Backgrounds: Pelvic cancer surgery has a high risk for venous thromboembolism (VTE). Pharmacologic venous thromboprophylaxis is not routinely accepted among surgical practice in Thailand due to the awareness of major bleeding complication. However, ACCP guideline recommends mechanical prophylaxis to be initially used in this condition and pharmacologic prophylaxis is subsequently administered during postoperative period with minimal risk of bleeding. Therefore, it was possible to evaluate the efficacy of VTE prophylaxis in pelvic cancer surgery among our population.

Objective: To evaluate the efficacy and safety of VTE prophylaxis in pelvic cancer surgery.

Material and Method: Patients with pelvic cancer including gynecologic cancer and urologic cancer to undergo surgery were enrolled in the present study. The patients with colorectal cancer were excluded from the present study due to their declination. The present study randomized the patients into 2 groups regarding the receiving VTE prophylaxis. In prophylaxis group, intermittent pneumatic compression (IPC) was initially applied at intraoperative period and at least 3 days postoperatively until full ambulation. During the minimal risk of postoperative bleeding in this group, Enoxaparin (0.4 ml subcutaneous daily) was administered for 4 weeks. In control group, there was no VTE prophylaxis. Assessment of VTE was carried out at the 2^nd and 5^th week after surgery. Postoperatively, diagnosis of deep vein thrombosis (DVT) was performed by duplex ultrasonography and diagnosis of pulmonary embolism (PE) was initially done by clinical manifestations and then confirmed by computed tomographic angiography of pulmonary artery.

Results: A total of 108 pelvic cancer patients including 70 patients with gynecologic cancer and 38 patients with urologic cancer. The prevalence of proximal DVT after pelvic cancer surgery in the present study was 2.8%, which were 3.7% in control group and 1.8% in prophylaxis group (p = 1.000). The relative risk reduction was 50%. In gynecologic cancer patients, prevalence of postoperative proximal DVT was 6.5% in control group and 2.6% in prophylaxis group (p = 0.580). The relative risk reduction was 60%. There was no postoperative proximal DVT in urologic patients. Postoperative symptomatic PE was not found in this study. Bleeding complications was 3.7% (1.8% major bleeding and 1.8% minor bleeding) in prophylaxis group compared with 0% in control group (p = 0.495).

Conclusion: After the implementation of VTE prophylaxis in pelvic cancer surgery, the prevalence of postoperative proximal DVT was decreased with significant risk reduction in gynecologic cancer surgery and the risk of postoperative bleeding was acceptable. VTE prophylaxis program may be benefit in gynecologic cancer surgery in Thai population.

Keywords: Venous thromboembolism, cancer surgery, DVT prophylaxis, VTE prophylaxis, deep vein thrombosis, pulmonary embolism