Fontan Operation: Indications, Short and Long Term Outcomes

Long-term incidence of arrhythmias in extracardiac conduit Fontan and comparison between systemic left and right ventricle

AIMS

The extracardiac conduit-Fontan (ECC) has become the preferred technique for univentricular heart palliation, but there are currently no data on the incidence of long-term arrhythmias. This study investigated the incidence of arrhythmias and relation to single ventricle morphology in the long-term follow-up (FU) in ECC.

METHODS AND RESULTS

All patients with ECC performed in our Centre between 1987 and 2017 were included (minimum FU 5 years). Of 353 consecutive patients, 303 [57.8% males, aging 8-50 (median 20) years at last FU] were considered and divided into two groups depending on left (194 in Group 1) or right (109 in Group 2) ventricular morphology. Eighty-five (28%) experienced ≥1 arrhythmic complications, with early and late arrhythmias in 17 (5.6%) and 73 (24.1%) patients, respectively. Notably, late bradyarrhythmias occurred after 6 years in 21 (11%) patients in Group 1, and in 15 (13.8%) in Group 2 [P = 0.48]. Late tachyarrhythmias occurred in 55 (18.2%) patients after 12 years: 33 (17%) in Group 1 and 22 (20.2%) patients in Group 2 [P  = 0.5]. Ventricular tachycardias (VT) were documented after 12.5 years in 14 (7.2%) patients of Group 1 and 15 (13.8%) of Group 2 [P = 0.06] with a higher incidence in Group 2 during the FU [P = 0.005].

CONCLUSION

Extracardiac conduit is related to a significant arrhythmic risk in the long-term FU, higher than previously reported. Bradyarrhythmias occur earlier but are less frequent than tachyarrhythmias. Interestingly, patients with systemic right ventricle have a significantly higher incidence of VT, especially in a very long FU.

Fontan surgery failure: risk factors and experience in a Colombian reference centre

BACKGROUND

The Fontan procedure is considered one of the most remarkable achievements in paediatric cardiology and cardiac surgery. Its final anatomical objective is a venous return through the superior and inferior vena cava. The complications inherent to this procedure and subsequent failure are its limitations.

OBJECTIVE

To describe the clinical and haemodynamic characteristics of patients with Fontan failure and define the risk factors associated with it, with its short- and long-term outcomes during a 21-year observation period.

METHODS

This is a retrospective follow-up study in which 15 patients diagnosed with Fontan failure in the single-ventricle programme of a high-complexity hospital in Medellín, Colombia, between 2001 and 2022 were included.

RESULTS

One hundred and eight patients were identified in whom the Fontan procedure was performed, and 17 met the failure criteria. 82.4% were men, with a median age of 4.3 years. Ebstein's anomaly was the most common diagnosis, 29.4%. All patients underwent Fontan with an extracardiac tube following the procedure. According to the type of failure, 58.8% of patients presented protein-losing enteropathy and 17.6% plastic bronchitis. During follow-up, 5.9% of patients died.

CONCLUSION

Fontan surgery in our centre is an option for patients with univentricular physiology. The correct selection of the patient is essential to mitigate failure risks.

Therapy of Patients with Cardiac Malposition

Positional abnormalities per se do not require treatment, but in their place, the accompanying pulmonary pathology in dextroposition patients and pathophysiologic hemodynamic abnormalities resulting from multiple defects in patients with cardiac malposition should be the focus of treatment. At the time of the first presentation, treating the pathophysiologic aberrations caused by the defect complex, whether it is by improving the pulmonary blood flow or restricting it, is the first step. Some patients with simpler or single defects are amenable to surgical or transcatheter therapy and should be treated accordingly. Other associated defects should also be treated appropriately. Biventricular or univentricular repair dependent on the patient's cardiac structure should be planned. Complications in-between Fontan stages and after conclusion of Fontan surgery may occur and should be promptly diagnosed and addressed accordingly. Several other cardiac abnormalities unrelated to the initially identified heart defects may manifest in adulthood, and they should also be treated.

Outcomes of treatment for right atrial isomerism with functional single ventricle and extracardiac total anomalous pulmonary venous connection beyond neonatal period: Delayed surgical treatment, improving outcomes

Objective

Total anomalous pulmonary venous connection (TAPVC) is frequently associated with right atrial isomerism (RAI), which is commonly complicated with an unbalanced atrioventricular canal with contralateral hypoplasia, complex systemic and pulmonary venous anatomy, and conotruncal abnormalities, resulting in increased risk of mortality. This study aimed to review the outcomes of delayed surgical treatment for patients with RAI complicated with functional single ventricle (FSV) and TAPVC at a single center.

Methods

In this retrospective study, we reviewed the medical records of 24 consecutive patients with RAI complicated with FSV and TAPVC who underwent initial surgical palliation after 5-month old between September 2008 and June 2019. Demographic data, concomitant anomalies, age at initial palliation, and surgical interventions were extracted and analyzed using the Cox proportional hazard model to assess risk factors for mortality and the Kaplan-Meier method to assess survival.

Results

The in-hospital mortality was 12.5% (three out of 24). The causes of death were pulmonary arterial hypertension and low cardiac output syndrome. Average follow-up was 65.2 ± 40.3 months (7-137 months). Another 4 patients died during the follow-up due to low cardiac output syndrome, protein-losing enteropathy and pulmonary arterial hypertension, respectively. Kaplan-Meier estimated survival at 1 and 5 years were 83.1 and 69.4%, respectively. Fontan completion was 45.8% (11/24). The mortality for patients with pulmonary venous obstruction (PVO) was 66.7% (4/6). Cox multivariate regression analysis indicated that preoperative PVO was the only risk factor for mortality (p = 0.032; hazard ratio, 10.000; CI 1.222-81.811).

Conclusion

Outcomes of delayed surgical treatment for patients with RAI complicated with FSV and TAPVC have improved significantly. The survival and Fontan completion were higher. However, preoperative PVO was still the risk factor for mortality.

Impact of older age at Fontan completion on mid-term survival

BACKGROUND

The optimum age of Fontan completion remains unknown. Currently, the majority of centers worldwide are performing Fontan completion at 2-4 years of age. In Indonesia, lack of awareness and limited resources probably explain why patients seek treatment at advanced stage. This study aimed to evaluate the impact of older age at Fontan completion on mid-term survival.

RESULTS

A single-center retrospective cohort study was performed on 261 patients who underwent Fontan completion between 2008 and 2019 and survived to discharge. The patients were followed up until April 2020, with a median follow-up period of 3 years (range 0-12 years). The median age was 5 years (range 2-24 years). The survival rates of patients with the age at operation ≤ 6 years and > 6 years were 92.1% and 82.8%, respectively. A subgroup analysis showed that the survival rates for age < 4 years, 4-6 years (reference age), 6-8 years, 8-10 years, 10-18 years, and > 18 years were 85.7%, 94.8%, 85.4%, 78.8%, 85.7%, and 66.7%, respectively. Age at Fontan completion of > 6 years (HR 3.84; p = 0.020) was associated with a lower 12-year survival rate. The age at operation of 8-10 years (HR 6.79; p = 0.022) and > 18 years (HR 15.30; p = 0.006) had the worst survival rates.

CONCLUSIONS

An older age at Fontan completion (> 6 years) significantly reduced mid-term survival rate. The age at Fontan of 8-10 years and > 18 years had higher risk of mid-term death than age of 4-6 years.

Double-Inlet Left Ventricle

Double-inlet left ventricle (DILV) is most frequent among univentricular atrioventricular connections. In DILV, there is a single functioning ventricle, most commonly with left ventricular structure. This chamber receives both atrioventricular valves and is connected to an outlet chamber with morphologic features of the right ventricle. The great vessels are often transposed, and pulmonary stenosis is seen in two-thirds of patients. The anatomy and pathophysiology can be defined by echo-Doppler studies with a rare need for other imaging studies. The management is mostly related to the nature of associated heart defects and the degree of pathophysiological abnormality. When the infants present initially, treatment to address the hemodynamic issues is undertaken. Subsequently, these babies need staged total cavo-pulmonary connection, i.e., the Fontan procedure which is undertaken in three stages; these stages are described in this review. The existence of inter-stage mortality and post-Fontan complications is recognized and was reviewed. The paper concludes that DILV can be successfully diagnosed with echo-Doppler studies and this heart anomaly can be effectively treated with the currently prevailing medical, catheter interventional, and surgical treatment practices.

Mitral Atresia with Normal Aortic Root

Mitral atresia with normal aortic root is a rare complex congenital heart defect (CHD) and constitute less than 1% of all CHDs. In this anomaly, the mitral valve is atretic, a patent foramen ovale provides egress of the left atrial blood, either a single ventricle or two ventricles with left ventricular hypoplasia are present, and the aortic valve/root are normal by definition. Clinical, roentgenographic and electrocardiographic features are non-distinctive, but echo-Doppler studies are useful in defining the anatomic and pathophysiologic components of this anomaly with rare need for other imaging studies. Treatment consists of addressing the pathophysiology resulting from defect and associated cardiac anomalies at the time of initial presentation, usually in the early infancy. These children eventually require staged total cavo-pulmonary connection (Fontan) in three stages. Discussion of each of these stages were presented. Complications are observed in-between the stages of Fontan surgery and following completion of Fontan procedure. Attempts to monitor for early detection of these complications and promptly addressing the complications are recommended.

Case report: PICC line for a toddler with bilateral bidirectional Glenn shunt, Fontan circulation, and persistent left superior vena cava

Performing peripherally inserted central catheters for children with bilateral bidirectional Glenn shunt, Fontan circulation, and persistent left superior vena cava differs from those with normal central venous anatomy. This study presents two PICC procedures for a toddler with this condition to demonstrate an accurate PICC approach for such children.

Children with bilateral bidirectional Glenn shunt, Fontan procedure, and persistent left superior vena cava require an unique PICC placement approach to prevent unexpected complications. Hence, it is extremely important to provide nurses with knowledge about this altered central venous anatomy and explicitly outline in the PICC placement guidelines.

Single Ventricle-A Comprehensive Review

In this paper, the author enumerates cardiac defects with a functionally single ventricle, summarizes single ventricle physiology, presents a summary of management strategies to address the single ventricle defects, goes over the steps of staged total cavo-pulmonary connection, cites the prevalence of inter-stage mortality, names the causes of inter-stage mortality, discusses strategies to address the inter-stage mortality, reviews post-Fontan issues, and introduces alternative approaches to Fontan circulation.

Management of Congenital Heart Disease: State of the Art-Part II-Cyanotic Heart Defects

In this review management of the most common cyanotic congenital heart defects (CHDs) was discussed; the management of acyanotic CHD was reviewed in Part I of this series. While the need for intervention in acyanotic CHD is by and large determined by the severity of the lesion, most cyanotic CHDs require intervention, mostly by surgery. Different types of tetralogy of Fallot require different types of total surgical corrective procedures, and some may require initial palliation, mainly by modified Blalock-Taussig shunts. Babies with transposition of the great arteries with an intact ventricular septum as well as those with ventricular septal defects (VSD) need an arterial switch (Jatene) procedure while those with both VSD and pulmonary stenosis should be addressed by Rastelli procedure. These procedures may need to be preceded by prostaglandin infusion and/or balloon atrial septostomy in some babies. Infants with tricuspid atresia require initial palliation either with a modified Blalock-Taussig shunt or banding of the pulmonary artery and subsequent staged Fontan (bidirectional Glenn and fenestrated Fontan with extra-cardiac conduit). Neonates with total anomalous pulmonary venous connection are managed by anastomosis of the common pulmonary vein with the left atrium either electively in non-obstructed types or as an emergency procedure in the obstructed types. Babies with truncus arteriosus are treated by surgical closure of VSD along with right ventricle to pulmonary artery conduit. The other defects, namely, hypoplastic left heart syndrome, pulmonary atresia with intact ventricular septum, double-outlet right ventricle, double-inlet left ventricle and univentricular hearts largely require multistage surgical correction. The currently existing medical, trans-catheter and surgical techniques to manage cyanotic CHD are safe and effective and can be performed at a relatively low risk.

Management of Congenital Heart Disease: State of the Art; Part I-ACYANOTIC Heart Defects

Since the description of surgery for patent ductus arteriosus in late 1930s, an innumerable number of advances have taken place in the management of congenital heart defects (CHDs). In this review the current status of treatment of seven of the most common acyanotic CHDs was reviewed. The discussion included indications for, and timing of, intervention and methods of intervention. The indications are, by and large, determined by the severity of the lesion. Pressure gradients in obstructive lesions and the magnitude of the shunt in left-to-right shunt lesions are used to assess the severity of the lesion. The timing of intervention is different for each lesion and largely dependent upon when the criteria for indications for intervention were met. Appropriate medical management is necessary in most patients. Trans-catheter methods are preferable in some defects while surgery is a better option in some other defects. The currently available medical, trans-catheter, and surgical methods to treat acyanotic CHD are feasible, safe, and effective.

Recent advances in managing septal defects: ventricular septal defects and atrioventricular septal defects

This review discusses the management of ventricular septal defects (VSDs) and atrioventricular septal defects (AVSDs). There are several types of VSDs: perimembranous, supracristal, atrioventricular septal, and muscular. The indications for closure are moderate to large VSDs with enlarged left atrium and left ventricle or elevated pulmonary artery pressure (or both) and a pulmonary-to-systemic flow ratio greater than 2:1. Surgical closure is recommended for large perimembranous VSDs, supracristal VSDs, and VSDs with aortic valve prolapse. Large muscular VSDs may be closed by percutaneous techniques. A large number of devices have been used in the past for VSD occlusion, but currently Amplatzer Muscular VSD Occluder is the only device approved by the US Food and Drug Administration for clinical use. A hybrid approach may be used for large muscular VSDs in small babies. Timely intervention to prevent pulmonary vascular obstructive disease (PVOD) is germane in the management of these babies. There are several types of AVSDs: partial, transitional, intermediate, and complete. Complete AVSDs are also classified as balanced and unbalanced. All intermediate and complete balanced AVSDs require surgical correction, and early repair is needed to prevent the onset of PVOD. Surgical correction with closure of atrial septal defect and VSD, along with repair and reconstruction of atrioventricular valves, is recommended. Palliative pulmonary artery banding may be considered in babies weighing less than 5 kg and those with significant co-morbidities. The management of unbalanced AVSDs is more complex, and staged single-ventricle palliation is the common management strategy. However, recent data suggest that achieving two-ventricle repair may be a better option in patients with suitable anatomy, particularly in patients in whom outcomes of single-ventricle palliation are less than optimal. The majority of treatment modes in the management of VSDs and AVSDs are safe and effective and prevent the development of PVOD and cardiac dysfunction.

Blood-threshold CMR volume analysis of functional univentricular heart

PURPOSE

To validate a blood-threshold (BT) segmentation software for cardiac magnetic resonance (CMR) cine images in patients with functional univentricular heart (FUH).

MATERIALS AND METHODS

We evaluated retrospectively 44 FUH patients aged 25 ± 8 years (mean ± standard deviation). For each patient, the epicardial contour of the single ventricle was manually segmented on cine images by two readers and an automated BT algorithm was independently applied to calculate end-diastolic volume (EDV), end-systolic volume (ESV), stroke volume (SV), ejection fraction (EF), and cardiac mass (CM). Aortic flow analysis (AFA) was performed on through-plane images to obtain forward volumes and used as a benchmark. Reproducibility was tested in a subgroup of 24 randomly selected patients. Wilcoxon, Spearman, and Bland-Altman statistics were used.

RESULTS

No significant difference was found between SV (median 57.7 ml; interquartile range 47.9-75.6) and aortic forward flow (57.4 ml; 48.9-80.4) (p = 0.123), with a high correlation (r = 0.789, p < 0.001). Intra-reader reproducibility was 86% for SV segmentation, and 96% for AFA. Inter-reader reproducibility was 85 and 96%, respectively.

CONCLUSION

The BT segmentation provided an accurate and reproducible assessment of heart function in FUH patients.

The Journey of an Indian Pediatric Cardiologist : Dr. K. C. Chaudhuri Lifetime Achievement Award/Oration at AIIMS, New Delhi, September 2017

The life journey of an Indian pediatric cardiologist, who bestowed considerable attention to the development of new knowledge and train/teach physicians around the world while providing care of patients with heart disease over a 45-y period, is reviewed. This appraisal focuses particular attention on the scientific contributions to the literature. These include spontaneous closure of physiologically advantageous ventricular septal defects, various issues related to a congenital heart defect namely, tricuspid atresia and transcatheter and, interventional pediatric cardiac procedures.