Use of therapeutic anticoagulation in splanchnic vein thrombosis associated with acute pancreatitis: a systematic review and meta-analysis

Background Splanchnic vein thrombosis is a well-recognized local vascular complication of acute pancreatitis (AP), estimated to occur in approximately 15% of patients. While splanchnic vein recanalization occurs spontaneously in approximately one third of patients, severe complications such as bowel ischemia and liver failure have also been reported. At present, there is no consensus on whether patients presenting with AP-associated splanchnic vein thrombosis should receive therapeutic anticoagulation. Methods We searched multiple databases from inception through December 2020 to collect studies that compared the clinical outcomes of patients with AP and splanchnic vein thrombosis who received therapeutic anticoagulation (AC group) with those who did not (N-AC group). A meta-analysis was performed to calculate the relative risk (RR) of vessel recanalization, bleeding complications, collateral formation and death in the 2 groups. Results Seven studies with 8353 patients, 339 of whom had splanchnic vein thrombosis, were included in the final analysis. A total of 154 patients (45.4%) had acute severe pancreatitis. A significantly higher proportion of patients had vessel recanalization in the AC group: RR 1.6, 95% confidence interval 1.17-2.27; I2=0%; P=0.004. There was no difference between the 2 groups in the RR of bleeding complications, collateral formation and death. Conclusions Our analysis demonstrated that, among patients with AP-associated splanchnic vein thrombosis, therapeutic anticoagulation resulted in recanalization of the involved vessels without significantly increasing the risk of bleeding complications. There was no difference in the RR of death or the rates of collateral vessel formation during the follow up.