Optimal size of transannular patches for tetralogy of Fallot repair

Purpose: Pulmonary regurgitation (PR) is a prevailing phenomenon subsequent to transannular patch repair (TAP) for tetralogy of Fallot in small pulmonary valve annulus (PVA). Nevertheless, it has been observed that certain patients present merely trivial or mild PR in the long-term. The aim is to investigate factors influencing PR after TAP.

Methods: One hundred forty-three patients underwent staged or primary intracardiac repairs (ICR) for tetralogy of Fallot/double outlet right ventricle (TOF/DORV) with pulmonary stenosis (PS) at three institutions from 2005 to 2023. Among them, 83 patients (83/143, 58.1%) who underwent TAP repair for TOF/DORV PS were enrolled. The transannular patch (TAP) repair was performed with ePTFE monocusp for right ventricular outflow tract (RVOT) reconstruction. The size of reconstructed PVA was calculated as (width of transannular patch [mm] + measured native PV annulus [mm] *3.14)/3.14. PVA Z scores were calculated based on the patients’ body surface area (BSA). Ventricular septal defect index (VSD) and RVOT index were calculated as the size of VSD or RVOT divided by BSA. Significant PR after ICR was defined as PR ≧moderate on the echocardiography. Cox proportional hazard analysis was performed to determine the factors influencing emergence of significant PR after ICR.

Results: There were no early and late deaths after ICRs. The median age of ICR was 232 days (IQR: 152-411), and that of body weight at ICR was 7.3 kg (IQR: 6.4-8.4). Fifty-three (63.9%) patients were symptomatic preoperatively. Significant PR after ICR was observed 46.5% of patients at 10-year after TAP repair (Figure A). The median of preoperative native PVA Z score was -3.01 (IQR: -4.65- -2.06), and that of reconstructed PVA Z score was 0.60 (IQR: -0.28 – 1.65). The median width of TAP with monocusp to reconstruct RVOT was 13.5mm (IQR: 13.5-15.0). The patients with reconstructed PVA Z score increased +5 from preoperative native PVA Z score had significantly lower event free ratio of PR (57.2% vs 45.2% at 10 years after TAP, P=0.004) (Figure B). Multivariate Cox proportional hazard analysis revealed that wider TAP (reconstructed PVA Z scores increased by 5 from preoperative values) and pulmonary artery coarctation were identified as risk factors for progressive PR after ICR (Table).

Conclusion: Wider TAPs and pulmonary artery coarctation were significant risk factors for progressive PR in the long-term follow up. Patients with reconstructed PVA Z scores increased by +5 from preoperative values exhibited worse event-free ratios of PR.

Identify the source of the funding for this research project: none