QS5: Extended Venous Thromboembolism Prophylaxis May Not Be Necessary For DIEP Flap Breast Reconstruction
Authors: Huang Hao , Bernstein Jaime , Otterburn David 
Published: July 2021

Purpose: Based on the 2005 Caprini Risk Assessment Model (RAM) for venous thromboembolism (VTE), the American Society of Plastic Surgeons (ASPS) established prevention guidelines in 2011 recommending one week of postoperative chemoprophylaxis for patients scoring between 3 and 6 and extended anticoagulation (up to four weeks) for patients scoring 7 or higher after a major procedure. Most patients who undergo deep inferior epigastric perforator (DIEP) flap breast reconstruction, while generally healthier than high-risk patient subgroups (e.g., head/neck cancer patients) in plastic surgery, would similarly be deemed high risk. At our institution, we avoid the blanket application of prolonged anticoagulation, and instead favor individualized regimens based on the patient’s unique risk factors and perioperative course, resulting in an overall limited use of chemoprophylaxis. The aim of this study is to describe our institutional experience in thromboembolism prevention and to assess the necessity of extended prophylaxis in DIEP flap patients.

Methods: Patients who underwent DIEP flap reconstruction from August 2011 to March 2020 by one attending plastic surgeon were included. Charts were retrospectively reviewed looking at patient demographics, VTE prophylaxis regimens, and development of postoperative complications including deep vein thrombosis (DVT) and pulmonary embolism (PE) within 60 days of surgery. Patients were considered positive for DVT or PE if diagnosed radiographically on ultrasound or CT scan, respectively. Caprini scores were calculated for all patients.

Results: 249 patients (439 flaps) were included in this study, with an average age of 50.6 and an average BMI of 27.1 kg/m2. Four patients had a history of thrombotic events. In terms of indication for procedure, 237 patients had a confirmed diagnosis of breast cancer, ten had a genetic predisposition, one had a congenitally absent breast, and one required reconstruction for acquired breast deformity. Out of the 249 patients in the cohort, 245 patients received chemoprophylaxis with unfractionated heparin only during hospitalization (average length of stay, 3.3 days), while four patients were additionally anticoagulated with enoxaparin for at least two weeks after discharge. The cohort’s average Caprini score was 6.0, with 72.7 percent of patients scoring between 3 and 6 and 26.5 percent of patients scoring 7 or higher. One patient, who scored a 7 and received limited prophylaxis, developed DVT postoperatively in the left femoral and popliteal veins. There were no cases of PE. There was no significant difference in VTE rate between patients who received chemoprophylaxis consistent with ASPS guidelines (0%, n=8) and those who did not (0.4%, n=241) (p=0.86).

Conclusions: Despite our limited use of chemoprophylaxis, our overall VTE incidence of 0.4 percent is low compared to other published rates in literature. Presenting the largest institutional cohort of DIEP flap patients to date in the analysis of postoperative VTE, this current work suggests that extended prophylaxis may not be warranted, and it further serves as impetus to re-evaluate the 2005 Caprini RAM in this subgroup of plastic surgery patients.