Severity of native pulmonary annular hypoplasia and late outcomes of tetralogy of Fallot: retrospective cohort study

OBJECTIVE

Pulmonary annular hypoplasia and valvar dysplasia are key morphological features affecting long-term outcomes of tetralogy of Fallot. This retrospective study aimed to analyse factors affecting contemporary long-term outcomes with a focus on pulmonary annular growth and function over time.

METHODS

131 consecutive isolated tetralogy of Fallot repairs performed between 2004 and 2014 at University Children's Hospital Zurich were included. Median age and weight at the time of repair were 4.8 (interquartile range [IQR] 3.2-6.3) months and 6.1 (IQR 5.1-7) kg, respectively. Based on the severity of native pulmonary annular hypoplasia, the cohort was divided into group 1 (preoperative pulmonary annular Z score < -4; n = 20), group 2 (Z score -2 to -4; n = 56) and group 3 (Z score > -2; n = 54). A transannular patch was used in 88/131 (67.2%) patients: 80%, 67.9% and 61.1% in groups 1, 2 and 3, respectively. The primary outcome was defined as right ventricular outflow tract (RVOT) reoperation or pulmonary valve replacement. Secondary outcome was composite pulmonary valve dysfunction defined as peak gradient >40 mm Hg or severe pulmonary regurgitation at follow-up. A multiple Cox regression model was used to quantify the association of age at tetralogy of Fallot repair, preoperative pulmonary annular Z score and RVOT approach with primary and secondary outcome. Follow-up was 98.5% complete, with a median follow-up duration of 9.6 (95% confidence interval [CI] 9-10.4) years.

RESULTS

All patients were alive at last follow-up resulting in 100% survival. 20/131 patients underwent pulmonary valve replacement (14 surgical and 6 catheter interventional) while 5/131 underwent RVOT reoperations other than valve replacement. The Kaplan-Meier 10-year freedom from primary outcome was 85% (95% CI 78-92%); 69% (46-100%), 91% (82-100%) and 84% (74-95%) for groups 1, 2 and 3, respectively (log rank p = 0.16). Composite dysfunction at follow-up was observed in 29.8% (overall): 45%, 28.6% and 25.9% for groups 1, 2 and 3, respectively (p = 0.12). The multiple Cox regression analysis for primary outcome indicated that the use of a transannular patch results in a Hazard Ratio (HR) of 3.3 (95% CI 0.7-14.7, p = 0.13). Additionally, the presence of composite dysfunction at discharge results in a HR of 2.1 (95% CI 0.8-5.4, p = 0.1). Age (in months) with a HR of 0.8 (95% CI 0.6-1, p = 0.06) and group 2 with a HR of 0.4 (95% CI 0.14-1.2, p = 0.11) showed a trend to being protective for the primary outcome. However, the 95% CI of all estimates included the HR of 1.

CONCLUSIONS

Transannular patch use and composite dysfunction at discharge, although not statistically significant at 5% level, may be associated with pulmonary valve replacement and RVOT reoperation. Avoiding the use of a transannular patch or using reconstructive techniques to achieve a better composite dysfunction at discharge could reduce the primary outcome. Large multicentre studies are needed to demonstrate more precisely the impact of pulmonary annulus Z scores on outcome.

Architecture matters: Tissue preservation strategies for tetralogy of Fallot repair

BACKGROUND

Great variability exists in repair strategies for the tetralogy of Fallot. While transannular patching, as introduced by Kirklin, was a breakthrough for primary repair, pulmonary regurgitation and a need for reoperation have led to the development of methods that preserve the natural morphology of the right ventricular outflow tract.

METHODS

State-of-the-art details of tetralogy of Fallot repair are explained from the standpoint of architectural preservation, especially with regard to sparing native tissue such as the annulus, valve, or infundibulum. Particular attention is given to the latest technical details of each approach, benefits and disadvantages, and any long-term data available.

RESULTS

The choice of procedure is complex and unique to each case as transannular patching alone may carry long-term pulmonary risks. Modifications that spare the annulus, valves, or infundibulum may thus be essential as preservation of natural morphology has resulted in excellent mid-term results.

CONCLUSIONS

The complexity of tetralogy of Fallot repair demands constant attention to clinical presentation and vigilance against long-term sequelae. Techniques will continue to improve over time as long-term data guides the refinement of these innovative surgical methods.

Pulmonary valve annular and right ventricular outflow tract size as predictions values for moderate to severe pulmonary regurgitation after repaired Tetralogy of Fallot

OBJECTIVE

This study sought to investigate the variation of right heart structure pre- and post-operation as risk factors for moderate to severe pulmonary regurgitation (PR) after repaired Tetralogy of Fallot and the best "cutoff" values for the transannular patch (TAP).

METHODS

We collected surgical, echocardiographic, and computed tomographic data of Teralogy of Fallot (TOF) patients over two years and calculated z-score values based on the echocardiographic data. Based on the PR level after follow-up, the patients were divided into two groups, trivial to mild PR and moderate to severe PR. A multivariate logistic regression analysis was performed, and the receiver operating characteristic curve analysis was used to find the best "cutoff" value for risk factors.

RESULTS

A total of 104 TOF patients were included in our cohort study. From the multivariate analysis, correction strategy (P = .002), difference in zRVOT (OR 1.974, 95% CI 1.354 to 2.878, P < .0001), and zPVA (OR 3.605, 95% CI 1.980 to 6.562, P < .0001) were the significant risk factors for moderate to severe PR. The "cutoff" value for the difference in zPVA that could predict moderate to severe PR in the TAP group was 3, and the optimal "cutoff" value for TAP was -1.4.

CONCLUSIONS

The TAP is a risk factor for significant PR after surgery. We recommend the optimal "cutoff" value for TAP is -1.4 calculated using Shan-Shan Wang's data set. During the procedure, to limit the RVOT resection and restrict the enlargement of pulmonary annulus within a variation of z-score as 3 would reduce significant PR.

Bidirectional Glenn for residual outflow obstruction in Tetralogy of Fallot

BACKGROUND

Residual right ventricular outflow obstruction during Tetralogy of Fallot repair necessitates peri-operative revision often requiring trans-annular patch with its negative sequels. Bidirectional Glenn shunt in this setting reduces trans-pulmonary gradient to avoid revision.

METHODS

Bidirectional Glenn shunt was added during Tetralogy repair in patients with significant residual obstruction. A total of 53 patients between January, 2011 and June, 2018 were included. Final follow-up was conducted in July, 2018.

RESULTS

Mean age at operation was 5.63±3.1 years. Right to left ventricular pressure ratio reduced significantly (0.91±0.09 versus 0.68±0.05; p&lt;0.001) after bidirectional Glenn, avoiding revision in all cases. Glenn pressures at ICU admission decreased significantly by the time of ICU discharge (16.7±3.02 versus 13.5±2.19; p&lt;0.001). Pleural drainage ≥ 7 days was seen in 14 (26.4%) patients. No side effects related to bidirectional Glenn-like facial swelling or veno-venous collaterals were noted. Mortality was 3.7%. Discharge echocardiography showed a mean trans-pulmonary gradient of 32.11±5.62 mmHg that decreased significantly to 25.64±5 (p&lt;0.001) at the time of follow-up. Pulmonary insufficiency was none to mild in 45 (88.2%) and moderate in 6 (11.8%). Mean follow-up was 36.12±25.15 months (range 0.5-90). There was no interim intervention or death. At follow-up, all the patients were in NYHA functional class 1 with no increase in severity of pulmonary insufficiency.

CONCLUSION

Supplementary bidirectional Glenn shunt significantly reduced residual right ventricular outflow obstruction during Tetralogy of Fallot repair avoiding revision with satisfactory early and mid-term results.

Right Heart-Pulmonary Circulation Unit in Congenital Heart Diseases

The right ventricle plays a major role in congenital heart disease. This article describes the right ventricular mechanics in some selected congenital heart diseases affecting the right ventricle in different ways: tetralogy of Fallot, Ebstein anomaly, and the systemic right ventricle.