Novel concepts and early results of repairing common arterial trunk.

OBJECTIVES: Common Arterial Trunk (CAT) continues to have a very poor prognosis globally. To address that, we have developed a novel technique targeting key concepts for the correction of all components of the anomaly, using autologous arterial tissue. This aims to enhance results, availability worldwide, and importantly to avoid the need for repeated reoperations. METHODS: From January 2019 to 4 January 2021, all patients with isolated CAT had repair of the defect using autologous arterial trunk tissue with direct right ventricle (RV) to pulmonary artery (PA) connection. Clinical outcomes, follow-up which included multi-slice computed tomography 3D segmentation and 4D cardiovascular magnetic resonance flow, are presented. RESULTS: Twenty patients were included in the study (median age 4.5 months). There were 2 hospital deaths due to systemic infection and pulmonary hypertensive crisis, respectively. Following discharge all patients remained asymptomatic with no signs of heart failure and improved pattern of growth (median follow-up: 8 months). Early postoperative 3D segmentation showed a conical shaped neo-right ventricular outflow chamber connecting the body of the RV to the main PA through a valveless ostium, and normal crossing of PA and neo-aorta. 4D cardiovascular magnetic resonance pattern of flow showed normal rapid laminar flow through the atrioventricular valves followed by a vortex towards the outflow tracts. There was laminar flow through the neo-aorta and neo-PA with velocity not exceeding 2.5 m/s. The PA regurgitant fraction was 25 ± 5% and was limited to early diastole. CONCLUSIONS: The initial results of utilizing the key concepts, using autologous arterial tissue for the repair of CAT, are encouraging, both clinically and by multimodality imaging.

Radial artery as a second conduit gains momentum: The RAPCO trial.

In coronary artery bypass grafting (CABG), the use of an internal mammary artery (IMA) to graft the left anterior descending coronary artery (LAD) improves survival and reduces the need for repeat revascularization. The other IMA, radial artery (RA), and saphenous vein (SV) have contested to complete the surgical revascularization. For that purpose, SV remains the most commonly used conduit despite current evidence in favor of arterial grafts. To determine which conduit is best for grafting the second most important coronary artery, Buxton and colleagues have recently published the long term results of their "Radial Artery Patency and Clinical Outcomes (RAPCO)" trial.

Clinical, cellular, and molecular characterisation of cardiac rhabdomyoma in tuberous sclerosis.

BACKGROUND: Rhabdomyoma is the most common cardiac tumour in children. It is usually associated with tuberous sclerosis complex caused by mutations in TSC-1 or TSC-2 genes. This tumour typically regresses by unknown mechanisms; however, it may cause inflow or outflow obstruction that necessitates urgent surgery. Here we investigate the clinical features and the genetic analysis of patients with tuberous sclerosis complex presenting with large rhabdomyoma tumours. We also investigate the potential role of autophagy and apoptosis in the pathogenesis of this tumour. METHODS: All the patients with cardiac rhabdomyoma referred to Aswan Heart Centre from 2010 to 2018 were included in this study. Sanger sequencing was performed for coding exons and the flanking intronic regions of TSC1 and TSC2 genes. Histopathological evaluation, immunohistochemistry, and western blotting were performed with P62, LC3b, caspase3, and caspase7, to evaluate autophagic and apoptotic signaling. RESULTS: Five patients were included and had the clinical features of tuberous sclerosis complex. Three patients, who were having obstructive tumours, were found to have pathogenic mutations in TSC-2. The expression of two autophagic markers, P62 and LC3b, and two apoptotic markers, caspase3 and caspase7, were increased in the tumour cells compared to normal surrounding myocardial tissue. CONCLUSION: All the patients with rhabdomyoma were diagnosed to have tuberous sclerosis complex. The patients who had pathogenic mutations in the TSC-2 gene had a severe disease form necessitating urgent intervention. We also demonstrate the potential role of autophagy and apoptosis as a possible mechanism for tumourigenesis and regression. Future studies will help in designing personalised treatment for cardiac rhabdomyoma.

Congenital Coronary Aneurysm: Unusual Presentation of Myocardial Ischemia in Children.

Coronary artery aneurysms in children are usually associated with inflammatory disease such as Kawasaki disease or connective tissue disease. Congenital coronary aneurysm is a rare entity with few case reports published in the literature. We report an unusual case of congenital coronary aneurysm in an 11-year-old boy presented to our center with an ischemic cardiac event. Further investigations including computed tomography scan, cardiac magnetic resonance imaging, and coronary angiography revealed a large aneurysm arising from the proximal segment of left anterior descending (LAD) artery. Surgical repair was done including aneurysm resection and roofing the LAD artery using autologous saphenous vein patch.

A New Technique for Shaping the Aortic Sinuses and Conserving Dynamism in the Remodeling Operation.

BACKGROUND: Preserving dynamism and recreating the sinuses in the Dacron graft are thought to be important for optimizing results of aortic valve-conserving operations. METHODS: We describe a novel technique that preserves dynamism and recreates the sinotubular junction. In addition, it tailors 3 sinuses of defined longitudinal and transverse curvatures in a straight Dacron tube during the operation. The technique has been used in 6 patients with varied aortic root pathology. We performed preoperative and postoperative multimodality imaging using computerized image analysis as well as 3-dimensional models. RESULTS: There was no early or midterm death. Upon discharge, patients were clinically well, with echocardiographic evidence of minimal (3 patients) or mild (3 patients) aortic regurgitation. Computed tomography and cardiac magnetic resonance imaging with extensive image analysis of the aortic root size, shape, and function showed partial or complete normalization of these parameters. This included the shape and dynamism of the aortic annulus and the size and shape of the geometric (effective) orifice. The 4-dimensional magnetic resonance imaging pattern of flow in the sinuses and ascending aorta showed favorable vortices in the sinuses, right-handed helical flow, and marked diminution of energy loss in the ascending aorta. CONCLUSIONS: The novel technique described here is simple, practical, and cost-effective because it uses a widely available straight Dacron tube. The technique does not use rigid internal or external support. The early results are encouraging. Larger series with longer follow-up are required.

Cor Triatriatum Sinister (Divided Left Atrium): Histopathologic Features and Clinical Management.

BACKGROUND: Cor triatriatum sinister (CTS), or divided left atrium, is a rare congenital cardiac disease in which the left atrium is divided into 2 chambers by a fibromuscular diaphragm that will cause blood flow obstruction to the left ventricle. Recent animal studies suggested the role of hyaluronidase-2 (HYAL-2) deficiency as a risk factor for developing CTS. The histopathologic features of this diaphragm and our surgical experience with the management of this disease are reviewed. METHODS: Ten patients underwent surgical correction of CTS between 2010 and 2018. All patients had complete clinical and imaging evaluation. The fibromuscular diaphragms were histologically evaluated with myosin, troponin, vimentin, smooth muscle actin, and HYAL-2 to characterize the structure of the CTS diaphragm. RESULTS: All patients underwent excision of CTS diaphragm using cardiopulmonary bypass with no early mortality. Most patients had the classic form of CTS in which the diaphragm separates the pulmonary and the vestibular chambers with no atrial septal defect. The histologic studies demonstrated the presence of fibrous, mesenchymal cells, along with cardiac muscle cells, at the site of membrane attachments. HYAL-2 enzyme was expressed in the CTS diaphragm. CONCLUSIONS: Surgical repair of CTS provides satisfactory results with low risk of death. Our histologic studies revealed the cellular composition of the CTS diaphragm. HYAL-2 deficiency may not explain the pathogenesis of CTS, and further studies are needed to evaluate the complex mechanisms involved in the development of this disease.

Revival and modification of the Mustard operation.

OBJECTIVE: The neonatal arterial switch operation is currently the procedure of choice for patients with transposition of the great arteries. However, a large number of patients present too late for the arterial switch operation and are best managed with the atrial switch operation. METHODS: We have used the Mustard operation in its original form or following a new modification designed to enhance the atrial functions and filling of the left ventricle in an attempt to improve long-term results. RESULTS: Between July 2013 and November 2018, a total of 101 patients underwent the Mustard operation, 86 with the new modification. The median age at operation was 16 months (6 months to 27 years). A total of 75 patients (74.3%) were male. Median preoperative oxygen saturation was 71%. There were no early deaths and there were 3 late deaths during a median follow-up period of 24.2 months (all in patients with large ventricular septal defect and established pulmonary vascular disease). At the latest follow-up, all patients were in stable sinus rhythm. There were no baffle leaks. Seven patients had asymptomatic narrowing of the superior baffle, and 1 patient required balloon dilatation. Follow-up is 100% complete and includes computed tomography and magnetic resonance imaging at regular intervals (75 patients to date). Computerized analysis of representative subsets showed enhanced rate and pattern of filling of the left ventricle in the modified operation compared with the classic operation. CONCLUSIONS: The use of the Mustard operation, particularly the modified technique should play an important role in treating late-presenting patients with transposition of the great arteries. Improving the pattern of filling of the left ventricle could enhance the long-term results of the Mustard operation.

Giant left atrial appendage aneurysm compressing the left anterior descending coronary artery.

Left atrial appendage aneurysm (LAAA) is a rare congenital structural heart disease. It is often diagnosed by echocardiography; however, other imaging modalities can add to its diagnosis and its potential effects on the surrounding structures. A 16-year-old boy presented with dyspnea and palpitation. Transthoracic echocardiography showed a large LAAA communicating with the LA through a narrow neck with impaired left ventricular (LV) systolic function. Multidetector cardiac tomography showed that the LAAA is compressing the left anterior descending artery. The LAAA was surgically resected followed by improvement of the LV systolic function.

Repair of very severe tricuspid regurgitation following detachment of the tricuspid valve.

We report on the case of 5-year-old girl with severe tricuspid regurgitation following previous repair of double outlet right ventricle with subaortic ventricular septal defect, performed through trans-atrial approach using detachment of tricuspid valve leaflet. The severe tricuspid regurgitation was found to be due to dehiscence at the site of the previous detachment and was repaired using a pericardial patch. In this report, we discuss the relative merits and risks of using this technique.

Anatomic correction of ALCAPA in an adult presenting with sudden cardiac death.

We report on a young adult with ALCAPA, who was successfully resuscitated after collapsing in ventricular fibrillation while playing football. This was followed by anatomical correction of the anomaly with a smooth recovery and return to his daily activities. The advantages of this approach are discussed in this brief report.