The incidence, prophylaxis and treatment of venous thromboembolism in patients undergoing breast cancer surgery

616 Background: Cancer patients are at an increased risk of venous thromboembolism (VTE), which includes both deep venous thrombosis (DVT) and pulmonary embolism (PE). The risk of VTE following abdominal and pelvic surgery is known, while the risk following breast cancer (BC) surgery is not established. We have developed clinical pathways for all BC patients undergoing surgery in order to minimize variation in treatment. Patients receive pre-operative teaching about immediate post-operative ambulation, application of intra-operative lower extremity elastic stockings and intermittent pneumatic compression boots. We wished to determine the peri-operative incidence and treatment of VTE in patients on these pathways. Methods: BC patients undergoing surgery between Jan 1, 2000 and Sep 30, 2003 and treated on the breast pathways were analyzed following IRB approval. VTE within 60 days post-operatively was determined from our prospective breast cancer, radiology and pharmacy databases, medical records and ICD-9-CM codes. Results: 3887 patients underwent 4449 procedures. The median age was 54.4 years (range 11–91.8). Seven patients with post-operative VTE were identified, for a rate of 0.16% per procedure. The median time from surgery to diagnosis of VTE was 14 days (range 2–60) with a mean of 21.8 days. No relationship was identified between the type of breast surgical procedure and development of VTE. Patients were diagnosed by Ventilation Perfusion scan (3), CT Pulmonary angiogram (3), Duplex Doppler of the lower extremities (2) and IV contrast CT of the abdomen and pelvis (1). Three patients respectively presented with only DVT or PE, while one patient was found to have both DVT and PE. One of 7 patients (14%) had received neo-adjuvant therapy. Treatment consisted of Low Molecular Weight Heparin (5) or IV heparin (2) all followed by warfarin. There were no deaths. Conclusions: The incidence and outcome of VTE in BC surgery patients has not been previously reported. VTE following surgery was rare in BC patients on clinical pathways. Based on these results, no additional systemic VTE prophylaxis is indicated in this group of patients. No significant financial relationships to disclose.