Randomized controlled trial to investigate the impact of anticoagulation on the incidence of splenic or portal vein thrombosis after laparoscopic splenectomy

Background: Splenic and portal vein thrombosis (SPVT) is a potentially life-threatening complication of splenectomy. There is a paucity of studies examining the role of prophylactic pre- and postoperative anticoagulation in the prevention of this complication. We designed a prospective randomized controlled trial (RCT) to more rigorously address the impact of prophylactic anticoagulation on the incidence of asymptomatic or symptomatic SPVT, detected on Doppler ultrasound, after laparoscopic splenectomy. Methods: This 2-centre, phase II, prospective, open-label, parallel-assignment RCT compared no postoperative anticoagulation to a regimen of 40 mg of enoxaparin subcutaneously once daily for 21 days. All patients underwent Doppler ultrasonography of the splenoportal system preoperatively and again 14-28 days after surgery to screen for nonocclusive or occlusive thrombosis. Results: From November 2006 to November 2008, 35 patients were enrolled in the RCT. Four patients withdrew, 1 required conversion to an open procedure and 1 died at 3 months (the cause of death was not related to the study). Of the 29 patients remaining, 15 were randomly assigned to the anticoagulation group and 14 to the nonanticoagulation group. One (3.4%) patient in the treatment group experienced portal thrombosis. Rates of postoperative bleeding were similar in both groups. Conclusion: This RCT of anticoagulation found a low overall risk of SPVT after laparoscopic splenectomy; however, this is an underpowered study, and further multi-centred clinical trials are needed.