Background: The rise in bariatric surgery has driven an increased number of complications from venous thromboembolism (VTE). Evidence supports obesity as an independent risk factor for VTE, but the specific derangements underlying the hypercoagulability of obesity are not well defined. To better characterize VTE risk for the purpose of tailoring prophylactic strategies, we developed a protocol for thrombophilia screening in patients presenting for bariatric surgery at our institution.
Methods: Between April 2004 and April 2006, 180 bariatric surgery candidates underwent serologic screening for inherited thrombophilias (Factor V-Leiden mutation, low Protein C activity, low Protein S activity, Free Protein S deficiency) and acquired thrombophilias (D-Dimer elevation, Fibrinogen elevation, elevation of coagulation factors VIII, IX, and XI, elevation of Lupus anticoagulants and homocysteine level, and Antithrombin III deficiency). Prevalence rate of each thrombophilia in the subject group was compared to the actual prevalence rate of the general population.
Results: Most plasma markers of both inherited and acquired thrombophilias were identified in higher than expected proportions, including D-Dimer elevation in 31%, Fibrinogen elevation in 40%, Factor VIII elevation in 50%, Factor IX elevation in 64%, Factor XI elevation in 50%, and Lupus anticoagulant in 13%.
Conclusions: Obesity is a well-described demographic risk factor for VTE. In bariatric surgery candidates routinely screened for serologic markers, both inherited and acquired thrombophilias occurred more frequently than in the general population, and may therefore prove to be useful for individualized VTE risk assessment and prophylaxis.