had type C either on the left or right side. Therefore, although the mechanism of involvement of venous drainage in idiopathic SAH is unknown, hemorrhage is not limited to a perimesencephalic pattern. The present findings support a previous hypothesis that variant venous drainage is involved in the occurrence of idiopathic SAH. The absence of a normal combination of venous drainage is an important factor to diagnose idiopathic SAH.
大脑深静脉引流变异，主要累及罗森塔尔基底静脉（BVR），可能是特发性蛛网膜下腔出血（SAH）的一个病因。在本研究中，对13例特发性SAH患者和35例经数字减影血管造影（DSA）诊断为动脉瘤性SAH的对照患者的深静脉引流情况进行了比较。通过DSA评估特发性SAH患者25侧和动脉瘤性SAH患者67侧的静脉回流情况，并将BVR与大脑大静脉之间的关系分为3类：A 型（正常连续）、B型（正常间断）和C型（原始变异型）。这三种类型的发生率分别为：特发性SAH，A型24%，C型40%；动脉瘤性SAH，A型49.3%，C型10.4%（p = 0.003）。双侧联合静脉引流分为正常组合（AA）、间断组合（AB、BB）和原始组合（AC、BC、CC），其发生率为：特发性SAH，正常0%，原始58.3%；动脉瘤性SAH，正常42.4%，原始21.2%。在特发性SAH中，左侧或右侧的静脉引流更常见为C型（原始型）（p = 0.006）。3例脑计算机断层扫描血肿分布存在左右差异的患者中，SAH优势侧分别有1例为A型、B型和C型。在血肿分布与原始变异侧之间未观察到明显趋势。一些特发性SAH患者在基底池有较厚的血肿。此外，3例特发性SAH患者呈现动脉瘤样形态而非中脑周围型形态。所有这些患者左侧或右侧均为C型。因此，尽管特发性SAH中静脉引流受累的机制尚不清楚，但出血并不局限于中脑周围型形态。目前的研究结果支持先前的一个假说，即变异的静脉引流与特发性SAH的发生有关。静脉引流不存在正常组合是诊断特发性SAH的一个重要因素。
