Intraoperative blood flow measurements in organ allografts can predict postoperative function

A reliable method to recognize the extent of ischemia/reperfusion injury in transplantation is needed in order to tailor the immunosuppressive scheme to the needs of a damaged organ. This study sought to assess the correlation between the total and the parenchymal blood flow into a transplanted kidney (n = 71) or liver (n = 15) shortly after revascularization with the early function of the organ after transplantation. The total blood flow in the renal artery in kidney recipients or in the hepatic artery and portal vein in liver recipients was measured by an electromagnetic flowmeter. The parenchymal blood flow (in several parts of the transplanted organ) was assessed using a laser-Doppler flowmeter. Two measurements were always taken after revascularization (5 to 60 minutes apart). Vascular resistance (VR) as calculated by the difference between the mean arterial pressure (MAP) and the central venous pressure (CVP) was correlated with immediate kidney or liver function parameters. Neither total renal blood flow (RBF) nor VR was different between the immediate function (IF) and delayed graft function (DGF) groups of kidney transplant patients. However, the cortical (parenchymal) blood flow was significantly greater in the IF than the DGF group at 5 minutes: 29.98 +/- 6.13 mL/min/100 g vs 23.56 +/- 6.46 mL/min/100 g (P < .001). The difference was even more significant at 35 minutes: 33.94 +/- 7.47 mL/min/100 g vs 15.47 +/- 3.34 mL/min/100 g (P < .0001). Among liver transplant patients, the results suggested a correlation between hepatic arterial blood flow and early graft viability and function. The most reliable predictor of early graft function was the portal blood flow, which correlated with the volume of secreted bile as well as the bilirubin, and transaminase levels and coagulation profile. Further studies must confirm the value of measurements of total and parenchymal blood flow in organ transplant recipients.