Portal inflow and pressure changes in right liver living donor liver transplantation including middle hepatic vein

Abstract

The middle hepatic vein may be included in the right liver graft in living donor liver transplantation (LDLT) to optimize hepatic venous outflow. We employed manometry of the portal system and ultrasonic flowmetry of graft inflow to study the graft’s ability in relieving portal hypertension and accommodating portal hyperperfusion. Possible correlation of the findings from such observations with surgical outcomes was investigated. The median ages of the recipients and donors of this 46 consecutive LDLT were 50 years (range, 16 to 66 years) and 31 years (range, 18 to 54 years), respectively. Graft to standard liver volume was 47.4% (range, 32.4 to 69.0%). The hospital mortality was 4.4% as two recipients had died from sepsis. Portal pressure dropped by 8 mmHg (range, -7 to 19 mmHg) from 23 mmHg (range, 8 to 37 mmHg) to 14 mmHg (range, 10 to 26 mmHg) after LDLT. Portal infl ow had a positive correlation with portal pressure before native liver hepatectomy (R2 = 0.305) (p = 0.000) and not graft size. Portal flow of the right liver increased from 81 mL/min/100 g (range, 35 to 210 mL/min/100 g) before donor right hepatectomy to 318 mL/min/100 g (range, 102 to 754 mL/min/100 g) after graft implantation. Graft portal flow had a linear correlation with the recipient portal pressure before hepatectomy of the native liver (R2 = 0.261) (p = 0.000) and graft to standard liver volume ratio (R2 = 0.247) (p = 0.000). The correlation was clearer with reference to a quotient derived from the recipient portal pressure divided by the graft to standard liver volume ratio (R2 = 0.381) (p = 0.000). The loss of such correlation with the portal pressure after graft implantation refl ected relief of the portal hypertension by graft implantation. Despite the high portal inflow after implantation, only one of the graft biopsies after implantation showed sinusoidal congestion of moderate severity. Complications of Clavien Grade 2 or above occurred in 12 recipients and were not related to the portal flow and pressure or their changes. Right liver LDLT including the middle hepatic vein effectively lowered the recipient portal pressure by allowing unimpeded venous outflow.