Optimal Pulmonary Valve Annulus Diameter for Annulus Preservation in Tetralogy of Fallot May Be Far Smaller Than Normal Annulus Size

Abstract

We hypothesized that optimal pulmonary valve annulus (PVA) diameter upon annulus preservation (AP) in tetralogy of Fallot (ToF) may be far smaller than the normal diameter. Retrospective review of the 61 consecutive patients who underwent ToF repair between January 2016 and September 2017 was performed. Median age, body weight, and median PVA (Z) at repair were 166 days (interquartile range, IQR, 141-182 days), 7.4 kg (IQR, 6.6-8.0 kg), and -1.83 (IQR, -2.56 to -0.90), respectively. Upon AP, subvalvar and supravalvar obstructions were completely eliminated, leaving a pressure gradient only at the valve level. AP was achieved in 58 patients (95.1%). Pulmonary valve intervention comprised commissurotomy in 35 patients, commissurotomy with bougination in 8 patients, and transannular patching in 3 patients. For 15 patients, the pulmonary valve was left intact. Median PVA diameter measured by Hegar dilator after PV intervention was 8 mm (IQR, 7-9 mm), which was 3.9 mm (IQR, 2.3-4.3 mm) smaller than normal dimension and translated to a PVA (Z) of -1.85 (IQR, -2.40 to -0.78). Postrepair right and left ventricular pressure ratio was 0.47 ± 0.12. During the median follow-up duration of 353 days (IQR, 191-482 days), 4 patients (including 3 who underwent transannular patching) developed significant pulmonary regurgitation. Freedom from reintervention for PS, significant PS, and PR at 1 year was 92.4%, 83.2%, and 90.6%, respectively. Optimal PVA for AP may be far smaller than the normal diameter. Minimizing PV intervention upon AP can prevent superfluous postoperative PR.

Keywords: Annulus preservation; Pulmonary valve annulus; Tetralogy of Fallot; Transannular patching.