Accuracy of elastography versus biopsy in assessing severity of liver fibrosis in young Fontan patients.

OBJECTIVES: We performed a single-centre retrospective study comparing the accuracy of non-invasive elastography with liver biopsy in accurate assessment of Fontan-associated liver disease. METHODS: Fontan patients who underwent combined assessment with a percutaneous liver biopsy and non-invasive elastography between January 2015 and December 2023 at our Children's hospital were included. Liver biopsies were classified using the Congestive Hepatic Fibrosis Score as early Fontan-associated liver disease (scores 1, 2) and advanced Fontan-associated liver disease (score 3/bridging fibrosis and score 4/cirrhosis). Elastography values were categorised as advanced Fontan-associated liver disease for liver elasticity >2.1 m/s by ultrasound and liver stiffness >5 KPa on magnetic resonance elastography. RESULTS: We included 130 patients (116 children, 89%, mean age at biopsy: 14.6 years ± 3.6) who underwent liver biopsy at a mean duration of 11.1 years (±0.3) following Fontan surgery. Advanced Fontan-associated liver disease was noted in 41 (31.5%) patients with 13 (10%) showing frank cirrhosis. Pre-biopsy ultrasound showed advanced liver fibrosis in 18/125 (14%), with low sensitivity (23%), high specificity (90%), and low accuracy (68%, k = 0.1) in diagnosing advanced Fontan-associated liver disease. Similarly, pre-biopsy magnetic resonance elastography showed advanced fibrosis in 23/86 (27%) of patients, with low sensitivity (30%), fair specificity (75%), and low accuracy (63%, k = 0.1). Interestingly, advanced Fontan-associated liver disease was missed by ultrasound in 29% and by magnetic resonance elastography in 25% of patients. Advanced Fontan-associated liver disease was associated with lower platelet count (p = 0.02) and higher Gamma-glutamyl Transferase levels (p = 0.02). CONCLUSION: Advanced hepatic fibrosis is common among paediatric Fontan patients. Non-invasive elastography may overestimate and underestimate the degree of liver fibrosis, and therefore, liver biopsy may be required for confirming disease severity.

Transthoracic Echocardiography in the Preoperative Assessment of Newborn Coarctation: Limiting Risks Associated with Advanced Imaging Techniques.

A newborn male child with prenatally identified aortic arch hypoplasia presented to our facility for cardiac management. He had been started on prostaglandins at the delivery facility and was subsequently placed on a high-flow nasal cannula due to associated apnea. On the day of life three, the patient underwent cardiac computed tomography scan for delineation of his anatomy. The patient remained intubated after his imaging study in anticipation of surgical intervention, which took place at the age of 5 days. The patient required a peritoneal dialysis catheter placement 2 days after his procedure due to oliguria. He progressed into renal failure requiring continuous renal replacement therapy. This patient was subsequently discussed at our departmental morbidity and mortality conference. The short time frame between contrast administration for the computed tomography and surgical intervention was thought to have contributed to his renal failure. We discussed the adequacy of transverse aortic arch imaging by echocardiogram and the utility of advanced imaging in the fragile neonatal period. This discussion resulted in our department asking, "Is transthoracic echocardiography accurate when diagnosing and characterizing aortic coarctation at our institution? Are advanced imaging studies necessary in instances of simple coarctation?"

Safety and utility of CardioMEMS device for remote pulmonary artery monitoring in paediatric Fontan patients: a case series.

Background: Patients with single ventricle congenital heart disease who undergo total cavo-pulmonary anastomosis (Fontan surgery) suffer from elevated pulmonary artery pressure (PAP), which leads to multiple adverse sequelae. Traditionally, the Fontan pressures are assessed via invasive haemodynamic catheterization that exposes these medically fragile patients to the risks of vascular injury and anaesthesia. While the CardioMEM remote PAP monitor has been extensively used in adults with heart failure, the safety of this device has not been established in children. Case summary: We report safety and utility of this device in eight paediatric Fontan patients. Our patients ranged from 9 to 18 years of age. There were no reported complications related to the implantation of the CardioMEMS device in our population. Discussion: This is the first case series of safety of CardioMEMS device in paediatric Fontan Powered by Editorial Manager® and ProduXion Manager® from Aries Systems Corporation patients. Our experience indicates that the device may be safely utilized for the management of Fontan-related complications in this vulnerable population.

Elevated Aortic Augmentation Index in Children Following Fontan Palliation: Evidence of Stiffer Arteries?

Children born with a functional single ventricle who undergo Fontan palliation are prone to early pump failure. Whether they develop early arterial stiffness with resultant increase in afterload is not well known. We hypothesized that the aortic stiffness is higher in pediatric Fontan patients when compared to healthy controls. A prospective study was conducted at the Children's Hospital of Michigan. Twenty-two Fontan patients (aged 6-21 years) were compared with 22 healthy controls (aged 9-17 years) selected from children referred to our clinic who had normal cardiac anatomy and function on the echocardiogram. Aortic stiffness was assessed noninvasively by measuring the aortic augmentation index (AAI) using applanation tonometry (Sphygmocor, Atcor, IL). AAI was calculated as AP/PP where augmentation pressure (AP) is the increase in aortic systolic blood pressure (BP) and pulse pressure (PP) is the difference between aortic systolic and diastolic BP. Ten patients (45 %) had hypoplastic left ventricle, and 11 (50 %) had undergone aortic arch surgery. The median AAI was significantly higher in Fontan patients when compared to controls (12.5, IQR 4.8, 17.3 vs 0, IQR -6.3, 5.8; p = 0.0003). History of aortic arch surgery and single ventricle morphology did not have a significant impact on AAI. Pediatric patients who undergo Fontan palliation have significantly higher AAI, a marker of aortic stiffness and increased afterload, compared to healthy controls. Larger longitudinal studies are warranted to elucidate the possible contribution of elevated AAI on pump failure in these patients.

Testing efficacy in determination of recurrent supraventricular tachycardia among subjectively symptomatic children following "successful" ablation.

BACKGROUND: Supraventricular tachycardia (SVT) in children can be successfully terminated using catheter ablation techniques; however, chronic, true success may be less. Sensed tachycardia (ST) is common following ablation and the differentiation from true arrhythmia recurrences can be challenging. METHODS: Records of all patients ≤ 18 years who underwent successful ablation for simple forms of SVT and followed-up for at least a year between 2002 and 2012 were reviewed. Patients with congenital heart disease, atrial muscle tachycardia, and associated ventricular tachycardia were excluded. The diagnostic utility of commonly performed tests was assessed. RESULTS: Among the 205 eligible subjects, 202 underwent successful ablation (98.5%), of who five were lost to follow-up before 1 year. The early success rate (6 weeks postablation) and mid-term success rate (1 year postablation) were high (97.5% and 87.4%, respectively) whereas the chronic success (5 years postablation) was only 75%. Although true arrhythmia recurrence was significantly higher in the young (mean 11.5 years vs 13.5 years, P = 0.03) and males (P = 0.02), the presence of diffuse, right-sided fibers was the only independent predictor of true recurrence (odds ratio = 2.7, P = 0.03, 95% confidence interval 1.1, 6.8). Significant ST was reported by 111 patients (56%). The 30-day ambulatory event monitor had the highest sensitivity (71%) when compared to exercise test (19%) and electrocardiogram (24%) in identifying true arrhythmia recurrence. CONCLUSIONS: Acute and early success may not guarantee chronic ablation success. Postablation, symptomatic patients can be most effectively evaluated using ambulatory event monitoring; however, true recurrence may still be missed and requires closer monitoring.

Abiotrophia endocarditis in children with no underlying heart disease: a rare but a virulent organism.

Infective endocarditis is extremely rare in children with structurally normal hearts. The most common etiological agents are staphylococcal and streptococcal species. Nutritionally variant streptococci also classified as Abiotrophia species are a group of fastidious organisms that account for only 5% to 6% of all cases of culture-negative infective endocarditis. Only seven cases of Abiotrophia infective endocarditis have been previously reported in children with no underlying structural heart disease. We report two cases of Abiotrophia infective endocarditis in children without any predisposing factors. Both patients presented with nonspecific symptoms leading to delay in diagnosis. While bacteriological clearance was achieved in both cases, both had a complicated course including development of brain mycotic aneurysms, splenic infarction, renal failure, and irreversible damage to the mitral valve. Both patients required surgical removal of the native mitral valve and replacement. We also present review of seven cases with similar diagnosis published previously in literature and highlight important differences. Our cases highlight special challenges in management of Abiotrophia endocarditis in pediatric patients. As the organism may not be isolated in routine culture media, may present with atypical clinical symptoms and may have a complicated course even without antibiotic failure, a high index of suspicion should be maintained in children with subacute symptoms even with no underlying structural cardiac disease.

A case of life-threatening Staphylococcus aureus endocarditis involving percutaneous transcatheter prosthetic pulmonary valve.

While right ventricle to pulmonary artery homograft is the surgical procedure of choice for relieving right ventricle outflow tract obstruction; it is limited by the need for multiple surgical replacements owing to progressive conduit obstruction, valve dysfunction, or patient growth. Since January 2010, percutaneous transcatheter placement of prosthetic pulmonary valve (Melody valve) has emerged as an attractive alternative to surgical replacement of dysfunctional right ventricle to pulmonary artery homograft in the United States. We report a case of 19-year-old girl born with truncus arteriosus who underwent transcatheter placement of prosthetic pulmonary valve due to homograft insufficiency. She presented after 4 months with a febrile episode and was found to have Staphylococcus aureus endocarditis of her prosthetic valve. The infection caused multi-organ dysfunction despite bacteriological clearance and led to severe dysfunction of the valve which ultimately required surgical removal. The case highlights a rare but serious complication of percutaneous prosthetic pulmonary valves.