Association between Lumbar Artery Coverage and Early Regional Muscle Volume Changes after Endovascular Aneurysm...

To evaluate early postoperative changes in pelvic and paraspinal muscle volume following endovascular aneurysm repair (EVAR) and explore associations between lumbar artery (LA) coverage and regional muscle volume changes. A secondary aim was to assess the feasibility of automated computed tomography (CT)-based multimuscle volumetry during EVAR surveillance.

Fifty-three patients who underwent elective EVAR for infrarenal abdominal aortic aneurysm were retrospectively analyzed. Preoperative and postoperative CT angiography at 1, 6, and 12 months was processed using a fully automated segmentation algorithm (TotalSegmentator). Volumetric analysis included bilateral gluteal, iliacus, and deep paraspinal muscle groups. Aneurysm diameter, LA count, number of large LAs (≥2 mm), and covered arteries were recorded. Longitudinal volume changes were assessed using linear mixed-effects models.

At 1 month after EVAR, significant reductions in muscle volume were observed in multiple pelvic and paraspinal muscles (P < 0.05). More pronounced early volume loss was observed in patients with coverage of multiple LAs ≥2 mm. Larger aneurysm diameter was associated with more pronounced volume changes in gluteal and iliopsoas muscles. Partial attenuation of volume loss was observed at later follow-up, although interpretation was limited by attrition. Automated volumetry was feasible and required no correction.

In this retrospective pilot study, LA coverage during EVAR was associated with early regional muscle volume changes in pelvic and paraspinal muscle groups. These findings are hypothesis-generating and warrant confirmation in prospective studies incorporating functional outcomes. Automated CT-based muscle volumetry may serve as a reproducible tool for exploring tissue-level effects of endovascular interventions.