Does a Change in Device Design Alter Device Size Selection? A Comparison of Conventional and Occlutech Duct Occluder Designs.

Abstract

The Occlutech duct occluder (ODO) with a novel design has been available for closure of patent ductus arteriosus (PDA) since 2011. Available data on initial experience with the ODO have shown that operators continue to choose device sizes based on their experience with conventional duct occluders (CDO). This study postulated that occlusion of the pulmonary arterial (PA) end of the ductus should achieve satisfactory PDA closure without additional complications. Accordingly, the size of the ODO was chosen such that the larger PA diameter in the new design exceeded the PA end of the ductus by 2-3 mm and 2-4 mm for normotensive and hypertensive ducts, respectively. It sought to examine the feasibility and safety of such an approach, and compared ODO and CDO devices with respect to device sizes deployed, to ascertain if the newer design had any advantages. This prospective study enrolled 105 infants, children and a few adults with various duct morphologies and PA pressures for ductal closure using the ODO from 2018-2020. The control group consisted of 105 ducts closed with CDO. A comparison of the two groups with respect to duct diameter and implanted device sizes was performed using appropriate statistical software. The study found that 40% of the ducts had moderate-to-severe pulmonary hypertension. Most ducts measured between 3-4 mm in both groups. The mean weight of the subjects in both groups was 12 kg. Although there was no change in the way that duct occluders were chosen in both groups (2-3 mm over the pulmonary artery diameter), ODO could be significantly downsized in most ducts measuring between 2.5-6.4 mm in diameter (p<0.05). This study found successful closure of relatively larger PDA in infants and children using smaller ODO compared with CDO, without embolisation or aortic narrowing. It also demonstrated that a different device size selection technique may be safely employed with the ODO.