Medium and long-term follow-up of the Pul-Stent in treating postoperative branch pulmonary artery stenosis in children with congenital heart disease / 中华儿科杂志

ABSTRACT

Objective: To evaluate the effectiveness and safety of Pul-Stent as the treatment of postoperative branch pulmonary artery stenosis in children with congenital heart disease. Methods: This was a retrospective study. Thirty-three patients who underwent Pul-Stent implantation in Shanghai Children's Medical Center due to postoperative residual pulmonary artery stenosis from August 2014 to June 2015 were included. The immediate curative effect, follow-up and complications of Pul-Stent implantation were assessed. Comparisons between groups were performed with unpaired Student t test. Results: Pul-Stent implantation of 33 patients (19 males and 14 females) were performed successfully. Thirty-one patients underwent percutaneous stenting, and 2 patients underwent hybrid stenting. A total of 35 Pul-Stents were implanted (19 of model small, 15 of model medium and one of model large), 23 stents were planted in the proximal left pulmonary artery and 12 stents were in the proximal right pulmonary artery. The initial diameter of dilation balloon ranged from 6 to 16 mm, and the long sheath of percutaneous implantation ranged from 8 to 10 F in 29 patients (29/31, 94%). After stenting, the diameter of the narrowest segment of pulmonary artery increased from (4.0±1.7) mm to (9.1±2.1) mm in all patients (t=-21.60, P<0.001). The pressure gradient at the stenosis in 26 patients after biventricular correction decreased from (30.5±12.3) mmHg (1 mmHg=0.133 kPa) to (9.9±9.6) mmHg (t=12.92, P<0.001), and the right ventricular to aortic pressure ratio decreased from 0.57±0.14 to 0.44±0.12 (t=7.44, P<0.001). The pressure of the superior vena cava after stenting in 5 patients after cavopulmonary anastomosis decreased from (17.0±1.9) mmHg to (14.0±0.7) mmHg (t=2.86, P=0.046). Two patients died during reoperation for repairing other cardiac malformations. The remaining 31 patients were clinically stable during the follow-up period of (5.3±1.6) years, and one stent fracture was found on chest X-ray. Cardiac catheterization reexaminations in 16 patients showed that restenosis was found in one stent, while stent position and patency were satisfactory in the remaining stents. Nine children underwent post-dilation without stent fracture, displacement or aneurysm formation. Cardiac tomography showed no stent stenosis, fracture observed, or significant change in diameter of the stent in 8 patients. The inner diameter and pulmonary blood perfusion could not be accurately evaluated due to artifacts by cardiac magnetic resonance imaging in 4 patients. Conclusions: Pul-Stent has good compliance and adequate radial strength, and can dilate further over time to accommodate for somatic growth. It performs safely and effectively in treating post-operative branch pulmonary artery stenosis in children.