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

本研究旨在探讨急性肠系膜缺血（AMI）的病理生理机制，并建立肠存活的判断标准。实验研究;（1）肠系膜动脉结扎后2小时，组织学改变主要局限于粘膜层，而静脉结扎后早期粘膜下层出现明显充血、出血和水肿。2)家兔SMA或SMV闭塞1或2小时后，再灌注1小时后的急性肠系膜缺血。SMV组在SMV阻断期间血压显著下降。激光多普勒血流仪（LDF）显示，SMV组局部血流明显低于SMA组。3)LDF是判断动、静脉阻断后小肠活力的有效方法。临床研究;回顾性分析17例急性上级肠系膜动脉闭塞（SMAO）和7例急性上级肠系膜静脉血栓形成（SMVT）患者的临床资料。SMAO组和SMVT组的平均年龄分别为69岁和59岁，SMAO组中有13例有心血管疾病史。临床症状无特异性，SMAO多为突发性，SMVT多为隐匿性。SMAO多表现为小肠和大肠的弥漫性梗死，而SMVT则以小肠节段性梗死为特征。SMAO组死亡率为65%，大多数在术后1个月内死亡。SMVT病死率43%，术后6个月死亡2例，早期诊断、SMAO术后加强监护、长期预防SMVT再发血栓是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.