Physician-modified endograft using three-dimensional model-assisted planning

Abstract

Objective: Case-specific and true-to-scale three-dimensional (3D) models have become increasingly useful tools for physician-modified endovascular grafting. This study aimed to validate the use of 3D model-assisted planning for fenestration design. Methods: Thirty-two consecutive patients (2019-2021) presenting with pararenal or juxtarenal abdominal aortic aneurysm (n = 16), paravisceral abdominal and Crawford’s extent IV thoracoabdominal aortic aneurysm (n = 12), and type I endoleak after endovascular repair (n = 4) were analyzed retrospectively. All cases were planned manually with a standard method using curved planar reconstruction stretch images and multiplanar images perpendicular to the centerlines. The design was finalized by intraoperative 3D model-assisted planning. Intermethod agreements were assessed for geometrical relationships (separation heights and angles) between the superior mesenteric and renal arteries. The datasets from 55 double measurements of the entire cohort in this series were used to assess measurement discrepancies (≥3 mm separation height or ≥15° angle difference) and fenestration mismatches (≥3 mm separation between the manually planned and 3D model-assisted-planned renal arterial centers on the device surface) between manual and 3D model-assisted planning. Statistical analyses were performed to test the impact of anatomical factors on the discrepancies and mismatches. The imposition accuracy of 3D model-assisted planning and short-term clinical results of the 32 cases were also evaluated. Results: Fourteen fenestration measurement discrepancies were detected. The size of the stent graft (P = .0381), the aortic angle (P = .0008), and the prior existence of stent graft (P = .0123) were found to have a statistically significant impact on the measurement discrepancy, using single logistic and Fisher’s exact tests. Twelve fenestration mismatches were observed and found to be significantly affected (P = .0039) by aortic angle. A cutoff value for fenestration mismatch was found to be 36.5°, with a sensitivity and specificity of 69.2% and 80.5%, respectively, using receiver operating characteristic analysis (area under the curve, 0.782 ± 0.081; P = .0023). A high level of branch preservation (100%) was achieved. During the observation period (1.3 years on average; range, 0.5-2.5 years), no patient experienced complications related to fenestration. Conclusions: The differences between the planning methods were non-negligible. However, 3D model-assisted planning increased the precision of the fenestration design when the conformation of the stent graft to the aortic anatomy is taken into account.

Keywords

• Abdominal aortic aneurysm
• Paravisceral
• Juxtarenal
• Fenestrated endovascular aneurysm repair
• Simulation