Early microcirculatory changes after ischemic preconditioning and small bowel autotransplantation.
OBJECTIVE
Ischemia-reperfusion injury contributes to the high complication rate of small bowel transplantation (SBTX). Ischemic preconditioning (IPC) protects against reperfusion injury in several organs, but the IPC-induced microcirculatory reaction in the intestine is unknown.


METHODS
We examined the effects of IPC on the macrohemodynamics and graft microcirculation in a canine model of SBTX during a 4-hour reperfusion period. In group 1 SBTX was performed, in group 2 IPC was induced before graft harvesting (ischemia 3 times for 5 min, followed by 10 min of reperfusion). Cardiac index and mesenteric blood flow were measured, and the mucosal microcirculation, villus epithelial thickness and functional capillary density were monitored by orthogonal polarization spectral imaging. Leukocyte-endothelial cell interactions were monitored in the postcapillary venules, with intravital fluorescence microscopy.


RESULTS
Reperfusion decreased cardiac index and mesenteric blood flow during reperfusion; IPC significantly improved these changes. Reperfusion was accompanied by decreased functional capillary density and epithelial thickness of the villi and increased leukocyte-endothelial cell interactions. IPC increased functional capillary density, prevented epithelial narrowing and reduced leukocyte rolling and adherence.


CONCLUSIONS
IPC improves the macrohemodynamics and the intestinal microcirculation and reduces leukocyte-mediated tissue injury during reperfusion. IPC can be an effective tool to limit reperfusion injury during SBTX.
Wolfárd
A
A
Department of Surgery, Institute of Surgical Research, University of Szeged, Szent-Gyorgyi Albert Medical Center, Szeged, Hungary.
Kaszaki
J
J
Varga
S
S
Lázár
G
G
Boros
M
M
D000818:Animals; D004285:Dogs; D007249:Inflammation / Q000473:pathology; D007421:Intestine, Small / Q000098:blood supply / Q000473:pathology / Q000637:transplantation*; D019194:Ischemic Preconditioning; D008833:Microcirculation / Q000502:physiology; D008856:Microscopy, Fluorescence; D008859:Microscopy, Polarization; D011184:Postoperative Period; D015424:Reperfusion; D013152:Splanchnic Circulation / Q000502:physiology