Pulmonary artery stents in the recent era: Immediate and intermediate follow-up

Background: Long-term follow-up after stent dilation of native and acquired pulmonary artery stenosis is scarce in the pediatric population. Most cohorts include a myriad of anatomies and associated conditions.

Method: In order to establish objective performance criteria, we performed a retrospective review of all patients who underwent unilateral pulmonary artery stenting in biventricular physiology at three centers from June 2006 to June 2011.

Results: Fifty-eight patients received 60 stents with Palmaz Genesis stent used most commonly (78%). Average age at implantation was 10.4 ± 10.3 years and weight 31.6 ± 21.8 kg. The immediate success rate was 98%, with improvement in minimal diameter from 5.1 ± 2 cm to 10.6 ± 3 cm (P < 0.01). There were 10 complications (7 major and 3 minor) and no acute mortality. One-year follow-up studies were available in 48 patients (83%), including echocardiogram (60%), catheterization (28%), MRI (29%), and lung perfusion (31%). Follow-up echocardiogram showed mild increase in stent gradient, from 5.7 ± 6.7 mm Hg post-procedure to 17.1 ± 11.7 mm Hg. Follow-up catheterization showed no significant change in minimal stent diameter (8.8 ± 2.6 to 7.8 ± 2.3 mm), gradient (7.7 ± 8.4 to 12.6 ± 12.2 mm Hg), or right ventricular pressures (43.7 ± 9 to 47.7 ± 10.5 mm Hg). Nine patients (16%) underwent scheduled stent redilation over a period of 12 days to 25 months.

Conclusion: In conclusion, stent implantation shows excellent immediate and 1-year follow-up results with maintenance of improved caliber of the stented vessel and lowered right ventricular systolic pressures.