Lateral tunnel versus extracardiac conduit fontan procedure: a concurrent comparison

Cardiac magnetic resonance ventricular parameters correlate with cardiopulmonary fitness in patients with functional single ventricle

Owing to advances in medical and surgical fields, patients with single ventricle (SV) have a greatly improved life expectancy. However, progressive functional deterioration is observed over time, with a decrease in cardiopulmonary fitness. This study aimed to identify, in patients with SV, the association between cardiac magnetic resonance imaging (CMR) parameters and change in cardiopulmonary fitness assessed by cardiopulmonary exercise test (CPET), and if certain thresholds could anticipate a decline in aerobic fitness. Patients with an SV physiology were retrospectively screened from 2011 and 2021 in a single-centre observational study. We evaluated (1) the correlation between baseline CMR and CPET parameters, (2) the association between baseline CMR results and change in peak oxygen uptake (peak VO2), and (3) the cut-off values of end-diastolic and end-systolic volume index in patients with an impaired cardiopulmonary fitness (low peak VO2 and/or high VE/VCO2 slope). 32 patients were included in the study. End-systolic volume index (r = 0.37, p = 0.03), end-diastolic volume index (r = 0.45, p = 0.01), and cardiac index (r = 0.46, p = 0.01) correlated with the VE/VCO2 slope. End-systolic ventricular volume (r = - 0.39, p = 0.01), end-diastolic ventricular volume (r = - 0.38, p = 0.01), and cardiac output (r = - 0.45, p < 0.01) inversely correlated with the peak VO2. In multivariate analysis, the cardiac index obtained from baseline CMR was inversely associated with the change in peak VO2 (p < 0.01). An end-diastolic volume index > 101 ml/m2 and an end-systolic volume index > 47 ml/m2 discriminated patients with impaired cardiopulmonary fitness. CMR parameters correlate with cardiopulmonary fitness in patients with SV and can therefore be useful for follow-up and therapeutic management of these patients.

Does the External Pericardial Lateral Tunnel Fontan Pathway Enlarge to Accommodate Somatic Growth? A Preliminary Analysis

Objectives: An ideal Fontan pathway should be capable of adapting to changes in circulatory demands. The external pericardial lateral tunnel Fontan (EPLTF) is constructed of viable, autologous tissue and may be capable of changing in size. We investigated the ability of the EPLTF to enlarge with increasing physiologic demands of somatic growth. Methods: Retrospective review of echocardiographic images for patients with a minimum of five years follow-up after EPLTF. Serial echocardiographic measurements of the EPLTF pathway were obtained at three distinct locations: the inferior vena cava junction with the EPLTF, midsection of the EPLTF, and cross-sectional area of the EPLTF visualized in a four-chamber view. Body surface area (BSA) was calculated at the time of each echocardiographic measurement. Changes in echocardiographic measurements over time were analyzed and compared with changes in BSA. Results: A total of 332 echocardiographic studies from 38 patients were reviewed. Significant enlargement of the EPLTF pathway is observed at the inferior vena caval junction (P < .001), midsection (P < .01), and cross-sectional area (P < .001). Repeated measures correlation between pathway measurements and BSA is highly significant (P < .001). Conclusions: The EPLTF pathway enlarges over time in correlation with increasing BSA. Further research is needed to define ideal pathway size, differentiate normal physiologic growth from pathologic enlargement, and correlate changes with clinical outcomes.

Prevalence of Arrhythmia in Adults after Fontan Operation

Structural, hemodynamic, and morphological cardiac changes following Fontan operation (FO) can contribute to the development of arrhythmias and conduction disorders. Sinus node dysfunction, junction rhythms, tachyarrhythmias, and ventricular arrhythmias (VAs) are some of the commonly reported arrhythmias. Only a few studies have analyzed this condition in adults after FO. This study aimed to determine the type and prevalence of arrhythmias and conduction disorders among patients who underwent FO and were under the medical surveillance of the John Paul II Hospital in Krakow. Data for the study were obtained from 50 FO patients (mean age 24 ± 5.7 years; 28 men (56%)). The median follow-up time was 4 (2–9) years. Each patient received a physical examination, an echocardiographic assessment, and a 24 h electrocardiogram assessment. Bradyarrhythmia was diagnosed in 22 patients (44%), supraventricular tachyarrhythmias in 14 patients (28%), and VAs in 6 patients (12%). Six patients required pacemaker implantation, and three required radiofrequency catheter ablation (6%). Arrythmias is a widespread clinical problem in adults after FO. It can lead to serious haemodynamic impairment, and therefore requires early diagnosis and effective treatment with the use of modern approaches, including electrotherapy methods.

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.

Perioperative outcomes of Fontan operation: Impact of heterotaxy syndrome

BACKGROUND/PURPOSE

Fontan operation is the standard surgical procedure for achieving long-term survival in single-ventricular complex congenital heart diseases (SV-CHD). We aim to identify the perioperative outcomes and impact of heterotaxy syndrome (HS) after Fontan operation in a tertiary pediatric cardiology center.

METHODS

Medical records were reviewed for all patients who received Fontan operation and who were born between 1997 and 2017 in our institution. Preoperative, operative, and postoperative risk factors for perioperative mortality and morbidity were analyzed.

RESULTS

Totally, 154 patients were enrolled (103 SV-CHD and 51 HS), and the male to female ratio was 92:62. The mean age of Fontan operation was 5.1 years, and extracardiac conduit comprised the majority (90.9%) of Fontan operation. Overall perioperative event-free survival to discharge was 91.6% (84.3% in HS and 95.1% in other SV-CHD, P = 0.032). For secondary outcomes, length of intensive care stay and duration of pleural effusion drainage were not significantly different between patients with HS and other SV-CHD, but postoperative arrhythmia was more common in HS group (31.4% vs. 12.6%, P = 0.005). In multivariable regression analysis, preoperative risk factors including operation year before 2007 and high PAP and postoperative factors of elevated postoperative CVP were associated with worse outcomes. HS was not a predictor of worse outcome after adjusting for preoperative PAP and operation era.

CONCLUSION

Surgical outcome has improved much in current era. Perioperative outcome is poorer in patients with HS than other SV-CHD, but HS is not a predictor of perioperative mortality after adjusting for hemodynamic factors.

The intra-extracardiac Fontan: preliminary results

OBJECTIVE

Since the intra-extracardiac Fontan (IECF) was popularized by Jonas in 2008, its claimed advantages over the traditional extracardiac or lateral tunnel Fontan are simplicity, suitability for nearly all subsets, flow characteristics, low risk of sinus node artery injury, and possibly, a lower incidence of arrhythmias. In this paper, we present our early experience with this modification of the Fontan operation.

METHODS

Between 2009 and 2018, 10 patients underwent IECF on cardiopulmonary bypass (CPB) and cardioplegic arrest at our institute. Analysis of preoperative, intraoperative, and early follow-up results was performed. A polytetrafluoroethylene (PTFE) graft was sutured proximally to the orifice of the inferior vena cava (IVC) and distally to the ipsilateral bidirectional superior cavopulmonary (BSCP) junction.

RESULTS

Nine patients had undergone a previous BSCP connection, and one patient had a primary IECF. Diagnoses were double outlet right ventricle (n = 2), unbalanced atrioventricular septal defect with associated atrioventricular valve regurgitation (n = 3), single ventricle with anomalies of cardiac situs (n = 2), and tricuspid atresia with borderline pulmonary arteries (n = 1) or tricuspid atresia with borderline pulmonary artery pressures (n = 2). Median aortic cross-clamp and CPB times were 42 min and 82 min respectively. There were no early or late deaths. Median intensive care stay was 3 days (1 to 23 days). There were no arrhythmias. Mean duration of pleural effusions was 9.5 (median 5.5) days. There were no arrhythmias at a median follow-up of 5 years (range 1 month to 9.3 years).

CONCLUSION

The IECF is simple, particularly at reoperations, in borderline patients and those needing concomitant intracardiac procedures. Early results are promising. These patients need constant surveillance.

Where are we after 50 years of the Fontan operation?

First introduced in 1971, the Fontan procedure is the final common destination for all patients with a functional single ventricle. The procedure itself has evolved tremendously over the last five decades. This review traces this journey and presents the importance, outcomes and future outlook of the procedure in the current era.

Fontan with lateral tunnel is associated with improved survival compared with extracardiac conduit

OBJECTIVES

The study aim was to compare Fontan patients undergoing lateral tunnel (LT) versus extracardiac conduit (ECC) technique.

METHODS

Fontan patients (LT vs ECC) from January 2000 to December 2017 were analyzed retrospectively. Baseline characteristics were analyzed as covariates. Primary outcomes (ie, mortality, Fontan failure, thrombosis, and pacemaker implantation) were compared using time-to-event models. Subgroup analysis including only initially fenestrated cases and propensity score matching were performed.

RESULTS

Eight hundred one Fontan patients: LT (n = 638) versus ECC (n = 163) were included. Median follow-up time was 4.8 years (range, 1.1-10.8 years). Baseline characteristics were similar except for age: LT versus ECC: 2.6 years (range, 2.2-3.2 years) versus 3.1 years (range, 2.6-4.7 years) (P < .01) and mean pulmonary artery pressure: LT versus ECC: 12 mm Hg (11-15 mm Hg) versus 11 mm Hg (10-13 mm Hg) (P < .05). Early mortality was significantly higher in ECC versus LT group (3.1%; vs 0.5%; P < .05). Freedom from death, heart transplantation and Fontan failure were significantly longer in LT vs ECC (P < .01). After correcting for age, diagnosis, surgical technique, surgeon, mean pulmonary artery pressure, and fenestration, the ECC group showed worse freedom from death (hazard ratio, 2.8; P < .01) and Fontan failure (hazard ratio, 3.0; P < .01). No difference in pacemaker implantation rate was demonstrated (P = .25). Early fenestration closure was associated with higher risk of early (hazard ratio, 30.5) and late mortality (hazard ratio, 3.5). After matching, log-rank tests showed significant differences between the 2 groups for Fontan failure at 5 and 10 years (P < .01) and mortality at 5 years (P = .02).

CONCLUSIONS

When compared with ECC, LT Fontan is associated with better short and midterm outcomes. Spontaneous fenestration closure is an independent risk factor for early/late mortality.

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.

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.

Utility of preoperative Holter monitoring in children undergoing extracardiac conduit Fontan operation

BACKGROUND

In patients undergoing extracardiac conduit Fontan (ECF) who require postoperative pacing, epicardial leads are usually required because of anatomical constraints. If indicated, these could be conveniently placed at the time of ECF. We have routinely performed ambulatory 24-hour Holter monitoring before ECF to determine the presence or absence of preoperative sinus node dysfunction, in an attempt to avoid repeat sternotomy at a later time.

METHODS

We performed a retrospective study of all patients undergoing ECF from January 2000 to December 2015.

RESULTS

Two hundred sixteen patients met inclusion criteria. Patients were separated into two groups, those with preoperative Holter monitoring (PHM, n = 150) and those without (No-PHM, n = 66). Ten patients (4.6%) underwent permanent pacemaker implantation at the time of ECF (eight patients [5.3%] in PHM vs two patients [3.0%] in No-PHM, P = 0.46). There were seven (3.2%) patients who underwent pacemaker implantation after ECF requiring repeat sternotomy (four patients [2.7%] in PHM vs three patients [4.5%] in No-PHM, P = 0.47). Fourteen (6.5%) patients underwent permanent epicardial lead placement without a pulse generator at the time of ECF. None from this group underwent pacemaker implantation to date (median follow-up of 5.7 years). The overall incidence of pacemaker implantation was 9.3% (20 patients).

CONCLUSIONS

In our series, arrhythmia disturbances requiring pacing after ECF occurred in just over 9% of patients. While PHM in those patients may help predict which patients might require postoperative pacing, this approach did not result in a significant decrease in those patients requiring repeat sternotomy for pacemaker implantation.

Comparison of extracardiac conduit and lateral tunnel for functional single-ventricle patients: A meta-analysis

OBJECTIVE

This study aims to assess and compare the early and long-term effects of extracardiac conduit (EC) and lateral tunnel (LT) in patients with a functional single ventricle through meta-analysis.

DESIGN

A systematic search was performed in PubMed, Embase, Cochrane Library, CNKI, VIP, CBM, and WanFang databases for papers that were published until August 1, 2016. Cochrane systematic review method was used for paper screening and information retrieve, and RevMan 5.3 software was applied for the meta-analysis.

RESULTS

Data for 10 studies with a total of 3814 patients were retrieved. The advantages of EC comparing to LT include: lower 30 day postsurgery supraventricular arrhythmia incidence (Relative Risk [RR] = 0.31 [0.17, 0.55], P < .001), lower protein loss enteropathy incidence (RR = 0.33 [0.11, 0.96], P = .04), and requiring no cardiopulmonary bypass. However, the chest drainage time was longer (mean difference [MD] = 1.99 [1.83, 2.15], P < .001) in EC. There were no significant differences in early postoperative mortality, long-term mortality, long-term arrhythmia, Fontan takedown, ventilator-assisted ventilation, ICU stay, thrombosis, pleural effusion, and pericardial effusion between EC and LT.

CONCLUSIONS

EC had a lower incidence of supraventricular arrhythmia (30 days after operation) and the rate of protein losing enteropathy than LT, and requiring no cardiopulmonary bypass. These show that EC has an advantage over the LT in patients with a functional single ventricle.

Lateral Atrial Tunnel Fontan Operation Predisposes to the Junctional Rhythm

The goal of the study was to compare the early postoperative course after fenestrated lateral atrial tunnel (LT) and non-fenestrated extracardiac conduit (EC) Fontan operation (FO) in a single center where both techniques were parallelly used. Between 2004 and 2012, 56(32.7%) children underwent LT and 113(66.1%) EC FO. The mean age was 3.7 ± 2.9 years and mean weight was 14.6 ± 7.3 kg. The most common malformation was hypoplastic left heart syndrome (50.9%). The general approach was to perform LT in children after hemi-Fontan operation and EC in patients after Glenn anastomosis. Medical records were retrospectively reviewed. The hospital survival was 100%. In EC group, cardiopulmonary bypass time (CPB) was shorter (p = 0.004) and less patients needed aortic cross-clamping (p < 0.001). Children after EC stayed longer in the hospital (p = 0.016) and manifested more often prolonged effusions (p = 0.038). The incidence of all forms of junctional rhythm was higher in the LT group, early postoperatively (p < 0.001), during hospitalization (p = 0.004) and at discharge (p < 0.001). Children after LT required more often temporary pacemaker stimulation (p < 0.001). Patients without postoperative normofrequent sinus rhythm had longer CPB time (p = 0.008) and were more often operated on with aortic cross-clamping (p = 0.028). Lateral atrial tunnel Fontan operation with fenestration facilitates early adaptation to the total passive pulmonary flow, but predisposes the patients to the loss of sinus rhythm. The crucial role in the preservation of sinus rhythm plays the last step of the multistage surgery of the single ventricle malformations, probably not only the surgical technique but also factors associated with the cardiopulmonary bypass.

Arrhythmias After Fontan Operation with Intra-atrial Lateral Tunnel Versus Extra-cardiac Conduit: A Systematic Review and Meta-analysis

Current studies on the incidence of arrhythmias after the intra-atrial lateral tunnel (ILT) Fontan operation and the extra-cardiac conduit (ECC) Fontan operation are limited, with controversial results. This systematic review aimed to compare the prevalence of arrhythmias in patients who underwent ECC or ILT Fontan. Relevant studies comparing the incidence of arrhythmias and pacemaker implantation in ILT with ECC were identified through a literature search using MEDLINE, EMBASE, and the cochrane central register of controlled trials. The outcome measures included baseline characteristics, early (≤30 days) and late (>30 days) arrhythmias and pacemaker implantation. 16 publications involving 3499 patients were included. In the meta-analysis, although the overall risk of early arrhythmias was lower for the ILT group, statistically, no significant difference was observed (odds ratio [OR] 0.78; 95% confidence interval [CI] 0.61-1.01; p = 0.06). Similarly, there was no significant difference between the two cohorts in the incidence of postoperative permanent pacemaker therapy (OR 1.36; 95% CI 0.86-2.14; p = 0.19). However, we found significantly increased incidence of late arrhythmias in ILT group compared with ECC group (OR 1.96; 95% CI 1.64-2.35; p < 0.01). Although our systematic review and meta-analysis suggested that there was no significant difference in early arrhythmias and in pacemaker implantation between the ILT and ECC groups, ECC procedure could significantly lower the risk of late arrhythmias after Fontan surgery. Given that some limitations cannot be overcome, well-designed randomized controlled trials are needed to confirm our findings.

Sinus Node Dysfunction After Extracardiac Conduit and Lateral Tunnel Fontan Operation: The Importance of the Type of Prior Superior Cavopulmonary Anastomosis

This review summarizes the influence of the type of prior superior cavopulmonary anastomosis in the studies that report a difference in the occurrence of sinus node dysfunction among extracardiac conduit Fontan and lateral tunnel Fontan operations along with clinical implications.

Arrhythmias in Cardiac Critical Care

OBJECTIVES

Here, we characterize the frequency, mechanisms, clinical impact, and potential treatment options for several arrhythmias commonly encountered in pediatric cardiac critical care.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

Arrhythmias among children in the cardiac critical care setting are common and clinically important, associated independently with prolonged mechanical ventilation, critical care unit stay, and an increase in mortality. The precise characterization of an arrhythmia may provide clues as to an underlying mechanism as well as serve to guide treatment. Arrhythmia therapy, pharmacologic or otherwise, is directed toward addressing the underlying mechanism, and as such may be applicable to the treatment of more than one specific rhythm disturbance. Decisions concerning therapy must call into consideration an arrhythmia's underlying etiology, mechanism, and associated hemodynamic embarrassment, along with the potential for adverse effects of treatment.

Modification of hemi-Fontan operation for patients with functional single ventricle and anomalous pulmonary venous connection to the superior vena cava: mid-term results

OBJECTIVES

Fontan candidates with mixed totally anomalous pulmonary venous connection often have postoperative pulmonary venous obstruction after cavopulmonary anastomosis. Because some pulmonary venous obstructions have no intimal hypertrophy at reoperation, we considered such pulmonary venous obstructions to be caused by 3D deformities arising from dissection or mobilization of the vessels, and hypothesized that keeping the pulmonary venous branches in a natural position could avoid such obstruction. Here, we evaluated a modified hemi-Fontan strategy consisting of minimal dissection with no division of vessels and patch separation between systemic and pulmonary venous flow.

METHODS

We retrospectively reviewed clinical records of infants with a functional single ventricle and supracardiac anomalous pulmonary venous connection who had undergone this procedure between 2002 and 2012.

RESULTS

Nine infants underwent this procedure (median age, 5.6 months; range 3.2-30), all with right atrial isomerism and several pulmonary venous branches directly and separately connecting to the superior vena cava. In 5 patients, all pulmonary veins drained into the superior vena cava; in 1, the right pulmonary veins drained into the superior vena cava and in 3, a pulmonary venous branch drained into the superior vena cava. The median follow-up was 6.9 years (0.8-13 years). Three patients underwent reoperation for postoperative pulmonary venous obstruction caused by intimal hypertrophy; however, we confirmed no pulmonary venous obstruction caused by 3D deformities on the pulmonary venous branches connecting separately to the superior vena cava. Although 2 patients were effectively relieved from pulmonary venous obstruction, 1 died due to recurrent pulmonary venous obstruction. There was no late death and no sinus-node dysfunction. Eight patients underwent successful Fontan operation and catheterization. The median interval from the Fontan operation to the latest catheterization was 3.7 years (0.9-3.7 years). The median arterial oxygen saturation was 94% (91-97%) and the central venous pressure was 12 mmHg (8-14 mmHg); no deficiency of pulmonary arteries and veins was noted.

CONCLUSIONS

For patients with functional single ventricle and anomalous pulmonary venous connections to the superior vena cava, our novel strategy of second-stage palliation could avoid postoperative pulmonary venous obstruction caused by 3D deformities, but may not eliminate pulmonary venous obstruction caused by intimal hypertrophy.

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.

Long-term outcome and anaesthetic management for non-cardiac surgery after Fontan palliation: a single-centre retrospective analysis

OBJECTIVES

The improved management of Fontan patients has resulted in good outcome. As such, these patients may necessitate care for non-cardiac surgery. We sought to determine the long-term outcome of our Fontan series palliated with the most recent surgical techniques. Our second objective was to report the incidence and the perioperative course after non-cardiac procedures. We reviewed the records of all patients with either a lateral tunnel or an extracardiac conduit Fontan between 1996 and 2008. Follow-up was recorded until June, 2013, including records regarding non-cardiac interventions.

RESULTS

Overall, 58 patients were included. Of them, one patient underwent a takedown of his Fontan, and five patients died in the immediate postoperative course. The cumulative survival of the remaining 52 patients was 81%. There was no significant difference in survival between right and left ventricle morphologies (p=0.56), nor between both types of Fontan (p=0.9). Chronic arrhythmias (25%), fatigue/dyspnoea (40%), thrombotic complications (19%), and embolic events (10%) were among the most recurrent comorbidities. In total, 45 non-cardiac interventions were performed on 26 patients, with three bleeding complications and one death.

CONCLUSIONS

This study shows excellent long-term survival after both lateral tunnel and extracardiac conduit Fontan. The incidence of cardiovascular morbidity remains high, however. We also report a high number of non-cardiac interventions. Thorough understanding of the Fontan physiology is mandatory when non-cardiac anaesthesiologists are in charge of these patients.

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>

Comparison of fenestrated and nonfenestrated patients undergoing extracardiac Fontan

BACKGROUND

The purpose of this study is to compare morbidity and mortality between fenestrated (F, 61 patients) and nonfenestrated (NF, 54 patients) extracardiac Fontan patients during two eras from July 1995 to December 2010: era 1(1995 to 2004) and era 2 (2005 to 2010).

METHODS

Variables evaluated included morphology, hemodynamics, chest tube volume and duration, intensive care and hospital stay, oxygen saturation, neurologic events, rhythm, and readmissions for chylous effusions. Follow-up in 114 hospital survivors was longer in the nonfenestrated cohort (F, 5.0 ± 3.3 years; NF, 7.1 ± 4.6 years; p < 0.005).

RESULTS

Cohorts were similar in body size, morphology, and hemodynamics. Fenestration in hypoplastic left heart syndrome was appreciatively higher in era 2. Bypass time (F, 69 ± 27 minutes; NF, 57 ± 21 minutes) and conduit size (F, 18.8 mm; NF, 19.1 mm) were similar. There was 1 early nonfenestrated Fontan death (1 of 54; 2%) and 4 late deaths (F, 2 of 61, 5%; NF, 2 of 53, 4%; p = 0.86). Room air saturation was higher in NF patients (F, 89%; NF, 94%; p < 0.05). Total chest tube volume was similar, but fenestration was associated with greater chest tube drainage among hypoplastic left heart patients (HLHS, 5,582 ± 3,286 mL; non-HLHS, 3,405 ± 2,533 mL; p = 0.06; odds ratio; 2.0). Readmission to treat chylous effusions, loss of sinus rhythm, actuarial freedom from death, all neurologic events, pacemaker insertion, and Fontan takedown were similar in both cohorts.

CONCLUSIONS

Fenestration was associated with lower discharge oxygen saturations, but late outcomes in fenestrated and nonfenestrated patients are equivalent.

Arrhythmias in adult congenital heart disease

Recent advances in pediatric cardiology and cardiac surgery have allowed a rapidly expanding population of patients with congenital heart disease to thrive well into their adult years. Often after prolonged uneventful clinical courses as children and adolescents, arrhythmias may surface later in life. These arrhythmias are a major source of morbidity. In addition, sudden death is the leading cause of mortality in adult patients with congenital heart disease. This review highlights the various types of brady- and tachyarrhythmias encountered in the more common forms of adult congenital heart disease and explores prognostic implications and therapeutic options.

Fontan hemodynamics from 100 patient-specific cardiac magnetic resonance studies: a computational fluid dynamics analysis

OBJECTIVES

This study sought to quantify average hemodynamic metrics of the Fontan connection as reference for future investigations, compare connection types (intra-atrial vs extracardiac), and identify functional correlates using computational fluid dynamics in a large patient-specific cohort. Fontan hemodynamics, particularly power losses, are hypothesized to vary considerably among patients with a single ventricle and adversely affect systemic hemodynamics and ventricular function if suboptimal.

METHODS

Fontan connection models were created from cardiac magnetic resonance scans for 100 patients. Phase velocity cardiac magnetic resonance in the aorta, vena cavae, and pulmonary arteries was used to prescribe patient-specific time-averaged flow boundary conditions for computational fluid dynamics with a customized, validated solver. Comparison with 4-dimensional cardiac magnetic resonance velocity data from selected patients was used to provide additional verification of simulations. Indexed Fontan power loss, connection resistance, and hepatic flow distribution were quantified and correlated with systemic patient characteristics.

RESULTS

Indexed power loss varied by 2 orders of magnitude, whereas, on average, Fontan resistance was 15% to 20% of published values of pulmonary vascular resistance in single ventricles. A significant inverse relationship was observed between indexed power loss and both systemic venous flow and cardiac index. Comparison by connection type showed no differences between intra-atrial and extracardiac connections. Instead, the least efficient connections revealed adverse consequences from localized Fontan pathway stenosis.

CONCLUSIONS

Fontan power loss varies from patient to patient, and elevated levels are correlated with lower systemic flow and cardiac index. Fontan connection type does not influence hemodynamic efficiency, but an undersized or stenosed Fontan pathway or pulmonary arteries can be highly dissipative.

Presurgical evaluation of Fontan connection options for patients with apicocaval juxtaposition using computational fluid dynamics

Apicocaval juxtaposition (ACJ) is a rare congenital heart defect associated with single ventricle physiology where optimal positioning of the Fontan conduit for completion of total cavopulmonary connection (TCPC) is still controversial. In ACJ, the cardiac apex is ipsilateral with the inferior vena cava (IVC), risking kinking and collapse of the Fontan conduit at the apex of the heart. The purpose of this study is to evaluate two viable routes for Fontan conduit connection in patients with ACJ, using computational fluid dynamics. Internal energy loss evaluations were used to determine contribution of conduit curvature to the energy efficiency of each cavopulmonary anastomosis configuration. This percentage of energy loss contribution was found to be greater in the case of a curved extracardiac conduit connection (44%, 4.1 mW) traveling behind the ventricular apex, connecting the IVC to the left pulmonary artery, than the straighter lateral tunnel conduit (6%, 1.4 mW) installed through the ventricular apex. In contrast, net energy loss across the anastomosis was significantly lower with extracardiac TCPC (9.3 mW) in comparison with lateral tunnel TCPC (23.2 mW), highlighting that a curved Fontan conduit is favorable provided that it is traded off for a superior cavopulmonary connection efficiency. Therefore, a relatively longer and curved Fontan conduit has been demonstrated to be a suitable connection option independent of anatomical situations.

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.

Increase in N-terminus-pro-B-type natriuretic peptide during exercise of patients with univentricular heart after a total cavopulmonary connection

An increase in N-terminus pro-B-type natriuretic peptide (NT-proBNP) during exercise is related to myocardial ischemia, myocardial dysfunction, and inflammatory stress. Its value for patients with a univentricular heart after total cavopulmonary connection (TCPC) is unknown. For 66 patients with TCPC, a cardiopulmonary exercise test was performed. Venous NT-proBNP samples were drawn with the patient at rest and then 2-3 min after peak exercise. The median NT-proBNP during rest was 82 ng/l (range, 11-2,554 ng/l), with 22 patients above the upper reference limit. A higher NT-proBNP during rest was related to a worse peak oxygen uptake (peak [Formula: see text]), a higher ventilatory equivalent (VE/VCO(2) slope), and a need for diuretics administration. A small but significant increase in NT-proBNP during exercise at 6 ng/l (range, 0-314 ng/l) was related mainly to its resting value. The relative increase was solely related to a higher body mass and not to any of the investigated functional parameters. Usually, NT-proBNP during rest is not elevated in TCPC patients. If so, it is a valuable predictor of cardiac function. During exercise, only a minor increase in NT-proBNP occurs. Its extent is not related to any of the investigated functional parameters. Maybe the filling restriction from the lungs prevents atrial and ventricular overload as well as BNP secretion in TCPC patients.

Heart rate variability in children with Fontan circulation: lateral tunnel and extracardiac conduit

The technique in Fontan surgery has developed from the lateral tunnel (LT) toward the extracardiac conduit (EC) used to reduce long-term complications such as atrial arrhythmia and sinus node dysfunction. Heart rate variability (HRV) examines cardiac nervous activity controlling the sinus node. This study aimed to investigate HRV in a cohort of children with univentricular hearts, focusing on the relation between HRV and surgical procedure. For 112 children with Fontan circulation, HRV was analyzed using power spectral analysis. Spectral power was determined in three regions: very-low-frequency (VLF), low-frequency (LF), and high-frequency (HF) regions. Patients were compared with 66 healthy controls subject. Patients with LT were compared with patients who had EC. The children with Fontan circulation showed a significantly reduced HRV including total power (P < 0.0001), VLF (P < 0.0001), LF (P < 0.0001), and HF (P = 0.001) compared with the control subjects. The LT and EC patients did not differ significantly. Reduced HRV was found in both the LT and EC patients. In terms of HRV reduction, EC was not superior to LT.

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.

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.

The intra/extracardiac conduit fenestrated fontan

The intra/extracardiac conduit technique for the Fontan procedure has important advantages relative to the extracardiac conduit. Fenestration is easily achieved and there is less risk of injury to the crista terminalis, so that the risk of late atrial arrhythmias may be reduced.

The Fontan procedure: evolution in technique; attendant imperfections and transplantation for "failure"

Application of the Fontan procedure has allowed the survival of many patients with univentricular cardiac lesions into mid adulthood. Despite its ingenious design, implementation, and thoughtful modifications, its attendant hemodynamic perturbations persist; central venous hypertension and reduced cardiac output. These aberrations in physiology have led to pernicious changes in organ function. A more thorough understanding of these derangements and attempts at Fontan revision have temporized, yet the morbidity and patient attrition persists. Mechanical assistance to normalize the circulation is being investigated and holds some promise. At present, cardiac transplantation remains the last stage of palliation for many.