Correlation between abdominal visceral volume measured by a simple procedure and bulging at the abdominal free flap donor site for breast reconstruction.

[BACKGROUND] Breast reconstructions using autologous abdominal tissue result in breasts with a natural shape and consistency. One of the major complications is abdominal bulging. Because of the increased abdominal wall tension, high visceral volume (not visceral fat alone) may increase the occurrence rate of abdominal bulging. A simple procedure involving CT imaging was used to assess this relationship in patients undergoing an abdominal free flap for unilateral breast reconstruction.

[METHODS] A total of 278 patients were enrolled in this study. The patients' demographics, the thicknesses of visceral volume were compared (Bulging (+) vs. Bulging (-)). Visceral volume was investigated based on the horizontal thickness, which was measured at the thickest part at the level of the umbilical fossa between both sides under the transverse abdominis muscles.

[RESULTS] Bulging (+) consisted of 39 patients (14.0%), whereas Bulging (-) included 239 patients. Patients with Bulging (+) were significantly older, had higher gestational history rate, and had thin rectus abdominis muscle. In terms of visceral volume, the Bulging (+) group had significantly higher horizontal thicknesses (median 233 mm vs. 219 mm, P < 0.001). No significant differences were observed with respect to other factors (age, BMI, history of laparotomy, and operative details). The multivariate logistic regression analysis revealed that the thickness of the rectus abdominis muscle, horizontal visceral volume, and gestational history were independently significant predictors.

[CONCLUSIONS] Not only the patients with thin rectus abdominis muscle but also patients with a thick horizontal visceral volume may have a higher risk of abdominal bulging.