Impact of stent implantation on pulmonary artery growth.

ABSTRACT

BACKGROUND: Goals of stent implantation (SI) in children with pulmonary artery (PA) stenosis are to relieve obstruction and improve flow to the distal vasculature. We evaluated stent impact on distal PA growth. METHODS: We compared data of children who underwent unilateral SI using the nonstenotic contralateral PA (CPA) as a control (1998-2005; f/u data through 2009). Main/lobar diameters measured at initial and f/u catheterizations were analyzed. RESULTS: For single ventricle (SV) patients (N = 18), the stented PA diameter (SPA D) increased 118%. At initial f/u catheterization (14 ± 9.6 months), both upper lobe (UL) and lower lobe (LL) growth of SPA was comparable to those of the CPA (UL7% vs. 7%; P = 0.97); (LL5% vs. 10%; P = 0.33). Subsequent f/u in 11/18 patients (mean 26 ± 20 months) revealed similar results: both UL and LL growth of SPA were comparable to those of the CPA (UL51% vs. 27%; P = 0.3); (LL18% vs. 21%; P = 0.62). For two-ventricle (2V) patients (N = 21), the SPAD increased 100%. At f/u, UL, and LL growth on SPA was similar to those of the CPA (UL 32% vs. 21%; P = 0.37); (LL 17% vs. 18%; P = 0.88). Subsequent f/u in 10/21 patients (mean 34 ± 14 months) showed UL growth of SPA was significantly greater than that of the CPA (44% vs. 21%; P = 0.05). LL growth of SPA was similar to that of the CPA (19% vs. 14%; P = 0.56). CONCLUSION: SI for PA stenosis is effective in promoting normal lobar growth in SV and 2V patients. Greater lobar growth was seen in 2V compared to SV pts at first f/u. Early, aggressive PA stenting is beneficial in promoting lobar branch growth.