Complications in DIEP Flap Breast Reconstruction After Mastectomy for Breast Cancer: A Prospective Cohort Study Comparing Unilateral Versus Bilateral Reconstructions.

BACKGROUND: The demand for bilateral breast reconstructions is rising worldwide. In the UK, approximately 30% of breast cancer patients undergoing mastectomy choose autologous tissue breast reconstruction. Although the deep inferior epigastric perforator (DIEP) flap is gaining popularity, bilateral DIEP flap breast reconstruction remains a complex procedure and reliable outcome data are lacking. In the absence of clinical trials, evidence from cohort studies is needed to better inform clinicians and patients. METHODS: Over a 6-year period, all consecutive patients undergoing DIEP flap breast reconstruction were prospectively included and categorized as unilateral or bilateral reconstruction for comparative analyses of outcomes and complications, with the patient as the unit of analysis. RESULTS: Overall, 565 DIEP flaps were performed on 468 women (371 unilateral and 97 bilateral reconstructions [194 flaps]). Postoperative complications requiring reoperation were twice as likely for bilateral reconstructions (risk ratio [RR] 2.1, 95% CI 1.4-3.4, p = 0.002) and were mainly due to venous congestion (RR 3.1, 95% CI 1.2-7.5, p = 0.011). The risk of total flap loss was six times greater in bilateral reconstruction (RR 6.4, 95% CI 1.6-26, p = 0.011). The rates of revision breast and abdominal surgery were similar between groups. CONCLUSIONS: Both unilateral and bilateral DIEP flap breast reconstructions are safe, with a low risk of complications; however, bilateral reconstruction was associated with a higher risk of complications and total flap loss. This information should be highlighted to patients requesting bilateral breast reconstruction, particularly those requesting risk-reducing mastectomy and reconstruction.