Prevalence and outcomes of patients with sinusoidal obstruction syndrome after liver transplantation: A ten year's experience of a single center in Japan.

Background: Sinusoidal obstruction syndrome (SOS) after liver transplantation (LT) is a rare and potentially lethal complication. We retrospectively reviewed the outcomes of patients with post-transplant SOS.

Methods: Between May 2001 and December 2019, of 332 patients who underwent LT, 5 (1.5%) developed SOS. The median age at LT was 1.7 years (range 0.1-66.5). SOS was histopathologically diagnosed and classified as early-onset (<1 month) or late-onset.

Results: The median time to diagnosis of SOS was one month after LT. All patients developed acute cellular rejection before SOS, and the cause of SOS was acute cellular rejection in four patients and unknown in one. The treatment of SOS included conversion to tacrolimus from cyclosporine, intrahepatic hepatic vein stent placement, strengthening of immunosuppression, and plasma exchange. The 5-year graft survival rates in patients with and without SOS were 53.0% and 92.5%, respectively (p < 0.001). Of three patients with early-onset SOS, two patients improved and are doing well, and one patient died of graft failure four months after LT.

Conclusions: The cause and treatment of post-transplant SOS are not yet defined. The poor outcomes in patients with early-onset SOS may be improved by strengthening of immunosuppression. Patients with late-onset SOS are ultimately treated by repeat LT.