Low Incidence of hepatic sinusoidal obstruction syndrome/veno-occlusive disease in adults undergoing allogenic stem cell transplantation with prophylactic ursodiol and low-dose heparin.

Hepatic sinusoidal obstruction syndrome (SOS)/veno-occlusive disease (VOD) is a complication after allogenic hematopoietic stem-cell transplantation (allo-HSCT) with high mortality. The purpose of this study was to assess the incidence and outcome of SOS in patients after allo-HSCT with the impact of ursodeoxycholic acid (UDCA) and low-dose heparin as SOS prophylaxis. Out of 1016 patients, 23 developed SOS, with a cumulative incidence of 2.3% (95% CI 1.3-3.3) 6 months after HSCT. Approximately one quarter of these patients (26.1%) had late-onset SOS. A high proportion were very severe SOS cases (74%), and 83% of the patients were treated with defibrotide (DF). In multivariate analysis, advanced disease (p = 0.003), previous HSCT (p = 0.025) and graft versus host disease (GvHD) prophylaxis by post-transplant cyclophosphamide (PTCy) (p = 0.055) were associated with the development of SOS. The 1-year overall survival (OS) was significantly lower in the SOS group compared to patients without SOS (13% versus 70%, p = 0.0001). In conclusion, we found a low incidence of SOS in patients receiving low-dose heparin and UDCA prophylactically, but among SOS patients, a high mortality. Low-dose heparin and UDCA might be a prophylactic approach for SOS.