CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 123 Dyspnoea occurs on exertion and the children characteristically squat for relief of dyspnoea.13,16 Polycythaemia occurs secondarily and is often well tolerated.13,16 However, haematocrit above 65% may result in sludging within the microcirculation due to increased viscosity of the blood. Isovolumic partial exchange is indicated for symptomatic treatment.14,16 Chest radiographs classically show a boot-shaped but normalsized heart with an upturned apex (coeur en sabot) in most cases of TOF.12,15 More than a quarter of patients with TOF have a right-sided aortic arch.14,15,17 Pulmonary vascularity is usually diminished bilaterally.7, 14,15 Two-dimensional echocardiography is the mainstay for the diagnosis and follow up of TOF.13-15,17 Cardiac magnetic resonance imaging (CMRI) or a cardiac computerised tomography scan (CCT) may be required to provide further relevant information for diagnosis and surgical intervention.14,15,17 Cardiac catheterisation may be required for further assessment of the haemodynamic status and for the identification of anomalies of the coronary artery that are difficult to detect with echocardiography and other non-invasive means.14,15,18 The goal of medical management is to delay surgery for some months and to avert hypercyanotic spells.15,19 Use of beta-blockers, such as propranolol, is preferred.13,18 Adequate hydration is also advised to prevent dehydration, which can trigger hypercyanotic spells as a result of the release of catecholamines.13,14 In 1945, the first palliative surgery for TOF was done and named after Alfred Blalock and Helen Taussig.18 The modified Blalock–Taussig (mBT) shunt consists of placing a prosthetic tube between the subclavian and pulmonary artery on the same side.13 The predictable management of TOF is surgical correction.13-15 The goal of surgery is directed at relieving the right ventricular outflow obstruction and closing the VSD.19 Relief of the RVOTO may be associated with varying degrees of pulmonary regurgitation, with all patients requiring lifelong follow up to allow for identification of the need for further surgery or intervention.17,19 In the developing world, the diagnosis of TOF is often made quite late or not at all. A large proportion of the children present for the first time with complications arising from the disease. Care of patients with TOF at the OAUTHC was limited to medical palliative care until the advent of open-heart surgery in 2016. This study reviews the incidence, pattern, management and treatment outcomes of TOF at the OAUTHC, Ile-Ife, Nigeria. Methods This study was a retrospective audit of the treatment and outcomes of all consecutive patients with TOF, seen over a period of four years and two months (January 2016 to February 2020) at the OAUTHC, Ile-Ife, Nigeria. Hospital records including pre- and postoperative echocardiograms and followup notes were reviewed. These patients all had a transthoracic echocardiographic diagnosis of TOF. Data reviewed included socio-demographic and clinical details suchvenoushaematocrit,plainchestradiographsandtransthoracic echocardiograms. Echocardiography was done using the Esaote™ MyLab30Gold® cardiovascular echocardiography machine (serial number 08538) with colour-coded Doppler echocardiography. The machine is fitted with paediatric transducers (2.5–8 MHz), which were used for the study. Each child had two-dimensional echocardiography, during which the diagnosis of TOF was made based on the presence of the four components of the disease. CCT and right-sided cardiac catheterisation were ordered in instances where detailed echocardiography studies could not be obtained or were inconclusive. Patients with polycythaemia, defined by a haematocrit value of 65% and above, were managed with partial exchange transfusion. Patients who had suffered complications of the disease were managed symptomatically. Surgical management in our patients was either by mBT shunt or corrective surgery. The mBT shunt was reserved for two neonates with severe RVOTO. A trans-sternal approach was employed and a 4-mm polytetrafluoroethylene graft was sutured between the innominate and right pulmonary artery to improve pulmonary blood flow. Thirty-one patients had corrective surgery. The goal was to relieve the RVOTO and close the VSD. In the theatre, general anaesthesia was administered with non-invasive and invasive monitoring. Following sternal division, cardiopulmonary bypass was established via aortobicaval cannulation. The heart was arrested and the surgery proceeded with moderate hypothermia. Obstructing bands in the RVOT were resected via the right atrium and in some cases, the right ventricle. The pulmonary arteries were augmented with a glutaraldehyde-treated pericardial patch. Some children with significantly hypoplastic annulus required a trans-annular glutaraldehyde-treated pericardial patch. The VSD was closed with a Dacron™ patch. The patients were subsequently weaned off cardiopulmonary bypass and were transferred to a seven-bed intensive care unit (ICU) at the conclusion of surgery. Mechanical ventilation was continued for a couple of hours as stipulated in our unit’s protocol. The patients were managed in a general ICU by an experienced paediatric intensivist in conjunction with a team of anaesthesiologist and ICU nurses. All patients had immediate post-operative and follow-up echocardiography performed daily for the first five days and again at one, three, six and 12 weeks following surgery. All echocardiograms were done and reviewed by at least two paediatric cardiologists. Statistical analysis Data were transcribed and entered in a secure personal computer, stored and analysed using the Windows version 25.0 of the Software, Statistical Programme for Service Solutions (IBM-SPSS Incorporated, Illinois, Chicago, USA). Appropriate descriptive and inferential statistics were used to analyse the variables. Continuous variables were summarised and presented using the mean and standard deviation (SD) while categorical variables were summarised and presented using proportions and percentages. Results A total of 72 children with TOF were managed within the period of the study. They were aged 0.17 to 22 years. The mean age of the patients was 4.7 ± 4.0 years. There were 37 males and 35 females, giving a male-to-female ratio of 1:0.95. Their treatment intervention and outcomes are shown in Table 1. Thirty-one patients (43.0%) had corrective surgery
RkJQdWJsaXNoZXIy NDIzNzc=