Preclinical Validation of a Patient-Specific Patch-Planning Workflow for Congenital Cardiovascular Reconstruction

Branch pulmonary artery (BPA) reconstruction is associated with high reintervention rates. We present in vitro validation of a patch-planning workflow accounting for vessel prestretch, tissue properties, and suture uptake, to achieve targeted reconstructed dimensions.

Two physiologically compliant, centrally stenosed BPA silicone models were created to represent neonatal and child-age repairs. Preoperative CTs were segmented to create 3D models for virtual planning. Patches were designed to restore stenotic regions to target diameters under two physiological pressure extremes, accounting for model and patch material distensibility. Finite-element simulation determined the loaded flat patch configuration. Analytical transformation produced unloaded designs for patches planned at high pressure. Designs were laser projected onto patch surfaces, patches sutured, and postoperative CTs acquired (n ≥ 3 per model/pressure/material). Virtual model credibility was evaluated following a recent credibility assessment framework.

Patches designed for low vs. high pressure differed in size by up to 25%. All samples were reconstructed to within 0.8 mm of the target diameter (n = 45), and all but three were within z-score ± 0.5. Through credibility assessment, we verified that simulations introduced < 3% error versus the analytical solution. Patch size was most sensitive to one standard deviation change in patch stiffness. From experiments, suture uptake exhibited highest variability from allocated offset.

Preclinical evaluation of a patch-planning workflow demonstrated accurate reconstruction of BPA stenosis. Incorporation of material properties is essential to achieve targeted reconstructed dimensions under physiological conditions. Model credibility assessment and in vitro validation of more complex patient-specific anatomy will precede prospective clinical trials.