Balancing Flap Perfusion & Donor Site Morbidity: An Evidence-Based Approach to Optimizing Outcomes for Free Flap Breast Reconstruction

Purpose: Attempts to reduce donor-site morbidity for abdominal-based free-flap breast reconstruction result in compromised flap perfusion. The optimal balance between flap perfusion and donor morbidity has not been elucidated.  We hypothesized that many of the factors that limit donor-site morbidity also compromise flap perfusion in a reciprocal relationship.

Methods and Materials:  We reviewed consecutive patients who underwent immediate or delayed breast reconstruction using deep inferior epigastric perforator (DIEP) and free transverse rectus abdominis musculocutaneous (FTRAM) flaps at a major cancer center over 10-years. We analyzed the effect of flap design (DIEP vs. FTRAM), perforator number (1, 2, or ≥3), and deep inferior epigastric artery (DIEA) branches (medial or lateral vs. both branches) on perfusion related complications (fat necrosis/partial flap necrosis) versus donor-site integrity (abdominal hernia).  We used univariate and multivariate logistic regression modeling to analyze the effect of patient and reconstruction characteristics on overall and specific postoperative outcomes.

Results: A total of 1418 flaps in 1127 patients were evaluated: 68.7% DIEP flaps vs. 31.3% FTRAM. Mean follow-up was 42.8 months. In general, we found that the three factors had a reciprocal effect on donor integrity and flap perfusion quality.  DIEP flaps had higher rates of fat necrosis/partial flap necrosis than FTRAM flaps (11.1% vs. 7.6%, respectively; p=0.02); however, hernias were less common (1.2% vs. 3.0%, respectively; p=0.03).  Flaps with one (15.2%) or two (11.1%) perforators experienced higher rates of fat necrosis/partial flap necrosis than flaps with ≥3 perforators (8.5%; p=0.05); however, one (0.8%) and two (0.8%) perforator flap donor sites developed fewer hernias than ≥3 perforator (1.8%) donor sites (p=0.05). Flaps that included perforators originating from a single medial or lateral branch of the DIEA developed more fat necrosis/partial flap necrosis than flaps with perforators from both DIEA branches (12.0% vs. 5.5%, respectively; p<0.01); however, hernias tended to be less common (1.7% vs. 3.2%, respectively; p=0.06).

Conclusions:  This study demonstrates that there is a reciprocal positive and negative consequence of intraoperative decisions when harvesting abdominal free flaps for breast reconstruction between DIEP vs. FTRAM flap design, perforator number, and harvesting a single vs. both DIEA branches.  With this evidence, surgeons can make more informed decisions to balance donor-site morbidity and flap perfusion.