Correlation of ductus arteriosus length and morphology between computed tomographic angiography and catheter angiography and their relation to ductal stent length

Background: Patent ductus arteriosus (PDA) stent placement in infants with ductal-dependent pulmonary blood flow is being increasingly used in clinical practice. Objective: To correlate computed tomographic (CT) angiography morphology and length of the PDA with catheter angiography and its relation to eventual PDA stent length. Materials and methods: We retrospectively identified all pediatric patients who underwent PDA stenting at our institute from 2004 to 2018. We included children who had CT angiography prior to stenting. PDA length was measured by a radiologist blinded to the catheter angiography data, using Syngo-via post-processing software (Siemens, Erlangen, Germany). Vessel centerline technique was used. We measured the actual length of the duct as well as straight length between aortic and pulmonary ends. PDA morphology tortuosity index was classified as straight (Type I), mildly tortuous with 1 turn (Type II) and tortuous with >1 turn (Type III), and the PDA origin was noted. The PDA was also measured and morphology classified on catheter angiography by an interventional cardiologist blinded to the CT angiography findings. We compared the CT angiography and catheter angiography lengths, straight lengths and stent length using scatter plots and intraclass correlation coefficient (ICC). Results: A total of 83 children who had PDA stenting were identified, of whom 17 had prior CT angiography. Fifteen of these were neonates. There was agreement between CT angiography and catheter angiography regarding the PDA morphology tortuosity index in 94% of cases and PDA origin in 100% of cases. There was moderate agreement between CT angiography and catheter angiography actual and straight PDA lengths, with ICC coefficients of 0.65 and 0.68, respectively. There was moderate agreement between CT angiography actual length, CT angiography straight length, catheter angiography actual length and eventual stented PDA length, with ICCs of 0.57, 0.67 and 0.73, respectively. There was poor agreement between catheter angiography straight length and eventual stented PDA length, with an ICC of 0.39. Conclusion: PDA length and morphology description on CT angiography correlates well with catheter angiography and can be a reliable guide for the interventional cardiologist in decision-making regarding appropriate choice of PDA stent length.