PERCUTANEOUS TREATMENT OF STENOSED MAJOR AORTOPULMONARY COLLATERALS WITH BALLOON DILATATION AND STENTING - WHAT CAN BE ACHIEVED

Background-The natural history major aortopulmonary collateral arterie s (MAPCAs) in patients with pulmonary atresia and ventricular septal d efect (PA-VSD) is frequently complicated by progressive stenosis, lead ing to pulmonary hypoperfusion and debilitating hypoxaemia. Objective- To evaluate balloon dilatation and stenting for relief of stenoses and improvement of pulmonary flow in patients with PA-VSD. Design-Retrosp ective analysis of all patients where dilatation of MAPCA stenoses was attempted. Patients-Twelve patients with stenotic MAPCAs. Interventio ns-Dilatation was attempted in 25 stenoses. Vessels were stented if el astic recoil was noticed (n = 3), in the presence of long segment sten osis (n = 4) or marked tortuosity (n = 1). Main outcome measures-Diame ter of stenoses before and after dilatation as web as arterial oxygen saturation data. Patients proceeding to surgical therapy. Results-Two stenosed MAPCAs could not be crossed by a catheter. Four lesions were non-dilatable despite the use of high inflation pressures (18 atm). Si x stenoses could be completely dilatated using angioplasty only; in fi ve, only partial dilatation was obtained; eight stenoses needed stenti ng. In the group with partial expansion the mean (SD) diameter increas ed from 1.7 (0.8) to 3.5 (1.7) mm (p < 0.05); where full dilatation wa s achieved it increased from 2.1 (0.8) to 4.8 (1.9) mm (p < 0.05); and in the stented group it increased from 2.3 (0.9) to 5.0 (2.5) mm (p < 0.01). Percutaneous arterial oxygen saturation increased from 75(8)% to 82(8)% (p < 0.001). No complications were experienced during the pr ocedures. Repeat dilatation was attempted in six stenoses, but only tw o procedures were successful. There were two episodes of vasospasm and in one an aneurysm had developed after redilatation. Two patients pro ceeded to outflow plasty and two subsequently had a unifocalisation pr ocedure. Conclusions-Pulmonary blood flow can be improved using balloo n angioplasty or stents in patients with stenotic MAPCA; however, 17% of the lesions were not dilatable. Procedures are generally safe, but carry a small risk of vasospasm, dissection, occlusion or aneurysm for mation.