Excellent Midterm Outcome of Extracardiac Conduit Total Cavopulmonary Connection: Results of 126 Cases

Anorexia nervosa in a postoperative patient with Ebstein's anomaly

Background

Along with the improved prognosis of patients with congenital heart disease, the associated diverse complications are under scrutiny. Due to various medical restrictions on their upbringing, patients with congenital heart disease often have coexisting mental disorders. However, reports on patients with congenital heart disease and coexisting eating disorders are rare. Here, we report the case of a patient who developed anorexia nervosa (AN) following surgery for Ebstein's anomaly.

Case Presentation

A 21-year-old female with Ebstein's anomaly who underwent Fontan surgery was transferred to our institution with suspected AN after >2 years of intermittent stays at a medical hospital for decreased appetite. Initially, she did not desire to lose weight or fear obesity, and we suspected that she was suffering from appetite loss due to a physical condition associated with Fontan circulation. However, the eating disorder pathology gradually became more apparent.

Conclusion

Our experience suggests that patients with congenital heart disease are more likely to have a psychological background and physical problems that might contribute to eating disorders than the general population.

Late outcome of Extracardiac Fontan Patients: 32 years of follow-up

OBJECTIVES

We sought to evaluate the long-term survival and risk factors for morbidity and mortality in our cohort of patients after Extracardiac (EC) Fontan.

METHODS

We collected and analyzed follow-up data until September 2020 for all patients who underwent EC Fontan operation at our institution from November 1988 to November 2015.

RESULTS

Out of 406 patients treated with EC Fontan at a mean age of 5.4 ± 4.5 years, 372 (91.6%) were discharged home; 15% were lost to follow-up. The Median follow-up was 14.6 years (IQR 8.7-20.3). Two hundred patients (54%) had a good long-term outcome, with an event-free long-term survival, but late adverse events of any kind needing interventional or surgical reoperations were reported in 128 patients (34%). Forty-four patients (12%) developed late Fontan failure. Thirty-seven survivors (10%) had late arrhythmias, with the need for pacemaker implantation. Obstruction of the cavopulmonary pathway occurred in forty-nine patients (13%), but just 8 pts needed conduit surgical replacement. At 32 years, the survival probability was 84%. The risk of orthotopic heart transplant (HT), considering death as a competing event, (showed as cumulative incidence) was 12.5%. A preoperative diagnosis of hypoplastic left heart syndrome (HLHS) was an independent risk factor for the need for HT.

CONCLUSIONS

The EC Fontan shows satisfactory long-term survival and low incidence of adverse events and late failure. Conduit replacement is rare, and its longevity may not represent a substantial issue in these patients. However, as with other technical variants, the need for reoperations during long-term follow-up is a significant challenge.

Hemodynamic Impact of Atrial Pacing in Patients with Fontan Physiology and Junctional Rhythm: A Cardiac Catheterization Study

Sinus node dysfunction is a common problem and adversely impacts patients who have undergone the Fontan operation. In Fontan patients with an adequate junctional escape rhythm, the benefit of atrial pacing to restore atrioventricular synchrony remains unclear. Data were collected retrospectively on all Fontan patients with junctional rhythm who underwent atrial pacing during cardiac catheterization. Hemodynamics were obtained at baseline and after atrial pacing for 5-10 min. Seven patients, mean age 10 years (3-21) were studied. The type of Fontan was extracardiac in 6 and lateral tunnel in one. Patients were paced at 10 bpm faster than their junctional rate. With pacing, there was a significant decrease in left atrial pressure from (mean ± SEM) 8.8 ± 2.6 to 5.5 ± 2.9 mmHg (p = 0.02), a significant increase in cardiac index from 2.7 ± 0.8 to 3.5 ± 1 L/min/m² (p = 0.01) and pulmonary blood flow from 2.1 ± 0.6 to 2.7 ± 0.7 L/min/m² (p = 0.001), and no significant change in pulmonary artery pressure, from 13.4 ± 2.8 to 12.4 mmHg ± 3.6 (p = 0.06) or pulmonary vascular resistance from 2.1 ± 0.86 to 3.25 ± 1.9 WU × M2 (p = 0.1). In Fontan patients with junctional rhythm, atrial pacing decreased the left atrial pressure, increased cardiac output and did not significantly change the pulmonary artery pressure. Our study supports further investigation into the utility of prophylactic atrial pacemaker implantation in Fontan patients with significant durations of JR on ambulatory monitoring.

Intrapulmonary artery septation for pulmonary artery growth in functionally univentricular hearts

The pulmonary artery anatomy is one of the important determinants of Fontan completion and its outcomes in patients with functionally univentricular hearts. Despite several modifications to Fontan operation, unbalanced pulmonary arteries pose a significant challenge in this subset of patients. Intrapulmonary artery septation is a technique, developed to rehabilitate the unilateral hypoplastic pulmonary artery following various initial palliative procedures in functionally univentricular hearts. Literature is sparse on this technique. This article reviews the basic concepts and literature on intrapulmonary artery septation. We also describe our experience with modified intrapulmonary artery septation.

Systematic Review of Tissue-Engineered Vascular Grafts

Pathologies related to the cardiovascular system are the leading causes of death worldwide. One of the main treatments is conventional surgery with autologous transplants. Although donor grafts are often unavailable, tissue-engineered vascular grafts (TEVGs) show promise for clinical treatments. A systematic review of the recent scientific literature was performed using PubMed (Medline) and Web of Science databases to provide an overview of the state-of-the-art in TEVG development. The use of TEVG in human patients remains quite restricted owing to the presence of vascular stenosis, existence of thrombi, and poor graft patency. A total of 92 original articles involving human patients and animal models were analyzed. A meta-analysis of the influence of the vascular graft diameter on the occurrence of thrombosis and graft patency was performed for the different models analyzed. Although there is no ideal animal model for TEVG research, the murine model is the most extensively used. Hybrid grafting, electrospinning, and cell seeding are currently the most promising technologies. The results showed that there is a tendency for thrombosis and non-patency in small-diameter grafts. TEVGs are under constant development, and research is oriented towards the search for safe devices.

A computational bio-chemo-mechanical model of in vivo tissue-engineered vascular graft development

Stenosis is the primary complication of current tissue-engineered vascular grafts used in pediatric congenital cardiac surgery. Murine models provide considerable insight into the possible mechanisms underlying this situation, but they are not efficient for identifying optimal changes in scaffold design or therapeutic strategies to prevent narrowing. In contrast, computational modeling promises to enable time- and cost-efficient examinations of factors leading to narrowing. Whereas past models have been limited by their phenomenological basis, we present a new mechanistic model that integrates molecular- and cellular-driven immuno- and mechano-mediated contributions to in vivo neotissue development within implanted polymeric scaffolds. Model parameters are inferred directly from in vivo measurements for an inferior vena cava interposition graft model in the mouse that are augmented by data from the literature. By complementing Bayesian estimation with identifiability analysis and simplex optimization, we found optimal parameter values that match model outputs with experimental targets and quantify variability due to measurement uncertainty. Utility is illustrated by parametrically exploring possible graft narrowing as a function of scaffold pore size, macrophage activity, and the immunomodulatory cytokine transforming growth factor beta 1 (TGF-β1). The model captures salient temporal profiles of infiltrating immune and synthetic cells and associated secretion of cytokines, proteases, and matrix constituents throughout neovessel evolution, and parametric studies suggest that modulating scaffold immunogenicity with early immunomodulatory therapies may reduce graft narrowing without compromising compliance.

Thoracic aortic surgery: status and upcoming novelties

Several novel technological developments and surgical approaches have characterized the field of aortic surgery in the recent decade. The progressive introduction of endovascular procedures, minimally invasive surgical techniques and hybrid approaches have changed the practice in aortic surgery and generated new trends and questions. Also, the advancements in the manufacturing of tissue engineered vascular grafts as substitutes for aortic replacements are enlightening new avenues in the treatment of aortic disease. This review will provide an overview of the current novel perspectives, debates and trends in major thoracic aortic surgery.

Cross-Sectional Magnetic Resonance and Modeling Comparison From Just After Fontan to the Teen Years

BACKGROUND

Little is known of baseline anatomic, hemodynamic, and fluid dynamic cardiac magnetic resonance data in single-ventricle patients immediately after Fontan. A comparison from that time point to the teen years can demonstrate clinical course, potentially predict future events, and may shed some light regarding how to optimize outcome. This cross-sectional study is meant to characterize these variables from just after Fontan to the teenage years.

METHODS

The anatomy, flows, and computational fluid dynamic modeling of 22 patients 3 to 9 months after Fontan (age 3 ± 1.1 years) and 25 teens (age 16 ± 1.8 years) were compared. Significance was defined as P less than .05.

RESULTS

The percentage of Fontan pathway stenosis was greater with cardiac index and fenestration flow while caval return was lower in teens than in younger patients (for Fontan pathway stenosis, 43% vs 21%, P = .009); however, hepatic flow distribution was more evenly distributed in older patients. Pulmonary artery size kept up with somatic growth. In the teen group, indexed power loss (R = .39), percentage of Fontan pathway stenosis (R = .62), and particle resident time (R = .42) deteriorated as time from Fontan increased (P < .04 for all).

CONCLUSIONS

There are mostly aspects of deterioration with a few bright spots of stability in anatomy, blood flow, and fluid dynamic variables in Fontan patients from the postoperative period to the teenage years. Most notably, Fontan pathway stenosis increases with decreasing flows while pulmonary artery size and hepatic flow distribution remain stable or improved. These data may be aid in designing improved Fontan reconstruction to optimize clinical outcome and to understand future complications.

Clinical Outcomes in Adolescents and Adults After the Fontan Procedure

BACKGROUND

Long-term outcomes of Fontan patients who survive to age ≥16 years have not been well characterized. The Australian and New Zealand Fontan Registry (ANZFR) provides a unique opportunity to understand survival and complication rates in Fontan patients who transition to adult congenital heart disease centers.

OBJECTIVES

This study sought to describe the survival and complications of adult patients who have had a Fontan procedure.

METHODS

The study analyzed outcomes in patients ≥16 years of age who were prospectively enrolled in the ANZFR.

RESULTS

Data from all 683 adult survivors from the ANZFR were analyzed. Mortality status was confirmed from the National Death Index. There were 201 atriopulmonary (AP) connections and 482 total cavopulmonary connections (249 lateral tunnels and 233 extracardiac conduits). For these subjects, the survival rate at age 30 years was 90% (95% CI: 87% to 93%), and it was 80% (95% CI: 75% to 87%) at 40 years of age. Survival at age 30 years was significantly worse for the patients with AP connections (p = 0.03). At latest follow-up, only 53% of patients were in New York Heart Association functional class I. After the age of 16 years, 136 (20%) had experienced at least 1 new arrhythmia, 42 (6%) required a permanent pacemaker, 45 (7%) had a thromboembolic event, and 135 (21%) required a surgical reintervention. Only 41% (95% CI: 33% to 51%) of Fontan patients were free of serious adverse events at 40 years of age.

CONCLUSIONS

This comprehensively followed cohort showed that a variety of morbid complications is common in Fontan adults, and that there is a substantial incidence of premature death, particularly in patients with AP connections.

Dacron Conduit for Extracardiac Total Cavopulmonary Anastomosis: A Word of Caution

BACKGROUND

The extracardiac conduit technique is a valid option for completing total cavopulmonary anastomosis (TCPC) in patients with a single ventricle. The technique allows for beating heart surgery, optimal flow dynamics, and reduced postoperative atrial arrhythmia. Different types of conduit have been proposed. This study reported a single-centre experience with two different types of conduit.

METHODS

Consecutive patients referred for TCPC at the current institution between January 2001 and September 2013 were included. Retrospective extraction of pertinent variables was accomplished through electronic patient chart review. Patients were stratified based on the type of conduit used to perform the TCPC: polytetrafluoroethylene (PTFE) conduit (Group A) and polyethylene-terephthalate (Dacron) conduit (Group B).

RESULTS

The patient population included 105 patients: Group A had 80 patients, and Group B had 25 patients. The two groups were similar in major clinical and procedural variables, including conduit size and Nakata index. Eighteen patients (Group A: one [1.25%]; Group B: 17 [68%]) had conduit occlusion or severe stenosis requiring intervention after a mean 46.9±35months after the operation. The percentage of patients in Group A who were free of conduit obstruction at 3, 5, and 10 years was 100%, 100%, and 96%, respectively, whereas these figures were 68%, 52%, and 35% in Group B (log-rank <0.000). Conduit re-intervention was associated with an increased risk of overall mortality after primary intervention (p<0.004). Dacron tube was found to be an independent risk factor for mid-term stenosis or obstruction (hazard ratio, 62.9; 95% CI, 8.2-482.2; p=0.000).

CONCLUSION

Dacron conduit for TCPC surgery was associated with a higher risk of obstruction and need for early re-intervention compared with PTFE conduit. Surgical or percutaneous re-interventions for conduit obstruction increased the risk of late mortality.

Pathophysiology of thrombosis and anticoagulation post Fontan surgery

The Fontan procedure has transformed the lives of children born with single-ventricle physiology, previously deemed inoperable. Worldwide, there are an increasing number of children with Fontan circulation, with the potential for survival into adulthood. Due to the abnormal circulation, Fontan patients have an increased risk of thromboembolic (TE) events, with up to 25% of events leading to death. Despite the importance of preventing TE events in this patient population, there is currently no clinical consensus on the optimal monitoring, thromboprophylaxis therapies, and treatment of these events. This paper reviews the available literature regarding anticoagulation in the pediatric and adult Fontan population, including the mechanisms for thrombosis and current antithrombotic therapies.

Tissue-engineered Vascular Grafts in Children With Congenital Heart Disease: Intermediate Term Follow-up

Tissue engineering holds great promise for the advancement of cardiovascular surgery as well as other medical fields. Tissue-engineered vascular grafts have the ability to grow and remodel and could therefore make great advances for pediatric cardiovascular surgery. In 2001, we began a human clinical trial evaluating these grafts in patients with a univentricular physiology. Herein, we report the long-term results of patients who underwent implantation of tissue-engineered vascular grafts as extracardiac total cavopulmonary conduits. Tissue-engineered vascular grafts seeded with autologous bone marrow mononuclear cells were implanted in 25 patients with univentricular physiology. The graft is composed of a woven fabric of poly-l-lactide acid or polyglycolic acid and a 50:50 poly (l-lactic-co-ε-caprolactone) copolymer. Patients were followed up with postoperatively in a multidisciplinary clinic. Median patient age at operation was 5.5 years and the mean follow-up period was 11.1 years. There was no graft-related mortality during the follow-up period. There was also no evidence of aneurysmal formation, graft rupture, graft infection, or calcification. Seven (28%) patients had asymptomatic graft stenosis and underwent successful balloon angioplasty. Stenosis is the primary complication of the tissue-engineered vascular graft. Avoidance of anticoagulation therapy would improve patients' quality of life. Tissue-engineered vascular grafts have feasibility in pediatric cardiovascular surgery.

Life After Surviving Fontan Surgery: A Meta-Analysis of the Incidence and Predictors of Late Death

AIM

We now know that 20-40% of patients with a single ventricle will develop heart failure after the second decade post-Fontan surgery. However, we remain unable to risk-stratify the cohort to identify patients at highest risk of late failure and death. We conducted a systematic review of all reported late outcomes for patients with a Fontan circulation to identify predictors of late death.

METHODS

We searched MEDLINE, Embase and PubMed with subject terms ("single ventricle", "Hypoplastic left heart syndrome", "congenital heart defects" or "Fontan procedure") AND ("heart failure", "post-operative complications", "death", "cause of death", "transplantation" or "follow-up studies") for relevant studies between January 1990 and December 2015. Variables identified as significant predictors of late death on multivariate analysis were collated for meta-analysis. Survival data was extrapolated from Kaplan-Meier survival curves to generate a distribution-free summary survival curve.

RESULTS

Thirty-four relevant publications were identified, with a total of 7536 patients included in the analysis. Mean follow-up duration was 114 months (range 24-269 months). There were 688 (11%) late deaths. Predominant causes of death were late Fontan failure (34%), sudden death (19%) and perioperative death (16%). Estimated mean survival at 5, 10 and 20 years post Fontan surgery were 95% (95%CI 93-96), 91% (95%CI 89-93) and 82% (95%CI 77-85). Significant predictors of late death include prolonged pleural effusions post Fontan surgery (HR1.18, 95%CI 1.09-1.29, p<0.001), protein losing enteropathy (HR2.19, 95%CI 1.69-2.84, p<0.001), increased ventricular end diastolic volume (HR1.03 per 10ml/BSA increase, 95%CI 1.02-1.05, p<0.001) and having a permanent pacemaker (HR12.63, 95%CI 6.17-25.86, p<0.001).

CONCLUSIONS

Over 80% of patients who survive Fontan surgery will be alive at 20 years. Developing late sequelae including protein losing enteropathy, ventricular dysfunction or requiring a pacemaker predict a higher risk of late death.

Lessons Learned From a Critical Analysis of the Fontan Operation Over Three Decades in a Single Institution

Background:

The Fontan operation (FO) has evolved and many centers have demonstrated improved results relative to those from earlier eras. We report a single-institution experience over three decades, describing the outcomes and evaluating risk factors.

Methods:

Successive patients undergoing primary FO were divided into era I (1984-1994), era II (1995-2004), and era III (2005-2014). Clinical and operative notes were reviewed for demographic, anatomic, and procedure details. End points included early and late mortality and a composite of death, heart transplantation (HTX), or Fontan takedown.

Results:

A total of 420 patients underwent 18 atriopulmonary connections, 82 lateral tunnels (LT), and 320 extracardiac conduit (EC) Fontan procedures. Forty-six (11%) patients died; early and late mortality were 7.9% and 3.1%, respectively. Eight (1.9%) patients underwent HTX, 11 (2.6%) underwent Fontan conversion to EC, and 1 (0.2%) takedown of EC to bidirectional Glenn shunt. Prevalence of concomitant valve surgery ( P < .001) and pulmonary artery reconstruction ( P < .001) differed over the eras. Preoperative valve regurgitation was associated with likelihood of early mortality (odds ratio [OR] = 3.5, P = .002). Embolic events (OR = 1.9, P = .047), preoperative valve regurgitation (OR = 2.3, P = .029), diagnosis of unbalanced atrioventricular canal defect (OR = 1.14, P = .03), and concomitant valve replacement (OR = 6.9, P = .001) during the FO were associated with increased risk of the composite end point (death, HTX, or takedown).

Conclusion:

Technical modifications did not result in improved results across eras, due in part to more liberal indications for surgery in the recent years. Valve regurgitation, unbalanced atrioventricular canal, embolic events, or concomitant valve replacement were associated with FO failure.

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.

Current Expectations for Cardiac Transplantation in Patients With Congenital Heart Disease

Congenital heart disease accounts for 40% of pediatric heart transplants and presents unique challenges to the transplant team. Suitability for transplantation is defined in part by degree of sensitization, pulmonary vascular resistance, and hepatic reserves. The incremental transplant risk for patients with congenital heart disease occurs within the first 3 months, after which survival is equivalent to transplantation for cardiomyopathy. Single ventricle with prior palliation, and especially the failing Fontan, carry the highest risk for transplantation and are least amenable to bridging with mechanical circulatory support. More effective bridging to transplant with mechanical circulatory support will require improvements in the adverse event profile of available pumps and the introduction of miniaturized continuous flow technology. The major barriers to routine long-term survival are chronic allograft failure and allograft vasculopathy. Despite these many challenges, continuing improvements in the care of pediatric heart transplant patients have pushed the median posttransplant survival past 15 years for children and to 20 years for infants.

Intermediate-Term Results After Extracardiac Conduit Fontan Palliation in Children and Young Adults with Single Ventricle Physiology-A Single-center Experience

The Fontan operation and its modifications are currently the standard palliation in patients with single ventricle physiology. The advantages of extracardiac conduit Fontan operation (ECF) have previously been described. We evaluated the outcome of patients who underwent ECF operation at our center since the year 2000 to assess morbidity, mortality and New York Heart Association (NYHA) functional class in the current era. Medical records of 97 patients who underwent ECF operation from November 2000 till October 2013 were reviewed to determine the diagnosis, age at surgery, surgical technique, postoperative complications, NYHA class at last follow-up, echocardiographic parameters, and most recent Holter monitor results. The median age at surgery was 3.4 years with 4 total deaths until last follow-up (hospital mortality was 1 %, and mortality after hospital discharge was 3 %). Seventy-eight of the 97 patients (80 %) underwent fenestrated Fontan surgery. Median duration of follow-up was 3.9 years (IQR 0.2-12.2 years). At the latest follow-up, 62 patients (67 %) were determined to be in NYHA class I, 25 patients (27 %) in NYHA class II, and 6 (6 %) patients in NYHA class III, and the median oxygen saturation was 92 % (IQR 86-96). There were 15 patients with history of preoperative arrhythmias and 6 of them required pacemaker placement at the time of surgery. One patient developed ectopic atrial tachycardia, and 1 patient had clinical thromboembolism on follow-up. Systolic function of the single ventricle by transthoracic echocardiogram at the latest follow-up was described as normal in 77 patients (83 %), fair in 15 patients (16 %), and poor in 1 patient (1 %). The results of our study show that patients who undergo extracardiac conduit Fontan operation in the modern era may have significantly less morbidity and mortality when compared to earlier years.

Clinical outcome following total cavopulmonary connection: a 20-year single-centre experience

OBJECTIVES

This study aims to evaluate the clinical outcome following total cavopulmonary connection (TCPC) and to identify factors affecting early and late outcome.

METHODS

Between May 1994 and March 2015, 434 patients underwent TCPC with 50 lateral tunnels and 374 extracardiac conduits. The clinical outcome, exercise capacity and liver examination results were retrospectively reviewed.

RESULTS

Thirty-day survival was 98.2%, and the estimated survival rate at 15 years was 92.3%. Freedom from tachyarrhythmia at 15 years was 91.0%. Other late morbidities included bradyarrhythmia in 17, protein-losing enteropathy (PLE) in 15, thromboembolism in 3 and plastic bronchitis in 3 patients. At last follow-up, normal systemic ventricular function (ejection fraction >50%) was observed in 88.2%. Atrioventricular valve (AVV) regurgitation was mild or less in 90% of patients with systemic left ventricle, in 63% of those with systemic right ventricle and 58% of the patients with unbalanced atrioventricular septal defect or common inlet ventricles. Cardiopulmonary exercise capacity showed impaired peak oxygen uptake (71% of normal) in a sub-group of 120 patients at a mean of 9 years postoperatively. Biochemistry of 338 patients at last follow-up revealed a gamma-glutamyl transferase value beyond normal in 90 patients (26%), with a positive correlation between the level and the time after the initial operation (P < 0.01). Pre-TCPC high transpulmonary gradient emerged as a predictor for delayed hospital recovery (P = 0.002), late mortality (P = 0.016) and reoperation (P = 0.015) in multivariable analysis.

CONCLUSIONS

Contemporary TCPC can be performed with low risk and provides excellent survival in the long-term. Classic morbidities of the original Fontan procedure, such as Fontan pathway revision, tachyarrhythmia and thromboembolism seem mitigated. However, exercise limitations, PLE and liver dysfunction remain an issue. AVV insufficiency and ventricular dysfunction are still a concern.

Early and intermediate-term results of the extracardiac conduit total cavopulmonary connection for functional single-ventricle hearts

BACKGROUND/PURPOSE

Fontan operation has evolved from atriopulmonary connection to total cavopulmonary connection (TCPC) due to its advantages in terms of hemodynamics and reduction of atrium-related complications. We analyzed the early and intermediate-term results of extracardiac conduit TCPC (EC-TCPC) procedure in patients with functional single ventricle to investigate the risk factors of surgical mortality and intermediate failure.

METHODS

Retrospective review of the medical records of 88 consecutive patients with functional single ventricle who underwent EC-TCPC from 2000 to 2013 was conducted.

RESULTS

The follow-up was 100% complete, ranging from 3 months to 13 years (mean 7.0 ± 3.8 years). There were two (2.3%) hospital and 18 (20.4%) late deaths. The estimated event-free survival rates at 1 year, 5 years, and 10 years were 90.6%, 89.3%, and 77.2%, respectively. On univariate analysis, fenestration was the only risk factor for surgical mortality (p = 0.027). On multivariate analysis, the significant atrioventricular valve regurgitation was the only risk factor for intermediate failure (p = 0.017).

CONCLUSION

The clinical results of EC-TCPC in patients with functional single ventricle were satisfactory. The patients who needed fenestration during operation had higher risk of surgical mortality. Significant atrioventricular valve regurgitation had negative impact on intermediate survival.

Arrhythmia diagnosis and management throughout life in congenital heart disease

Arrhythmias, covering bradycardia and tachycardia, occur in association with congenital heart disease (CHD) and as a consequence of surgical repair. Symptomatic bradycardia can occur due to sinus node dysfunction or atrioventricular block secondary to either unrepaired CHD or surgical repair in the area of the conduction system. Tachyarrhythmias are common in repaired CHD due to scar formation, chamber distension or increased chamber pressure, all potentially leading to abnormal automaticity and heterogeneous conduction properties as a substrate for re-entry. Atrial arrhythmias occur more frequently, but ventricular tachyarrhythmias may be associated with an increased risk of sudden cardiac death, notably in patients with repaired tetralogy of Fallot or aortic stenosis. Defibrillator implantation provides life-saving electrical therapy for hemodynamically unstable arrhythmias. Ablation procedures with 3D electroanatomic mapping technology offer a viable alternative to pharmacologic or device therapy. Advances in electrophysiology have allowed for successful management of arrhythmias in patients with congenital heart disease.

Results of extracardiac conduit total cavopulmonary connection in 500 patients

OBJECTIVES

This single-institution study aimed to evaluate the early to mid-term outcomes of extracardiac conduit total cavopulmonary connection (EC-TCPC).

METHODS

Between March 1994 and March 2014, 500 patients (median age, 3.4 years) underwent EC-TCPC at our hospital. One hundred and twenty-three patients (24.6%) showed heterotaxy, and fenestration was created in 6 patients (1.2%). The standard institutional treatment policy included postoperative anticoagulation and individualized cardiovascular medication. The mortality and morbidity rates, haemodynamic status, cardiopulmonary exercise capacity and liver examination results during the follow-up period (median, 6.7 years) were retrospectively reviewed.

RESULTS

There were 2 early and 17 late deaths. The Kaplan-Meier estimated survival rate was 96.2% at 10 years and 92.8% at 15 years. Bradyarrhythmia and tachyarrhythmia occurred in 19 and 13 patients, respectively. Other late-occurring morbidities included protein-losing enteropathy in 8, thromboembolism in 5, bleeding complications in 6 and liver cirrhosis in 1 patient. The rate of freedom from late-occurring morbidities was 82.1% at 15 years. In the multivariate analysis, heterotaxy was found to be a predictor for mortality (P = 0.02), whereas age at operation was a predictor for new-onset arrhythmias (P = 0.048). In the cardiopulmonary exercise test (n = 312), the peak VO2 was 84.9 ± 17.3% of the predicted value, which tended to decrease with age (R(2) = 0.32) and elapsed time since operation (R(2) = 0.21). Postoperative cardiac catheterization (n = 468; time from surgery, 3.6 ± 4.3 years) showed central venous pressure of 9.9 ± 2.4 mmHg, ventricular end-diastolic pressure of 5.2 ± 3.3 mmHg, cardiac index of 3.4 ± 0.8 l/min/m(2) and arterial oxygen saturation of 94.2 ± 4.8%. In 101 patients who were followed up for ≥10 years, amino-terminal type III procollagen peptide and collagen type IV levels exceeded the normal ranges in 52.9 and 75.2% of patients, respectively, and liver ultrasonography revealed hyper-echoic spots in 43.3% of patients.

CONCLUSIONS

The early to mid-term outcomes of post-EC-TCPC patients managed with individualized pharmacotherapy were excellent, with low mortality and morbidity rates; however, development of late-occurring morbidities specific to Fontan physiology, including exercise intolerance and liver disease, must be carefully monitored during the long-term follow-up.

Redefining Expectations of Long-Term Survival After the Fontan Procedure

Background—

The life expectancy of patients undergoing a Fontan procedure is unknown.

Methods and Results—

Follow-up of all 1006 survivors of the 1089 patients who underwent a Fontan procedure in Australia and New Zealand was obtained from a binational population-based registry including all pediatric and adult cardiac centers. There were 203 atriopulmonary connections (AP; 1975–1995), 271 lateral tunnels (1988–2006), and 532 extracardiac conduits (1997–2010). The proportion with hypoplastic left heart syndrome increased from 1/173 (1%) before 1990 to 80/500 (16%) after 2000. Survival at 10 years was 89% (84%–93%) for AP and 97% (95% confidence interval [CI], 94%–99%) for lateral tunnels and extracardiac conduits. The longest survival estimate was 76% (95% CI, 67%–82%) at 25 years for AP. AP independently predicted worse survival compared with extracardiac conduits (hazard ratio, 6.2; P <0.001; 95% CI, 2.4–16.0). Freedom from failure (death, transplantation, takedown, conversion to extracardiac conduits, New York Heart Association III/IV, or protein-losing enteropathy/plastic bronchitis) 20 years after Fontan was 70% (95% CI, 63%–76%). Hypoplastic left heart syndrome was the primary predictor of Fontan failure (hazard ratio, 3.8; P <0.001; 95% CI, 2.0–7.1). Ten-year freedom from failure was 79% (95% CI, 61%–89%) for hypoplastic left heart syndrome versus 92% (95% CI, 87%–95%) for other morphologies.

Conclusions—

The long-term survival of the Australia and New Zealand Fontan population is excellent. Patients with an AP Fontan experience survival of 76% at 25 years. Technical modifications have further improved survival. Patients with hypoplastic left heart syndrome are at higher risk of failure. Large, comprehensive registries such as this will further improve our understanding of late outcomes after the Fontan procedure.

Prevalence of arrhythmias late after the Fontan operation

The extracardiac conduit (ECC) modification of the Fontan procedure has been theorized to reduce the risk of sinus node dysfunction and atrial arrhythmia compared with the intra-atrial lateral tunnel (ILT) Fontan. This study aimed to compare the prevalence of early and late arrhythmias in patients who underwent ECC and ILT Fontan from a similar era with long-term follow-up at a single institution. A retrospective cohort study was conducted of all patients who underwent ECC or ILT Fontan from 1995 to 2005 at The Children's Hospital of Philadelphia. Bradyarrhythmias (including sinus node dysfunction), tachyarrhythmias, and pacemaker burden prevalence was determined throughout early (<30 days) and late (>30 days) postoperative periods. Of 434 patients undergoing the Fontan procedure during the study period, a total of 87 and 106 patients who underwent ECC and ILT Fontan, respectively, met the inclusion criteria. There were no significant differences in risk of sinus node dysfunction or tachyarrhythmia in both early and late postoperative periods. Although the overall risk of late postoperative pacemaker therapy was lower for the ECC cohort (4.9% vs 15.7%, p=0.03), when adjusting for follow-up time, no significant difference was observed (odds ratio 3.1, 95% confidence interval 0.6 to 15.2, p=0.16). In conclusion, the overall prevalence of late postoperative arrhythmias observed after contemporary Fontan modifications is low. Intra-atrial reentrant tachycardia, a potentially fatal complication of the atriopulmonary Fontan operation was infrequently encountered in both ECC and ILT Fontan cohorts. Pacemaker use was higher in the ILT group, although this difference may be explained by differences in follow-up time. Despite the low prevalence of arrhythmias after contemporary Fontan modifications, ongoing surveillance is warranted as the onset of arrhythmias may emerge after longer follow-up time.

Thrombosis and Thromboembolic Complications in Fontan Patients

Hemodynamic fluctuations and thromboembolic complications are significant areas of concern during the postoperative management of patients with univentricular hearts. The objective of this study is to review the incidence and risk factors associated with thrombosis and thromboembolic complications following total cavopulmonary anastomosis, the third stage of the palliative surgical procedure. A literature search of published evidence was conducted on OvidSP MEDLINE(R) and Embase followed by paired title, abstract, and full-text screening based on specific inclusion criteria. High risks of thromboembolic outcomes were identified across studies, with variable incidences between 3% and 20%, high mortality rates up to 38%, and an inverse relationship with prophylaxis treatment administration. Several risk factors for thrombotic complications, including chronic systemic venous hypertension, protein-losing enteropathy, passive blood flow, atrial arrhythmias, conduit stenosis, prosthetic material use, coagulation factor abnormalities, and several patient characteristics were identified. Based on these findings, a prophylactic anticoagulation algorithm has been proposed.

High incidence of Dacron conduit stenosis for extracardiac Fontan procedure

OBJECTIVES

Extracardiac conduits are widely used to complete a Fontan circulation in patients with univentricular hearts. Although polytetrafluoroethylene conduits have proven good long-term patency, Dacron (polyethylene terephthalate) prostheses are still infrequently applied, with, as yet, no information on the long-term patency.

METHODS

All patients who received an extracardiac Dacron conduit (n = 12) were retrospectively studied. The initial conduit size was 16 mm in all recipients. The mean age at Fontan completion was 3.1 ± 0.7 years. Patients with clinical symptoms and/or significant conduit stenosis (>50% of diameter) underwent reoperation.

RESULTS

Of the 12 patients, 8 underwent reoperation (75%) at a mean interval of 6.5 ± 1.8 years after the Fontan operation. All conduits were replaced by an 18-mm polytetrafluoroethylene graft. The explants showed ubiquitous tissue deposits on the inner surface, with a residual internal diameter from 8 to 11 mm. All patients survived the extracardiac conduit replacement. Recovery was uneventful, except that 1 patient experienced long-lasting pleural fluid drainage. The mean hospital stay was 10.6 ± 12.0 days.

CONCLUSIONS

The incidence of extracardiac Dacron conduit stenosis in total cavopulmonary connection patients is high. These data indicate that the use of this type of conduit should be avoided. Vigilant follow-up is advised for those patients who have undergone Fontan completion with a Dacron extracardiac conduit.

Extracardiac conduit Fontan procedure versus intra-atrial lateral tunnel Fontan procedure

The Fontan procedure has provided excellent surgical palliation for patients with various types of univentricular hearts, and it has evolved over time. Among many modifications, the lateral tunnel Fontan connection (LTF) and the extracardiac Fontan connection (ECF) are currently the most popular techniques for completing the total cavopulmonary connection. The advantages and disadvantages of both techniques are reviewed here. The advantages of the ECF includes adaptability to all types of univentricular hearts, ease of construction without aortic cross clamping and fewer atrial suture lines. The advantages of the LTF include the ability to complete Fontan circulation in young, very small patients with potential for growth. This review also compares post-operative arrhythmias and fluid dynamics associated with both techniques.

Hybrid Access to Atria via the Guiraudon Universal Cardiac Introducer for Arrhythmia Ablation after Total Cavopulmonary Derivation

We report the first use of a new platform, the Guiraudon Universal Cardiac Introducer (GUCI), in humans for accessing the left atrium for catheter-based ablations in patients with resistant atrial arrhythmias after total cavopulmonary derivation. The GUCI was originally designed for intracardiac access for closed, beating instrumental intracardiac surgery.

The patient was a 29-year-old man with problematic atrial arrhythmias resistant to antiarrhythmic drugs because of severe uncontrolled bradycardia and because his pacemaker was explanted for infection.

The GUCI was attached to the left atrial appendage via an anterior left thoracotomy. The GUCI was modified to accommodate introduction and manipulation of multiple catheters. This allowed electrophysiologists to perform catheter-based exploration and ablation. A DDD pacemaker was implanted, with an atrial endocardial lead introduced via the GUCI cuff and a ventricular epicardial lead.

Postoperative atrial arrhythmias were controlled using amiodarone and atrial pacing. At the 12-month follow-up, the patient was arrhythmia- and drug-free and returned to full employment.

This new access offers an additional new alternative atrial access to treat resistant arrhythmia after total cavopulmonary derivation. The current state-of-the-art makes patient selection difficult and uncomfortable for the surgeons because of incomplete preoperative electrophysiological data, such as a return to the beginning of surgery for arrhythmia; however, more cumulative experience with intraoperative electrophysiological data and new mapping technologies should address these limitations.

Atrioventricular valve repair for patient with heterotaxy syndrome and a functional single ventricle

Heterotaxy syndrome is a mortality risk factor for patients with complex heart disease. These patients often have common atrioventricular valve (CAVV) morphology and significant atrioventricular valve regurgitation - yet another mortality risk factor in congenital heart disease. Thus, patients with both heterotaxy syndrome and atrioventricular valve regurgitation are at highest risk of mortality. A large number of patients with heterotaxy syndrome have CAVV and a functional single ventricle. These patients are more difficult to operate than patients with biventricular morphology because in the former, the CAVV is often less adapted to systemic afterload than the mitral valve. Herein, we present the results of atrioventricular valve repair surgeries performed at the Okayama University Hospital on patients with heterotaxy syndrome, atrial isomerism, and a functional single ventricle. In addition, we review the current literature in this typically challenging patient population. In-depth understanding of reasonable management strategies and resolution of technical issues will help guide surgeons during this procedure.

Extracardiac versus intra-atrial lateral tunnel fontan: extracardiac is better

This article was prepared to summarize the points made in a debate that the first author (C.L.B.) had with Dr. Richard Jonas at the American Association for Thoracic Surgery 90th Annual Meeting. The topic of the debate was the optimal surgical approach for functional single-ventricle patients: extracardiac versus intra-atrial lateral tunnel Fontan. My role was to take the viewpoint that the extracardiac Fontan is better. This review summarizes our results at Children's Memorial Hospital (Chicago, IL) with 180 patients undergoing a primary Fontan procedure and 126 patients undergoing an extracardiac Fontan as part of a Fontan conversion. The world literature was reviewed on outcomes following the Fontan procedure, focusing on six main areas supporting the superiority of the extracardiac Fontan: hemodynamics, arrhythmias, applicability to complex anatomy, use of cardiopulmonary bypass, complications of fenestration and thromboembolism, and operative mortality. Based on this review, it is our conclusion that the extracardiac Fontan is the procedure of choice for patients with a functional single ventricle based on a very low operative mortality, a lower incidence of early and late arrhythmias, improved hemodynamics, fewer postoperative complications, and applicability to a wide variety of complex cardiac anatomy.

The Fontan operation: the pursuit of associated lesions and cumulative trauma

Our programmatic approach to the Fontan operation has evolved to include using an extracardiac conduit with aggressive presumptive treatment of associated lesions either in the catheterization laboratory or the operating room. Fenestration is used selectively based on hemodynamics, anatomy, and presence of associated lesions. We reviewed our experience to determine the effectiveness and outcome of this strategy and to assess the cumulative trauma to the patients. The records of 137 consecutive patients who underwent Fontan at Miami Children's Hospital from 1995 to 2008 were reviewed. At mean follow up of 5.76 years, freedom from death or transplantation is 94.2% (129/137). Median age at operation was 4.6 years. Longer length of stay correlated with older operative age (P = 0.0056). Pacemakers were implanted in 11.7% (16/137). Additional (not pre-Glenn or pre-Fontan) interventional catheterizations were performed in 51.8% (71/137). Additional operations were done in 10.2% (14/137). No patient has required replacement or revision of the extracardiac conduit. Our current approach to the Fontan operation provides acceptable midterm results. The pursuit of residual lesions results in a significant number of additional interventional catheterizations and operative procedures but might have an important influence on long-term survival after the Fontan procedure.

Staged Fontan operation for children with heterotaxy syndrome, bilateral ductus arteriosus, and nonconfluent pulmonary artery

We report two cases of successful Fontan operation in children with heterotaxy syndrome associated with univentricular physiology and absent and nonconfluent central pulmonary arteries with both distal pulmonary arteries directly connected to the ipsilateral ductus arteriosus. After unilateral systemic-pulmonary shunt, the central pulmonary artery was reconstructed with a polytetrafluoroethylene prosthetic graft concomitantly with bidirectional cavopulmonary shunt. Finally, extracardiac total cavopulmonary connection was performed as an off-pump procedure. Children with bilateral ductus arteriosus and a nonconfluent pulmonary artery with univentricular physiology present a particular challenge in regard to completing Fontan operations. Careful attention should be directed at ensuring balanced growth of the bilateral distal pulmonary arteries. When planning reconstruction of the central pulmonary artery with a prosthesis, late reconstruction may be beneficial, as it enables utilization of a larger-caliber graft, obviating the need for replacement during a subsequent Fontan operation.

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-term results of tissue-engineered vascular grafts in humans

OBJECTIVE

The development of a tissue-engineered vascular graft with the ability to grow and remodel holds promise for advancing cardiac surgery. In 2001, we began a human trial evaluating these grafts in patients with single ventricle physiology. We report the late clinical and radiologic surveillance of a patient cohort that underwent implantation of tissue-engineered vascular grafts as extracardiac cavopulmonary conduits.

METHODS

Autologous bone marrow was obtained and the mononuclear cell component was collected. Mononuclear cells were seeded onto a biodegradable scaffold composed of polyglycolic acid and epsilon-caprolactone/L-lactide and implanted as extracardiac cavopulmonary conduits in patients with single ventricle physiology. Patients were followed up by postoperative clinic visits and by telephone. Additionally, ultrasonography, angiography, computed tomography, and magnetic resonance imaging were used for postoperative graft surveillance.

RESULTS

Twenty-five grafts were implanted (median patient age, 5.5 years). There was no graft-related mortality (mean follow-up, 5.8 years). There was no evidence of aneurysm formation, graft rupture, graft infection, or ectopic calcification. One patient had a partial mural thrombosis that was successfully treated with warfarin. Four patients had graft stenosis and underwent successful percutaneous angioplasty.

CONCLUSION

Tissue-engineered vascular grafts can be used as conduits in patients with single ventricle physiology. Graft stenosis is the primary mode of graft failure. Further follow-up and investigation for the mechanism of stenosis are warranted.

Exercise Tolerance in Extracardiac Total Cavopulmonary Connection

Cardiopulmonary adaptation during exercise was compared in patients with an extracardiac total cavopulmonary connection and controls with biventricular repair of Fallot's tetralogy. Heart rate, blood pressure, respiratory frequency, and transcutaneous oxygen saturation increased with treadmill exercise intensity below grade 3 in patients who had undergone extracardiac total cavopulmonary connection. When exercise intensity exceeded grade 4, blood pressure and oxygen saturation decreased continuously, respiratory rate kept increasing, and heart rate showed no significant change. In cases of fenestrated cavopulmonary connection, heart rate peaked at grade 5 exercise intensity, and blood pressure at grade 4; but both peaked at grade 3 in nonfenestrated patients. During all exercise testing, fenestrated patients had a higher respiratory rate but lower oxygen saturation than those without fenestration. Exercise tolerance was below normal after a cavopulmonary connection, but patients still adapted to exercise below grade 3 with appropriate increases in heart rate and respiratory rate. Due to insufficient right heart systems, patients with a cavopulmonary connection showed obvious exercise limitation at exercise intensity grade 3 or more. Total exclusion of the right heart system may also have adverse effects on the sinoatrial node, leading to impaired heart rate regulation.