Revision of previous Fontan connections to total extracardiac cavopulmonary anastomosis: A multicenter experience

Canadian Cardiovascular Society 2022 Guidelines for Cardiovascular Interventions in Adults With Congenital Heart Disease

Interventions in adults with congenital heart disease (ACHD) focus on surgical and percutaneous interventions in light of rapidly evolving ACHD clinical practice. To bring rigour to our process and amplify the cumulative nature of evidence ACHD care we used the ADAPTE process; we systematically adjudicated, updated, and adapted existing guidelines by Canadian, American, and European cardiac societies from 2010 to 2020. We applied this to interventions related to right and left ventricular outflow obstruction, tetralogy of Fallot, coarctation, aortopathy associated with bicuspid aortic valve, atrioventricular canal defects, Ebstein anomaly, complete and congenitally corrected transposition, and patients with the Fontan operation. In addition to tables indexed to evidence, clinical flow diagrams are included for each lesion to facilitate a practical approach to clinical decision-making. Excluded are recommendations for pacemakers, defibrillators, and arrhythmia-directed interventions covered in separate designated documents. Similarly, where overlap occurs with other guidelines for valvular interventions, reference is made to parallel publications. There is a paucity of high-level quality of evidence in the form of randomized clinical trials to support guidelines in ACHD. We accounted for this in the wording of the strength of recommendations put forth by our national and international experts. As data grow on long-term follow-up, we expect that the evidence driving clinical practice will become increasingly granular. These recommendations are meant to be used to guide dialogue between clinicians, interventional cardiologists, surgeons, and patients making complex decisions relative to ACHD interventions.

Efficacy of heart transplantation in patients with a failing Fontan: a systematic review and meta-analysis

Background

As the population of patients with Fontan palliation grows, so does the number of patients with Fontan failure, necessitating heart transplantation. However, due to mainly small-sized studies, outcomes after heart transplantation in these patients remain unclear. The objective of this study was to review the available literature and conduct a meta-analysis to provide well-powered and generalizable estimates of outcomes after heart transplantation in patients with a failing Fontan.

Main text

PubMed, Embase, and MEDLINE databases were searched for original studies of patients with a failing Fontan who underwent heart transplantation. The outcomes included were 1-year and 5-year survival, acute rejection, renal dysfunction, sepsis, and multi-organ failure. Proportions were pooled using random effects models to derive pooled proportions (PPs) and corresponding 95% confidence intervals (CIs). Meta-regression analysis was done to study the effects of age and gender on key outcomes. Sixteen retrospective single-center cohort studies with 426 Fontan patients undergoing heart transplantation were included in this meta-analysis. Pooled analysis of this study further revealed that 1-year survival after heart transplantation was 79.9% ([75.8%, 83.7%]; I2 = 1.92%), and 5-year survival rate was 72.5% ([62.1%, 81.9%]; I2 = 72.12%). Secondary outcomes after heart transplantation of failed Fontan procedure were acute rejection (PP 20% [7.4%, 36.8%]; I2 = 72.48%), renal dysfunction (PP 31.3% [10.5%, 57.2%]; I2 = 75.42%), multi-organ failure (PP 18.6% [2.8 to 43.9%]; I2= 69.60%), and sepsis (PP 21.1% [9%, 36.8%]; I2 = 61.19%).

Conclusion

Cardiac transplantation in patients with a failing Fontan is associated with acceptable interventional success and improved survival rates.

Reoperation after modified Björk procedure for tricuspid atresia

Rarely performed nowadays, the Björk procedure is an alternative to the Fontan palliation for biventricular repair in patients with tricuspid atresia. The right atrium to right ventricle conduit failure leads to serious long-term complications. The management of such patients at high surgical risk remains challenging. We report a successful reoperation in a young adult 25 years after the modified Björk intervention, who presented with severely narrowed and calcified valved conduit.

Forns Index is a predictor of cardiopulmonary bypass time and outcomes in Fontan conversion

Recent reports suggested that cardiopulmonary bypass (CPB) time is one of the risk factors for postoperative complications after Fontan conversion. Although Fontan conversion may be performed for the patients with hepatic fibrosis after initial Fontan procedure, there is no predictive indicator regarding the liver function associated with hemostasis which can affects CPB time. Thirty-one patients who underwent Fontan conversion using the same surgical procedure (extracardiac conduit conversion with right atrium exclusion) were enrolled. In multivariate analyses including age at Fontan conversion, interval from initial Fontan to conversion, hemodynamic data such as right atrial pressure, ventricular end-diastolic pressure, and cardiac index, hepatic data such as platelet count, prothrombin time international normalized ratios, serum total bilirubin, hyaluronic acid levels, five known indices for hepatic fibrosis (Forns Index, APRI, FIB4, FibroIndex, and MELD-XI), and liver stiffness measured by ultrasound elastography, only the Forns Index remained independently associated with the CPB time (P < 0.01) and blood transfusions (plasma transfusions and platelet concentrations: P < 0.01 for both). The cutoff level for Forns Index to predict the prolonged CPB time (exceeding 240 min) was 4.85 by receiver-operating characteristic curve (area under the curve 0.823, sensitivity 76.9%, and specificity 72.2%). Three patients with Forns Index > 7.0 had poor outcomes with long CPB time and massive blood transfusions in contrast with the other 28 patients. In conclusion, Forns Index could serve as a practical predictor of CPB time and is associated with blood transfusion volume in Fontan conversion.

Approaches to Establish Extracardiac Total Cavopulmonary Connections in Animal Models—A Review

Background:

Long-term survival of patients with a single ventricle palliated with a Fontan procedure is still limited. No curative treatment options are available. To investigate the pathophysiology and potential treatment options, such as mechanical circulatory support (MCS), appropriate large animal models are required. The aim of this review was to analyze all full-text manuscripts presenting approaches for an extracardiac total cavopulmonary connection (TCPC) animal model to identify the feasibility and limitations in the acute and chronic setting.

Methods:

A literature search was performed for full-text publications presenting large animal models with extracardiac TCPCs on Pubmed and Embase. Out of 454 reviewed papers, 23 manuscripts fulfilled the inclusion criteria. Surgical procedures were categorized and hemodynamic changes at the transition from the biventricular to the univentricular condition analyzed.

Results:

Surgical procedures varied especially regarding coronary venous flow handling and anatomic shape of the TCPC. In most studies (n = 14), the main pulmonary artery was clamped and the coronary venous flow redirected by additional surgical interventions. Only in five reports, the caval veins were connected to the right pulmonary artery to create a true TCPC shape, whereas in all others (n = 18), the veins were connected to the main pulmonary artery. An elevated pulmonary vascular resistance was identified as a limiting hemodynamic factor for TCPC completion in healthy animals.

Conclusions:

A variety of acute TCPC animal models were successfully established with and without MCS, reflecting the most important hemodynamic features of a Fontan circulation; however, chronic animal models were not reported.

Heart transplantation for adults with congenital heart disease: current status and future prospects

Increased survival rates after corrective or palliative surgery for complex congenital heart disease (CHD) in infancy and childhood are now being coupled with increased numbers of patients who survive to adulthood with various residual lesions or sequelae. These patients are likely to deteriorate in cardiac function or end-organ function, eventually requiring lifesaving treatment including heart transplantation. Although early and late outcomes of heart transplantation have been improving for adult survivors of CHD, outcomes and pretransplant management could still be improved. Survivors of Fontan procedures are a vulnerable cohort, particularly when single ventricle physiology fails, mostly with protein-losing enteropathy and hepatic dysfunction. Therefore, we reviewed single-institution and larger database analyses of adults who underwent heart transplantation for CHD, to enable risk stratification by identifying the indications and outcomes. As the results, despite relatively high early mortality, long-term results were encouraging after heart transplantation. However, further investigations are needed to improve the indication criteria for complex CHD, especially for failed Fontan. In addition, the current system of status criteria and donor heart allocation system in heart transplantation should be arranged as suitable for adults with complex CHD. Furthermore, there is a strong need to develop ventricular assist devices as a bridge to transplantation or destination therapy, especially where right-sided circulatory support is needed.

The Long-Term Management of Children and Adults with a Fontan Circulation: A Systematic Review and Survey of Current Practice in Australia and New Zealand

Although long-term survival is now the norm, Fontan patients face significant morbidity and premature mortality. Wide variation exists in long-term Fontan management. With an aim of improving their long-term management, we conducted a systematic review to identify best available evidence and gaps in knowledge for future research focus. We also surveyed cardiologists in Australia and New Zealand managing Fontan patients, to determine the alignment of current local practice with best available evidence. A systematic review was conducted using strict search criteria (PRISMA guidelines), pertaining to long-term Fontan management. All adult congenital and paediatric cardiologists registered with The Australia and New Zealand Fontan Registry were invited to respond to an online survey. Reasonable quality evidence exists for non-inferiority of aspirin over warfarin for thromboprophylaxis in standard-risk Fontan patients. No strong evidence is currently available for the routine use of ACE inhibitors, beta blockers or pulmonary vasodilators. Little evidence exists regarding optimal arrhythmia treatment, exercise restriction/prescription, routine fenestration closure, elective Fontan conversion and screening/management of liver abnormalities. Although pregnancy is generally well tolerated, there are high rates of miscarriage and premature delivery. Thirty-nine out of 78 (50 %) cardiologists responded to the survey. Heterogeneity in response was demonstrated with regard to long-term anti-coagulation, other medication use, fenestration closure and pregnancy and contraception counselling. Substantial gaps in our knowledge remain with regard to the long-term management of Fontan patients. This is reflected in the survey of cardiologists managing these patients. We have identified a number of key areas for future research.

Outcomes of Fontan conversion for failing Fontan circulation: mid-term results

OBJECTIVES

We investigated the results of a revision of a previous Fontan connection to total cavopulmonary connection (TCPC) in patients with failing Fontan circulation.

METHODS

From July 1998 to April 2013, 21 patients who had failing Fontan circulation underwent revision of the previous Fontan operation to TCPC. The median age at TCPC conversion was 17.9 years (range, 4.6-38.1 years) and the median interval between initial Fontan operation and TCPC was 13.8 years (range, 2.1-25.4 years). There were 37 indications for Fontan revision in 21 patients. The indications were huge right atrium (n = 15), atrial arrhythmia (n = 8), intra-atrial thrombi (n = 6), protein-losing enteropathy (PLE) (n = 3) and more than mild atrioventricular valve regurgitation (n = 5). The previous Fontan operation was revised to extracardiac conduit replacement (n = 20) and intra-atrial lateral tunnel (n = 1). Concomitant surgery for atrial arrhythmia was performed in 8 patients. Fenestration was performed in 7 patients. The median follow-up duration was 7.1 years (range, 0.3-13.4 years).

RESULTS

There were no operative deaths and two late deaths occurred 7.9 and 8.1 years after operation. Actuarial 5- and 10-year survival rates were 92.3 and 83.1%, respectively. Postoperative complications included bleeding (n = 3), deep sternal infection (n = 1) and prolonged pleural effusion for more than 2 weeks (n = 5). During follow-up, atrial arrhythmia recurred in 6 patients, PLE recurred in 2 patients and pleural effusion recurred in 2 patients. All patients were classified as New York Heart Association Class I (n = 15) or Class II (n = 4).

CONCLUSIONS

Fontan conversion to TCPC in patients with failing Fontan circulation can be performed with low risk of morbidity and mortality. The procedure confers better quality of life and is functional for patients with failed Fontan circulation.

Fontan Conversion

Early survival after the Fontan operation has improved significantly leading to a lifetime of Fontan circulation for patients. There is a natural progression of pulmonary artery pressure during the human lifetime that is easily tolerated in two-ventricle physiology but is deleterious for single-ventricle physiology. Obstructions in the venous to pulmonary artery pathway and pulmonary venous return or ventricular outflow, atrioventricular valve dysfunction (regurgitation), pulmonary arteriovenous malformations, venous thrombosis, and the development of atrial arrhythmias can lead to reduced functional status. These complications have been demonstrated in older patients with largely atriopulmonary connections owing to time accrual and unfavorable flow characteristics. Various surgical and catheter interventions aimed at reducing morbidity and mortality have been attempted to treat these identifiable abnormalities. The purpose of this article is to review the extant literature on Fontan Conversion and to assess the lessons learned over 20 years.

Postoperative care of the adult with congenital heart disease

An increasing number of children with congenital heart disease survive to adulthood, but many adults require surgical intervention and can present complex management challenges in the perioperative period. This review will address common considerations that surgeons, anesthesiologists, and intensivists are likely to face in caring for this growing population.

Fontan Operation: Indications, Short and Long Term Outcomes

Fontan operation, since its original description, has undergone a number of modifications so that it is now a staged, total cavo-pulmonary connection with fenestration. Stage I is palliation, depending upon the pathophysiology of the defect complex in early life, Stage II is bidirectional Glenn at about the age of 6 mo and Stage III is transfer of inferior vena caval blood to the pulmonary circuit along with fenestration between 2 to 4 y. Any patient that has only one functioning ventricle is a candidate for Fontan surgery. The morbidity and mortality have remarkably improved since the institution of staged, total cavo-pulmonary connection with fenestration. Complications during follow up continue to occur, though diminished with the newer modifications, and should be promptly addressed.

Atrial macroreentry in congenital heart disease

Macroreentrant atrial tachycardia is a common complication following surgery for congenital heart disease (CHD), and is often highly symptomatic with potentially significant hamodynamic consequences. Medical management is often unsuccessful, requiring the use of invasive procedures. Cavotricuspid isthmus dependent flutter is the most common circuit but atypical circuits also exist, involving sites of surgical intervention or areas of scar related to abnormal hemodynamics. Ablation can be technically challenging, due to complex anatomy, and difficulty with catheter stability. A thorough assessment of the pa-tients status and pre-catheter ablation planning is critical to successfully managing these patients.

Transplantation in the Fontan patient

The failing Fontan circulation presents difficult treatment challenges. When Fontan revision and or intervention for treatable arrhythmias is not feasible, heart transplantation is the only therapeutic option. Particular challenges presented by these patients include limited ability to assess hemodynamics, complex anatomy, multiple prior procedures, and unique underlying pathologic states. These issues complicate the decision-making process for further surgical intervention verses transplantation. The pre-transplant evaluation, transplant operation, and post-operative management are more problematic for these patients compared with most patients undergoing transplantation. Consequently, failing Fontan patients constitute one of the highest risk heart transplant subsets.

Outcomes of the Extracardiac Fontan Procedure Using Cardiopulmonary Bypass: Early Results

<p><strong>Background</strong>: Although the avoidance of cardiopulmonary bypass during the Fontan procedure has potential advantages, using cardiopulmonary bypass during this procedure has no adverse effects in terms of morbidity and mortality rates. In this study, we assessed the postoperative outcomes of our first 9 patients who have undergone extracardiac Fontan operation by the same surgeon using cardiopulmonary bypass.</p><p><strong>Methods</strong>: Between September 2011 and April 2013,  9 consecutive patients (3 males and 6 females) underwent extra-cardiac Fontan operation. All operations were performed under cardiopulmonary bypass at normothermia by the same surgeon.  The age of patients ranged between 4 and 17 (9.8 ± 4.2) years. Previous operations performed on these patients were modified Blalock-Taussig shunt procedure in 2 patients, bidirectional cavopulmonary shunt operation in 6 patients, and pulmonary arterial banding in 1 patient. Except 2 patients who required intracardiac intervention, cross-clamping was not applied. In all patients, the extracardiac Fontan procedure was carried out by interposing an appropriately sized tube graft between the infe-rior vena cava and right pulmonary artery.</p><p><strong>Results</strong>: The mean intraoperative Fontan pressure and transpulmonary gradient were 12.3 ± 2.5 and 6.9 ± 2.2 mm Hg, respectively. Intraoperative fenestration was not required. There was no mortality and 7 patients were discharged with-out complications. Complications included persistent pleural effusion in 1 patient and a transient neurological event in 1 patient. All patients were weaned off mechanical ventila-tion within 24 hours. The mean arterial oxygen saturation increased from 76.1% ± 5.3% to 93.5% ± 2.2%. All patients were in sinus rhythm postoperatively. Five patients required blood and blood-product transfusions. The mean intensive care unit and hospital stay periods were 2.9 ± 1.7 and 8.2 ±  1.9 days, respectively.</p><p><strong>Conclusions</strong>: The extracardiac Fontan operation per-formed using cardiopulmonary bypass provides satisfactory results in short-term follow-up and is associated with favor-able postoperative hemodynamics and morbidity rates.</p>

Surgical outcome of Fontan conversion and arrhythmia surgery: Need a pacemaker?

Background

Atrial tachyarrhythmias are frequent complications in the late period after the Fontan procedure, and important risk factors for a poor prognosis. The impact of Fontan conversion and arrhythmia surgery in failed Fontan patients has been described in many reports.

Objective

We evaluated our experience with Fontan conversion procedures, concomitant arrhythmia surgery, and pacemaker implantation.

Methods

We reviewed the hospital records of 25 consecutive patients who underwent a Fontan conversion procedure from January 2004 to March 2012. Twenty-four patients had arrhythmia surgery using cryoablation and radiofrequency ablation at the time of conversion. A bilateral atrial maze procedure was performed in 6 patients, right-side maze in 15, and isthmus block in 3. Three patients with a diagnosis of corrected transposition of the great arteries underwent simultaneous pacemaker implantation electively.

Results

There was no early death and one late death during a mean follow-up period of 21.2 months. Three tachyarrhythmia recurrences developed, and there were 4 occurrences of sinus bradycardia. Five of these patients required postoperative pacemaker implantation.

Conclusion

The mid-term results of Fontan conversion and arrhythmia surgery in our institute were satisfactory. The occurrence of unexpected postoperative pacemaker requirement was high in the patients who underwent a right atrial or bilateral atrial maze procedure. Pacemaker or lead implantation is recommended for patients planned to undergo a right-side or full maze procedure.

Long-term Issues After the Fontan Procedure

The Fontan procedure is used to treat various serious congenital heart defects. Although many people who have had the procedure live productively into adulthood, as they age, they face several health issues due to the physiology of the Fontan circulation. This article reviews the 4 types of Fontan procedures and the changes caused by the surgery, including single-ventricle physiology, nonpulsatile pulmonary perfusion, systemic venous hypertension, and intracardiac scarring, as well as their sequelae. Key nursing assessment items and possible treatment strategies are reviewed. Additional topics, including pregnancy in patients who have undergone the procedure, infective endocarditis prophylaxis, and health-related quality of life, are briefly discussed. Options for Fontan failure, including Fontan conversion or transplantation, are presented. Potential future solutions are outlined.

Fontan Operation for Patients With Complex Anatomy: The Intra-Atrial Conduit Technique

The extracardiac conduit type of total cavopulmonary connection (TCPC) is the most common variation of the modified Fontan operation in current use. For patients with some forms of complex anatomy (eg, dextrocardia in situs solitus or asplenia syndrome), we have adopted a different technique: interposition of an intra-atrial conduit between the inferior vena cava (IVC) and the superior vena cava–right pulmonary artery (SVC-RPA) connection. We report our experience with six patients.

Hypoplastic left heart syndrome: current considerations and expectations

In the recent era, no congenital heart defect has undergone a more dramatic change in diagnostic approach, management, and outcomes than hypoplastic left heart syndrome (HLHS). During this time, survival to the age of 5 years (including Fontan) has ranged from 50% to 69%, but current expectations are that 70% of newborns born today with HLHS may reach adulthood. Although the 3-stage treatment approach to HLHS is now well founded, there is significant variation among centers. In this white paper, we present the current state of the art in our understanding and treatment of HLHS during the stages of care: 1) pre-Stage I: fetal and neonatal assessment and management; 2) Stage I: perioperative care, interstage monitoring, and management strategies; 3) Stage II: surgeries; 4) Stage III: Fontan surgery; and 5) long-term follow-up. Issues surrounding the genetics of HLHS, developmental outcomes, and quality of life are addressed in addition to the many other considerations for caring for this group of complex patients.

Congenital Heart Defects in Adults : A Field Guide for Cardiologists

Advances in cardiology and cardiac surgery allow a large proportion of patients with congenital heart defects to survive into adulthood. These patients frequently develop complications characteristic of the defect or its treatment. Consequently, adult cardiologists participating in the care of these patients need a working knowledge of the more common defects. Occasionally, patients with congenital heart defects such as atrial septal defect, Ebstein anomaly or physiologically corrected transposition of the great arteries present for the first time in adulthood. More often patients previously treated in pediatric cardiology centers have transitioned to adult congenital heart disease centers for ongoing care. Some of the more important defects in this category are tetralogy of Fallot, transposition of the great arteries, functionally single ventricle defects, and coarctation. Through this field guide, we provide an overview of the anatomy of selected defects commonly seen in an adult congenital practice using pathology specimens and clinical imaging studies. In addition, we describe the physiology, clinical presentation to the adult cardiologist, possible complications, treatment options, and outcomes.

Protein-losing enteropathy: integrating a new disease paradigm into recommendations for prevention and treatment

Protein-losing enteropathy is a relatively uncommon complication of Fontan procedures for palliation of complex congenital cardiac disease. However, the relative infrequency of protein-losing enteropathy belies the tremendous medical, psychosocial and financial burdens it places upon afflicted patients, their families and the healthcare system that supports them. Unfortunately, because of the complexity and rarity of this disease process, the pathogenesis and pathophysiology of protein-losing enteropathy remain poorly understood, and attempts at treatment seldom yield long-term success. The most comprehensive analyses of protein-losing enteropathy in this patient population are now over a decade old, and re-evaluation of the prevalence and progress in treatment of this disease is needed. This report describes a single institution experience with the evaluation, management, and treatment of protein-losing enteropathy in patients with congenital cardiac disease in the current era, follows with a comprehensive review of protein-losing enteropathy, focused upon what is known and not known about the pathophysiology of protein-losing enteropathy in this patient population, and concludes with suggestions for prevention and treatment.

Arrhythmias in a contemporary fontan cohort: prevalence and clinical associations in a multicenter cross-sectional study

OBJECTIVES

Our aim was to examine the prevalence of arrhythmias and identify independent associations of time to arrhythmia development.

BACKGROUND

Since introduction of the Fontan operation in 1971, long-term results have steadily improved with newer modifications. However, atrial arrhythmias are frequent and contribute to ongoing morbidity and mortality. Data are lacking regarding the prevalence of arrhythmias and risk factors for their development in the current era.

METHODS

The Pediatric Heart Network Fontan Cross-Sectional study evaluated data from 7 centers, with 520 patients age 6 to 18 years (mean 8.6 +/- 3.4 years after the Fontan operation), including echocardiograms, electrocardiograms, exercise testing, parent-reported Child Health Questionnaire (CHQ) results, and medical history.

RESULTS

Supraventricular tachycardias were present in 9.4% of patients. Intra-atrial re-entrant tachycardia (IART) was present in 7.3% (32 of 520). The hazard of IART decreased until 4 to 6 years post-Fontan, and then increased with age thereafter. Cardiac anatomy and resting heart rate (including marked bradycardia) were not associated with IART. We identified 3 independent associations of time to occurrence of IART: lower CHQ physical summary score (p < 0.001); predominant rhythm (p = 0.002; highest risk with paced rhythm), and type of Fontan operation (p = 0.037; highest risk with atriopulmonary connection). Time to IART did not differ between patients with lateral tunnel and extracardiac conduit types of Fontan repair. Ventricular tachycardia was noted in 3.5% of patients.

CONCLUSIONS

Overall prevalence of IART was lower in this cohort (7.3%) than previously reported. Lower functional status, an atriopulmonary connection, and paced rhythm were determined to be independently associated with development of IART after Fontan. (Relationship Between Functional Health Status and Ventricular Performance After Fontan-Pediatric Heart Network; NCT00132782).

Canadian Cardiovascular Society 2009 Consensus Conference on the management of adults with congenital heart disease: complex congenital cardiac lesions

With advances in pediatric cardiology and cardiac surgery, the population of adults with congenital heart disease (CHD) has increased. In the current era, there are more adults with CHD than children. This population has many unique issues and needs. They have distinctive forms of heart failure and their cardiac disease can be associated with pulmonary hypertension, thromboemboli, complex arrhythmias and sudden death. Medical aspects that need to be considered relate to the long-term and multisystemic effects of single ventricle physiology, cyanosis, systemic right ventricles, complex intracardiac baffles and failing subpulmonary right ventricles. Since the 2001 Canadian Cardiovascular Society Consensus Conference report on the management of adults with CHD, there have been significant advances in the field of adult CHD. Therefore, new clinical guidelines have been written by Canadian adult CHD physicians in collaboration with an international panel of experts in the field. Part III of the guidelines includes recommendations for the care of patients with complete transposition of the great arteries, congenitally corrected transposition of the great arteries, Fontan operations and single ventricles, Eisenmenger's syndrome, and cyanotic heart disease. Topics addressed include genetics, clinical outcomes, recommended diagnostic workup, surgical and interventional options, treatment of arrhythmias, assessment of pregnancy risk and follow-up requirements. The complete document consists of four manuscripts, which are published online in the present issue of The Canadian Journal of Cardiology. The complete document and references can also be found at www.ccs.ca or www.cachnet.org.

Late reoperations for Fontan patients: state of the art invited review

Conversion of the atriopulmonary Fontan to a total cavopulmonary extracardiac connection with concomitant arrhythmia surgery and pacemaker placement is a safe and efficacious procedure for this patient population. From 1994 to 2007 a total of 118 patients have undergone this procedure with one (0.8%) early and nine (7.6%) late deaths. During the course of our experience with Fontan conversion our surgical strategy has evolved to include various ablative techniques to treat macro re-entrant atrial tachycardia, focal (automatic) atrial tachycardia, atrioventricular nodal reentry tachycardia, atrial tachycardia due to accessory connections, atrial fibrillation, and ventricular tachycardia. The various mechanisms that we use to treat the underlying atrial arrhythmias are described in this review. We have also encountered patients with variations of the Fontan and other complex anatomic and pathophysiologic aberrations who were not amenable to standard takedown and ablative procedures. We describe those circumstances and the solutions we found to treat those patients.

Mid-term results following surgical treatment of congenital cardiac malformations in adults

The long term consequences of untreated of residual or recurrent lesions pose unique challenges in the growing population of adults with congenitally malformed hearts. In our unit, 335 patients aged from 18 to 72 years, with a mean age of 35 plus or minus 14 years, presented for correction of congenital cardiac disease from September, 1997, through December, 2006. Of the group, 42 (12.5%) had undergone one or more prior surgical procedures, 3 were admitted as emergencies, and a further 10 (3%) had suffered prior cardiac related complications. Symptoms had been noted by 181 patients (54%), and 42 (12.5%) had an established arrhythmia. Chromosomal anomalies were identified in 13 (3.8%), and diagnostic catheterisation was required in 201 (60%) patients. Of the overall group, 2 patients died early (0.6%). Complications occurred in 61 patients (18%), including atrial fibrillation, pneumothorax, postoperative haemorrhage, pericardial or pleural effusions requiring drainage, stroke, complete heart block, endocarditis, wound dehiscence, and peripheral neuropathy. The median length of stay in the intensive care unit and hospital were 2 and 7 days, respectively. Death occurred later in 2 further patients (0.6%), due to atrial fibrillation and pulmonary hypertension. At mean follow-up of 63 plus or minus 30 months, the majority of the remaining patients are well with resolution or significant improvement in their symptoms. Despite the long term deleterious effects of untreated, residual or recurrent congenital cardiac lesions in adults, therefore, we conclude that surgical correction can be achieved with low mortality and acceptable morbidity. Most significant complications are related to arrhythmias.

Patient-activated antitachycardia pacing to terminate atrial tachycardias with 1:1 atrioventricular conduction in congenital heart disease

A young girl with complex congenital heart disease and a Fontan procedure presented with frequent episodes of atrial tachycardias with 1:1 atrioventricular conduction. The patient underwent placement of a dual-chamber AT500 pacemaker with epicardial leads but because of the detection algorithm requiring > or = 2:1 AV relation, she received no antitachycardia therapy. Installation of special software AT500 TPARx v2.1 allowed use of patient-activated antitachycardia pacing for 1:1 atrial tachycardias. Since the installation of this application, the patient has successfully pace-terminated her tachycardia multiple times.

The failing Fontan: options for surgical therapy

The Fontan procedure has been a significant contribution to the therapeutic armamentarium of congenital heart surgeons for the treatment of single ventricle anomalies. However, it has its limitations. Patients may have failure of the Fontan circulation acutely postoperatively or late during the long-term follow-up. Early failure is often related to an intraoperative myocardial injury or unsuspected elevated pulmonary vascular resistance; this has a very high mortality. Late failure of the Fontan procedure may present with symptoms typical for heart failure. However, protein-losing enteropathy is another condition related to late failure of the Fontan operation. Late failure may be related to a number of different factors, many of which are amenable to reoperation. Every effort should be made to identify which hemodynamic factors are responsible for late failures. However, cardiac transplantation will likely be necessary for the majority of patients.