Comparison of outcomes of arterial end-to-side versus end-to-end anastomosis in autologous deep inferior epigastric perforator (DIEP) flap breast reconstruction: DIEP-ES study protocol.

Background: End-to-end anastomosis to the internal mammary artery (IMA) is the current standard anastomosis technique for women undergoing autologous breast reconstruction with deep inferior epigastric perforator (DIEP) flap. This approach fails to preserve the length of the IMA, compromising its availability for cardiac surgery use in women who develop coronary heart disease. A viable alternative may be end-to-side anastomosis, but data on its feasibility is currently lacking. Methods: This pilot study will involve 60 patients at a single-center institute over approximately 24 months. Inclusion criteria are female sex, age >18 years, history of breast cancer, and eligibility for unilateral autologous DIEP breast reconstruction. Exclusion criteria include patients with a legal guardian, inability to consent, and history of blood clotting disorders or hypercoagulability. Data will be collected at 2 weeks, 6 weeks, 6 months, and 1-year post-surgery. The primary outcome is "major complication" of the recipient site, including anastomotic insufficiency, arterial thrombosis, hematoma, reoperation, or flap loss. Secondary outcomes are abdominal perfusion and major donor site complications, such as wound healing disorders. Patient satisfaction will be assessed using the SF-36 and BREAST-Q (reconstructive module) questionnaires. Study status: The DIEP-ES study has begun enrolment in February 2023. As this is an ongoing trial, no results have been gathered yet. The results will be reported upon completion of the study. We anticipate that the primary and secondary outcomes of the end-to-side approach will be comparable to the accepted standard of care, i.e., end-to-end anastomoses. Conclusions: End-to-side anastomosis may be a safe alternative for DIEP breast reconstruction, especially for patients at risk for coronary heart disease. This pilot study aims to evaluate the feasibility and safety of the end-to-side anastomosis technique in DIEP-flap breast reconstruction. The preliminary findings will inform the design of future multicentric trials to confirm the efficacy of this approach.