Applicability and Durability of Valve-Sparing Tetralogy of Fallot Repair

Comparing clinical and echocardiographic outcomes following valve-sparing versus transannular patch repair of tetralogy of Fallot: a systematic review and meta-analysis

OBJECTIVES

Transannular patch (TAP) repair of tetralogy of Fallot (ToF)relieves right ventricular tract obstruction but may lead to pulmonary regurgitation. Valve-sparing (VS) procedures can avoid this situation, but there is a potential for residual pulmonary stenosis. Our goal was to evaluate clinical and echocardiographic outcomes of TAP and VS repair for ToF.

METHODS

A systematic search of the PubMed, Embase, Scopus, Cochrane Central Register of Controlled Trials and Web of Science databases was carried out to identify articles comparing conventional TAP repair and VS repair for ToF. Random-effects models were used to perform meta-analyses of the clinical and echocardiographic outcomes.

RESULTS

Forty studies were included in this meta-analysis with data on 11 723 participants (TAP: 6171; VS: 5045). Participants who underwent a VS procedure experienced a significantly lower cardiopulmonary bypass time [mean difference (MD): -14.97; 95% confidence interval (CI): -22.54, -7.41], shorter ventilation duration (MD: -15.33; 95% CI: -30.20, -0.46) and shorter lengths of both intensive care unit (ICU) (MD: -0.67; 95% CI: -1.29, -0.06) and hospital stays (MD: -2.30; 95% CI: [-4.08, -0.52). There was also a lower risk of mortality [risk ratio: 0.40; 95% CI: (0.27, 0.60) and pulmonary regurgitation [risk ratio: 0.35; 95% CI: (0.26, 0.46)] associated with the VS group. Most other clinical and echocardiographic outcomes were comparable in the 2 groups.

CONCLUSIONS

This meta-analysis confirms the well-established increased risk of pulmonary insufficiency following TAP repair while also demonstrating that VS repairs are associated with several improved clinical outcomes. Continued research can identify the criteria for adopting a VS approach as opposed to a traditional TAP repair.

The American Association for Thoracic Surgery (AATS) 2022 Expert Consensus Document: Management of infants and neonates with tetralogy of Fallot

OBJECTIVE

Despite decades of experience, aspects of the management of tetralogy of Fallot with pulmonary stenosis (TOF) remain controversial. Practitioners must consider newer, evolving treatment strategies with limited data to guide decision making. Therefore, the TOF Clinical Practice Standards Committee was commissioned by the American Association for Thoracic Surgery to provide a framework on this topic, focused on timing and types of interventions, management of high-risk patients, technical considerations during interventions, and best practices for assessment of outcomes of the interventions. In addition, the group was tasked with identifying pertinent research questions for future investigations. It is recognized that variability in institutional experience could influence the application of this framework to clinical practice.

METHODS

The TOF Clinical Practice Standards Committee is a multinational, multidisciplinary group of cardiologists and surgeons with expertise in TOF. With the assistance of a medical librarian, a citation search in PubMed, Embase, Scopus, and Web of Science was performed using key words related to TOF and its management; the search was restricted to the English language and the year 2000 or later. Articles pertaining to pulmonary atresia, absent pulmonary valve, atrioventricular septal defects, and adult patients with TOF were excluded, as well as nonprimary sources such as review articles. This yielded nearly 20,000 results, of which 163 were included. Greater consideration was given to more recent studies, larger studies, and those using comparison groups with randomization or propensity score matching. Expert consensus statements with class of recommendation and level of evidence were developed using a modified Delphi method, requiring 80% of the member votes with 75% agreement on each statement.

RESULTS

In asymptomatic infants, complete surgical correction between age 3 and 6 months is reasonable to reduce the length of stay, rate of adverse events, and need for a transannular patch. In the majority of symptomatic neonates, both palliation and primary complete surgical correction are useful treatment options. It is reasonable to consider those with low birth weight or prematurity, small or discontinuous pulmonary arteries, chromosomal anomalies, other congenital anomalies, or other comorbidities such as intracranial hemorrhage, sepsis, or other end-organ compromise as high-risk patients. In these high-risk patients, palliation may be preferred; and, in patients with amenable anatomy, catheter-based procedures may prove favorable over surgical palliation.

CONCLUSIONS

Ongoing research will provide further insight into the role of catheter-based interventions. For complete surgical correction, both transatrial and transventricular approaches are effective; however, the smallest possible ventriculotomy should be utilized. When possible, the pulmonary valve should be spared; and if unsalvageable, reconstruction can be considered. At the conclusion of the operation, adequate relief of the right ventricular outflow obstruction should be confirmed, and identification of a significant fixed anatomical obstruction should prompt further intervention. Given our current knowledge and the gaps identified, we propose several key questions to be answered by future research and potentially by a TOF registry: When to palliate or proceed with complete surgical correction, as well as the ideal type of palliation; the optimal surgical approach for complete repair for the best long-term preservation of right ventricular function; and the utility, efficacy, and durability of various pulmonary valve preservation and reconstruction techniques.

Fate of the Right Ventricular Outflow Tract Following Valve-Sparing Repair of Tetralogy of Fallot

Valve-sparing repair (VSR) of tetralogy of Fallot (TOF) tends to result in higher residual right ventricular outflow tract (RVOT) gradients. We evaluated the progression and clinical implications of RVOT gradients following VSR of TOF. Demographic, clinical, and operative data were retrospectively collected from consecutive TOF patients who underwent VSR at our institution between 01/2010 and 06/2021. RVOT gradient, pulmonary valve annulus (PVA) diameter and Boston Z-scores were recorded from serial echocardiograms. Data are presented as median and interquartile range or number and percentage. A total of 156 children (boys 92, 59%) underwent VSR at 6.5 (4.9-8.4) months of age and 6.6 kg (5.6- 7.7) weight. There was 1 (0.6%) operative mortality. The remaining 155 patients were followed for 69.4 months (4-106.2). RVOT gradient was 2.4m/s (1.7-2.9) at discharge. It transiently increased, then declined and stabilized during follow-up. PVA Z-score was -1.7 (-3.1 to 0.5) at discharge and 'grew' to -0.8 (-1.7 to 0.4) at last follow-up. Freedom from RVOT re-intervention was 97%, 94% and 91% at 1, 5 and 10-year follow-up. Among 67 (43%) patients with PVA Z-score < -2, a similar RVOT gradient pattern was observed and freedom from RVOT re-intervention was 97%, 95% and 95% at 1, 5 and 8-year follow-up. Following VSR of TOF, RVOT gradients transiently increase and then fall as PVA growth catches up, resulting in durable intermediate outcomes. Patients with PVA Z-score < -2 demonstrated a similar pattern of hemodynamics in the RVOT and excellent freedom from reintervention.

Preserving the pulmonary valve in Tetralogy of Fallot repair: Reconsidering the indication for valve-sparing

BACKGROUND

Tetralogy of Fallot (TOF) repair is a frequent procedure, and although valve-sparing (VS) repair is preferred, determining which patients can successfully undergo this operation remains controversial. We sought to identify parameters to determine a selective, accurate indication for VS repair.

METHODS

We reviewed 71 patients (82%) undergoing VS repair. We analyzed hemodynamic data, intraoperative reports, and follow-up echocardiography results to identify acceptable indications. Patients requiring pulmonary valve (PV) reintervention versus no reintervention were compared.

RESULTS

PV annulus size at repair was z-score of -2.0 (-5.3, 1.3). Approximately half (51%) had a z-score less than -2. Cox regression results showed this was not a risk factor for reintervention (p = .59). Overall, 1-, 3-, 5-, and 10-year freedom from PV reintervention rates were 95.8%, 92.8%, 91% and 77.8%, respectively. Residual pulmonary stenosis (PS) at initial repair was relatively higher in the reintervention group compared with no reintervention group (40 [28, 51] mmHg vs. 30 [22, 37] mmHg; p = .08). For patients with residual PS, pressure gradient (PG) was consistent over time across both groups (PV reintervention: -3 [-15, 8] mmHg vs. no reintervention: 0 [-9, 8] mmHg). The risk of PV reintervention is 3.7-fold higher when the PG from intraoperative TEE is greater than 45 mmHg (p = .04).

CONCLUSIONS

Our review of the midterm outcomes of expanded indication for VS suggests intraoperative decision to convert to transannular patch is warranted if intraoperative postprocedure TEE PG is greater than 45 mmHg or RV pressure is higher than half of systemic pressure to prevent reintervention.