Prothrombotic disorders in a cohort of 25 patients undergoing transplantation: investigation and management implications.

Background. Many patients referred for intestinal transplantation have a history of thrombosis. We undertook an analysis of transplanted patients to describe the history and frequency of thrombosis, clinical course, and management strategies used. Results. Twenty-five patients underwent transplantation of intestine containing blocks between 2007 and 2012; 20 of 25 are still alive. Five of 25 patients were transplanted with history of portomesenteric thrombosis, 6 of 25 had experienced loss of venous access due to thrombosis, and 6 of 25 had history of mesenteric ischemia. Pretransplantation, 16 of 25 patients were anticoagulated. Thrombophilia screens identified 3 of 16 patients who were JAK2 positive, 1 of 25 who had antithrombin deficiency, and 1 of 25 who had a factor V Leiden heterozygote. Post-transplantation, of all 16 patients who were anticoagulated pretransplantation and continued postoperatively, 1 of 16 infarcted their small bowel graft and 4 of 16 developed a further venous thrombosis despite anticoagulation. Of the 9 without a previous history of thrombosis, 1 had a pulmonary embolus more than a decade after transplantation and another had an upper limb deep vein thrombosis associated with a line. Both were then anticoagulated. Seven of 25 are not anticoagulated, although they are administered antiplatelet prophylaxis. Postoperative bleeding complications of anticoagulation occurred in 3 patients. After a subarachnoid hemorrhage in 1 of those 3 patients, anticoagulation was stopped. The other 2 patients bled during ileal biopsy, and both remain on low molecular weight heparin treatment. Conclusion. Those with identifiable thrombophilic tendency and a history of venous or arterial thrombosis are considered to be at high risk for recurrent thrombosis. Those without such a history could be considered low risk. Our practice is to anticoagulate all high-risk individuals before and after transplantation and offer antiplatelet prophylaxis to low-risk patients as the risk of anticoagulation probably outweighs the risk of thrombosis for them. Early input from hematologists is vital in the management of high-risk patients, particularly those who thrombose when anticoagulated.