Technical modification enabling pulmonary valve-sparing repair of a severely hypoplastic pulmonary annulus in patients with tetralogy of Fallot†

Although pulmonary valve-sparing repair is preferable for patients with tetralogy of Fallot, the repair of very small pulmonary valves is challenging. The present study evaluates our modification for preserving severely hypoplastic pulmonary valves in patients with tetralogy of Fallot. Sixty-eight consecutive patients who underwent complete repair of a tetralogy of Fallot between 2005 and 2011 were retrospectively reviewed. Patients with pulmonary atresia, absence of a pulmonary valve, atrioventricular septal defect and/or subarterial ventricular septal defect were excluded. There were 19 (28%) patients with a severely hypoplastic pulmonary annulus determined by preoperative echocardiography (z-score <-4). For these patients, we collected echocardiographic data and information about their postoperative course. Valve preserving was successful in 11 of 19 (58%) of the z < -4 group, compared with 48 of 49 (98%) of the z > -4 group. In the z < -4 valve-sparing subgroup (n = 11), the preoperative pulmonary valve diameter z-score was -4.9 (range -6.3 to -4.3), and an approach involving ventriculotomy with no transannular patch was employed at a mean age of 6.9 (range 2.2-16.1) months. In this subgroup, residual right ventricular outflow tract velocity was 2.4 +/- 0.6 m/s at discharge from the hospital. During a mean follow-up of 2.6 +/- 2.4 years, no reintervention was necessary. Late right ventricular outflow tract velocity was 2.2 +/- 0.6 m/s, and there was no severe pulmonary regurgitation. The pulmonary valve annulus grew in relation to the patient's body surface area (z = -0.51, range -4.2-0.24) without any aneurysmal changes in the right ventricular outflow tract. Although our modification of valve-sparing repair for severely hypoplastic pulmonary valves in patients with tetralogy of Fallot could not be applied in all patients, this strategy enabled acceptable growth of the valve annulus, with only mild stenosis during the early to mid-term follow-up. This modification seems to be an option, even for a very small pulmonary valve.