Objective
To evaluate whether cooling of ischemic intestine before and immediately after the release of the obstruction is more advantageous than is warming in an isolated ileal loop rat model.
Design
Prospective randomized experimental trials.
Setting
Laboratory.
Materials
Male Sabra rats.
Interventions
An isolated loop of ileum was created in rats and constantly perfused with warmed normal saline (37°C). Intestinal ischemia was caused by clamping of the superior mesenteric artery for 15 minutes. Cooling of the isolated ileal loop to 32°C by the application of cold saline was done for the last half of the ischemic period and continued during the first 10 minutes of reperfusion. The intestine was warmed to 37°C for the next 20 minutes of reperfusion.
Main Outcome Measures
The chromium 51—labeled ethylenediaminetetraacetic acid (51Cr-EDTA) plasma-to-lumen clearance rate was used for the evaluation of intestinal mucosal injury. Multiple intestinal samples were harvested at the end of the reperfusion period, and the histological features were evaluated.
Results
The51Cr-EDTA plasma-to-lumen clearance rates were significantly lower (P<.001) in the rats in which cooling of the ischemic intestine was performed in comparison with the control group, indicating reduced intestinal mucosal injury in all three 10-minute reperfusion periods. Cooling also significantly changed the resultant histological damage to the intestinal mucosa exerted by ischemia (P<.001).
Conclusion
Cooling of the ischemic intestine before the release of the obstruction and for a short period during reperfusion provides significant protection from ischemia/ reperfusion injury compared with the traditional method of warming the ischemic intestine.
Arch Surg. 1997;132:406-409
