Immediate angiographic residual shunt using the Nit-Occlud device for patent ductus arteriosus closure

Introduction
The Nit-Occlud PDA device is a newer coil-type device with a high degree of efficacy and safety. There are concerns about the high incidence of immediate angiographic residual shunt with this device. To compare immediate angiographic residual shunts and their outcomes following PDA device closure with the Nit-Occlud device.

Material and methods
A single-institution, retrospective chart review of PDA closures was performed. Thirty patients who underwent Nit-Occlud PDA closure were compared with 34 patients who underwent PDA closure with an Amplatzer Duct Occluder-1 (ADO-1) and 25 patients who underwent PDA closure with coils.

Results
The three groups were similar in age, weight, and procedural characteristics. The PDA dimensions were smaller in the coils group. Technical success in the ADO-1 and Nit-Occlud groups was 100%. A small angiographic residual shunt was seen more often in the Nit-Occlud group (70%) than in the ADO-1 (59%) and coils (26%) groups (p = 0.005). Most residual shunts in the Nit-Occlud group disappeared in the echocardiogram performed 4 h later (90% echocardiographic closure). Echocardiographic closure (100%) was seen at 2 months and 6 months in the Nit-Occlud group. No correlation was noted between the angiographic residual shunt and Nit-Occlud device orientation with respect to the ductus, the device-ductal angle or the number of loops at the pulmonary artery end.

Conclusions
Despite the higher immediate angiographic residual shunt rate in the Nit-Occlud group than the other groups, high echocardiographic closure rates were seen within hours after device closure, which persisted at follow-up. The angiographic residual shunt is not related to the device orientation and should not be a deterrent in using this device.