Assessment of the risk of bulge/hernia formation after abdomen-based microsurgical breast reconstruction with the aid of preoperative computed tomographic angiography-derived morphometric measurements

Background: No preoperative risk assessment tool is available to predict postoperative bulge formation after abdomen-based breast reconstruction. The authors evaluated the association between clinical variables and morphometric measurements on preoperative computed tomographic (CT) angiography and postoperative abdominal wall morbidity. Methods: The authors evaluated all cases of postoperative bulge/hernia and normal controls in patients who underwent preoperative CT angiography and abdomen-based microsurgical breast reconstruction between July 2009 and January 2018. CT-based abdominal wall profiles, including abdominal wall protrusion, abdominopelvic cavity cross-sectional area (CSA), and abdominopelvic cavity-to-total body CSA ratio, were obtained and analyzed. A novel risk stratification scoring system to stratify the risk of bulge/hernia was developed. Results: Among 463 patients who underwent abdomen-based breast reconstruction, 23 were diagnosed as having a bulge/hernia. Age (OR 2.912; 95% CI 1.157–7.333), lateral row perforator (OR 5.065; 95% CI 1.834–13.986), and abdominal wall protrusion (OR 3.687; 95% CI 1.494–9.100) were significant risk factors associated with postoperative bulge/hernia in the multivariate analysis. Using the risk stratification scoring system, the incidence rates of postoperative bulge/hernia were 1.7%, 4.8%, and 19.0% for low-, intermediate-, and high-risk patients, respectively (p<0.001). Conclusions: Age, lateral row perforator, and abdominal wall protrusion were significantly associated with postoperative bulge/hernia formation after abdomen-based microsurgical breast reconstruction. The authors’ risk score based on the three variables may help predict and minimize donor-site morbidity.