Tetralogy of Fallot: influence of right ventricular outflow tract reconstruction on late outcome

Transannular patch repair of tetralogy of Fallot with or without monocusp valve reconstruction: a meta-analysis

Background

Tetralogy of Fallot (TOF) is one of the most common cyanotic congenital heart diseases. Pulmonary regurgitation is the most common and severe comorbidity after transannular patch (TAP) repair of TOF patients. It has not been confirmed whether a TAP repair with monocusp valve reconstruction would benefit TOF patients in perioperative period compared to those without monocusp valve reconstruction. The purpose of the study is to review and analyze all clinical studies that have compared perioperative outcomes of TOF patients undergoing TAP repair with or without monocusp valve reconstruction and conduct a preferable surgery.

Methods

Eligible studies were identified by searching the electronic databases. The year of publication of studies was restricted from 2000 till present. The primary outcome was perioperative mortality, and secondary outcomes included cardiopulmonary bypass time, aortic cross-clamp time, ventilation duration, ICU length of stay, hospital length of stay, perioperative right ventricular outflow tract (RVOT) pressure gradient, and moderate or severe pulmonary regurgitation (PR). The meta-analysis and forest plots were drawn using Review Manager 5.3. Statistically significant was considered when p-value ≤ 0.05.

Results

Eight studies were included which consisted of 8 retrospective cohort study and 2 randomized controlled trial. The 10 studies formed a pool of 526 TOF patients in total, in which are 300 undergoing TAP repair with monocusp valve reconstruction (monocusp group) compared to 226 undergoing TAP repair without monocusp valve reconstruction (non-monocusp group). It demonstrated no significant differences between two groups in perioperative mortality (OR = 0.69, 95% CI 0.20–2.41, p = 0.58). It demonstrated significant differences in perioperative cardiopulmonary bypass time (minute, 95% CI 17.93–28.42, p < 0.00001), mean length of ICU stay (day, 95% CI − 2.11–0.76, p < 0.0001), and the degree of perioperative PR (OR = 0.03, 95% CI 0.010.12, p < 0.00001). Significant differences were not found in other secondary outcomes.

Conclusion

Transannular patch repair with monocusp valve reconstruction have significant advantages on decreasing length of ICU stay and reducing degree of PR for TOF patients. Large, multicenter, randomized, prospective studies which focuse on perioperative outcomes and postoperative differences based on long-term follow-up between TAP repair with and without monocusp valve reconstruction are needed.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12893-022-01474-6.

CT and MRI for Repaired Complex Adult Congenital Heart Diseases

An increasing number of adult congenital heart disease (ACHD) patients continue to require life-long diagnostic imaging surveillance using cardiac CT and MRI. These patients typically exhibit a large spectrum of unique anatomical and functional changes resulting from either single- or multi-stage palliation and surgical correction. Radiologists involved in the diagnostic task of monitoring treatment effects and detecting potential complications should be familiar with common cardiac CT and MRI findings observed in patients with repaired complex ACHD. This review article highlights the contemporary role of CT and MRI in three commonly encountered repaired ACHD: repaired tetralogy of Fallot, transposition of the great arteries after arterial switch operation, and functional single ventricle after Fontan operation.

Asymptomatic right ventricular dysfunction in surgically repaired adult tetralogy of fallot patients

Background:

Right ventricular (RV) dysfunction after surgical repair of Tetralogy of Fallot (TOF) is often asymptomatic and may be detected by tissue Doppler imaging (TDI). The severity of RV dysfunction is more after intracardiac repair with transannular patch (TAP).

Methods:

One hundred seventy-three adult patients who have undergone surgical repair for TOF were prospectively analyzed for RV function using 2D echocardiography and TDI. RV function was compared between patients who have undergone intracardiac repair with and without TAP.

Results:

In both the patient sub-groups, TDI derived myocardial performance index (MPI) and myocardial velocities were abnormal even when 2D echocardiography derived RV functional area change was normal. TDI derived MPI was significantly higher (0.5 ± 0.1 vs. 0.4 ± 0 P < 0.001) and Systolic tricuspid annular velocity (Sa) (9.2 ± 1.3 vs. 10.8 ± 1.6 P < 0.001) was significantly lower in the TAP group. Older age at surgery and severity of pulmonary regurgitation on follow-up were among the significant predictors of TDI derived MPI.

Conclusions:

Asymptomatic RV dysfunction in surgically repaired adult TOF atients can be detected by TDI. Extent of RV dysfunction was significantly greater with patients requiring TAP, in those operated at older age, and in patients with severe pulmonary regurgitation.

Mutational and functional analysis of the BVES gene coding region in Chinese patients with non-syndromic tetralogy of Fallot

Tetralogy of Fallot (TOF) is a common congenital heart defect (CHD). However, the genetic causes are largely unknown. Blood vessel epicardial substance (BVES) is postulated to play a role in embryonic development, and we previously found that the expression of BVES is upregulation in patients with congenital septal defect and that BVES participates in cardiocyte differentiation. We hypothesized that BVES is a candidate gene of TOF. In the present study, the entire coding sequence and splice junctions of BVES were sequenced in 114 unrelated patients with TOF and 400 unrelated healthy individuals used as controls. The functional effects of the exon mutant BVES were characterized in contrast to its wild-type counterpart using a luciferase reporter assay system. Four novel BVES mutations (c.166T>C, c.909C>T, c.540-80C>T, c.958+30A>G) were identified in patients with TOF but not in the 400 controls. Functional analysis indicated that the c.166T>C mutation of BVES was associated with an increased transcriptional activity. This finding suggests that BVES as a novel TOF gene may provide further insight into the molecular mechanisms involved in TOF.

Early outcome of tetralogy of Fallot repair in the current era of management

BACKGROUND

Traditional use of trans-annular patch (TAP) to release right ventricular outflow tract (RVOT) obstruction during tetralogy of Fallot (TOF) repair may lead to a harmful pulmonary regurgitation. Different approaches have been used to release RVOT obstruction and spare the pulmonary valve (PV) function. In this study, we aim to evaluate the post-operative course of patients who had TOF repair in the current era that emphasizes on protective strategy of releasing RVOT obstruction and preserving PV function.

METHODS

A retrospective study of all TOF cases repaired in our institute between March 2002 and December 2007 was conducted. Cases were classified into two groups; group I included patients that had a TAP, while group II included cases that had simple TOF repair without TAP. Group I was subdivided into two groups, group (A) which include patients who had TAP without a valve. Group (B) includes those who had TAP with a monocuspid valve (Contegra). We compared post-operative care and outcome of all groups.

RESULTS

Eighty-three patients fulfilled the study criteria. There were 64 cases (77%) in group I, and 19 cases (23%) in group II. All children tolerated surgical repair and did well. We observed no statistically significant difference in the post-operative ICU care, complications rates and morbidity between all groups. There was no surgical mortality in all groups.

CONCLUSION

Children undergoing TOF repair had excellent short-term outcome with the current protective strategy aiming to spare valvular function, and conserving myocardial function. Applying a monocuspid patch technique did not show clear short-term benefits. Long term follow up is needed to evaluate future difference in different techniques.

Right ventricular peak systolic longitudinal strain is a sensitive marker for right ventricular deterioration in adult patients with tetralogy of Fallot

The aim of this study was to evaluate the feasibility of right ventricular (RV) longitudinal peak systolic strain (LPSS) assessment for the follow-up of adult patients with corrected tetralogy of Fallot (TOF). Adult patients (n = 18) with corrected TOF underwent echocardiography and CMR twice with a time interval of 4.2 ± 1.7 years. RV performance was derived from CMR, and included RV volumes and ejection fraction (EF). LPSS was calculated globally (GLPSS) and in the RV free wall (LPSS FW), with echocardiographic speckle-tracking strain-analysis. Baseline (G)LPSS values were compared between patients and healthy controls; the relation between (G)LPSS and CMR parameters was evaluated and the changes in (G)LPSS and CMR parameters during follow-up were compared. GLPSS and LPSS FW were significantly reduced in patients as compared to controls (−14.9 ± 0.7% vs. −21.6 ± 0.9% and −15.5 ± 0.9% vs. −22.7 ± 1.5%, P < 0.01). Moderate agreement between LPSS and CMR parameters was observed. RV EF remained unchanged during follow-up, whereas GLPSS and LPSS FW demonstrated a significant reduction. RVEF showed a 1% increase, whereas GLPSS decreased by 14%, and LPSS FW by 27%. RV LPSS is reduced in TOF patients as compared to controls; during follow-up RV EF remained unchanged whereas LPSS decreased suggesting that RV LPSS may be a sensitive marker to detect early deterioration in RV performance.

The current strategy of repair of tetralogy of Fallot in children and adults

OBJECTIVES

The strategies of repair of tetralogy of Fallot change with the age of patients. In children older than 4 years and adults, the optimal strategy may be to use different method of reconstruction of the right ventricular outflow tract from those followed in younger children, so as to avoid, or reduce, the pulmonary insufficiency that is increasingly known to compromise right ventricular function.

METHODS

From April, 2001, through May, 2008, we undertook complete repair in 312 patients, 180 male and 132 female, with a mean age of 11.3 years +/-0.4 years, and a range from 4 to 48 years, with typical clinical and morphological features of tetralogy of Fallot, including 42 patients with the ventriculo-arterial connection of double outlet right ventricle. The operation was performed under moderate hypothermia using blood cardioplegia. The ventricular septal defect was closed with a Dacron patch. When it was considered necessary to resect the musculature within the right ventricular outflow tract, or perform pulmonary valvotomy, we sought to preserve the function of the pulmonary valve by protecting as far as possible the native leaflets, or creating a folded monocusp of autologous pericardium.

RESULTS

The repair was achieved completely through right atrium in 192, through the right ventricular outflow tract in 83, and through the right atrium, the outflow tract, and the pulmonary trunk in 36 patients. A transjunctional patch was inserted in 169 patients, non-valved in all but 9. There were no differences regarding the periods of aortic cross-clamping or cardiopulmonary bypass. Of the patients, 5 died (1.6%), with no influence noted for the transjunctional patch. Of those having a non-valved patch inserted, three-tenths had pulmonary regurgitation of various degree, while those having a valved patch had minimal pulmonary insufficiency and good right ventricular function postoperatively, this being maintained after follow-up of 8 to 24-months.

CONCLUSIONS

Based on our experience, we suggest that the current strategy of repair of tetralogy of Fallot in older children and adults should be based on minimizing the insertion of transjunctional patches, this being indicated only in those with very small ventriculo-pulmonary junctions. If such a patch is necessary, then steps should be taken to preserve the function of the pulmonary valve.

Mutation analysis of the Vangl2 coding region revealed no common cause for Tetralogy of Fallot

Vangl2 (Van Gogh-like 2) protein acts via non-canonical Wnt signalling to regulate polarized cell movements during development of the proximal outflow tract in vertebrate embryos. Recently, it has been shown that mutations of the Vangl2 gene cause aortic arch defects that are characteristic of the loop-tail (Lp) mouse and they have also became a strong candidate for causing congenital outflow tract defects in humans. Thus, in this study Tetralogy of Fallot (ToF), which comprises a group of syndromes that constitutes the most frequent cause of congenital cardiac outflow abnormalities in humans, was analysed for mutations within all coding regions of the Vangl2 gene. Based on direct sequencing data from a combination of 20 patients with ToF and 22 healthy people, three polymorphisms have been identified in exon 6 and exon 7 which do not change the amino acid sequence. It was concluded, therefore, that there is no specific mutation responsible for the ToF phenotype in the Vangl2 gene.

A New Technique of Transannular Monocusp Patch-Repair of the Right Ventricular Outflow Tract in Repair of Tetralogy of Fallot

Reconstruction of the right ventricular outflow tract (RVOT) is a key procedure in repair of Tetralogy of Fallot (TOF). The procedure creates pulmonary insufficiency (PI) that may compromise the right ventricular (RV) function, particularly during late follow-up. A simple way to reduce PI is to create a monocusp patch from xenografts, homografts, fascia lata, and autologous pulmonary artery or pericardium. Each of those has limitations. The autologous pericardial valve sewn on another pericardial patch is one of the earliest monocusp patches used clinically but loses anti-PI effect soon after the operation presumably due to degeneration or absorption of the monocusp. I have therefore designed and used a new technique (folded monocusp patch) to create a monocusp for TOF repair in children and adults. The technique has been used in nine patients of the 18 TOF patients who needed transannular patch-repair in total 74 TOF repairs. The monocusp patch-repaired patients had minimal or mild PI and good RV function beyond 8-12 months. The long-term results await follow-up and further study in multi-institutions.

Surgery Insight: late complications following repair of tetralogy of Fallot and related surgical strategies for management

Biventricular correction of tetralogy of Fallot was devised more than 50 years ago. Current short-term outcomes are excellent. The potential for late complications is, however, an important concern for the growing number of postrepair survivors. Progressive pulmonary valve regurgitation leading to right heart failure and arrhythmia are centrally important problems faced by these patients. New techniques are, however, likely to change the future outcomes for postrepair survivors. These techniques include percutaneous valve replacement, arrhythmia ablation surgery, and strategies that emphasize preservation of the pulmonary valve even at the cost of leaving some residual valvular stenosis. The objectives of this Review are to outline the major complications that arise late after repair of tetralogy of Fallot, to describe the surgical approaches that have been developed to avoid and manage arising complications, and to briefly explore how novel treatment paradigms could change the future long-term outlook for patients following tetralogy repair.

The BNP concentrations and exercise capacity assessment with cardiopulmonary stress test in patients after surgical repair of Fallot's tetralogy

Adult patients after surgical repair of Fallot's tetralogy usually present with satisfactory exercise capacity years after the original procedure, though they never tolerate as high levels of exercise as their healthy counterparts. The aim of the study was to assess exercise capacity with cardiopulmonary stress test and BNP levels in adult survivors of surgical repair of Fallot's tetralogy. We studied 60 patients with no or only mild symptoms (including 29 males), at the mean age of 27.6+/-8.2 years at the time of follow-up screening, operated on at the age of 7.5+/-5.3 years. In 34 patients moderate to severe pulmonary regurgitation (PR+) was observed. Control group consisted of 28 healthy volunteers (13 males), aged 28.7+/-5.1 years. Peak oxygen uptake (VO2) in studied group was found to be significantly lower than in control group (24.7+/-5.5 vs. 36.6+/-7.6 ml/kg/min, p=0.00001), VE/VCO2 slope, the marker of respiratory effort, was higher in surgical treatment group as compared to the control group (36.5+/-6.3 vs. 29.7+/-4.7, p=0.004). In patients with PR+, peak VO2% was higher than in PR- individuals (69.6+/-11.8% vs. 58.5+/-12.1%, p=0.0005). The BNP concentration in the studied group (34.8+/-27.1 pg/ml) was higher than in healthy subjects (11.5+/-6.5 pg/ml, p=0.00001). Levels of BNP correlated inversely with peak VO2 (r=-0.286, p=0.03), FVC (r=-0.265 p=0.04) and positively with VE/VCO2 (r=0.361, p=0.005). Additionally the levels of BNP correlated positively with the age of patients at the time of surgical repair (r=0.250, p=0.04). We concluded that exercise capacity in adults after repair of Fallot's tetralogy, especially those PR+, was lower than in healthy volunteers. Concentrations of BNP in surgical treatment survivors were higher and correlated well with cardiopulmonary stress study parameters.

Sleep disordered breathing in pediatric patients with tetralogy of Fallot

Adverse effects on the pulmonary circulation in obstructive sleep disordered breathing (SDB) may place children with heart lesions affecting the right ventricle at increased risk for morbidity and mortality. We examined the distribution and effects of SDB in pediatric patients with tetralogy of Fallot (TOF). Families of 37 pediatric patients with TOF completed a survey of cardiac symptoms and school performance as well as a Pediatric Sleep Questionnaire (PSQ), a validated questionnaire for the screening of SDB in children 2-18 years of age. Medical records were reviewed for growth parameters, medical history, and most recent electrocardiogram (ECG) findings. Data from patients with SDB (PSQ score > or = 8, n = 14) were compared to data from patients without SDB (PSQ score < 8; n = 23). The prevalence of SDB in this population (38%) was significantly higher than the published prevalence of 5% in a healthy general pediatric population (p < 0.001). No significant difference was found in age, gender, or age and sex standardized body mass index between patients with or without SDB. No difference was seen in medication use or timing of surgical repair, whether primary or palliative. Patients with SDB had a significantly higher cardiac symptom score (p = 0.01) and increasing PSQ scores correlated with worsening cardiac symptom scores (p = 0.006). Increasing PSQ scores also correlated with worsening school performance (p = 0.001). No differences were seen in ECG data. The screened prevalence of SDB in the pediatric population with TOF is higher than in the general population; patients with TOF and SDB are more likely to have worse cardiac symptoms and poor school performance.