Pulmonary Valve-Sparing Techniques for Tetralogy of Fallot: A Systematic Approach for Maximizing Success and Minimizing Risk

Optimal Surgical Management of Tetralogy of Fallot

Tetralogy of Fallot with pulmonary stenosis has a diverse clinical spectrum with the degree of right ventricular outflow tract obstruction (RVOTO) and size of the branch pulmonary arteries driving clinical management. Optimal surgical management involves consideration of patient clinical status and degree and location (subvalvar, valvar, and supravalvar) of RVOTO. Timing of repair requires multidisciplinary decision-making and complete surgical repair with relief of RVOTO by either transannular patch or valve sparing repair techniques. The central goals of contemporary surgical management of tetralogy of Fallot incorporate maximizing survival, minimizing reintervention, and preserving right ventricular function across the lifespan.

Pulmonary valve preservation during tetralogy of Fallot repair: midterm functional outcomes and risk factors for pulmonary regurgitation

OBJECTIVES

Many centres have recently adopted pulmonary valve (PV) preservation (PVP) during tetralogy of Fallot (ToF) repair. We sought to identify the midterm functional outcomes and risk factors for pulmonary regurgitation after this procedure.

METHODS

All patients undergoing PVP during transatrial-transpulmonary repair for ToF with PV stenosis at our institution between January 2007 and December 2020 were reviewed.

RESULTS

Overall, 73 patients were included. At the index surgery, the body surface area was 0.31 ± 0.04 m2, the age was 4.9 ± 2.9 months and the preoperative PV z-score was -3.02 ± 1.11. At a mean follow-up of 5.3 ± 2.7 years, the fractional area change of the right ventricle (RV) was 47.1 ± 5.2%, and the tricuspid annular plane systolic excursion z-score was -3.31 ± 1.89%. The 5-year freedom from moderate/severe PV regurgitation was 61.3% [95% confidence interval (CI): 48, 73%]. There was a significant correlation between RV function and moderate/severe PR at follow-up (R2: 0.08; P = 0.03). A comparison with a group of patients undergoing a transannular patch procedure (N = 33) showed superior outcomes for patients with PVP. The preoperative PV z-score and the degree of PR at discharge were risk factors for the early development of moderate/severe PR at follow-up [hazard ratio (HR): 0.64; 95% CI: 0.48, 0.86, P = 0.01 and HR: 2.31; 95% CI: 1.00, 5.36, P = 0.04, respectively]. A preoperative PV annulus z-score ≤ -2.85 was found to be predictive for moderate/severe PR at 5 years after PVP (HR: 2.56; 95% CI: 1.31, 5.01, P = 0.002).

CONCLUSIONS

A pulmonary valve preservation strategy during tetralogy of Fallot repair should always be attempted. However, a preoperative PV annulus z-score < -2.85 and moderate/severe regurgitation upon discharge are risk factors for midterm pulmonary regurgitation.

Comparison of Long-term Outcomes of Valve-Sparing and Transannular Patch Procedures for Correction of Tetralogy of Fallot

IMPORTANCE

The choice of the right surgical technique for correction of tetralogy of Fallot (TOF) is contentious for patients with a moderate to severe right outflow tract obstruction. The use of a transannular patch (TAP) exposes patients to chronic pulmonary regurgitation, while valve-sparing (VS) procedures may incompletely relieve pulmonary obstruction.

OBJECTIVE

To compare 30-year outcomes of TOF repair after a VS procedure vs TAP.

DESIGN, SETTING, AND PARTICIPANTS

This retrospective population-based cohort study was conducted among all patients with TOF born in the province of Quebec, Canada, from 1980 to 2015 who underwent complete surgical repair. Patients who received a TAP or VS procedure were matched using a propensity score based on preoperative factors in a 1:1 ratio. Data were analyzed from March 2020 through April 2021.

EXPOSURES

The study groups were individuals who received TAP and those who received VS. The VS group was further stratified by the presence of residual pulmonary stenosis.

MAIN OUTCOMES AND MEASURES

The primary outcome was all-cause mortality, with 30-year survival evaluated using Cox proportional-hazards models. Secondary outcomes included the cumulative mean number of cardiovascular interventions, pulmonary valve replacements (PVRs), and cardiovascular hospitalizations were evaluated using marginal means/rates regressions.

RESULTS

Among 683 patients with TOF (401 patients who underwent TAP [58.7%] and 282 patients who underwent a VS procedure [41.3%]), adequate propensity score matching was achieved for 528 patients (264 patients who underwent a VS procedure and 264 patients who underwent TAP). Among this study cohort, 307 individuals (58.1%) were men. The median (interquartile range [IQR]) follow-up was 16.0 (8.1-25.4) years, for a total of 8881 patient-years, including 63 individuals (11.9%) followed up for more than 30 years. Individuals who received a VS procedure had an increased 30-year survival of 99.1% compared with 90.4% for individuals who received TAP (hazard ratio [HR], 0.09 [95% CI, 0.02-0.41]; P = .002). Patients who underwent TAP had an increased 30-year cumulative mean number of cardiovascular interventions compared with patients who underwent a VS procedure without residual pulmonary stenosis (2.0 interventions [95% CI, 1.5-2.7 interventions] vs 0.7 interventions [95% CI, 0.5-1.1 interventions]; mean ratio [MR], 0.36 [95% CI, 0.25-0.50]; P < .001) and patients who underwent a VS procedure with at least moderate residual stenosis (1.3 interventions [95% CI, 0.9-1.9 interventions]; MR, 0.65 [0.45-0.93]; P = .02). Results were similar for PVR, with a 30-year cumulative mean 0.3 PVRs [95% CI, 0.1-0.7 PVRs] for patients who underwent a VS procedure without residual pulmonary stenosis (MR, 0.22 [95% CI, 0.12-0.43]; P < .001) and 0.6 PVRs (95% CI, 0.2-1.5 PVRs) for patients with at least moderate residual stenosis (MR, 0.44 [95% CI, 0.21-0.93]; P = .03), compared with 1.4 PVRs (95% CI, 0.8-2.5 PVRs) for the TAP group. No statistically significant difference was found for cardiovascular hospitalizations.

CONCLUSIONS AND RELEVANCE

This study found that patients who underwent a VS procedure had increased 30-year survival, fewer cardiovascular reinterventions, and fewer PVRs compared with individuals who underwent TAP, even in the presence of significant residual pulmonary stenosis. These findings suggest that it is beneficial to perform a VS procedure when possible, even in the presence of moderate residual stenosis, compared with the insertion of a TAP.