Abdominal wall muscle remodeling after open transversus abdominis release: a CT-based analysis

To evaluate abdominal wall muscle remodeling after posterior component separation using the transversus abdominis release (TAR) technique, and to explore potential associations between muscle remodeling and clinical, demographic, and anatomical variables. This retrospective study included adults with incisional ventral hernia who underwent abdominal wall reconstruction with TAR between 2019 and 2023. Pre- and postoperative abdominal CT scans (≥ 6 months) were analyzed to measure bilateral cross-sectional areas of the rectus abdominis (RA), internal oblique (IO), and external oblique (EO) muscles at L3–L4 level. Percentage variation in muscle cross-sectional area (CSA), calculated using bilateral mean values, was used to characterize morphometric remodeling. Associations with demographic factors, clinical variables, hernia characteristics, and postoperative outcomes were assessed using Wilcoxon and Spearman tests. Thirty-seven patients met inclusion criteria. Paired analyses demonstrated a consistent postoperative increase in CT-derived muscle CSA across RA, IO, and EO (all p < 0.001). In exploratory analyses, no demographic, clinical, or anatomic variable demonstrated a statistically significant association with bilateral mean muscle remodeling. Patients undergoing open TAR demonstrate consistent postoperative abdominal wall morphometric remodeling on CT, characterized by RA expansion and coordinated changes in the oblique muscles following midline restoration. The clinical significance of these imaging findings remains uncertain and warrants prospective studies integrating functional outcomes.