Efficacy and safety of short-term (3 days) enoxaparin in preventing venous thromboembolism after gastric cancer surgery: A single-center, prospective cohort study

Background Pharmacologic prophylaxis such as enoxaparin for venous thromboembolism (VTE) is rarely used in Japan, even following abdominal cancer surgery, for which it is recommended in relevant guidelines (at least 7 days of use) along with mechanical prophylaxis with intermittent pneumatic compression. Reasons for enoxaparin's unpopularity include concerns over postoperative bleeding and its inconvenience in clinical practice. Here, we conducted a prospective clinical study of short-term (3 days) use of enoxaparin, which is considered to minimally impact postoperative management without increasing bleeding risk. Methods Gastric cancer patients who underwent gastrectomy received enoxaparin for 3 days from postoperative day (POD) 1–4. The primary endpoint was the incidence of deep vein thrombosis (DVT), which was examined primarily via Doppler ultrasonography of the lower limbs between POD 8 and 14. The planned sample size was 70, which was calculated based on an estimated incidence rate of 9% and an upper limit of incidence rate of 20%, with alpha of 0.05 and beta of 0.2. Results A total of 70 gastric cancer patients were enrolled, and ultimately, 68 patients received the protocol intervention and DVT evaluation. Sixty-seven patients completed 6 enoxaparin injections, but 1 patient did not complete the course due to abdominal bleeding after initiation. The incidence of DVT was 4.4% (3/68), and the 95% upper confidence interval was 12.2%, lower than the 20% threshold we set as the upper limit of DVT incidence. DVT was detected only in the peripheral veins of the lower extremities in all 3 affected patients. The incidence of bleeding-related complications, which were not severe, was 1.5% (1/68). Conclusions Short-term (3 days) use of enoxaparin was shown to be effective and safe for VTE prophylaxis, comparable to regular use (at least 7 days), in postoperative management of gastric cancer surgery.