This is the largest study to date comparing donor-site morbidity following medial or lateral DIEA branch harvest. Choice of perforators should be based on quality, size, and orientation. Medial versus lateral row perforators should not be harvested preferentially to reduce donor-site hernia or bulge.

Background Anatomic studies suggest the deep inferior epigastric artery (DIEA) medial branch perfuses more tissue across the midline than the lateral branch. We hypothesized that unilateral DIEP and MS FTRAM flaps based on medial branch perforators would have fewer perfusion-related complications. Methods We evaluated 2043 consecutive free flap breast reconstructions and included unilateral reconstructions where DIEP or MS FTRAM flaps were definitively harvested from a single DIEA branch. We grouped flaps by tissue volume, i.e., Hemiflaps, Cross-Midline Flaps, and Total Flaps. Primary outcome measures were fat necrosis and partial flap necrosis. Logistic regression was used to evaluate the association between patient and reconstruction characteristics and perfusion outcomes. Results We included 228 patients: 120 (52.6%) medial and 108 (47.4%) lateral branch flaps. Mean follow-up was 33.2 months. Cross-Midline Flaps (79.8%) were most common, followed by Hemiflaps (15.4%) and Total Flaps (4.8%). Overall fat necrosis and partial flap necrosis rates were 10.5% and 3.1%, respectively. Medial and lateral branch flaps had similar rates of fat necrosis (8.3% vs. 13.0%, respectively; p=0.26) and partial flap necrosis (3.3% vs. 2.8%, respectively; p=1.0). DIEP and MS FTRAM flaps had no difference in the incidence of fat necrosis (10.2% vs. 11.3%; p=0.81) or partial necrosis (3.2% vs. 2.8%; p=1.0). Medial and lateral branch flap perfusion-related complications were also similar among the flap volume classifications. Conclusions We suggest that surgeons base their decisions regarding DIEA branch harvest on the clinical assessment of perforator perfusion quality rather than relying on the theoretic benefit of medial branch perforator harvest.