Splenectomy in living donor liver transplantation and risk factors of portal vein thrombosis.

BACKGROUND: Graft inflow modulation (GIM) during adult-to-adult living donor liver transplantation (LDLT) is a common strategy to avoid small-for-size syndrome, and some transplant surgeons attempt small size graft strategy with frequent GIM procedures, which are mostly performed by splenectomy, in LDLT. However, splenectomy can cause serious complications such as portal vein thrombosis and overwhelming postsplenectomy infection. METHODS: Forty-eight adult-to-adult LDLT recipients were enrolled in this study and retrospectively reviewed. We applied the graft selection criteria, which routinely fulfill graft-to-recipient weight ratio ≥ 0.8%, and consider GIM as a backup strategy for high portal venous pressure (PVP). RESULTS: In our current strategy of LDLT, splenectomy was performed mostly due to hepatitis C and splenic arterial aneurysms, but splenectomy for GIM was intended to only one patient (2.1%). The final PVP values ≤ 20 mmHg were achieved in all recipients, and no significant difference was observed in patient survival or postoperative clinical course based on whether splenectomy was performed or not. However, 6 of 18 patients with splenectomy (33.3%) developed postsplenectomy portal vein thrombosis (PVT), while none of the 30 patients without splenectomy developed PVT after LDLT. Splenectomy was identified as a risk factor of PVT in this study (P < 0.001). Our study revealed that a lower final PVP could be risk factor of postsplenectomy PVT. CONCLUSIONS: Using sufficient size grafts was one of the direct solutions to control PVP, and allowed GIM to be reserved as a backup procedure. Splenectomy should be avoided as much as possible during LDLT because splenectomy was found to be a definite risk factor of PVT. In splenectomy cases with a lower final PVP, a close follow-up is required for early detection and treatment of PVT.