Does adult liver transplantation without venovenous bypass result in renal failure?

Thirty-eight adult orthotopic liver transplant recipients were studied to compare renal hemodynamics and renal function with (17 patients) and without (21 patients) venovenous bypass. Bypass was used when mean arterial blood pressure decreased by greater than 30% or cardiac index decreased by greater than 50%, or both, during a 5-min trial of clamping of the suprahepatic and infrahepatic vena cava and portal vein. Intraoperative measurements were performed 2 h after induction of anesthesia, 10 min before the end of the anhepatic phase, and 2 h after cava unclamping. During the anhepatic stage, renal perfusion pressure decreased significantly in the group with no bypass (79 +/- 20 vs 60 +/- 17 mm Hg, P less than 0.05) (mean +/- SD), whereas it remained unchanged in the group with bypass (77 +/- 14 vs 74 +/- 16 mm Hg, NS); urinary output was not modified in the bypass group, whereas it decreased significantly in the group with no bypass compared with the dissection phase (0.7 +/- 0.6 vs 1.7 +/- 2.0 mL.kg-1.h-1, P less than 0.05). However, during the postreperfusion phase, urinary output was similar in both groups and was more when compared with the dissection phase (P less than 0.05). Serum creatinine level was increased in both groups on the third postoperative day, but no difference occurred between the groups (bypass group 107 +/- 49 mmol/L; nonbypass group 126 +/- 95 mmol/L). No patient required dialysis in either group in the postoperative period. This study suggests that in patients without preoperative renal failure and who tolerate the trial of clamping well, venovenous bypass is not required to maintain postoperative renal function after liver transplantation.