Muscle Preservation after Abdominal Aortic Aneurysm Repair: A Retrospective Comparison of Endovascular and Open Surgical Approaches

Abstract Purpose: Older patients undergoing abdominal aortic aneurysm (AAA) repair are at risk of functional decline. Endovascular aneurysm repair (EVAR) has better perioperative outcomes than open abdominal surgery (OAS), but its impact on postoperative muscle preservation is unclear. We compared rectus femoris muscle changes after EVAR versus OAS. Methods: We retrospectively analyzed 50 patients undergoing elective AAA repair (EVAR n = 30; OAS n = 20) at a single center (2012–2014). The primary endpoint was the pre- to postoperative change in the bilateral rectus femoris short-axis diameter product on computed tomography (mm 2 ) at the level of the pubic symphysis 3–6 months after surgery. Baseline and follow-up rectus femoris values were 1120 ± 410 versus 1132 ± 441 mm 2 (EVAR) and 791 ± 336 versus 805 ± 431 mm 2 (OAS); baseline values were lower in the OAS group. Propensity score matching (1:1 nearest-neighbor, caliper 0.05, with replacement) produced 30 matched pairs. Treatment effects were estimated using a two-time-point difference-in-differences (DiD) model; effect sizes were summarized as standardized mean differences (Cohen’s d ). Results: After matching, EVAR was associated with better preservation of the rectus femoris muscle than OAS (DiD 17.25 mm²; 95% confidence interval 2.54–31.97; P = 0.02). Conclusion: EVAR may confer advantages over OAS in preserving rectus femoris muscle mass after AAA repair, particularly in older patients at risk of postoperative functional decline.