CAROLINA RINSE ATTENUATES POSTISCHEMIC MICROVASCULAR INJURY IN RAT SMALL-BOWEL ISOGRAFTS

Background. Apart from rejection-related events, the manifestation of ischemia/reperfusion (I/R) injury remains a major problem, hampering s uccess in human small bowel transplantation (SBTx). Therefore the aim of this study was to determine the potential of Carolina rinse (CR) to attenuate microvascular reperfusion injury in rat intestinal isograft s. Methods. After 18 hours of cold preservation in 4 degrees C Univers ity of Wisconsin solution (UW), rat SBTx was performed. Immediately be fore reperfusion the intestine was flushed with 4 degrees C or 37 degr ees C Ringer's lactate (RL, groups 1 and 2) or CR (groups 3 and 4), re spectively In vivo fluorescence microscopy was used to analyze the gra fts' microcirculation. Results. In group I severe microvascular I/R in jury was observed in mucosa and muscle layers. Microcirculatory deteri oration was paralleled by enhanced leukocyte accumulation in submucosa l venules and by impaired subserosal lymphatic capillary drainage (FCL D). Rinsing the grafts with 37 degrees C RL attenuated leukocyte-endot helial cell interaction and improved subserosal FCLD; however; it did not affect mucosal microvascular reperfusion damage. In contrast, 4 de grees C CR dramatically improved nutritive perfusion within muscle and mucosa (p < 0.05) and attenuated leukocyte adherence within sub mucos al venules (p < 0.05). Additional prewarming of CR almost completely p revented mucosal I/R injury (p < 0.05 versus group 3) and caused a fou rfold increase of FCLD. Conclusions. With this study we demonstrate th at CR in combination with rewarming of the graft before reperfusion is an effective regimen to prevent leukocyte accumulation and to counter act microvascular injury after SBTx.