Comparison of Microcirculation in Ileocecal Flap and Epigastric Groin Flap after Ischemia/Reperfusion Injury: A Rat Model

Abstract

Purpose: To evaluate the changes of microcirculation of ileocecal flap and epigastric groin flap after ischemia/reperfusion injury in a rat model. Method: Nine Winstar rats were divided to 3 groups (A, B and C). Group A and B respectively received 1 hour and 2 hours of ischemia of ileocecal flap, following 90 minutes of reperfusion. Group C received 2 hours of ischemia and following 90 minutes of reperfusion on epigastric groin flap. The changes of microcirculation were recorded continuously with Laser Doppler Flowmetry in perfusion unit. The perfusion ratios based on the pre-ischemia baseline were analyzed. Result: All rats survived during the experiment. The rats of group A all survived the day after experiment though two of three rats died due to surgical complications 4 days later. The rats of group B all died after 2-3 hours after the experiment. The flaps in group C was grossly viable although one flap developed partial slough after following up for 1 week. The microcirculations after 10 minutes reperfusion showed significant difference (P＜0.05) in two types of flap. There was marked reactive hyperemia in two groups of ileocecal flap after ischemia/reperfusion while the group with epigastric groin flap didn't show this phenomenon. The microcirculation after 90 minutes reperftision didn't show significant difference. Conclusion: Based on the wave patterns of microcirculation recorded by Laser Doppler Flowmetry, there was significant difference in the response to ischemia/reperfusion injury between skin flap and intestinal flap during the 10 minutes after reperfusion. After 90 minutes reperfusion, the microcirculation of ileocecal flaps with 1 hour and 2 hours ischemia didn't show significant difference. At the time point, assessment of the viability on the flap only according to the microcirculation should be careful. Continuous monitoring was necessary.