Stenting of branch pulmonary artery stenosis in children: initial experience and mid-term follow-up of the pul-stent

Abstract

Not all stents are suitable for children. For instance, premounted stents can be used in infants and small children but cannot dilate with age to accommodate adult-sized pulmonary arteries. Conversely, the Pul-Stent adapts to somatic growth. Thus, our hospital implemented the Pul-Stent in pediatric patients with branch pulmonary artery stenosis. This study summarizes our initial experience with Pul-Stents in this patient population, including the efficacy and safety. We implanted 37 Pul-Stents in 35 patients between August 2014 and June 2015. The patients’ mean age and weight at stent implantation were 6.7 ± 3.0 years and 20.9 ± 8.7 kg, respectively. Bench testing revealed that axial shortening of the Pul-Stent was minimal with further dilation, and the radial strength did not change. The stents were successfully deployed in all cases, except two with minor malpositioning. Primarily, 8–12 mm mounting balloons were used for the initial implantation, and a long sheath (8–10 F) was used for delivery. After stent implantation, the minimal lumen diameter in the stenosed segment increased by 50% in 97% (34/35) of patients. Furthermore, the pressure gradient across the stenosed segment decreased by 50% in 77% (23/30) of biventricular patients. One stent fracture and one stent restenosis were noted during the follow-up visits (mean follow-up time: 4.6 ± 1.7 years). Eighteen patients (51%) underwent repeat catheterization; ten had successful redilation. No aneurysms or stent fractures were observed. Our initial results indicate that the Pul-Stent is safe and effective in pediatric patients and can be further dilated over time to accommodate somatic growth. Moreover, the Pul-Stent has good compliance and adequate radial strength to treat pulmonary artery stenosis effectively.