Efficacy and safety of thrombolytic therapy for portal venous system thrombosis: A systematic review and meta-analysis

Background and aims The role of thrombolytic therapy in patients with portal venous system thrombosis (PVST) remains ambiguous. This study aimed to systematically collect available evidence and evaluate the efficacy and safety of thrombolysis for PVST. Methods Eligible studies were searched via PubMed, EMBASE, and Cochrane Library databases. Among the cohort studies, meta-analyses were performed to assess the outcomes of PVST patients receiving thrombolysis. Pooled proportions were calculated. Among the case reports and case series, logistic regression analyses were performed to identify the risk factors for outcomes of PVST patients receiving thrombolysis. Odds ratios (ORs) were calculated. Results Among the 2134 papers initially identified, 29 cohort studies and 131 case reports or case series were included. Based on the cohort studies, the pooled rates of overall response to thrombolytic therapy, complete recanalization of PVST, bleeding events during thrombolysis, further bowel resection, thrombosis recurrence, and 30-day mortality were 93%, 58%, 18%, 3%, 1%, and 4%, respectively. Based on the case reports and case series, acute pancreatitis (OR = 0.084), history of liver transplantation (OR = 13.346), and interval between onset of symptoms and initiation of thrombolysis <= 14 days (OR = 3.105) were significantly associated with complete recanalization of PVST; acute pancreatitis (OR = 6.556) was significantly associated with further bowel resection; but no factors associated with the overall response to thrombolytic therapy, bleeding events during thrombolysis, thrombosis recurrence, and 30-day mortality were identified or could be calculated. Conclusion Early initiation of thrombolysis should be effective for the treatment of PVST. But its benefits for PVST secondary to acute pancreatitis are weakened.