John Hewitson

Left ventricular sub-valvar mitral aneurysms

We retrospectively reviewed the surgical treatment of 12 patients (nine female, mean age 16.1+/-8.7 years) with sub-mitral aneurysms managed in our institution between 1991 and 2002. We identified three groups of patients in accordance with the degree of posterior mitral annular involvement by the aneurysm. A single aneurysm neck was found in seven patients, multiple necks in two and involvement of the entire posterior mitral annulus in three patients. Involvement of the entire posterior annulus by the aneurysmal process has not been previously described. The mean age of this latter group 29+/-5.1 years was significantly older than the former (P=0.001), suggesting a possible progressive nature of sub-mitral aneurysms. An intracardiac surgical approach was used in six patients and a combined intra and extracardiac approach in the remainder. There was no operative mortality. The mitral valve was initially repaired in eight patients. Failure of closure of the aneurysm necessitating reoperation occurred in four patients (33.3%). An understanding of the inter-relationship between the aneurysm and mitral valve is essential for successful surgical repair. Histology of the aneurysm tissue showed rheumatic heart disease in two patients and tuberculosis in two patients. Hence, although sub-valvar aneurysms are thought to be congenital, a third of our patients had evidence of co-existent rheumatic heart disease or tuberculosis.

Role of thoracic surgery for childhood tuberculosis.

Abstract. Lymphadenopathy is the hallmark of intrathoracic tuberculosis in children. The role of the thoracic surgeon in treating childhood tuberculosis is to relieve the more severe symptoms of lymphadenopathy, prevent the more long-term secondary damage that lymphadenopathy may cause to the lung, and treat the sequelae of thoracic tuberculosis. We reviewed the role of surgery in childhood tuberculosis at Red Cross Children’s Hospital from January 1981 to January 1996 in 161 children under 13 who were admitted for 168 therapeutic surgical interventions for proved intrathoracic tuberculosis and its related complications. We classified patients according to the pathophysiology of their disease to clarify the role of surgery in their management. Successful decompression of lymph nodes that were acutely compromising major airways was done in 25 children, and decompression for chronic airway compression was successful in 8 of 11 children. Therapeutic bronchoscopy successfully opened an airway obstructed by intraluminal tissue in 68% of 28 patients, with long-term pulmonary reexpansion in 50%. Pulmonary resections for postprimary tuberculous damage were done in 72 patients with a mortality of 2.7% and morbidity of 16.7%. Another 17 patients were operated on for pleural disease and 15 for other tuberculosis-related problems. The mortality for all patients undergoing surgery for complications of tuberculosis during childhood was 1.9% (3/161), suggesting that when indicated, an aggressive surgical approach is relatively safe.

Hyperchloraemic metabolic acidosis following open cardiac surgery

Aims: To describe acid–base derangements in children following open cardiac surgery on cardiopulmonary bypass (CPB), using the Fencl–Stewart strong ion approach. Methods: Prospective observational study set in the paediatric intensive care unit (PICU) of a university children’s hospital. Arterial blood gas parameters, serum electrolytes, strong ion difference, strong ion gap (SIG), and partitioned base excess (BE) were measured and calculated on admission to PICU. Results: A total of 97 children, median age 57 months (range 0.03–166), median weight 14 kg (range 2.1–50), were studied. Median CPB time was 80 minutes (range 17–232). Predicted mortality was 2% and there was a single non-survivor. These children showed mild metabolic acidosis (median standard bicarbonate 20.1 mmol/l, BE −5.1 mEq/l) characterised by hyperchloraemia (median corrected Cl 113 mmol/l), and hypoalbuminaemia (median albumin 30 g/l), but no significant excess unmeasured anions or cations (median SIG 0.7 mEq/l). The major determinants of the net BE were the chloride and albumin components (chloride effect −4.8 mEq/l, albumin effect +3.4 mEq/l). Metabolic acidosis occurred in 72 children (74%) but was not associated with increased morbidity. Hyperchloraemia was a causative factor in 53 children (74%) with metabolic acidosis. Three (4%) hyperchloraemic children required adrenaline for inotropic support, compared to eight children (28%) without hyperchloraemia. Hypoalbuminaemia was associated with longer duration of inotropic support and PICU stay. Conclusions: In these children with low mortality following open cardiac surgery, hypoalbuminaemia and hyperchloraemia were the predominant acid–base abnormalities. Hyperchloraemia was associated with reduced requirement for adrenaline therapy. It is suggested that hyperchloraemic metabolic acidosis is a benign phenomenon that should not prompt escalation of haemodynamic support. By contrast, hypoalbuminaemia, an alkalinising force, was associated with prolonged requirement for intensive care.

Pulmonary artery banding; adequacy and long-term outcome

OBJECTIVE Pulmonary artery banding remains a palliative option for patients with congenital heart disease and excessive pulmonary blood flow, if there is unfavourable anatomy or frail condition. In contrast to more developed countries, our patients at Red Cross Childrens Hospital, Cape Town, often present to medical services late and in poor nutritional condition. We retrospectively reviewed patients undergoing pulmonary artery banding to determine major variables that influenced long-term outcome. METHODS In a 10-year period ending June 1992, 135 consecutive patients underwent pulmonary artery banding; 89 with ventricular septal defect type non-mixing disorders, and 46 with mixing or complex disorders. The median age was 3.0 months and weight 3.5 kg with 74.8% of patients weighing less than the third percentile (NCHS adapted), and 39.3% had an additional serious medical illness. RESULTS Pulmonary banding mortality was 8.1%, and was higher in neonates (22.2%), P = 0.04) but was not related to congenital disorder, associated medical illness, or associated coarctation or interrupted aortic arch. The pulmonary band was inadequate at follow-up in 28.9%, which occurred more commonly if banding was necessary before 3 months of age (41.5%, P = 0.003) but was not related to weight, congenital disorder or associated respiratory infection. Sixty patients (44.4%) have now proceeded to definitive repair with a mortality of 23.3%, which was increased if the pulmonary band was inadequate at the time of definitive repair (44.4%: P = 0.02), but was not related to the congenital disorder. CONCLUSIONS An inadequate pulmonary artery band adversely affects outcome and demands further aggressive management prior to definitive repair.

Extended Cardiopulmonary Preservation: University of Wisconsin Solution Versus Bretschneider's Cardioplegic Solution

Application of the University of Wisconsin cold storage solution has rapidly expanded to include medium-term to long-term preservation of virtually all intraabdominal organs. Its use in intrathoracic organ transplantation has also been suggested. We therefore examined the efficacy of the University of Wisconsin solution in a primate allotransplantation model for preservation of hearts, and as a simple single-solution system for static preservation of heart-lung blocks, for periods of ischemia ranging from 6 to 24 hours. For comparison, we employed the histidine-tryptophane-ketoglutarate cardioplegic solution of Bretschneider. University of Wisconsin solution provided superior results with regard to clinical outcome and hemodynamic recovery of hearts after ischemic periods of up to 16 hours. This was in contrast to Bretschneiders solution, which allowed storage of hearts for periods of only up to 10 hours. Heart-lung blocks were equally well preserved with either University of Wisconsin or Bretschneiders solution after 6 to 12 hours, although the University of Wisconsin solution group exhibited a more notable increase in pulmonary water content. This was in accordance with histological data, which suggested that, although hemodynamic recovery of hearts stored for periods longer than 10 hours was poor, preservation of pulmonary ultrastructure was far superior using Bretschneiders solution as compared with University of Wisconsin solution after an ischemic period of up to 16 hours.

Is cardiac surgery warranted in children with Down syndrome? A case-controlled review

OBJECTIVES To compare children with Down syndrome and children without Down syndrome and investigate whether there is a significant difference in the burden that is placed on the health care system between these two groups only in respect of the repair of congenital heart disease at Red Cross War Memorial Childrens Hospital, Cape Town, South Africa. DESIGN This study is a retrospective case control review. SETTING Red Cross War Memorial Childrens Hospital, Cape Town, South Africa. SUBJECTS The sample group of 50 Down syndrome children who had received cardiac surgery between January 1998 and June 2003 was compared with a control group of 50 nonsyndromic children who had received cardiac surgery during the same period. OUTCOME MEASURES Sex and diagnoses (cardiac and noncardiac), number of days spent in hospital and in ICU, complication rates, re-operation rates, early mortality rates, planned further cardiac surgery. Costs of these outcomes were not quantified in exact monetary terms. RESULTS There was no significant difference between the two groups in terms of the burden that was placed on the health care system. Similar complication rates, re-operation rates and early mortality rates were recorded for both groups. The Down syndrome group appeared to benefit more from cardiac surgery than the non-Down syndrome group. CONCLUSION Denying cardiac surgery to children with Down syndrome does not improve the efficiency of resource allocation. It is therefore not reasonable to suggest that the problem of scarce resources can be ameliorated by discriminating against children with Down syndrome.

Children's heart disease in sub-Saharan Africa: Challenging the burden of disease

Children with heart disease in Africa have little or no access to treatment of any kind, and cardiac surgical services are virtually absent outside a handful of centres in a few of the wealthier nations. There is little reliable data concerning the prevalence of congenital or acquired heart disease in African children, but there is sufficient information to indicate that the burden of cardiac disease is vast. This major non-communicable disease is largely hidden, overshadowed by the incidence of communicable diseases. There is as yet little evidence of the hoped-for epidemiological transition toward non-communicable diseases amongst children in Africa. The burden of congenital heart disease is only part of the problem, with rheumatic heart disease (RHD) remaining the commonest cardiac problem, related to poor socioeconomic conditions. RHD is the most preventable form of cardiac disease, yet there is little preventive work being done. The many obstacles to developing paediatric cardiac care are discussed, and some possible ways forward are proposed.

Audit of paediatric cardiac services in South Africa

Objective: To evaluate paediatric cardiac services in South Africa with respect to referral base, services provided and human resources. Study design: A descriptive study design was used. An audit of the referral base, personnel and activity of paediatric cardiac units throughout South Africa was conducted by means of a questionnaire. A specialist from each centre was asked to provide the relevant data. Where accurate data was not available, estimates were provided by practitioners within each centre. Results: All identified units participated in the audit. Three were private sector units while the other five were primarily public sector units. Twenty four paediatric cardiologists, equally distributed between public and private sector units, were practicing in the country as at end 2008, with a further eight paediatricians undergoing training in paediatric cardiology. This is significantly less than the 88 paediatric cardiologists required for the population of South Africa. Eight paediatric cardiac surgeons were operating predominantly on children in public hospitals and five in private institutions. An estimated 1370 operations for congenital heart disease were performed over a one year period, with 800 of these in the public sector. Extrapolating from accepted estimates of congenital heart disease incidence, this represents conservatively, less that 40% of operations required for the population. Additionally, only 26% of the estimated 114 simple transposition of great arteries born annually were operated on, indicating serious deficiencies in the ability to adequately detect and intervene in serious congenital heart disease presenting in the neonatal period. Conclusion: The infrastructure and resources to detect and manage heart disease in children in South Africa, particularly within the public sector, are grossly inadequate.

Why are some South African children with Down Syndrome not being offered cardiac surgery

About 1 in 1,000 children has Down syndrome. Extra chromosomal material results in a myriad of potential problems for the affected individual. About 40% of Down syndrome children will have cardiac abnormalities, ranging from the simple arterial duct to the complex atrioventricular septal defect. Virtually all these defects are amenable to surgical correction and extended survival is possible. In South Africa many of these children do not undergo cardiac surgery.

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.