A survey of thrombosis prophylaxis use in patients undergoing arthroscopic surgery

The risk of venous thromboembolism (VTE) following minimally invasive joint surgery is poorly defined. Furthermore, few prospective studies have evaluated the effect of prophylaxis on the risk of VTE. The lack of data to guide therapy in such patients is concerning as many lower extremity orthopedic procedures are performed each year. The reported risk of VTE following knee arthroscopy varies from 0.6 to 17.9% [1–5], with the variation in rates attributable to study design and to diagnostic techniques. To our knowledge, only two studies have assessed the efficacy and safety of pharmacological prophylaxis with low molecular weight heparin (LMWH) in this patient setting [6,7]. However, in both studies the sample size was small, thus neither study was able to assess the impact of thromboembolism prophylaxis on the rate of clinical VTE. Because of the lack of clinical guidelines and the uncertain definition of the levels of risk, we tested the hypothesis that there is significant practice variation amongst orthopedic surgeons in the use of anti-thrombotic prophylaxis in such patients. We performed a telephone survey to assess the use of VTE prophylaxis after knee arthroscopy among Italian orthopedic surgeons. The selection of the sample and the interviews were carried out by a group specialized in epidemiological surveys, ISIS Research (Milan, Italy). Two-hundred orthopedic surgeons, representing 200 orthopedic departments throughout the country, were selected. All interviewed physicians were asked if they routinely prescribe anti-thrombotic prophylaxis in patients undergoing knee arthroscopy, if prophylaxis is prescribed either to all patients or to selected patients, the type of prophylaxis and the timing of administration. A large majority of orthopedic surgeons (84%) answered that they believe there is sufficient evidence to prescribe anti-thrombotic prophylaxis to patients undergoing knee arthroscopy, and 94% of them regularly prescribe pharmacological anti-thrombotic prophylaxis. Among prescribers, 83% prescribe anti-thrombotic prophylaxis to all patients undergoing knee arthroscopy irrespective of the level of risk,whereas17%selectpatientson thebasisof theconcomitant presence of risk factors (Table 1). Of all orthopedic surgeons whodoprescribe anti-thrombotic prophylaxis, 97.3%answered they prescribe LMWH, 2.7%prescribe unfractionated heparin. Of interest, the main reason why LMWH is the preferred antithrombotic drug is safety (45.7%). Only 18.6% select LMWH because of a better efficacy profile. Themost selected timing for starting prophylaxis is 12 h before the procedure (59.0%). A periprocedural administration is selected by 36.7%. In particular, 13.8% answered they start less than 6 h prior to the procedure, 10.1% immediately before the starting of the intervention,and12.8%between6and12 hafter theprocedure. Post-operative prophylaxis (i.e.more than 12 h)was selected by 0.5%. Finally, anti-thrombotic prophylaxis is prescribed for more than 10 days by 59%of the orthopedic surgeons, until the patient returns to normal weight bearing by 21.8%, for 5–10 days by 14.9%, for less than 5 days by 1.6%, and according to the type of procedure by 2.7%. Despite the lack of adequate information on the risk of VTE in patients following minimally invasive joint surgery