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Updated: Oct 7, 2026
The Helsinki Rat Microsurgical Sidewall Aneurysm Model
Published on: October 12, 2014
A STANDARDIZED 50-MM ANALYTICAL MODEL FOR REPRODUCIBLE ANEURYSM VOLUMETRY AFTER EVAR
Ma Lourdes Del Río-Solá1, Joan Roedan-Oliver2, Manuel Diez-Martínez3
1Department of Vascular Surgery; University Hospital, Valladolid (Spain). Department of Surgery, Ophthalmology, Otorhinolaryngology, Physiotherapy; University of Valladolid. Department of Health Siciences; Miguel de Cervantes European University, Valladolid, Spain.
Background:
Conventional volumetric assessment after endovascular aneurysm repair (EVAR) is limited by variability in anatomical landmark selection and inconsistent measurement regions, which may affect longitudinal reproducibility. This study evaluated the reproducibility and sensitivity of Volmax50, a standardized volumetric framework based on a patient-specific 50-mm analytical segment automatically identified within the region of maximal aneurysm dilatation, compared with conventional full-length volumetry.
Methods:
A prospective single-center study included 98 patients undergoing endovascular aneurysm repair (EVAR). Sac and thrombus volumes were obtained using semi-automated segmentation and analyzed with two approaches: traditional full-length volumetry and Volmax50, which evaluates a fixed 50-mm segment centered on maximal sac dilatation. Measurements were performed at baseline, 6, and 12 months. Agreement, intra- and interobserver reproducibility, and sensitivity for detecting sac enlargement ≥5 mL were assessed.
Results:
Baseline sac and thrombus volumes were comparable between methods. During follow-up, Volmax50 yielded slightly larger sac volumes (T6: 110 vs 105 mL, p=0.041; T12: 114 vs 107 mL, p=0.019) and thrombus volumes (T12: 52 vs 50 mL, p=0.044). Reproducibility was superior with Volmax50 (ICC 0.93, 95% CI 0.90-0.96) compared with the traditional method (ICC 0.82, 95% CI 0.76-0.87), with lower intra- and interobserver variability (2.8% and 3.4% vs 6.5% and 7.9%). Bland-Altman analyses confirmed smaller bias and narrower limits of agreement. Sensitivity for detecting sac enlargement ≥5 mL was significantly higher with Volmax50 (92% vs 68%, p<0.001).
Conclusions:
Volmax50 provides more reproducible and sensitive volumetric assessment than conventional volumetry for AAA surveillance after EVAR. By standardizing the analytical region and reducing observer-related variability, it improves the detection of sac volume changes and may represent a useful adjunct for routine postoperative monitoring.
