Effects of Obesity on Postoperative Complications After Breast Reconstruction Using Free Muscle-Sparing Transverse Rectus Abdominis Myocutaneous, Deep Inferior Epigastric Perforator, and Superficial Inferior Epigastric Artery Flap: A Systematic Review and Meta-analysis.

BACKGROUND: Although several studies have found obesity to increase the risk of postoperative morbidity in autologous breast reconstruction, there remains some controversy over the influence of obesity for muscle-conserving abdominal flaps, including muscle-sparing transverse rectus abdominis myocutaneous (msTRAM), deep inferior epigastric perforator (DIEP), and superficial inferior epigastric artery (SIEA) flaps. This review evaluates the effects of obesity on complications in breast reconstruction using muscle-conserving abdominal flaps and compares them to those for conventional free transverse rectus abdominis myocutaneous (TRAM) flaps. METHODS: A literature search was conducted using MEDLINE, Ovid, and Cochrane databases for studies reporting complication rates for obese and nonobese patients undergoing breast reconstruction using msTRAM, DIEP, and SIEA flaps and conventional free TRAM flaps. The pooled relative risks (RRs) of the obesity for flap-related and donor complications were estimated in the muscle-conserving flaps by meta-analytic methodology and the pooled complication rates in obese patients were compared between muscle-conserving flaps and conventional TRAM flaps. Here, only those studies following the World Health Organization definition of obesity (body mass index ≥ 30 kg/m) were included. RESULTS: A total of 17 articles were analyzed. Eight studies were used to compute the obesity-related risks of flap-related and donor complications for msTRAM, DIEP, and SIEA flaps. Obesity increased the risk of total flap loss [RR, 1.68; 95% confidence interval (CI), 0.85-3.33], partial flap loss (RR, 2.26; 95% CI, 1.01-5.02), abdominal bulge or hernia (RR, 1.72; 95% CI, 1.00-2.95), and overall abdominal complications (RR, 1.53; 95% CI, 1.10-2.14). The results of a pooled analysis with 15 studies are consistent with those of the meta-analysis. In comparison to free TRAM flaps, muscle-conserving abdominal flaps showed a lower pooled incidence of flap loss, fat necrosis, and abdominal bulge or hernia in obese patients. CONCLUSIONS: This review suggests that obesity increases the risk of both flap-related and donor-site complications in breast reconstruction using msTRAM, DIEP, and SIEA flaps. In comparison to conventional TRAM flaps, however, muscle-conserving abdominal flaps may have an advantage in reducing the morbidity in obese patients.