Stent treatment of ostial branch pulmonary artery stenosis: initial and medium-term outcomes and technical considerations to avoid and minimise stent malposition.

OBJECTIVE: Stenting of ostial pulmonary artery stenosis presents several unique challenges. These include difficulty in defining anatomy and need for precise stent placement in order to avoid missing the ostial stenosis or jailing either the contralateral branch pulmonary artery or the ipsilateral upper lobe branch. DESIGN: A retrospective review of outcomes was conducted in 1.5 or 2-ventricle patients who underwent stent placement for ostial branch pulmonary artery stenosis. Specific catheterisation lab techniques were reviewed. RESULTS: Forty-seven branch pulmonary arteries underwent stent placement for ostial stenosis in 43 patients. The median age and weight were 3.7 (0.3-18.1) years and 14.2 (5.6-70.0) kg, respectively. Three (2-8) angiographic projections were needed to profile the ostial stenosis. Open-cell stents were used in 23 and stents were modified in 5 cases. Following stent implantation, the minimum diameter improved from 3.6 (0.8-10.5) to 8.1 (4.2-16.5) mm (p < 0.001). The gradient improved from 21 (0-66) to 4 (0-27) mmHg (p < 0.001). Stent malposition occurred in eight (17%) of the stents placed. Five migrated distally causing suboptimal ostial coverage necessitating placement of a second stent in four. Three migrated proximally and partially jailed the contralateral pulmonary artery. Intentional jailing of the upper lobe branch occurred in four additional cases. At a follow-up of 2.4 (0.3-4.9) years, 15 stents underwent further dilation and 1 had a second stent placed within the exiting stent. CONCLUSION: Ostial branch pulmonary artery stenosis may require additional angiography to accurately define the ostial stenosis. Treatment with stents is effective but carries high rates of stent malposition.