Abdominal Wall Thickness Vs. BMI As a Predictor of Complications after Abdominally-Based Free Flaps to Treat Mastectomy Defects
Adee J. Heiman, M.D.1, Makai Dunne, B.S.1, Megan Gray, M.D.1, Ashit Patel, MBChB1, Joseph A. Ricci2.
1Albany Medical Center, Albany, NY, USA, 2Montefiore Medical Center, Bronx, NY, USA.
BACKGROUND: Although BMI above 30 kg/m2 is often considered a relative or absolute contraindication for abdominally-based free flaps, there is mixed evidence in the literature that BMI correlates with complication rate. The purpose of this study was to determine whether BMI or abdominal wall thickness correlated with post-operative complication rate. METHODS: A retrospective chart review was conducted on 151 patients who underwent abdominally-based free flap reconstruction after mastectomy. Pre-operative axial computed tomography scans were used to measure the distance from the skin surface to the abdominal wall at the umbilicus and at the lower abdomen (8 cm inferior to the umbilicus). Mean BMI, mean Abdominal Wall Thickness at the Umbilicus (AWTU), and mean Lower Abdominal Wall Thickness (LAWT) were then compared between patients who did and did not develop overall, abdominal donor site, and breast flap complications. The mean LAWT was also compared between patients who had and had not experienced different subtypes of abdominal and breast complications (unpaired t test). Patients were then stratified into four groups based on LAWT, and complication rates were then compared between all four groups (Chi-squared). RESULTS: Mean BMI did not differ significantly between patients who did or did not experience any complication, abdominal complications, or breast complications. Mean AWTU was significantly higher in patients with overall (p=0.005) and abdominal complications (p=0.003) but did not differ significantly between those who did and did not experience breast complications. Mean LAWT was significantly higher in patients who experienced all three types of complications (p=0.001, 0.0001, 0.02, respectively), and so this point was chosen as the major comparison point. Patients with abdominal complications requiring re-operation (p=0.001), abdominal wound healing complications (p<0.0001), and breast wound healing complications (p=0.004) had a higher mean LAWT compared to those without these respective complications, but no there was no significant difference between those who did and did not experience abdominal or breast infectious complications, breast complications requiring re-operation, or breast fat necrosis. After stratification of complication rates based on LAWT groups, the rates of overall abdominal complications and abdominal wound healing complications significantly increased as LAWT increased (p=0.01, 0.03, respectively). Breast wound healing complications were also higher in the high LAWT groups, although this did not reach statistical significance (p=0.2). CONCLUSIONS: Abdominal wall thickness is a better predictor of complications after abdominally-based free flaps compared to BMI.
Back to 2020 Abstracts