Ischemia-reperfusion injury following superior mesenteric artery occlusion and strangulation obstruction

Intestinal ischemia-reperfusion injury (IRI) is a serious and common clinical entity resulting in severe tissue injury. This study was designed to compare IRI in superior mesenteric artery (SMA) occlusion and strangulation obstruction (SO).

Thirty Wistar-Albino rats were assigned randomly to three groups. In the control group, a sham operation was performed. In the SMA occlusion group, a vascular clamp was placed across the SMA to occlude arterial circulation. In the SO group, a 15-cm segment of small intestine was looped to prevent venous circulation. Sixty minutes of ischemia was followed by 60 min of reperfusion. Following reperfusion, biopsies of small intestine were taken to assess morphologic damage, tissue levels of malonyldialdehyde (MDA) as an index of lipid peroxidation reflecting oxygen free radicals (OFR) were determined, and serum biochemical analyses were performed.

The levels of tissue MDA were significantly higher in the SO group than in the SMA occlusion group (P < 0.05). Biochemical parameters of SO and SMA occlusion groups were higher than those in the control group and there was a significant difference between the SMA occlusion and the SO models, except for ALP levels. Histopathologically, transmural intestinal damage were present in seven cases of SO and in six cases in the SMA occlusion group.

Despite no significant difference between the two groups in terms of intestinal tissue damage, OFR-induced injury was higher in the strangulation obstruction group.