Long term prophylactic anticoagulation for portal vein thrombosis after splenectomy: A systematic review and meta-analysis

AIM: The aim of this study was to evaluate the efficacy and safety of the anticoagulants for the prevention of portal vein system thrombosis (PVST) in patients with cirrhosis after splenectomy and explore the optimal time of anticoagulant administration. METHODS: A systematic literature search was performed using PubMed, Embase and China Biology Medicine disc (CBM)databases, so as to screen out studies comparing the prognoses between cirrhotic post-splenectomy patients treated with and without anticoagulants. The parameters that were analyzed included the incidence of PVST and postoperative bleeding. RESULTS: With a total of 592 subjects, we included 8 studies (6 observational and 2 randomized trials) that fulfilled the inclusion criteria. We found that the incidence of PVST was significantly lower in the anticoagulation group during the first 6 months of anticoagulant administration. And the largest difference in the incidence of PVST between the anticoagulation and control groups was observed at 3 months (odds ratio 0.17(0.11~0.27); P = 0.767; I2 = 0.0%) and 6 months (OR = 0.21(0.11~0.40); P = 0.714; I2 = 0.0%) postoperatively. The incidence of bleeding was not significantly higher in the anticoagulation group (odds ratio 0.71 (0.30~1.71); P = 0.580; I2 = 0.0%). CONCLUSION: Low-molecular weight heparin (LMWH) and warfarin can decrease the incidence of PVST in post-splenectomy cirrhotic patients without an increased risk of bleeding. And the optimal use time of warfarin is 6 months after splenectomy.