Pre-Catheterization Computed Tomography Angiography Aids in the Selection of Ductus Arteriosus Stent Length for Ductal-Dependent Pulmonary Blood Flow

PDA stenting is increasingly utilized for patients with ductal-dependent pulmonary blood flow. Predicting optimal stent length prior to and during the intervention remains a challenge. The utility of pre-catheterization computed tomography angiography (CTA) to predict stent length was evaluated. All patients that received a PDA stent for pulmonary blood flow between 2019 and 2022 with a pre-stent CTA were reviewed. Several CTA and catheter angiography-based measurements of the native and stented PDA were performed. Curvilinear and straight-line PDA lengths were determined by pre-catheterization CTA and used to calculate the tortuosity index ([Curvilinear-Straight]/Curvilinear). The stented ductal length (SDL) was determined by catheter angiography after stent deployment by subtracting the aortic and pulmonary overhang from the total stent length. A linear regression model was created using an Akaike information criteria (AIC) analysis to identify CTA measurements that correlate with SDL. 31 patients met inclusion criteria. The SDL lies between the pre-stent CTA straight length (mean of 11.6 mm) and curvilinear length (mean of 17.8 mm) for most patients. As the PDA tortuosity index increases, the curvilinear length increases exponentially, while the SDL remains closer to the straight length. From our AIC analysis, only CTA straight length was significantly associated with SDL. Linear regression modeling predicts that the SDL is 1.14 times the CTA straight length (R² = 0.97, p < 0.001). Pre-intervention CTA can aid in the selection of PDA stent length prior to catheterization. The SDL is well approximated by the pre-stent CTA straight length with a small correction.