Liver Cirrhosis After the Fontan Procedure: Impact of Atrioventricular Valve Failure.

BACKGROUND: Liver cirrhosis is now well recognized as a potential complication after the Fontan procedure, although associated risk factors and optimal timing of liver screening remain unclear. METHODS: All patients who underwent an extracardiac conduit Fontan procedure at The Royal Children's Hospital, Melbourne, were identified using the Australia and New Zealand Fontan Registry. Cirrhosis was diagnosed based on liver biopsy, or a combination of imaging findings and clinical evaluation by a hepatologist. RESULTS: Between 1997 and 2020, 398 patients underwent an extracardiac conduit Fontan procedure at our center, and 276 had ongoing follow-up in Victoria. Ninety-five patients (34%) underwent liver assessment at a mean age of 18.2 ± 6.7 years (11.8 ± 5.5 years post-Fontan). Fifteen patients (16%) were diagnosed with cirrhosis at a mean age of 22.7 ± 5.9 years (14.0 ± 5.2 years post-Fontan). The need for prior or concomitant atrioventricular valve repair or replacement was associated with an increased risk of cirrhosis (univariable hazard ratio [HR] 7.09, 95% confidence interval [CI] 2.13-23.61, P = .001). By multivariable analysis, factors associated with development of cirrhosis were atrioventricular valve failure prior to Fontan (HR 3.27, 95% CI 1.15-9.31, P = .026) and older age at Fontan operation (HR 1.13 per year increase, 95% CI 1.01-1.26, P = .034). The proportion of patients alive, nontransplanted, and without cirrhosis at 10, 15, and 20 years was 93.4% (95% CI 88.4%-98.7%), 79.6% (95% CI 69.7%-90.8%), and 64.6% (95% CI 51.0%-81.9%), respectively. CONCLUSIONS: Early commencement of liver screening should be considered for patients with a history of atrioventricular failure during Fontan palliation.

The Australia and New Zealand Congenital Outcomes Registry for Surgery (ANZCORS): methodology and preliminary results.

BACKGROUND: Analysis of multi-institutional data and benchmarking is an accepted accreditation standard in cardiac surgery. Such a database does not exist for congenital cardiac surgery in Australia and New Zealand (ANZ). To fill this gap, the ANZ Congenital Outcomes Registry for Surgery (ANZCORS) was established in 2017. METHODS: Inclusion criteria included all cardiothoracic and extracorporeal membrane oxygenation (ECMO) procedures performed at five participating centres. Data was collected by data managers, validated by the surgical team, and securely transmitted to a central repository. RESULTS: Between 2015 and 2019, 9723 procedures were performed in 7003 patients. Cardiopulmonary bypass was utilized for 59% and 9% were ECMO procedures. Fifty-seven percent (n = 5531) of the procedures were performed in children younger than 1 year of age. Twenty-four percent of procedures (n = 2365) were performed in neonates (≤28 days) and 33% (n = 3166) were performed in children aged 29 days to 1 year (infants). The 30-day mortality for cardiac cases (n = 6572) was 1.3% and there was no statistical difference between the participating centres (P = 0.491). Sixty-nine percent of cases had no major post-operative complications (5121/7456). For cardiopulmonary bypass procedures (n = 5774), median stay in intensive care and hospital was 2 days (IQR 1, 4) and 9 days (IQR 5, 18), respectively. CONCLUSION: ANZCORS has facilitated pooled data analysis for paediatric cardiac surgery across ANZ for the first time. Overall mortality was low. Non-risk-adjusted 30-day mortality for individual procedures was similar in all units. The continued evaluation of surgical outcomes through ANZCORS will drive quality assessment in paediatric cardiac surgery across ANZ.

Surveillance of End-Organ Damage in Fontan Patients Prior to Transition to Adult Care: Are We There Yet?

BACKGROUND: Recently published guidelines and consensus statements have outlined recommended screening practices for monitoring of end-organ dysfunction in Fontan patients. We reviewed the current approach to end-organ screening in a local population of Fontan patients at the time of transition to adult care. METHODS: Patient data from the Australia and New Zealand Fontan Registry and patient medical records were used to review investigations performed in Fontan patients transitioned from The Royal Children's Hospital Melbourne to an adult centre between 1 July 2015 and 30 June 2020. RESULTS: A total of 32 patients were referred for transition to an adult centre between 1 July 2015 and 30 June 2020 at a mean age of 18.5±0.7 years (12.7±2.5 years post-Fontan). Liver function tests were performed in 22 patients (69%) within 5 years prior to transition and were abnormal in 15 patients (68%). Liver ultrasound was performed in 13 patients (41%) within 5 years prior to the date of transition, of whom 10 (77%) had abnormal findings (features suggestive of hepatic fibrosis in seven [54%], cirrhosis in two [15%], and portal hypertension in three [23%]). Fourteen (14) patients (44%) had no record of a liver ultrasound being performed between the date of the Fontan procedure and the time of transition to adult care. Hepatocellular carcinoma was diagnosed in one patient at 18 months following transition. A total of 24 patients (75%) had a serum creatinine measured within the 5 years prior to transition, and two (8%) had an estimated glomerular filtration rate (eGFR) less than 90 mL/min/1.73 m2. No patient had a urine protein-creatinine ratio measured between the date of the Fontan procedure and the time of transition to adult care. CONCLUSIONS: In this study we have identified that the majority of patients transitioned from a tertiary paediatric centre to an adult centre within the last 5 years did not undergo routine surveillance for end-organ dysfunction. Routine screening for end-organ complications of the Fontan circulation should be incorporated into clinical practice and is an important part of Fontan patient care both pre- and post-transition to adult services.

Pre- and Post-operative determinants of transplantation-free survival after Fontan. The Australia and New Zealand experience.

BACKGROUND: This review identifies the predictors of late mortality and heart transplantation that remain relevant in the contemporary population of patients with a Fontan circulation, focusing on the potential impact of post-Fontan morbidities on the late outlook of these patients. METHODS AND RESULTS: A total of 1561 patients who had survived the Fontan operation in Australia or New Zealand from 1975 to 2018 were included in this review. Over a median duration of 11.4 years, there was a total of 117 deaths (7%) and 32 heart transplantations (2%). Freedom from death and heart transplantation at 10, 20 and 35 years post Fontan surgery were 94% (95% CI 93-95%), 87% (95 %CI 85-90%) and 66% (95 %CI 57-78%) respectively. Being male, having an atriopulmonary Fontan, pre-Fontan atrioventricular valve intervention, or prolonged pleural effusions post Fontan were predictive of late death or heart transplantation. However, time-dependent variables such as the development of atrial arrhythmia, protein/losing enteropathy or late ventricular dysfunction were stronger predictors of the same outcome. Patients who developed a time-dependent risk factor had a freedom from death and heart transplantation rate of 54% (95 %CI 43-66) at 15 years and 44% (95 %CI 33-57) at 25 years post Fontan. However, 95% (95 %CI 91-99) of patients without any of the identified risk factors were free from death or heart transplantation rate at 25 years post Fontan. CONCLUSION: In conclusion, the occurrence of post-operative complications such as PLE, arrhythmia and ventricular dysfunction will likely precede the late demise of these patients.

Protein-losing enteropathy and plastic bronchitis after the Fontan procedure.

OBJECTIVES: Protein losing enteropathy and plastic bronchitis are severe complications in Fontan circulation, with 5-year survival ranging from 46% to 88%. We report risk factors and outcomes of protein losing enteropathy and plastic bronchitis in patients undergoing the Fontan. METHODS: We performed a retrospective analysis of 1561 patients from the Australia New Zealand Fontan Registry. Two end points were death and cardiac transplantation examined with Cox regression (if no competing risks) or cumulative incidence curves and cause-specific Cs regression. RESULTS: A total of 55 patients with protein losing enteropathy/plastic bronchitis were included. Their median age at the Fontan was 5.7 years, and time to onset after the Fontan for protein losing enteropathy was 5.0 years and plastic bronchitis was 1.7 years. Independent predictors for developing protein losing enteropathy/plastic bronchitis were right-ventricular morphology with hypoplastic left-heart syndrome (hazard ratio, 2.30; confidence interval, 1.12-4.74), older age at Fontan (hazard ratio, 1.13; confidence interval, 1.03-1.23), and pleural effusions after Fontan (hazard ratio, 2.43; confidence interval, 1.09-5.41); left-ventricular morphology was protective (hazard ratio, 0.36; confidence interval, 0.18-0.70). In the protein losing enteropathy/plastic bronchitis population, freedom from death or transplantation after protein losing enteropathy/plastic bronchitis diagnosis at 5, 10, and 15 years was 70% (confidence interval, 58-85), 65% (confidence interval, 51-83), and 43% (confidence interval, 26-73), respectively; only older age (hazard ratio, 1.23; confidence interval, 1.01-1.52) was an independent predictor. Twenty-six surgical interventions were performed in 20 patients, comprising Fontan revisions (n = 5), fenestrations (n = 11), Fontan conversions (n = 5), atrioventricular valve repairs (n = 3), and hepatic vein diversion (n = 2). CONCLUSIONS: Protein losing enteropathy and plastic bronchitis remain severe complications, preferably affecting patients with dominant right single ventricle, with older age at Fontan being a predictor of developing protein losing enteropathy/plastic bronchitis and poorer prognosis. Heart transplantation remains the ultimate treatment, with 30% dying or requiring transplantation within 5 years, and the remaining being stable for long periods.

Long-term outcomes following Fontan takedown in Australia and New Zealand.

OBJECTIVE: Fontan takedown remains an option for the management of Fontan failure. We sought to evaluate early and late outcomes after Fontan takedown. METHODS: The Australia and New Zealand Fontan Registry was interrogated to identify all patients who had a Fontan takedown. RESULTS: Over a 43-year study period (1975-2018), 36 of 1540 (2.3%) had a Fontan takedown. The median age at takedown was 5.1 years (interquartile range [IQR], 3.7, 7.0). Nine (25%) patients had a takedown within 48 hours, 6 (16%) between 2 days and 3 weeks, 14 (39%) between 3 weeks and 6 months, whereas 7 (19%) had a late takedown (>6 months). Median interval to takedown was 26 days (IQR, 1.5, 127.5). Sixteen (44%) patients died at a median of 57.5 days (IQR, 21.8, 76.8). The greatest mortality occurred between 3 weeks and 6 months (<2 days: 1/9, 11%; 2 days to 3 weeks: 2/6, 33%; 3 weeks to 6 months: 11/14, 79%; >6 months: 2/7, 28%; P = .007). At median follow-up of 9.4 years (IQR, 4.5, 15.3), 11 (31%) patients were alive with an intermediate circulation (10 in New York Heart Association class I/II). Five (14%) patients underwent a successful second Fontan. Freedom from death/transplant after Fontan takedown was 59%, 56%, and 52% at 1, 5, and 10 years, respectively. CONCLUSIONS: The incidence of Fontan takedown is low, but mortality is high. The majority of takedowns occurred within 6 months. Mortality was lowest when takedown occurred <2 days and highest between 3 weeks and 6 months. A second Fontan is possible in a small proportion of survivors.

Acute and Chronic Kidney Disease Following Congenital Heart Surgery: A Review.

BACKGROUND: There is an increasing prevalence of chronic kidney disease in the population of adults currently living with congenital heart disease. A considerable proportion of children who undergo congenital heart surgery experience postoperative acute kidney injury. Whether there is an association between acute kidney injury after cardiac surgery in childhood and development of chronic kidney disease is unclear. METHODS: Three electronic databases were searched to capture relevant studies exploring the relationship between acute kidney injury after congenital heart surgery in children and progression to chronic kidney disease. RESULTS: A literature search identified a total of 212 research articles, 7 of which were selected for in-depth review. CONCLUSIONS: There is a likely association between acute kidney injury in children undergoing congenital heart surgery and progression to chronic kidney disease. Research should be developed to mitigate factors contributing to postoperative acute kidney injury in neonates, infants, and children undergoing cardiac surgery. Better targeted follow-up protocols to monitor renal function in children undergoing cardiac surgery should be implemented. A universal definition for acute kidney injury and chronic kidney disease is needed to improve detection and research in this field.

Fontan-associated nephropathy: Predictors and outcomes.

BACKGROUND: Nephropathy is a known complication of the Fontan circulation, but its determinants have not been identified and patient outcomes are also still unknown. METHODS: The Australia and New Zealand Fontan Registry was used to identify those who underwent Fontan operation before and survived beyond 16-years-old with an intact Fontan circulation. Serum creatinine values were collected for each patient between 16 and 25 years and at recent follow-up. The Modification of Diet in Renal Disease (MDRD) equation was used to calculate eGFR. Patient outcomes were obtained from the Registry. Fontan failure was defined as death, transplantation, plastic bronchitis, protein losing enteropathy, Fontan takedown and NYHA class III-IV. RESULTS: Serum creatinine measurements were available for 328 patients. Renal dysfunction was defined as eGFR <90 mL/min/1.72m2. Renal dysfunction was present in 67/328 (20%) and 3/328 (1%) patients had an eGFR <60 mL/min/1.72m2. The 10-year survival and 10-year freedom from death and transplantation were the same, 96% (95% CI: 0.9-1) for those with renal dysfunction, and 89% (0.83-0.95; p = 0.1) and 87% (95% CI: 0.81-0.94; p = 0.05) for patients without dysfunction. The 10-year freedom from failure were also similar, 83% (95% CI: 0.70-0.97) for those without renal dysfunction vs 80% (95% CI: 0.74-0.89; p = 0.84). There was no change in mean eGFR for the renal dysfunction group over a mean of 8 ± 5.5 years. CONCLUSION: By the time they reach adulthood, 20% of patients with a Fontan circulation have renal dysfunction by eGFR calculation. Over the course of one decade, Fontan-associated nephropathy appears well tolerated.

Creatinine-based estimation of glomerular filtration rate in patients with a Fontan circulation.

BACKGROUND: Patients with a Fontan circulation are at risk of renal dysfunction. We analyzed cross-sectional data in pediatric and adult Fontan patients in order to assess the accuracy of commonly used serum creatinine-based methods in estimating glomerular filtration rate (GFR). METHODS: A total of 124 Fontan patients (58 children, 66 adults) were enrolled across three study centers. Measurement of GFR (mGFR) using in vivo 99m Tc-DTPA clearance was performed. Various serum creatinine-based equations were used to calculate estimated GFR (eGFR). RESULTS: Mean mGFR was 108 ± 28 mL/min/1.73 m2 in children and 92 ± 20 mL/min/1.73 m2 in adults. Fourteen children (25%) and 28 adults (45%) had an mGFR <90 mL/min/1.73 m2 . There was no significant correlation between mGFR and eGFR (Schwartz) in children (r = 0.22, P = .1), which substantially overestimated mGFR (bias 50.8, 95%CI: 41.1-60.5 mL/min/1.73 m2 , P < .0001). The Bedside Schwartz equation also performed poorly in the children (r = 0.08, P = .5; bias 5.9, 95%CI: -2.9-14.6 mL/min/1.73 m2 , P < .0001). There was a strong correlation between mGFR and both eGFR (CKD-EPI) and eGFR (MDRD) in adults (r = 0.67, P < .0001 in both cases), however, both methods overestimated mGFR (eGFR(CKD-EPI):bias 23.8, 95%CI: 20-27.6 mL/min/1.73 m2 , P < .0001; eGFR (MDRD):bias 16.1, 95%CI: 11.8-20.4 mL/min/1.73 m2 , P < .0001). None of the children with an mGFR <90 mL/min/1.73 m2 had an eGFR (Schwartz) <90 mL/min/1.73 m2 . Sensitivity and specificity of eGFR (CKD-EPI) and eGFR (MDRD) for mGFR <90 mL/min/1.73 m2 in adults were 25% and 92% and 39% and 100%, respectively. CONCLUSIONS: This study identifies the unreliability of using creatinine-based equations to estimate GFR in children with a Fontan circulation. The accuracy of formulas incorporating cystatin C should be further investigated and may aid noninvasive surveillance of renal function in this population.

Hepatic and renal end-organ damage in the Fontan circulation: A report from the Australian and New Zealand Fontan Registry.

BACKGROUND: Hepatic and renal dysfunction have been observed in survivors of the Fontan procedure, however their incidence and associated factors remain poorly defined. METHODS: A total of 152 participants from a Registry of 1528 patients underwent abdominal ultrasound, transient elastography (FibroScan), serum fibrosis score (FibroTest), in vivo Tc-99m DTPA measurement of glomerular filtration rate (mGFR), and urine albumin-creatinine ratio (ACR). RESULTS: Mean age and time since Fontan were 19.8 ±â€¯9.3 and 14.1 ±â€¯7.6 years, respectively. Features suggestive of hepatic fibrosis were observed on ultrasound in 87/143 (61%) and no patient was diagnosed with hepatocellular carcinoma. FibroScan median kPa was ≥10 in 117/133 (88%), ≥15 in 75/133 (56%), and ≥20 in 41/133 (31%). Fifty-four patients (54/118, 46%) had a FibroTest score ≥0.49 (equivalent to ≥F2 fibrosis). FibroTest score correlated with FibroScan value (r = 0.24, p = 0.015) and ACR (r = 0.29, p = 0.002), and patients with ultrasound features of hepatic fibrosis had a higher FibroScan median kPa (19.5 vs 15.4, p = 0.002). Renal impairment was mild (mGFR 60-89 ml/min/1.73 m2) in 46/131 (35%) and moderate (mGFR 30-59 ml/min/1.73 m2) in 3/131 (2%). Microalbuminuria was detected in 52/139 participants (37%). By multivariable analysis, time since Fontan was associated with increased FibroScan median kPa (ß = 0.89, 95% CI 0.54-1.25, p = 0.002) and decreased mGFR (ß = -0.77, 95% CI -1.29-0.24, p = 0.005). CONCLUSIONS: In the second decade after Fontan hepatic and renal structure and function are abnormal in a significant number of patients: close to 60% have ultrasonographic evidence of structural hepatic abnormalities, 46% have elevated serum hepatic fibrosis scores, and 57% have either reduced glomerular filtration rate or microalbuminuria. Hepatic and renal function should be monitored for potential impacts on outcomes after Fontan completion.

Twenty-Five Year Outcomes of the Lateral Tunnel Fontan Procedure.

The objective of this study was to characterize late outcomes of the lateral tunnel (LT) Fontan procedure. The outcomes of all patients who underwent an LT Fontan procedure in Australia and in New Zealand were analyzed. Original files were reviewed and outcomes data were obtained through a binational registry. Between 1980 and 2014, a total of 301 patients underwent an LT Fontan procedure across 6 major centers. There were 13 hospital mortalities, 21 late deaths, 8 Fontan conversions and revisions, 8 Fontan takedowns, and 4 heart transplantations. Overall survival at 15 and 25 years was 90% (95% confidence interval [CI]: 86%-93%) and 80% (95% CI: 69%-91%), respectively. Protein-losing enteropathy or plastic bronchitis was observed in 14 patients (5%). Freedom from late failure at 15 and 25 years was 88% (95% CI: 84%-92%) and 82% (95% CI: 76%-87%), respectively. Independent predictors of late Fontan failure were prolonged pleural effusions post Fontan operations (hazard ratio [HR] 3.06, 1.05-8.95, P = 0.041), age >7 years at Fontan (vs 3-5 years, HR 9.7, 2.46-38.21, P = 0.001) and development of supraventricular tachycardia (HR 4.67, 2.07-10.58, P < 0.001). Freedom from tachy- or bradyarrhythmias at 10 and 20 years was 87% (95% CI: 83%-91%) and 72% (95% CI: 66%-79%), respectively. Thromboembolic events occurred in 45 patients (16%, 26 strokes), and freedom from symptomatic thromboembolism at 10 and 20 years was 93% (95% CI: 89%-96%) and 80% (95% CI: 74%-86%), respectively. Over a 25-year period, the LT technique has achieved excellent late survival. As this population ages, it is at an increasing risk of failure and adverse events. We are likely to see an increasing proportion requiring heart transplantation and late reintervention.

An unusually large paraesophageal hernia mimicking a Bochdalek hernia.

Hiatal hernias are due to defects in the esophageal hiatus in the diaphragm and can be classified into sliding or paraesophageal hernias. A 31-year-old male raised a suspicion of a Bochdalek hernia but at surgery had a large paraesophageal hernia. Bochdalek hernia, a congenital diaphragmatic hernia presents in adulthood asymptomatically or with vague abdominal symptoms. It is paramount to confirm the diagnosis and rule out any fatal complications with imaging studies. Prompt surgical management with large complicated hernias, such as in our case presentation would ensure the most favorable outcome.

Evolution of Left Ventricular Size in Late Survivors of Surgery for Hypoplastic Left Heart Syndrome.

BACKGROUND: Aortic atresia and mitral atresia are predictors of adverse events in early life in patients with hypoplastic left heart syndrome, but it is unclear whether late outcomes are also affected, and whether this impact is related to a small hypertrophied left ventricle (LV) that impairs right ventricle (RV) function. METHODS: Thirty patients with hypoplastic left heart syndrome surviving with a Fontan procedure were identified. Follow-up echocardiograms were available at birth, before the Fontan procedure, and several years after. Mean follow-up time was 10.9 ± 3.1 years. Measurements included interventricular septum thickness and ventricular length. The LV/RV length ratio at birth was calculated, and its impact on later LV and septal growth was examined. The primary endpoint was a composite of death, transplantation, or Fontan takedown. RESULTS: A cutoff LV/RV length ratio of 0.55 was identified: length ratio was 0.55 or less in group A (18 patients) and more than 0.55 in group B (12 patients) The LV/RV length ratio and interventricular septum thickness decreased over time in group A while remaining static in group B. The LV length at birth did not affect late adverse outcomes (hazard ratio 2.7, 95% confidence interval: 0.31 to 23.4, p = 0.37), whereas aortic atresia and mitral atresia were the most potent predictors of death or transplantation or takedown (hazard ratio 8.5, 95% confidence interval: 1.2 to 57.7, p = 0.029). CONCLUSIONS: Patients with aortic atresia and mitral atresia have worse outcomes even after Fontan independently of a small, thick, hypertrophied LV. The most severely hypoplastic LVs do not grow proportionally as much as the RVs.

Improved long-term outcomes in double-inlet left ventricle and tricuspid atresia with transposed great arteries: systemic outflow tract obstruction present at birth defines long-term outcome.

OBJECTIVES: In 2 subtypes of functional single ventricle, double inlet left ventricle (DILV) and tricuspid atresia with transposed great arteries (TA-TGA), systemic output passes through an outflow chamber before entering the aorta. Intracardiac obstruction to this pathway causing systemic outflow tract obstruction (SOTO) may be present at birth or develop over time. Long-term survival after Fontan has not been defined. We defined outcomes utilizing records from 2 centres that were cross-checked with data from a bi-national Fontan Registry for completeness and accuracy. METHODS: Two hundred and eleven patients were identified, 59 TA-TGA,152 DILV. Median follow-up was 17 years (range 4 days to 49.8 years). The Kaplan-Meier method was used for all of the time to event analyses and the log-rank test was used to compare the time-to-events. Cox proportional hazard models were used to test the association between potential predictors and time-to-event end-points. RESULTS: TA-TGA had reduced survival compared to DILV (cumulative risk of death 28.8% vs 11%, hazard ratio (HR) 3.1 (95% confidence interval (CI) 1.6-6.1), P = 0.001). In both groups, SOTO at birth carried a worse prognosis HR 3.54 (1.36-9.2, P = 0.01). SOTO was not more common in either morphology at birth ( P = 0.20). Periprocedural mortality accounted for 40% of deaths. Fontan was achieved in 82%, DILV were more likely to achieve Fontan than TA-TGA (91% vs 60%, P <0.001). After Fontan there were 9 deaths (4%) with no difference according to morphology. CONCLUSIONS: Patients with TA-TGA have poorer outcomes than those with DILV, affecting survival and likelihood of achieving Fontan. SOTO at birth carries a high risk of mortality suggesting that, when present, initial surgical management should address this.