Abstract
Objective:
To describe and bench-validate a shareable, version-locked computer-aided design (CAD) to 3-dimensional (3D)-print workflow that generates a cylindrical template to guide fenestration placement during preparation of physician-modified endografts (PMEGs).
Methods:
Five computed tomographic angiograms were used to script a CAD template in Onshape with standardized geometry (height 100 mm, diameter 30 mm, wall 4 mm, celiac 20 mm from the top, fenestration diameter 6 mm) and a 12-o’clock reference. Templates were sliced in PreForm v3.5.1 and printed on a desktop stereolithography printer using BioMed Amber, BioMed Clear, and Dental resins. Accuracy was assessed on bench models by comparing measured versus planned fenestration centers, expressed as arc-length bias (mm along the circumference) and height bias (mm along the longitudinal axis). Secondary analysis examined the impact of resin type, fenestration print order (first-fourth), and target vessel.
Results:
Across 54 printed fenestrations, median arc-length bias and height bias were 0.3 mm (interquartile range [IQR] 0.2-0.5) and 0.2 mm (IQR 0.2-0.3), respectively. Median arc-length bias by resin type was as follows: Dental 0.3 mm (IQR 0.1-0.6), Amber 0.3 mm (IQR 0.2-0.6), and BioMed Clear 0.3 mm (IQR 0.2-0.5). The height bias for Dental, Amber, and Clear resins was 0.2 mm (IQR 0.1-0.3), 0.2 mm (IQR 0.1-0.2), and 0.3 mm (IQR 0.2-0.3), respectively. There was no consistent degradation or improvement for the fenestration positioning depending on the sequence in which fenestrations were created during the printing for a specific template, or by target vessel.
Conclusion:
Using a 3D-printed cylindrical template during PMEGs holds potential to facilitate precise, reliable positioning of fenestrations on the endograft. The current workflow could provide a reproducible tool to standardize back-table transfer of the preoperative plan for PMEGs.
Clinical Impact
Physician-modified endograft remains a valuable option for endovascular treatment of complex abdominal aortic aneurysms, particularly given the limited availability of custom-made devices in some centers, their high cost, and prolonged manufacturing times. Although clinical outcomes of PMEGs have been promising, standardization across centers remains limited. From a clinical perspective, high accuracy and reproducibility are essential, as positional deviations may compromise alignment, potentially leading to prolonged catheterization times and target vessel instability. The use of a 3D-printed model within a standardized workflow, such as the one described in the present study, may facilitate reliable and reproducible transfer of the preoperative plan onto the endograft.
Keywords
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