Kageyama Y, Fukuda K, Kobayashi S, Odaki M, Nakamura H, Satoh A, Watanabe Y
Department of Neurosurgery, Chiba Emergency Medical Center.
Neurol Med Chir (Tokyo). 1992 Sep;32(10):733-8. doi: 10.2176/nmc.32.733.
The possible causes of postoperative brain damage were examined in 100 cases of cerebral aneurysms operated on by the pterional approach. Postoperative brain damage occurred in 15% of cases, located mostly in the inferior frontal lobe. Its incidence was higher in early than in delayed operation and increased with severity of preoperative clinical conditions but not correlated with patient age and aneurysm location. The venous perfusion patterns in the inferior frontal lobe were classified into three types based on preoperative venograms: Sylvian type drained mainly into the superficial Sylvian veins (SSVs), Frontal type drained mainly into the frontal bridging veins, and Intermediate type. Postoperative brain damage was most frequent in the Sylvian type with statistical significance (p < 0.01). The brain retraction procedure impairs regional cerebral blood flow (rCBF). Venous congestion in the retracted inferior frontal lobe, caused by stretching and narrowing of SSVs due to both brain retraction and dissection of the Sylvian fissure, also reduces rCBF. Thus, a marked reduction in rCBF in the retracted area causes postoperative brain damage. Postoperative venograms showed the SSVs to be obscured in 24% of patients, indicating that the pterional approach possibly influences the SSV perfusion. A venous perfusion disorder during the pterional approach is the most important factor in postoperative brain damage, and careful preoperative assessment of cerebral veins is indispensable.
对100例行翼点入路手术的脑动脉瘤患者术后脑损伤的可能原因进行了研究。15%的病例发生了术后脑损伤，主要位于额下叶。其发生率早期手术高于延期手术，且随术前临床病情严重程度增加，但与患者年龄和动脉瘤位置无关。根据术前静脉造影，将额下叶的静脉灌注模式分为三种类型：主要引流至大脑外侧浅静脉（SSV）的外侧裂型、主要引流至额桥静脉的额型和中间型。术后脑损伤在外侧裂型中最为常见，具有统计学意义（p<0.01）。脑牵拉操作会损害局部脑血流（rCBF）。由于脑牵拉和大脑外侧裂分离导致SSV拉伸和变窄，牵拉的额下叶出现静脉淤血，也会降低rCBF。因此，牵拉区域rCBF的显著降低会导致术后脑损伤。术后静脉造影显示24%的患者SSV模糊不清，表明翼点入路可能影响SSV灌注。翼点入路期间的静脉灌注障碍是术后脑损伤的最重要因素，术前仔细评估脑静脉必不可少。
