Long-term evolution of stents implanted in branch pulmonary arteries

Abstract

Background: Branch pulmonary artery stenosis complicates the management of congenital heart diseases. Surgical branch pulmonary artery angioplasty is associated with a high reintervention rate. As an alternative, percutaneous or intraoperative branch pulmonary artery stents have been implanted to improve efficiency, but long-term evaluations are limited.

Aim: To describe the long-term evolution of branch pulmonary artery stents.

Methods: We conducted a retrospective cohort study at Tours University Hospital. All stents implanted by surgery or catheterization in branch pulmonary arteries with a minimum follow-up of 12 months and at least one catheterization control were included. The primary endpoint combined cardiovascular mortality, surgical or percutaneous reintervention for stent complication or new stent implantation.

Results: Between 2007 and 2017, 76 stents in 51 patients were included (62 stents implanted by surgery, 14 by catheterization). At implantation, the patients' mean age and weight were 4.7years (interquartile range 4.2years) and 17.3kg (interquartile range 11.0kg), respectively. Mean branch pulmonary artery minimum diameter was 4.1±2.1mm (mean Z-score-4.9±2.9), and mean initial stent diameter was 9.1±3.1mm. During a follow-up of 5.3years (range 0-11.2 years), freedom from primary endpoint was 86.8% (95% confidence interval 79.6-94.8%) at 1 year, 71.5% (95% confidence interval 61.9-82.7%) at 5years and 69.6% (95% confidence interval 59.6-81.2%) at 10 years. We did not identify any factors associated with major adverse cardiovascular events. Among stents without major adverse cardiovascular events, the mean branch pulmonary artery diameter Z-score at last evaluation had increased by +4.8±3.2 compared with the initial diameter (P<0.001). After stent implantation, a median of 2 re-expansions were performed for each stent (range 0-7).

Conclusions: Stent implantation should offer a good long-term solution for branch pulmonary artery stenosis, although iterative re-expansions are required.

Keywords: Cardiac catheterization; Cardiac surgical procedures; Cathétérisme cardiaque; Congenital heart defects; Interventions chirurgicales cardiaques; Malformations cardiaques congénitales; Pulmonary artery stenosis; Stents; Sténose artère pulmonaire.