Striving for physiologic coaptation: An experimental and innovative approach towards designing and implanting aortic neo-leaflets

Aortic valve repair has emerged as the treatment of choice for congenital aortic valvular disease, avoiding the need for a reoperation associated with stented prosthesis overgrowth. The introduction of a leaflet implant represents a recent advancement in a field that originated early techniques, such as simple commissurotomies. In our experimental approach, we assessed two established leaflet-sizing techniques by analysing their resultant coaptation areas. Although both techniques produced competent valves, the large coaptation areas differed significantly from the native aortic valve. This observation prompted us to revisit the functional anatomy of the aortic valve, our goal being to refine leaflet design and implantation for enhanced efficacy and longevity in neo-leaflet procedures. We designed a novel aortic valvar neo-leaflet, utilizing porcine pericardium as our primary source material, and we implanted four tri-leaflet valves in four porcine hearts. All tri-leaflet valves were competent and closely resembled the coaptation area of the native aortic valve. This study serves as a pilot for further experimental aortic valve repair surgery using neo-leaflet implants.

Importance of Acute Anterior Angulation in Double Aortic Arch Needing Attention at Primary Surgery

Background

Vascular rings are rare congenital abnormalities of the aortic arch. There are many embryological variants including a double aortic arch. In symptomatic children, division of ring and release of airway structures may be sufficient. Persistence of symptoms can be related to an anterior angle formed between the two arches. The aim of this study is to evaluate the clinical efficacy in improving symptoms and on changing this angle at the primary surgery.

Methods

All children who had surgery for double aortic arch between 2005 and 2020, were studied. Relevant factors were analyzed for persistent symptoms including anatomical substrates and surgical details.

Results

A total of 87 out of 224 children had surgery for a double aortic arch. At presentation, airway symptoms (n = 74/87) were more common than esophageal symptoms (n = 27/87). Early onset symptoms within 1 year were seen in 49 children. In addition to division of one arch, surgical steps also included realigning the anterior left arch, thereby eliminating the acute angle in 36 children (after 2014). After surgery, symptom relief within 12 months following surgery was seen in 64% of children (56 out of 87) but in 27 out of 36 children (75%) with additional surgical modification, as against 29 out of 51 (57%) in those with division of the arch. Symptoms persisted beyond 1 year needing reintervention in eight children.

Conclusion

Anterior arch angulation plays an important role in double aortic arch by causing a “nutcracker” phenomenon. Repair in double aortic arch should consider this aspect and include modification of surgical steps by realigning the corresponding aortic arch branches and an anterior pexy in selected cases.

Diazoxide-induced pulmonary hypertension in hyperinsulinaemic hypoglycaemia: Recommendations from a multicentre study in the United Kingdom

OBJECTIVE

Diazoxide is first-line treatment for hyperinsulinaemic hypoglycaemia (HH) but diazoxide-induced pulmonary hypertension (PH) can occur. We aim to characterize the incidence and risk factors of diazoxide-induced PH in a large HH cohort to provide recommendations for anticipating and preventing PH in diazoxide-treated patients with HH.

DESIGN AND PATIENTS

Retrospective cohort study involving four UK regional HH centres; review of case notes of HH patients on diazoxide.

MEASUREMENTS

The diagnosis of PH was based on clinical and echocardiography evidence. Patient and treatment-related risk factors were analysed for association.

RESULTS

Thirteen (6 men) of 177 HH diazoxide-treated patients developed PH, an incidence of 7%. In the PH group, HH was diagnosed at median (range) of 9 (1,180) days, with diazoxide commenced 4 (0,76) days from diagnosis and reaching a maximum dose of 7 (2.5,20) mg/kg/d. The majority (8 of 13 patients) developed PH within 2 weeks of diazoxide. Complete diazoxide withdrawal, but not dose reduction, led to PH resolution at 41 (3,959) days. In three patients, PH continued beyond 12 months. Risk factors for the development of PH included the presence of congenital heart disease (CHD) (P = .008), and total fluid volume exceeding 130 mL/kg/d in the immediate 24 hours preceding diazoxide (P = .019).

CONCLUSION

Pulmonary hypertension can occur in 7% of diazoxide-treated HH patients. Risk factors include the presence of congenital heart disease and fluid overload. Recommendations include echocardiography and fluid restriction to 130 mL/kg/d prior to diazoxide treatment and immediate discontinuation of diazoxide if PH develops.

Addison's disease presenting with perimyocarditis

BACKGROUND

Polyglandular autoimmune syndrome (PGA) and eosinophilic granulomatosis with polyangiitis (EGPA) do not seem to represent a coincidental association.

CASE PRESENTATION

A case of a 15-year-old boy is reported who presented with severe systemic inflammation, perimyocarditis and cardiogenic shock, in whom EGPA was initially suspected and later diagnosed with autoimmune adrenalitis with PGA.

CONCLUSIONS

The severity of the systemic inflammation and perimyocarditis suggests a more widespread autoimmune-mediated process. Autoimmune adrenal insufficiency should be considered in all cases of pericarditis and perimyocarditis, especially when the severity of clinical manifestations exceeds the expected for the severity of the cardiac findings, as timely identification and prompt treatment may be life-saving.

Echocardiographic arterial measurements in complex congenital diseases before bidirectional Glenn: comparison with cardiovascular magnetic resonance imaging

Aims

This study sought to investigate diagnostic accuracy of echocardiographic measures of great vessels in patients before bidirectional cavopulmonary connection (BCPC) compared with cardiovascular magnetic resonance (CMR).

Methods and results

Seventy-two patients (61% after Norwood operation) undergoing BCPC between 2007 and 2012 were assessed pre-operatively using echocardiography and CMR. Bland-Altman analysis and correlation coefficients were used for comparison of echocardiography and CMR measurements. Sensitivity, specificity, and positive and negative predictive values were calculated to assess the ability of echocardiography to detect vessel stenosis. Twenty-four percent of all vessel measurements could not be made by echocardiography due to poor image quality. Acquisition of unsatisfactory images was higher in non-sedated patients. Although there was a reasonable correlation (0.68-0.90) and low bias (-0.8 to 0.5), there were wide limits of agreement between echocardiography and CMR demonstrating poor agreement. Sensitivity and specificity for pulmonary branches were moderate [sensitivity for right pulmonary artery (RPA) 67%, left pulmonary artery (LPA) 54%, specificity for RPA 65%, LPA 72%] with low levels of accuracy (RPA and LPA 42%). Sensitivity, specificity, and accuracy were better for aorta (82, 86, and 63%, respectively).

Conclusion

This study demonstrates modest agreement between echocardiographic and CMR measures of vessel diameter and stenosis detection. Approximately a quarter of all vessel segments could not be measured using echocardiography due to poor image quality, which was significantly lower in non-sedated patients. These findings show that echocardiography cannot substitute CMR for reliable identification of great vessel stenoses in complex patients prior to the BCPC, particularly those with Blalock-Taussig shunts.

Cardiovascular status after Kawasaki disease in the UK

OBJECTIVE

Kawasaki disease (KD) is an acute vasculitis that causes coronary artery aneurysms (CAA) in young children. Previous studies have emphasised poor long-term outcomes for those with severe CAA. Little is known about the fate of those without CAA or patients with regressed CAA. We aimed to study long-term cardiovascular status after KD by examining the relationship between coronary artery (CA) status, endothelial injury, systemic inflammatory markers, cardiovascular risk factors (CRF), pulse-wave velocity (PWV) and carotid intima media thickness (cIMT) after KD.

METHODS

Circulating endothelial cells (CECs), endothelial microparticles (EMPs), soluble cell-adhesion molecules cytokines, CRF, PWV and cIMT were compared between patients with KD and healthy controls (HC). CA status of the patients with KD was classified as CAA present (CAA+) or absent (CAA-) according to their worst-ever CA status. Data are median (range).

RESULTS

Ninety-two KD subjects were studied, aged 11.9 years (4.3-32.2), 8.3 years (1.0-30.7) from KD diagnosis. 54 (59%) were CAA-, and 38 (41%) were CAA+. There were 51 demographically similar HC. Patients with KD had higher CECs than HC (p=0.00003), most evident in the CAA+ group (p=0.00009), but also higher in the CAA- group than HC (p=0.0010). Patients with persistent CAA had the highest CECs, but even those with regressed CAA had higher CECs than HC (p=0.011). CD105 EMPs were also higher in the KD group versus HC (p=0.04), particularly in the CAA+ group (p=0.02), with similar findings for soluble vascular cell adhesion molecule 1 and soluble intercellular adhesion molecule 1. There was no difference in PWV, cIMT, CRF or in markers of systemic inflammation in the patients with KD (CAA+ or CAA-) compared with HC.

CONCLUSIONS

Markers of endothelial injury persist for years after KD, including in a subset of patients without CAA.

Successful reversal of propionic acidaemia associated cardiomyopathy: evidence for low myocardial coenzyme Q10 status and secondary mitochondrial dysfunction as an underlying pathophysiological mechanism

Dilated cardiomyopathy is a rare complication in propionic acidaemia (PA). Underlying pathophysiological mechanisms are poorly understood. We present a child of Pakistani consanguineous parents, diagnosed with late-onset PA at 18months of age. He presented a mild phenotype, showed no severe further decompensations, normal growth and psychomotor development on a low protein diet and carnitine supplementation. At 15years, a mildly dilated left ventricle was noticed. At 17years he presented after a 2-3month history of lethargy and weight loss with severe decompensated dilated cardiomyopathy. He was stabilised on inotropic support and continuous haemofiltration; a Berlin Heart biventricular assist device was implanted. He received d,l-hydroxybutyrate 200mg/kg/day, riboflavin and thiamine 200mg/day each and coenzyme Q10 (CoQ10). Myocardial biopsy showed endocardial fibrosis, enlarged mitochondria, with atypical cristae and slightly low respiratory chain (RC) complex IV activity relative to citrate synthase (0.012, reference range 0.014-0.034). Myocardial CoQ10 was markedly decreased (224pmol/mg, reference range 942-2738), with a marginally decreased white blood cell level (34pmol/mg reference range 37-133). The dose of CoQ10 was increased from 1.5 to 25mg/kg/day. Cardiomyopathy slowly improved allowing removal of the external mechanical cardiac support after 67days. We demonstrate for the first time low myocardial CoQ10 in cardiomyopathy in PA, highlighting secondary mitochondrial impairment as a relevant causative mechanism. According to these findings, a high-dose CoQ10 supplementation could be a potential adjuvant therapeutic to be considered in PA-related cardiomyopathy.

Thoracoscopic Pericardiectomy for Constrictive Pericarditis in a Pediatric Patient With Mulibrey Nanism

Mulibrey nanism is a rare autosomal recessive disease with multisystem involvement. Clinical deterioration is most often related to cardiac involvement in the form of restrictive or constrictive disorders, and pericardiectomy may be required. We report a case of Mulibrey nanism in a patient of non-Finnish origin, where a thoracoscopic pericardiectomy helped in good palliation and clinical recovery.

A modified method for determination of diffusivities of low molecular substances in non-Newtonian liquids

A modified method for determination of diffusivities of low molecular substances in non-Newtonian liquids described by the power-law model has been proposed. It is based on the dissolution of Geiss body, with a parameter m=1/3 rotating in an infinite fluid. In this case, the solution of the differential equations of motion and mass transfer is available as an analytical formula for calculating the diffusivity coefficient.The method allows the extension of the variety of media and diffusing species. It has been illustrated with dissolving of gypsum in water and five non-Newtonian liquids. The results obtained have been interpreted taking into account the interaction between calcium ions and polymer molecules of the non-Newtonian system, as well as the heterogeneity of the system near to the dissolving surface.