Preoperative Computed Tomographic Angiogram Measurement of Abdominal Muscles Is a Valuable Risk Assessment for Bulge Formation after Microsurgical Abdominal Free Flap Breast Reconstruction

Background: A major shortcoming associated with abdominal tissue breast reconstruction is long-term abdominal wall morbidity. Although abdominal muscle size on computed tomographic angiography has been correlated with morbidity following many abdominal operations, it has not been studied for breast reconstruction. Therefore, the authors evaluated the association between preoperative computed tomography angiography-derived measurements of abdominal core muscles and postoperative abdominal wall morbidity after abdominal tissue breast reconstruction. Methods: In this retrospective matched case-control study of women who underwent microsurgical abdominal flap breast reconstruction at one institution between January 2011 and June 2015, the authors evaluated all cases of postoperative bulge/hernia, matched by type of abdominal flap and body mass index in a ratio of 1:2 to controls without bulge/hernia. The authors obtained morphometric measurements of abdominal core muscles on preoperative computed tomographic angiographs. Using univariable and multivariable logistic regressions, the authors examined the effects of clinical risk factors and computed tomographic angiography morphometric measurements on postoperative bulge/hernia formation. Results: Of the 589 patients who underwent abdominal free flap breast reconstruction, symptomatic bulges/hernias were identified in 35 patients (5.9 percent). When compared to the 70 matched controls, multivariable analysis showed that decreased area of rectus abdominis muscle (OR, 0.18; p < 0.01) and increased inter-rectus abdominis distance (OR, 1.14; p < 0.01) on computed tomographic angiography were significant risk factors associated with postoperative bulge/hernia. Conclusion: Preoperative computed tomographic angiography allows objective measurements of the patient's abdominal muscle anatomy that provide valuable prognostic information on the risk of bulge/hernia formation following abdominally based microsurgical breast reconstruction.