What is Pulmonary Artery Banding ?
Banding of pulmonary trunk is done to reduce pulmonary flow in a baby. It is seldom done for isolated ventricular septa] defect. Multiple muscular ventricular septal defects (Swiss cheese defects) are difficult to close in infancy and so pulmonary artery banding may treat them. It is also the procedure of choice for tricuspid atresia with VSD and other types of univentricular hearts without
pulmonary stenosis. Pulmonary artery banding is done with a view to Fonton type of correction at a later stage.
Technique : The operation may be performed through a small left anterolliteral thoracotomy or median sternotomy. The latter approach is preferable. Pericardium opened and aorta and pulmonary trunk are dissected and a right-angled clamp passed around it. A 3 to 4 mm wide polyester tape impregnated with silicon is used for banding. The tightness of band depends on the circumference of the band applied. According to Trusler's formula, the circumferential length of the band is 20 mm + weight of the baby in kilograms (taken as millimetres). For a complex cardiac anomaly like univentricular heart the measurement is 24mm + weight of the baby in Kg (taken as millimetres). While tightening the band, aortic pressure and left pulmonary artery pressures are monitored. Properly banded, the pulmonary artery pressure should fall to less than 50 per cent of aortic pressure. Systemic arterial oxygen saturation (SAO,) should be maintained at 80-85 percent. Haemoclips are applied to tighten the band to the correct level. Haemoclips are useful as they can be removed and re-applied at the desired levels. After banding, the band is anchored at two places by prolene sutures to the adventitia of the pulmonary artery.