Obstructing Spontaneous Major Shunt Vessels is Mandatory to Keep Adequate Portal Inflow in Living-Donor Liver Transplantation

Background. It has not been addressed whether the major spontaneous portosystemic shunt vessels should be ligated in living-donor liver transplantation (LDLT). Methods. We performed a retrospective analysis of 324 cases of adult-to-adult LDLT. Results. Factors associated with the presence of major (>10 mm) shunt vessels (n=130) included portal vein (PV) thrombosis (27.7%), lower PV pressure at laparotomy, Child-Pugh class C, and transplantation of right-side grafts. The types of major portosystemic shunt vessels included splenorenal shunts (46.2%), gastroesophageal shunts (26.9%), mesocaval shunts (13.8%), and others (13.1%). Ligation of the major shunt vessels increased PV pressure (mean [SD], from 16.8 [3.9] mm Hg to 18.6 [4.3] mm Hg; P<0.001) and PV flow (mean [SD], from 1.35 [0.67] L/min to 1.67 [0.67] L/min; P<0.001) into the grafts. Post-LDLT computed tomography showed patent major shunts in 14 patients. Nine of such patients (64.3%) with unligated major shunt vessels (undetected shunt vessels, n=5; incomplete ligation, n=2; and the shunt was newly created or left open to maintain high PV pressure after reperfusion, n=3) required secondary interventions. Two of these patients died because of graft dysfunction. PV flow was significantly lower in the nine patients who underwent secondary ligation of the major shunt vessels compared with patients with successful primary ligation (mean [SD], 0.96 [0.34] L/min vs. 1.65 [0.63] L/min; P=0.001). Conclusions. It is an appropriate option to obstruct the major portosystemic shunt vessels to ensure adequate graft inflow in LDLT.