A prospective study comparing the functional impact of SIEA, DIEP, and muscle-sparing free TRAM flaps on the abdominal wall: Part I. Unilateral reconstruction

Background: The purpose of this two-part study was to demonstrate the impact of free flap breast reconstruction on the abdominal wall. In Part I, the authors present the results for unilateral techniques. Methods: A blinded, prospective, cohort study was performed involving 234 free flap breast reconstruction patients. Patients were evaluated preoperatively, and followed for 1 year. At each encounter, patients underwent abdominal strength testing using the Upper and Lower Rectus Abdominis Manual Muscle Function Test, the Functional Independence Measure, and psychometric testing using the 36-Item Short-Form Health Survey. Patients also completed a satisfaction questionnaire specific to breast reconstruction. Statistical analysis included the Kruskal-Wallis, Mann-Whitney, Friedman, and Wilcoxon signed rank tests. Results: Two-hundred thirty-four patients were enrolled. Of these, 157 underwent reconstruction (75 of which were unilateral), completed follow-up, and were included in the analysis. There was a significantly greater decline in upper abdominal strength in patients undergoing muscle-sparing free transverse rectus abdominis musculocutaneous (TRAM) flap surgery compared with deep inferior epigastric perforator (DIEP) flap surgery at early (p = 0.01) and late follow-up (p = 0.02). Unilateral superficial inferior epigastric artery flap procedures (n = 3) were too few for a meaningful conclusion to be reached. Lower abdominal and Functional Independence Measure scores showed no significant differences. Psychometric testing showed that there was a significant decline in physical health within the free TRAM flap group. No significant difference among groups was appreciable. Conclusion: In unilateral cases, the impact of the muscle-sparing free TRAM flap versus the DIEP flap follows theoretical predictions based on the degree of muscle sacrifice: the muscle-sparing free TRAM flap demonstrated a greater decline than the DIEP flap in certain measurable parameters.