Die Mikrozirkulation des humanen Pankreas in der frühen Reperfusion nach Pankreastransplantation

Abstract

Introduction: There is abundant experimental evidence to indicate that microcirculatory deteriorations developing in response to post-ischemic reperfusion are key determinants for manifestation of graft pancreatitis and subsequent exo- and endocrine organ dysfunction. Using non-invasive orthogonal spectral (OPS) imaging this study was aimed to intraoperatively visualize and quantitatively assess pancreatic microcirculation in patients undergoing simultaneous pancreas/kidney transplantation. Methods: In nine patients undergoing simultaneous pancreas/kidney transplantation microcirculation of the pancreas graft was analyzed at 5 and 30 min following graft reperfusion using OPS-imaging. Pancreatic microcirculatory parameters of six healthy individuals undergoing donor operation for living-related liver transplantation served as controls. Assessment of microcirculatory parameters included capillary diameter, functional capillary density (FCD) and red blood cell velocity (V_RBCV). Based on these parameters the heterogeneity index (HI) and volumetric capillary blood flow (vCBF) were calculated. Results: During early graft reperfusion capillary perfusion was significantly impaired as an increased intercapillary distance, reduced capillary blood flow and microvascular thrombosis in terms of post-ischemic ‘no reflow’ were characteristically observed. The FCD and RBCV were found constantly decreased throughout the entire study period when compared to controls. Furthermore, capillary diameter were significantly increased following graft reperfusion. Calculation of vCBF and HI displayed only a slight increase most pronounced at 30 min of reperfusion. Conclusion: Intraoperative OPS-imaging permits for the first time to non-invasively visualize and quantitatively assess human pancreas microcirculation. It further allows in vivo estimation of conservation- and ischemia/reperfusion-associated microvascular injury during early reperfusion period. Early microvascular response to pancreas transplantation in humans is characterized by persistently decreased acinar perfusion including capillary dilation and nutritive dysfunction. Recognition of initial microcirculatory disturbances may have therapeutic implications for preventing ischemia/ reperfusion-induced exo- and endocrine graft dysfunction and should allow a correlation to the individual clinical course.