Farirai F. Takawira

Evaluation of the Extracardiac Conduit Modification of the Fontan Operation for Thrombus Formation using Magnetic Resonance Imaging

BACKGROUND The prevalence of thrombosis after the Fontan procedure depends upon the surgical technique used and the method of detection employed. Current investigations for thrombosis lack sensitivity and specificity or, in the paediatric population, require a general anaesthetic. We undertook a study to examine the feasibility of using magnetic resonance imaging (MRI) to detect thrombosis within the conduit, cardiac chambers and pulmonary arteries after the extracardiac conduit modification of the Fontan procedure. METHODS Of the 50 children who had undergone this procedure at our institution between 1997 and 2002, 26 were eligible for, and 13 underwent, MRI study. The mean age was 10.2 years (range 8.2-16.8 years, median 9.5 years) and the average time from operation was 63 months (range 29-79 months, median 68 months). The mean age at Fontan operation was 4.9 years (range 2.1-10.5 years). Ten were on low dose aspirin, two were on warfarin and one was not anti-coagulated. In all cases, satisfactory imaging of the venous pathways and pulmonary arteries was obtained and there were no thrombi detected. CONCLUSIONS We conclude that MRI is a potentially useful tool for the detection of thrombus in patients who have undergone the Fontan operation.

Anomalous origin of the left pulmonary artery from the ascending aorta in two children with pulmonary atresia, sub-aortic ventricular septal defect and right-sided major aorto-pulmonary collateral arteries

We report two rare cases of an anomalous origin of the left pulmonary artery (AOLPA) from the ascending aorta, associated with pulmonary atresia, a ventricular septal defect and a left aortic arch. The cases are unusual because AOLPA is more commonly associated with a right aortic arch and it is more usual for the right pulmonary artery to originate anomalously from the ascending aorta. The pulmonary blood supply to the right lung in both patients was absent and provided instead by major aorto-pulmonary collateral arteries which were stenosed at multiple levels. The AOLPA in both patients originated from the postero-lateral aspect of the ascending aorta just distal to the sino-tubular junction. Only one patient showed the more common association of an unusual aortic arch branching pattern in the form of an anomalous right subclavian artery. Neither patient was in heart failure and the chest X-ray in both revealed differential pulmonary perfusion with prominent vascularity of the left lung. Cardiac catheterisation showed systemic pressures within the anomalous left pulmonary artery. Karyotyping revealed normal chromosomes, and fluorescent in-situ hybridisation done in one patient was negative for chromosome 22q11.2 microdeletion. Both patients have been managed conservatively.

Development of a subaortic aneurysm secondary to disseminated tuberculosis in a child.

Subvalvular aneurysms of the left ventricle are very rare and often the cause is uncertain. Most of the cases of subvalvular left ventricular aneurysms described in the literature are due to congenital weakness of the fibromuscular annuli. We describe a unique case of a child with a tuberculous subaortic aneurysm observed at different stages of development by serial transthoracic echocardiography. The patient underwent successful cardiac surgery after the initial conservative treatment for tuberculosis.

Endovascular Covered Stent Treatment for Descending Aorta Pseudoaneurysm Following Coarctation of the Aorta Repair in an Infant

The development of a pseudoaneurysm is a rare complication following repair of a coarctation of the aorta. Surgical management of pseudoaneurysms is associated with high morbidity and mortality. We describe the successful endovascular deployment of a covered stent in a sick infant with a descending aorta pseudoaneurysm, following the repair of an aortic coarctation. We highlight the challenges we encountered. Endovascular repair is a safe palliative alternative to re-do open surgery in unstable infants with large pseudoaneurysms following aortic coarctation repair. The role of endovascular stents as the final definitive therapy will remain limited by the deployable, small-size stents in small, growing children.

An Unusual Case of Congenitally Unguarded Tricuspid Valve Orifice Associated with Pulmonary Valve Atresia and Intact Ventricular Septum

We report on a premature neonate who presented with cyanosis soon after birth. She was found on echocardiography to have an unguarded tricuspid valve orifice associated with pulmonary valve atresia and an intact interventricular septum. Owing to the small‐sized pulmonary arteries, she was initially managed conservatively with prostaglandin infusion, and at one year of age underwent a successful bidirectional cavo‐pulmonary (Glenn) shunt operation.

Unusual variant of scimitar syndrome associated with an absent right pulmonary artery, stenosis of the inferior vena cava, hemi-azygous continuation and the VACTERL association.

We report on a two-month-old infant with an unusual form of scimitar syndrome, associated with an absent right pulmonary artery, obstructed inferior vena cava, hemi-azygous continuation and the VACTERL association. The infant posed a major management problem and eventually died from a lower respiratory tract infection.

Optimal paediatric cardiac services in South Africa – what do we need?

Most children with congenital heart disease have a good outcome if treated appropriately, however the majority of children with heart disease in South Africa do not receive appropriate care. This is related to serious deficiencies in the mechanisms and training for early detection as well as a major shortage of skilled personnel to care for these children at all levels. Most public sector hospitals are unable to cope with the number of patients requiring surgery, mainly due to inadequate theatre time allocation and intensive care facilities. Key interventions to address these deficiencies include: 1. Strategies to improve both the training and the retention of all professionals involved in the care of congenital heart disease. 2. Programmes to increase awareness of both congenital and acquired heart disease in children among health care personnel. 3. Ensuring appropriate infrastructure and equipment designed for children with congenital heart disease are available. 4. Development of congenital heart surgery as an independent subspecialty with dedicated resources and personnel. 5. Dedicated intensive care facilities for paediatric heart surgery. In addition, development of appropriate patterns of referral, stimulation of research and positive private-public partnerships are all necessary to ensure that appropriate care is delivered.

Cryptogenic Cirrhosis and Hepatopulmonary Syndrome in a Boy with Hepatic Hemangioma in Botswana: A Case Report and Review of the Literature

Hepatic hemangiomas are considered to be the most common benign tumors of the liver. They are often found incidentally while investigating for other causes of liver disease. Hemangiomas that are less than 10 cm are not expected to cause any problems. Typically, they do not enlarge and, apart from regular follow-up, no definitive treatment is indicated. This is a posthumous case report of a male child with a medium-sized hemangioma from infancy, complicated by cryptogenic cirrhosis and hepatopulmonary syndrome. It demonstrates the challenges of managing a child with such complicated conditions in a resource-limited setting.