Optimizing Risk Stratification in Portal Vein Thrombosis after Splenectomy and its Primary Prophylaxis with Antithrombin III Concentrates and Danaparoid Sodium in Liver Cirrhosis with Portal Hypertension

BACKGROUND: Decreased antithrombin III (ATIII) activity and large splenic vein diameter (SVD) are risk factors for portal vein thrombosis (PVT) after splenectomy in liver cirrhosis with portal hypertension. Antithrombin III concentrates can prevent PVT. This study was designed to stratify risks for PVT after splenectomy in cirrhotic patients and to develop prophylactic protocols for PVT. STUDY DESIGN: In 53 patients (testing cohort), the cutoff level of preoperative ATIII activity (≤60%) was evaluated for administration of ATIII concentrates. Antithrombin III activity and SVD were re-evaluated as criteria for prophylaxis of PVT. In 57 patients (validation cohort), the risk stratification of PVT and prophylactic protocols were validated. RESULTS: In the testing cohort, 10 (19%) of 53 patients had PVT. Risk level of PVT was stratified and prophylactic protocols were developed. Patients at low risk (ATIII activity ≥70% and SVD <10 mm) were not treated; those at high risk (ATIII activity <70% or SVD ≥10 mm) received ATIII concentrates (1,500 U/day) for 3 days; and those at highest risk (SVD ≥15 mm) received ATIII concentrates for 3 days, followed by danaparoid sodium (2,500 U/day) for 14 days and warfarin. In the validation cohort, 0 of 14 low-risk and 2 of 32 high-risk patients had PVT. Although 8 of 11 patients at highest risk had temporary PVT, it disappeared within 3 months postoperatively. Finally, only 2 (3.5%) of 57 patients had PVT. CONCLUSIONS: Risk stratification of PVT after splenectomy and prophylaxis with ATIII concentrates and danaparoid sodium dramatically reduced the incidence of PVT.