[Should postoperative thromboembolism prevention be extended to the post-hospitalization phase?]

A large number of patients medically treated for deep vein thrombosis and pulmonary embolism have a history of surgery in the immediate past. We therefore inquired whether it is possible to identify specific risk factors which would allow general recommendations for anticoagulation therapy in the postdischarge period. During the 30-month study period 325 patients were treated at the Cantonal Hospital, Aarau, for DVT and/or pulmonary embolism. 35 (10.8%) had undergone surgery 8 weeks previous to admission. Perioperative management (anticoagulation, chronology, mobility etc.) was analyzed retrospectively. 20% of the 35 patients with postdischarge deep vein thrombosis and/or pulmonary embolism had previously undergone an ambulatory surgical procedure. A large number of thromboembolic complications occurred between the 4th and 12th day after discharge. In 40% of the patients, however, they occurred after the 14th posthospital day. High- and low-risk patients were impossible to define on the basis of the type of surgery, length of hospital stay and time course of thromboembolic complications. We conclude that prophylaxis of thromboembolism in ambulatory surgery should be re-thought: patients undergoing arthroscopy should receive prophylaxis for thromboembolism for at least 4-6 weeks post discharge.