Real-time energy metabolism of intestine during arterial versus venous occlusion in the rat

Background. Although it is less frequently encountered, mesenteric vein occlusion poses as important a problem as mesenteric artery occlusion. The energy metabolism of intestinal tissue during venous occlusion and reperfusion was studied. Methods. Male Wistar rats were studied in four groups of 17 animals each. Intestinal ischemia was induced by clamping the superior mesenteric artery ([SMA] occlusion [O]) or vein (SMVO) for 30 or 60 min, followed by reperfusion. Magnetic resonance spectroscopy was employed to continuously monitor the energy metabolism. Additionally, intestinal motility was monitored and histological examination was performed on resected specimens. Results. Energy metabolism in SMVO during ischemia was reduced more slowly than in SMAO, but recovery after reperfusion was poorer in SMVO. During ischemia, the contractive response of the intestine lasted longer in SMVO than in SMAO. Histologically, mucosal and subserosal hemorrhage was more severe in SMVO. Conclusions. In contrast to SMAO, SMVO caused less severe reduction of energy metabolism, at the expense of hemorrhage and tissue damage.