Research on free radical on acute mesenteric ischemia and intestinal viability.

本研究的目的是探讨急性肠系膜缺血（AMI）的病理生理，并建立肠活力的判断。实验研究；1)结扎肠系膜动脉2小时后的组织学改变多局限于粘膜层，另一方面，结扎静脉术后早期粘膜下层出现明显的充血、出血、水肿。2)家兔1小时再灌注后1或2小时SMA或SMV闭塞后急性肠系膜缺血。SMV组在SMV阻断期间血压明显下降。激光多普勒血流仪（LDF）显示，smv组局部血流量明显低于sma组。3) LDF是判断动脉和静脉闭塞情况下肠道活力的有效方法。临床研究；对17例急性肠系膜上动脉闭塞（SMAO）和7例急性肠系膜上静脉血栓形成（SMVT）进行回顾性分析。SMAO组平均年龄69岁，SMVT组平均年龄59岁，其中SMAO组有心血管病史13例。症状无特异性，但smo的发作往往是突然的，而SMVT的发作则是隐匿的。在大多数SMAO病例中，小肠和大肠弥漫性梗死，但在SMVT中，小肠节段性梗死是特征性的。SMAO的死亡率为65%，大多数病例在术后1个月内死亡。SMVT的死亡率为43%，2例术后6个月因SMVT复发死亡。早期诊断、术后重症监护和长期预防血栓复发是AMI成功治疗的关键。

The aim of this research is to investigate pathophysiology of acute mesenteric ischemia (AMI), and to establish the judgment for intestinal viability. Experimental studies ; 1) Histological changes after 2-hour mesenteric artery ligation were mostly limited in the mucosal layr, on the other hand, marked congestion, hemorrhage and edema in the submucosal layr were observed in early stage after venous ligation. 2) Acute mesenteric ischemia after 1 or 2-hr SMA or SMV occlusion, following 1-hr reperfusion in rabbits. SMV-group showed a significant fall of blood pressure during SMV occlusion. Local blood flow, assessed by Laser Doppler flowmetry (LDF), of SMV-group were significantly lower than that of SMA-group. 3) LDF was an useful method to judge the intestinal viability both in arterial and venous occlusion. Clinical study ; 17 patients of acute superior mesenteric arterial occlusion (SMAO) and seven of acute superior mesenteric venous thrombosis (SMVT) were analyzed retrospectively. Mean age was 69 in SMAO and 59 in SMVT,and in SMAO,13 cases had histories of cardiovascular diseases. Presenting symptoms were nonspecific, but the onset of SMAO were often sudden, but those of SMVT were insidious. In most cases of SMAO,small and large bowel were diffusely affected, but in SMVT,segmental infarctions of small intestine were characteristic. In SMAO,mortality was 65% and most of the cases died within one month ater operation. In SMVT,mortality was 43% and 2 cases died 6 months after operation due to recurrence of SMVT.Early diagnosis, postoperative intensive care in SMAO and long-term prophylaxis of recurrent thrombosis in SMVT are critical for successful management of AMI.