Results of staged total cavopulmonary connection for functionally univentricular hearts; comparison of intra-atrial lateral tunnel and extracardiac conduit

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

AIMS

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

METHODS AND RESULTS

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

CONCLUSION

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

Tachyarrhythmia after the total cavopulmonary connection: incidence, prognosis, and risk factors

OBJECTIVE

The purpose of this study is to evaluate the incidence and outcomes regarding tachyarrhythmia in patients after total cavopulmonary connection.

METHODS

A retrospective analysis of 620 patients who underwent total cavopulmonary connection between 1994 and 2021 at our institution was performed. Incidence of tachyarrhythmia was depicted, and results after onset of tachyarrhythmia were evaluated. Factors associated with the onset of tachyarrhythmia were identified.

RESULTS

A total of 52 (8%) patients presented with tachyarrhythmia that required medical therapy. Onset during hospital stay was observed in 27 patients, and onset after hospital discharge was observed in 32 patients. Freedom from late tachyarrhythmia following total cavopulmonary connection at 5, 10, and 15 years was 97, 95, and 91%, respectively. The most prevalent late tachyarrhythmia was atrial flutter (50%), followed by supraventricular tachycardia (25%) and ventricular tachycardia (25%). Direct current cardioversion was required in 12 patients, and 7 patients underwent electrophysiological study. Freedom from Fontan circulatory failure after onset of tachyarrhythmia at 10 and 15 years was 78% and 49%, respectively. Freedom from occurrence of decreased ventricular systolic function after the onset of tachyarrhythmia at 5 years was 85%. Independent factors associated with late tachyarrhythmia were dominant right ventricle (hazard ratio, 2.52, p = 0.02) and weight at total cavopulmonary connection (hazard ratio, 1.03 per kilogram; p = 0.04). Type of total cavopulmonary connection at total cavopulmonary connection was not identified as risk.

CONCLUSIONS

In our large cohort of 620 patients following total cavopulmonary connection, the incidence of late tachyarrhythmia was low. Patients with dominant right ventricle and late total cavopulmonary connection were at increased risk for late tachyarrhythmia following total cavopulmonary connection.

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.

Impact of Optimal Fenestration Size on Outcomes of High-Risk Fontan Patients

BACKGROUND

We aimed to analyze mid-term outcomes of the fenestrated Fontan procedure, focusing on the fenestration size.

METHODS

We retrospectively reviewed the outcomes of the fenestrated Fontan procedure. Among 165 patients who underwent the Fontan procedure from 2011 to 2021, fenestration was created in 27 patients with the highest risks, including those with hypoplastic left heart syndrome, hypoplastic pulmonary arteries, heterotaxy syndrome with high pulmonary vascular resistance, and pulmonary arterial pressure >15 mm Hg. The patients underwent the procedure at a median age of three years (body weight, 11.4 kg; body surface area, 0.54 m2). Fenestration sizes were 3.5 to 5 mm.

RESULTS

Spontaneous fenestration closure occurred within one year postoperatively in nine patients. Among them, three experienced Fontan failure, necessitating refenestration. Although fenestration size did not differ, the size corrected by body surface area at the time of surgery was smaller in patients with fenestration closure (6.4 mm/m2 vs 8.3 mm/m2, P < .05). Patients with a fenestration <7 mm/m2 were more likely to have fenestration closure within one year postoperatively, and those with a fenestration >9 mm/m2 were more likely to have severe desaturation and require home oxygen therapy following discharge.

CONCLUSIONS

Spontaneous fenestration closure affected the frequency of Fontan complications. A very small fenestration size corrected by body surface area was a significant risk factor for spontaneous closure. Conversely, a very large fenestration size corrected by body surface area resulted in severe desaturation. The optimal fenestration size to prevent early spontaneous closure and severe desaturation is approximately 8 mm/m2.

27 years of experience with the Fontan procedure: characteristics and clinical outcomes of children in a tertiary referral hospital

BACKGROUND

The Fontan operation has improved the survival of children born with congenital heart disease with single ventricle physiology. The most widely adopted variations of the Fontan procedure are the extracardiac conduit, the lateral tunnel ve the intra/extracardiac conduit with fenestration. Despite advances in the treatment and prevention of early and late complications that may develop after Fontan surgery, morbidity still remains an important problem.

METHODS

304 patients who underwent Fontan surgery in our center between 1995 and 2022 were included in our study. The complications that developed in patients who underwent primary Fontan or lateral tunnel surgery and extracardiac conduit Fontan application were compared.

RESULTS

Classic Fontan surgery and lateral tunnel surgery were performed in 26 of the patients, and extracardiac Fontan surgery was performed in 278 patients. 218 of 304 cases were patients with single ventricular pathology. 86 cases were patients with two ventricular morphologies but complex cardiac pathology. Fenestration was performed in only 6 patients, other patients did not require fenestration. The mean follow-up period of our patients was 12 years (3 months-27 years). When the complications between Fontan procedures were compared in our study, it was found that the length of hospital stay and mortality were statistically significantly reduced in patients who underwent extracardiac Fontan surgery. There was no significant difference in terms of complications that can be seen after Fontan surgery and the length of stay in the intensive care unit.

CONCLUSION

Fontan complex is a palliative surgery for children with complex heart disease. Palliative surgical operations aimed at the preparation of the Fontan circulation lead to the preparation of the pulmonary vascular bed and the preservation of ventricular function. The techniques applied in Fontan surgery affect the early and long-term complications and the survival of the patients. In our study, when we examined the patients who extracardiac conduit Fontan procedure for the non-cardiac route, we found that mortality and morbidity were minimal.

Postoperative Alanine Aminotransferase Levels Are Associated with Outcomes in Pediatric Patients Undergoing Total Cavopulmonary Connection

Background: This single-center, retrospective study aims to determine the association between alanine aminotransferase (ALT) and outcomes in pediatric patients undergoing total cavopulmonary connection (TCPC). Methods: In total, 256 pediatric patients undergoing TCPC were included and divided into a normal-ALT group and a high-ALT group. Clinical data were collected for comparisons between groups, and risk factors of high postoperative ALT were identified by univariate and multivariate analysis. A ROC analysis of the predictive value of postoperative ALT was conducted. Results: Compared to the normal-ALT group, the members of the high-ALT group were 1.6 years older and had significantly higher preoperative creatinine and direct bilirubin levels. The high-ALT group had increased fluid overload, higher vasoactive inotropic drug scores, and inferior central venous pressure. The short-term outcomes in the high-ALT group were markedly worse: they suffered a longer duration of mechanical ventilation (MV), had a higher ICU and hospital length of stay (LOS), and higher rates of mortality, infection, and reintubation. Prolonged ICU and hospital LOS, longer MV, and reintubation were identified as independent risk factors for high postoperative ALT. Postoperative ALT was of high value in predicting reintubation, MV, ICU LOS, and mortality. Conclusions: Elevated postoperative ALT levels are associated with poor short-term outcomes in pediatric patients undergoing TCPC.

The Fontan Pathway: Change in Dimension and Catheter-Based Intervention over Time

An unobstructed Fontan pathway is essential for optimal hemodynamics. We hypothesize that more extracardiac conduit (ECC) Fontan pathways develop obstruction compared to lateral tunnel (LT) Fontans and that the dilation typically observed in LTs results in similar mid-term clinical outcomes. A single-center, retrospective study was done including all Fontan cardiac catheterizations from 2006 to 2019. Angiography and medical records were reviewed to define Fontan pathway dimensions, interventions, and clinical outcomes. 232 patients underwent cardiac catheterization, where 60% were ECCs and 30% LTs. The minimum cross-sectional area (CSA) of ECCs was significantly smaller than LTs and LTs dilated over time. 13% of patients had Fontan pathway stenting at a median age of 16.2 years. The minimum CSA for patients who underwent intervention was significantly smaller than patients who did not. Lower weight at Fontan surgery was associated with intervention on the Fontan pathway, with a threshold weight of 15 kg for patients with an ECC. The median follow-up was 3.3 years. Patients who had Fontan pathway intervention were not more likely to experience the composite adverse clinical outcome. LTs were more likely than ECCs to have worse clinical outcome, when liver fibrosis was included. This is the first study to describe angiographic dimensions of the Fontan pathway in a large number of patients over time. ECCs tend to become stenotic. Lower weight at Fontan surgery is a potential risk for Fontan pathway intervention. LTs may experience worse clinical outcomes in follow-up. This information can help inform the optimal timing and method of post-Fontan surveillance.

Risk Factors for Thrombus Formation at Stage 2 Palliation and Its Effect on Long-Term Outcome in Patients With Univentricular Heart

Thrombus formation is a feared complication following bidirectional cavopulmonary shunt (BCPS). We aimed to investigate the effect of thrombus formation on outcome. BCPS was performed in 525 patients at our center between 1998 and 2018. The impacts of thrombus formation on survival and probability of Fontan completion were analyzed, and risk factors for thrombus formation were examined. Thrombus formation occurred in 30 patients (5.7%). Compared with the remaining 495 patients, there was no significant difference in the median age at BCPS (4.9 vs 4.7 months; P = 0.587). However, unbalanced atrioventricular septal defects (17 vs 5%; P = 0.008) and preoperative ventricular dysfunction (23.3 vs 8%; P = 0.004) were more frequent in patients who developed a thrombus. Thrombolytic therapy was performed in all patients and surgical thrombus removal was required in 13 patients. In-hospital mortality was higher in patients with thrombus (30.0 vs 2.2%; P < 0.001). Of 505 hospital survivors, an estimated survival at 1 year after hospital discharge following BCPS was 84.4% (95% CI, 76.1-92.7%) in patients with thrombus and 96.8% (95% CI, 96.0-97.6%) in those without (P < 0.001). Cumulative incidence of Fontan completion at 3 years after BCPS was 52.8% (95% CI, 30.3-75.2%) in patients with thrombus and 90.1% (95% CI, 87.2-92.9%) in those without (P = 0.004). Higher left atrial pressure (OR = 1.165; P = 0.029) and longer cardiopulmonary bypass time (OR = 1.013, P = 0.001) at BCPS were independent risk factors for thrombus formation after BCPS. Thrombus formation after BCPS poses a significant risk for survival and Fontan completion. Preoperative higher left atrial pressure and longer cardiopulmonary bypass time are significant risk factors.

The mid-term outcome of Fontan conversion compared with primary total cavopulmonary connection

BACKGROUND

The indication of Fontan conversion (FC) from atriopulmonary connection (APC) to total cavopulmonary connection (TCPC) is unclear. We sought to analyze the mid-term outcome of prophylactic and therapeutic Fontan conversion compared with that of primary TCPC.

METHODS

Patients with a univentricular heart who underwent cardiac catheterization at >18 years of age between July 2005 and July 2019 were included and divided into three groups: symptomatic APC patients who underwent therapeutic FC (t-FC, n = 13), asymptomatic APC patients after prophylactic FC (p-FC, n = 15), and patients who had primary TCPC procedure (pTCPC, n = 24).

RESULTS

The mean last follow up was at the age of 32.0 ± 7.8, 26.8 ± 3.8, and 27.3 ± 7 years (p = 0.07) in t-FC, p-FC, and pTCPC, respectively. There was no late death. All of t-FC and 12 (80%) of p-FC cases underwent concomitant arrhythmic surgery. Consequently, five and four patients in t-FC and p-FC groups required pacemaker implantations mostly due to sinus node dysfunction. Thromboembolism was seen in 2 cases in both t-FC (15%) and p-FC (13%), and 1 case in pTCPC (4%) (p = 0.50). The last cardiac catheterization was performed at the age of 29.5 ± 8.5, 24.6 ± 3.8, and 26.3 ± 7.1 years (p = 0.11) in t-FC, p-FC, and pTCPC patients, respectively. There was no significant difference in central venous pressure, aortic pressure, and cardiac index among the three groups. There was no late supraventricular tachyarrhythmic event seen in t-FC and p-FC, whereas two patients in pTCPC had newly developed atrial flutter.

CONCLUSIONS

FC is a safe and feasible procedure to bring APC patients back onto the same track of primary TCPC patients in terms of hemodynamics as well as arrhythmia. The antiarrhythmic procedure should be carefully chosen because sinus node dysfunction can frequently occur and FC itself would reduce the risk of arrhythmia.

Staged total cavopulmonary connection: serial comparison of intra-atrial lateral tunnel and extracardiac conduit taking account of current surgical adaptations

OBJECTIVES

Our goals were to compare the outcome of the intra-atrial lateral tunnel (ILT) and the extracardiac conduit (ECC) techniques for staged total cavopulmonary connection (TCPC) and to compare the current modifications of the TCPC technique, i.e. the prosthetic ILT technique with the current ECC technique with a ≥18-mm conduit.

METHODS

We included patients who had undergone a staged TCPC between 1988 and 2008. Records were reviewed for patient demographics, operative details and events during follow-up (death, surgical and catheter-based reinterventions and arrhythmias).

RESULTS

Of the 208 patients included, 103 had the ILT (51 baffle, 52 prosthetic) technique and 105 had the ECC technique. Median follow-up duration was 13.2 years (interquartile range 9.5-16.3). At 15 years after the TCPC, the overall survival rate was comparable (81% ILT vs 89% ECC; P = 0.12). Freedom from late surgical and catheter-based reintervention was higher for patients who had ILT than for those who had ECC (63% vs 44%; P = 0.016). However, freedom from late arrhythmia was lower for patients who had ILT than for those who had ECC (71% vs 85%, P = 0.034). In a subgroup of patients who had the current TCPC technique, when we compared the use of a prosthetic ILT with ≥18-mm ECC, we found no differences in freedom from late arrhythmias (82% vs 86%, P = 0.64) or in freedom from late reinterventions (70% vs 52%, P = 0.14).

CONCLUSIONS

A comparison between the updated prosthetic ILT and current ≥18-mm ECC techniques revealed no differences in late arrhythmia-free survival or late reintervention-free survival. Overall, outcomes after the staged TCPC were relatively good and reinterventions occurred more frequently in the ECC group, whereas late arrhythmias were more common in the ILT group.

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.

Assessment of Late Thromboembolic Complications Post-Fontan Procedure in Relation to Different Antithrombotic Regimens: 30-Years' Follow-up Experience

Background: The current CHEST guidelines recommend the use of antithrombotic therapy, either aspirin or warfarin, as a primary thromboembolic complications (TECs) prophylaxis in patients who undergo Fontan procedure, without specification on drug selection or duration of therapy. Objective: To investigate the incidence rate of late TECs, occurring after 1-year post-Fontan procedure and to assess the difference in rate of late TECs between warfarin and aspirin. Methods: A retrospective cohort study included patients who had Fontan procedures between 1985-2010 at our institution. Patients were stratified according to the antithrombotic regimen-warfarin, aspirin, or no therapy-at the time of TECs. Results: We screened 499 patients who underwent Fontan procedures; 431 procedures met the inclusion criteria. Over a median follow-up of 13.6 years (IQR= 8.7), freedom from late TECs at 5, 10, 15, and 20 years was 97.54%, 96.90%, 90.78%, and 88.07%, respectively. There was no difference in late TEC incidence rates per 1000 patient-years between warfarin and aspirin: 7.82 and 5.83 events, respectively; rate ratio= 1.34 (95% CI= 0.68-2.60). Warfarin was associated with a higher major bleeding incidence rate per 1000 patient-years: 3.70 versus 2.91 events with aspirin; rate ratio= 1.27 (95% CI= 0.49 to 3.29). Conclusion and Relevance: The incidence rate of late clinical TECs post-Fontan procedure in our population is low. Warfarin was not superior to aspirin for prevention of late TECs. Yet warfarin was associated with a higher rate of bleeding. This finding suggests a simpler antithrombotic regimen for prevention of TEC after 1-year post-Fontan procedure.

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.

Late Follow-up of Patients Submitted to Total Cavopulmonary Derivation: Clinical Aspects, Reinterventions, and Complications Interfering in Morbidity and Mortality

Objective

To identify main complications in outpatient follow-up, as well as factors before or during operation that may interfere in patient's evolution.

Methods

Retrospective study of patients submitted to total cavopulmonary shunt with extracardiac conduit from 2000 to 2014 at the Hospital do Coração (São Paulo, Brazil) and who underwent clinical follow-up at this institution.

Results

One hundred and fifty surgeries were performed and 59 patients maintained outpatient follow-up. The mean age of these patients at the time of surgery was 4.45 years (median of 45 months) and 70.2% of them were males. Among the patients undergoing outpatient follow-up, postoperative time at evaluation ranged from 10 days to 145 months; 30 (50.8%) patients had single left ventricle and 29 (49.2%) had single right ventricle (48.2% of these presented with hypoplastic left heart syndrome [HLHS]). Patients with single left ventricle had a higher percentage of reintervention-free survival, but without statistically significant difference. 40% of the patients had no complications and 35% of them presented with thrombosis at some point in the follow-up period, with ventricular dysfunction being the second most frequently found complication (15% of cases), mainly among patients with single right ventricle morphology (P=0.04). Between the patients currently under follow-up, 20 (35%) of them had been evaluated by ultrasonography and had some degree of hepatic congestion and/or hepatomegaly. 16.7% of the patients with such alteration had HLHS (P=0.057).

Conclusion

Except for the right ventricular morphology, no other factor has been shown to interfere in late evolution after total cavopulmonary shunt.

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.

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.

Development of Tachyarrhythmias Late After the Fontan Procedure: The Role of Ablative Therapy

Patients with a Fontan circulation are at a high risk of developing a variety of cardiac dysrhythmias after cardiac surgery. These dysrhythmias are most often supraventricular tachyarrhythmias (SVT), but ventricular tachyarrhythmias (VT) may also occur. Mechanisms underlying SVT are variable, including both ectopic activity and reentry. Over time, successive SVT may be caused by different mechanisms. The acute success rate of ablative therapy of atrial tachyarrhythmias is considerably high yet during long-term follow-up 'recurrences' frequently occur. It is most likely that these 'recurrences' are caused by a progressive atrial cardiomyopathy instead of arrhythmogeneity of prior ablative lesions.

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.

Normal Sinus Rhythm-Sinus Bradycardia is Common in Young Children Post-extracardiac Fontan

We hypothesized that normal sinus rhythm-sinus bradycardia is common in young children following extracardiac Fontan. After excluding patients with sinus pauses, junctional rhythm, tachy-brady syndrome, frequent ectopics, or ectopic atrial rhythm, we found an ambulatory 24-h Holter monitor average heart rate of 78 ± 12 beats per minute (bpm) in 33 post-extracardiac Fontan children with a median age of 6 years (5-10). A 24-h average heart rate of 78 ± 12 bpm is statistically significantly lower than a 24-h average heart rate value of 90 ± 10 bpm derived from a similarly aged control population (p < 0.01). We conclude that after excluding those with significant arrhythmias, normal sinus rhythm-sinus bradycardia is common in children post-extracardiac Fontan.

Does functional health status predict health-related quality of life in children after Fontan operation?

PURPOSE

It is important to identify those children with a Fontan circulation who are at risk for impaired health-related quality of life. We aimed to determine the predictive value of functional health status - medical history and present medical status - on both physical and psychosocial domains of health-related quality of life, as reported by patients themselves and their parents.

METHODS

We carried out a prospective cross-sectional multi-centre study in Fontan patients aged between 8 and 15, who had undergone staged completion of total cavopulmonary connection according to a current technique before the age of 7 years. Functional health status was assessed as medical history - that is, age at Fontan, type of Fontan, ventricular dominance, and number of cardiac surgical procedures - and present medical status - assessed with magnetic resonance imaging, exercise testing, and rhythm assessment. Health-related quality of life was assessed with The TNO/AZL Child Questionnaire Child Form and Parent Form.

RESULTS

In multivariate prediction models, several medical history variables, such as more operations post-Fontan completion, lower age at Fontan completion, and dominant right ventricle, and present medical status variables, such as smaller end-diastolic volume, a higher score for ventilatory efficiency, and the presence of sinus node dysfunction, predicted worse outcomes on several parent-reported and self-reported physical as well as psychosocial health-related quality of life domains.

CONCLUSIONS

Medical history and worse present medical status not only predicted worse physical parent-reported and self-reported health-related quality of life but also worse psychosocial health-related quality of life and subjective cognitive functioning. These findings will help in identifying patients who are at risk for developing impaired health-related quality of life.

Decision-Making for Surgery in the Management of Patients with Univentricular Heart

A series of technical refinements over the past 30 years, in combination with advances in perioperative management, have resulted in dramatic improvements in the survival of patients with univentricular heart. While the goal of single-ventricle palliation remains unchanged - normalization of the pressure and volume loads on the systemic ventricle, the strategies to achieve that goal have become more diverse. Optimal palliation relies on a thorough understanding of the changing physiology over the first years of life and the risks and consequences of each palliative strategy. This review describes how to optimize surgical decision-making in univentricular patients based on a current understanding of anatomy, physiology, and surgical palliation.

[Prevention and treatment of cardiac arrhythmia in patients with congenital heart defects: surgical aspects]

Catheter ablation procedures have become established over the years due to their effectiveness and low invasiveness and have changed the indications for surgical treatment. The main field of activity of cardiac surgery remains the treatment of patients with congenital heart defects which show arrhythmia and necessitate surgical treatment. The combination of surgical ablative measures with a good view of the site using modern ablation instruments, atrial reduction by tissue resection and correction of the defect with the resulting volume relief, bring the best conditions for a curative treatment of arrhythmia. The same applies to the treatment of ventricular tachycardia resulting from old scars and residual defects. Special attention should be given to patients who received a Fontan conversion. This operation is a unique opportunity to relieve volume which in turn reduces the atrial size and at the same time to take ablative measures to restore sinus rhythm. The results are promising with low mortality and morbidity, high efficiency and finally a clear improvement of the functional status of patients. In appropriate cases minimally invasive surgical procedures can help where pharmacological and catheter ablation therapies remain ineffective.

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.

Exercise capacity in children after total cavopulmonary connection: lateral tunnel versus extracardiac conduit technique

OBJECTIVES

In patients with univentricular heart disease, the total cavopulmonary connection (TCPC) is the preferred treatment. TCPC can be performed using the intra-atrial lateral tunnel (ILT) or extracardiac conduit (ECC) technique. The purpose of the present study was to evaluate exercise capacity in contemporary TCPC patients and compare the results between the 2 techniques.

METHODS

A total of 101 TCPC patients (ILT, n=42; ECC, n=59; age, 12.2±2.6 years; age at TCPC completion, 3.2±1.1 years) underwent cardiopulmonary exercise testing. The patients were recruited prospectively from 5 tertiary referral centers.

RESULTS

For the entire group, the mean peak oxygen uptake was 74%±14%, peak heart rate was 90%±8%, peak workload was 62%±13%, and slope of ventilation versus carbon dioxide elimination (VE/VCO2 slope) was 127%±30% of the predicted value. For the ILT and ECC groups, patient age, age at TCPC completion, body surface area, peak workload, and peak heart rate were comparable. The percentage of predicted peak oxygen uptake was lower in the ILT group (70%±12% vs 77%±15%; P=.040), and the percentage of predicted VE/VCO2 slope was greater in the ILT group (123%±36% vs 108%±14%; P=.015). In a subgroup analysis that excluded ILT patients with baffle leak, these differences were not statistically significant.

CONCLUSIONS

Common exercise parameters were impaired in contemporary Fontan patients. Chronotropic incompetence was uncommon. The peak oxygen uptake and VE/VCO2 slope were less favorable in ILT patients, likely related to baffle leaks in some ILT patients. These results have shown that a reduced exercise capacity in Fontan patients remains an important issue in contemporary cohorts. The ECC had a more favorable exercise outcome at medium-term follow-up.

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.

Thromboembolic complications in Fontan patients: population-based prevalence and exploration of the etiology

After the Fontan procedure, patients face an increased risk for thromboembolic events (TE). The etiology for this increased thrombogenecity is incompletely understood. This study aimed to determine the prevalence of TE in Danish Fontan patients and to bring new insights into the etiology of TE. Using a population-based design, we retrospectively identified all TEs in 210 Fontan patients. Whole blood assays (thromboelastography, thromboelastography functional fibrinogen and Multiplate) reflecting global hemostasis, clot strength and platelet aggregation were analyzed prospectively in 112 patients and plasma was analyzed in 76 patients for biomarkers reflecting endothelial-, glycocalyx-, platelet-, and fibrinolysis function (histone-complexed DNA fragments, Protein C, soluble CD40 ligand, soluble thrombomodulin, syndecan-1, tissue-type plasminogen activator). The results were compared in groups stratified according to age, antithrombotic therapy, TE, and glycocalyx degradation (syndecan-1 < or ≥ median). Correlation between biomarkers and demographic-, anatomical-, clinical- and biochemical parameters was investigated. The prevalence of TE was 8.1 % after a mean follow-up of 8.4 years. None of the stratified groups demonstrated evidence of hypercoagulability in the whole blood assays and no unexpected significant differences were found between the groups. All biomarkers, except protein C, correlated with one another and after stratification of glycocalyx degradation only syndecan-1 levels ≥ median correlated with other biomarkers. The prevalence of TEs was 8.1 % after mean follow-up of 8.4 years. Overall, the hemostatic profile appeared normal, however, in a subset of patients, evidence of some endothelial activation/damage including glycocalyx degradation and fibrinolysis was found, identifying a potentially more thrombogenic group.

Treatment planning for a TCPC test case: a numerical investigation under rigid and moving wall assumptions

The hemodynamics in patients with total cavopulmonary connections (TCPC) is generally very complex and characterized by patient-to-patient variability. To better understand its effect on patients' outcome, CFD models are widely used, also to test and optimize surgical options before their implementation. These models often assume rigid geometries, despite the motion experienced by thoracic vessels that could influence the hemodynamics predictions. By improving their accuracy and expanding the range of simulated interventions, the benefit of treatment planning for patients is expected to increase. We simulate three types of intervention on a patient-specific 3D model, and compare their predicted outcome with baseline condition: a decrease in pulmonary vascular resistance obtainable with medications; a surgical revision of the connection design; the introduction of a fenestration in the TCPC wall. The simulations are performed both with rigid wall assumption and including patient-specific TCPC wall motion, reconstructed from a 4DMRI dataset. The results show the effect of each option on clinically important metrics and highlight the impact of patient-specific wall motion. The largest differences between rigid and moving wall models are observed in measures of energetic efficiency of TCPC as well as in hepatic flow distribution and transit time of seeded particles through the connection.

Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Neonates and children differ from adults in physiology, pharmacologic responses to drugs, epidemiology, and long-term consequences of thrombosis. This guideline addresses optimal strategies for the management of thrombosis in neonates and children.

METHODS

The methods of this guideline follow those described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

RESULTS

We suggest that where possible, pediatric hematologists with experience in thromboembolism manage pediatric patients with thromboembolism (Grade 2C). When this is not possible, we suggest a combination of a neonatologist/pediatrician and adult hematologist supported by consultation with an experienced pediatric hematologist (Grade 2C). We suggest that therapeutic unfractionated heparin in children is titrated to achieve a target anti-Xa range of 0.35 to 0.7 units/mL or an activated partial thromboplastin time range that correlates to this anti-Xa range or to a protamine titration range of 0.2 to 0.4 units/mL (Grade 2C). For neonates and children receiving either daily or bid therapeutic low-molecular-weight heparin, we suggest that the drug be monitored to a target range of 0.5 to 1.0 units/mL in a sample taken 4 to 6 h after subcutaneous injection or, alternatively, 0.5 to 0.8 units/mL in a sample taken 2 to 6 h after subcutaneous injection (Grade 2C).

CONCLUSIONS

The evidence supporting most recommendations for antithrombotic therapy in neonates and children remains weak. Studies addressing appropriate drug target ranges and monitoring requirements are urgently required in addition to site- and clinical situation-specific thrombosis management strategies.

Late Arrhythmias Following Fontan Surgery

The incidence of atrial arrhythmias following Fontan repairs varies by the type of surgery and duration of follow-up. The incidence of late atrial tachycardia has been reduced from 60% to less than 20% by surgical modifications. Late ventricular tachycardia is reported in 3% to 12% of patients. Aggressive efforts to eliminate tachycardia and improve hemodynamics may improve clinical status.

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.

Catheter takedown in the management of the acutely failing Fontan circulation

The acutely failing Fontan circulation requires urgent management to decompress the systemic venous pressures and augment cardiac output. This may involve the use of extracorporeal membrane oxygenation support to preserve life. Catheter-based effective Fontan takedown is an alternative to surgery in these patients, who are acutely unstable, and offers the potential for an adjustable fenestration.

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.

Intracardiac cavopulmonary connection in patients with univentricular heart using intra-atrial lateral tunnel and intra-atrial conduit techniques

BACKGROUND

In this study, we analyzed the time course of hemodynamic efficiency and follow-up in Fontan candidates who underwent the bidirectional Glenn procedure for staged intracardiac cavopulmonary connection (ICPC).

METHODS

Between 1991 and 2008, 52 patients with univentricular heart (mean age, 3.3 years; range, 2-8 years; 27 female patients [51.9%]) underwent ICPC. The cardiac malformations were as follows: tricuspid atresia, 25 cases (48.0%); common ventricle, 16 cases (30.7%); and pulmonary atresia with intact ventricular septum, 11 cases (21.1%). The intracardiac cavopulmonary procedure was indicated for all 52 cases. In 42 patients (80.7%), an intra-atrial lateral tunnel was constructed with a bovine pericardium patch. In the last 10 consecutive cases (19.3%), we performed a modified surgical technique in which we implanted an intra-atrial corrugated bovine pericardium tube sutured around the superior and inferior vena cava ostium. In all cases, a 4-mm fenestration was made to reduce the intratunnel pressure. All 52 patients had previously undergone a Glenn operation.

RESULTS

There were 2 hospital deaths (3.8%) and no recorded late deaths. During the follow-up, all patients were medicated with antiplatelet drugs. To evaluate the hemodynamic performance, we used Doppler echocardiography, computed tomography, and magnetic nuclear resonance studies. There were no prosthesis thromboses during this followup period. To evaluate cardiac arrhythmias, we conducted a Holter study. The last 10 patients with an intra-atrial conduit (IAC) presented with sinus rhythm and no arrhythmias during the last 4 years. The 50 surviving patients (96.1%) have been followed up for 6 to 204 months; all these patients are free of reoperation.

CONCLUSION

The Glenn operation, which is performed at an early age, prepares the pulmonary bed to receive the ICPC. The midterm results of the intracardiac Fontan procedure seem to be good. The modified surgical procedure (IAC) can be a good alternative technique to the Fontan procedure in suitable patients.