Guidance
2 The procedure
2 The procedure
2.1 Indications
2.1.1 Radiofrequency valvotomy is used to treat pulmonary atresia, a congenital malformation of the pulmonary valve in which the valve orifice fails to develop. The valve is completely closed, thereby obstructing the outflow of blood from the heart to the lungs. Babies with this type of cyanotic congenital heart disease survive only for the first few days of life. During those first few days, if there is no operation to open the pulmonary valve or to make a shunt between the aorta and the pulmonary arteries, the condition is fatal.
2.1.2 The standard treatment for pulmonary atresia is open heart surgery that includes the Fontan procedure (the surgical creation of a right ventricular bypass by directly connecting either the right atrium or the superior or inferior vena cava with the pulmonary artery) and the Blalock-Taussig shunt (a palliative procedure in which a shunt is created to allow blood to pass from the aorta to the pulmonary artery by dividing the left subclavian artery and connecting it to the left pulmonary artery). Further open heart surgery may include open surgical valvotomy.
2.2 Outline of the procedure
2.2.1 Radiofrequency valvotomy is a minimally invasive cardiac catheterisation procedure that involves creating an opening in the blocked pulmonary valve followed by dilatation using balloon angioplasty. It avoids the need for open surgery but some children will later need a permanent shunt procedure or surgical relief of pulmonary valve obstruction.
2.3 Efficacy
2.3.1 The evidence was limited to one small nonrandomised comparative study and four small uncontrolled studies. The success rate of the procedure varied between 75% (9/12) and 93% (14/15). The proportion of patients with establishment of a biventricular circulation was reported in four studies. In the comparative study, 63% (12/19) of patients had a biventricular circulation established after radiofrequency valvotomy, compared with 50% (7/14) after surgical valvotomy. In the other three studies, a biventricular circulation was established in between 42% (5/12) and 53% (16/30) of patients. For more details, refer to the Sources of evidence section.
2.3.2 One Specialist Advisor commented that proper patient selection was important in order to achieve good clinical outcomes.
2.4 Safety
2.4.1 In the comparative study, the mortality rate for patients who underwent radiofrequency valvotomy was 16% (3/19), compared with 29% (4/14) for patients who underwent surgical valvotomy. The largest non-comparative study (of 30 patients) reported three postoperative deaths and two late deaths. Other complications reported in the studies included perforation of the pulmonary artery in between 3% (1/30) and 33% (4/12) of patients, and perforation of the right ventricular outflow tract in 17% (3/18) of patients. For more details, refer to the Sources of evidence section.
2.4.2 The Specialist Advisors considered the main risks of the procedure to be death, perforation of the heart, cardiac tamponade, cardiac or pulmonary artery perforation/rupture, arrhythmias, infection and multiple organ failure.