3D modeling and printing in large native right ventricle outflow tract to plan complex percutaneous pulmonary valve implantation

Abstract

ObjectiveInvestigating accuracy of cardiac tomography (CT) derived post-processing3D reconstruction (CT-PPR) and 3D printing to predict percutaneous pulmonary valve implantation (PPVI) feasibility. BackgroundPPVI feasibility remains challenging in large native regurgitant right ventricle outflow tract (RVOT). MethodsFifteen patients with large native RVOT were investigated. CT-PPR consisted in RVOT long-axis curvilinear reconstruction (LACR) to measure the landing zone (LZ), and 3D volume rendering for morphological evaluation. A STL was generated to create 3D printed model (flexible resin). Balloon sizing was subsequently performed to measure LZ diameter (3D-MBD), compared to invasive balloon diameter (IBD) during catheterization, considered as the Gold Standard. Two operators predicted the feasibility of PPVI using CT-PPR and 3D printed models independently and blinded to outcome. ResultsOn 3D printed models, RVOT shape was tubular in 5 patients, divergent in 5 patients, concave in 4 patients and convergent in one. Agreement with CT-PPR RVOT shape morphology assessment was observed in 93% of cases (Kappa coefficient 0.91, p < 0.0001). Minimal IBD was 26.0 [24.4–27.9] mm. Minimal LZ LACR diameters were well correlated to IBD (Spearman rho = 0.67, p = 0.007; r2 = 0.55, p = 0.002) with a mean underestimation bias of 2.8 mm. Minimal 3D-MBD was correlated to IBD (Spearman rho = 0.55, p = 0.04, r2 = 0.50, p = 0.003) with mean underestimation bias of 0.9 mm.PPVI was successful and uneventful in 11 patients, challenging in one and non-feasible in 3. Using CT-PPR and 3D printed models, interventionists predictions agreement with outcome was 93% and 87% (Kappa coefficient = 0.86, p = 0.0001, and Kappa coefficient = 0.65, p = 0.0007 respectively). ConclusionRVOT 3D CT-PPR and printing allow reliable assessment of RVOT shape and LZ diameter prior to PPVI. Prediction of PPVI feasibility in challenging cases is facilitated.