Patterns of late diameter change after balloon angioplasty of branch pulmonary artery stenosis: Evidence for vascular remodeling

Angiographic diameters of 36 pulmonary artery stenoses (26 patients; median age, 3.3 years) before and after balloon angioplasty and at repeat angiography after 2-64 months were compared to diameters of 31 untreated pulmonary artery stenoses (20 patients) at a median age of 3.6 years and after 4-76 months. In the treatment group, an acute diameter gain of >50% was achieved in 58%. On follow-up, 16 lesions remained unchanged, 6 lesions had >20% late loss, and 12 lesions had >20% late gain. The three patterns of vascular response were confirmed when compared to the control group. In the late gain group, overall diameter increase was 125% compared to 41% initial increase. The net result was a long-term success rate of 57%. Patterns of late diameter change appear to suggest vascular remodeling after balloon angioplasty of pulmonary arteries.