Timing and type of surgery for severe pulmonary regurgitation after repair of tetralogy of Fallot

Abstract

Repaired tetralogy of Fallot (rTOF) has an excellent long-term prognosis; however, survival is somewhat less than normal. Of all the residual lesions and sequellae after rTOF, pulmonary regurgitation (PR) is the most important, correlating with right ventricular (RV) size, exercise intolerance and serious ventricular arrhythmias. Pulmonary valve replacement (PVR) has beneficial effects on RV size and function, provided it is performed early, before irreversible RV dysfunction ensues. Moreover, PVR is associated with an improvement in patients' symptoms and exercise tolerance and combined with arrhythmia surgery (cryoablation) it leads to a dramatic decrease in the incidence of fatal ventricular arrhythmias. Associated lesions, especially branch pulmonary artery stenosis, which aggravates PR, and tricuspid regurgitation, which further impacts on RV size and function, need addressing. Large right ventricular outflow (RVOT) akinetic and aneurysmal regions are frequent and further compromise RV function; therefore, resection during PVR should be attempted. Despite excellent mid-term results, homografts and xenografts, usually used for RVOT reconstruction, suffer late dysfunction and failure, committing patients and surgeons to further operations. Therefore, the decision to operate should be based on the balance between progressive RV dilatation, exercise intolerance, symptoms, arrhythmias and the fact that further reoperations will be needed. Research on the ideal valve for RVOT reconstruction is ongoing. Prospective follow-up of patients with rTOF with exercise testing and assessment of RV size and function, preferably with magnetic resonance, will define better the natural history of the disease and will probably provide firm guidelines for PVR timing especially in asymptomatic patients.