CARDIOVASCULAR JOURNAL OF AFRICA • Volume 33, No 3, May/June 2022 AFRICA 125 It is widely accepted that the outcome following early corrective surgery of TOF in infancy is superior to corrective surgery later in life.20-22 In a systematic review of 143 articles comprising 21 427 patients, Romeo et al.22 studied the outcome after corrective surgery of TOF. They concluded that corrective surgery of TOF in infancy was associated with a low mortality rate and good long-term survival, even though most patients required intensive follow up all through life. None of our patients had had corrective surgery in infancy, the youngest and oldest of our patients were older than one year and 17 years, respectively. Advanced age at surgery has been linked with a higher mortality rate and this has been attributed to prolonged hypoxia and right ventricular hypertension.23 In Nigeria today, the National Health Insurance Scheme does not cover the cost of open-heart surgery, so patients have to pay out of pocket. Even though the cost of surgery is subsidised, especially when compared with the cost in developed nations, surgery is still out of reach for most patients. Among the 29 patients who had corrective surgery, three died, resulting in a mortality rate of 9.7% in this group. They had arrhythmias and cardiac dysfunction following surgery. Reports from several studies have shown that corrective surgery can be done with a relatively low mortality rate.18,20 In a cohort of 819 consecutive patients with TOF, Chiu et al.23 reported an early mortality rate of 3.3%. This is far lower than the value obtained in our study. They studied a larger population of patients and this could account for the disparity in mortality rates observed. Azari et al.21 from Iran reported an early mortality rate of 12.2% among 74 children who had corrective surgery of TOF. This mortality rate is similar to that obtained in our study. Corrective surgery for TOF is associated with excellent longterm results and a survival rate greater than 90%.23 However, there are recognised long-term electrical and anatomical complications that may occur.22-25 We have been able to monitor our patients only for a maximum of four years (range two months to four years). Our outcome thus far has been quite good. All our patients have recovered from the immediate postoperative complications, except for those who still have free pulmonary regurgitation and pulmonic stenosis. None of our patients has required re-operation. The most common complication we observed among our patients postoperatively was malaria and this was due to the use of blood and blood products during the period of surgery. Malaria is endemic in Nigeria. Globally, malaria is one of the most frequent transfusion-transmitted infections.26 Woolsey in 1911 gave the first description of transfusiontransmitted malaria (TTM).26, 27 TTM is an unintended infection with Plasmodium species resulting from the transfusion of whole blood or any component of blood from a donor infected with malaria to a recipient.26,27 Malaria transmitted by blood transfusion has potentially grave consequences, as infection with Plasmodium falciparum may progress rapidly and become fatal.27,28 In endemic countries such as Nigeria, a significant proportion of donors are potentially infected with malaria parasites and donated blood is not routinely screened for malaria parasites, unlike what is practised in non-malaria endemic regions.27,28 All our patients who developed malaria following surgery made an excellent recovery following treatment with routine anti-malaria medications and none suffered neurological complications of malaria. Most of the patients had fever clinically and infection was confirmed by the evidence of the malaria parasite in a peripheral blood film. Arrhythmia was observed in 22.6% of our patients following surgery. Arrhythmia following cardiac surgery causes haemodynamic imbalance and often requires treatment. It increases the propensity for mortality.23 Postoperative arrhythmia has been classified as early (occurring within the first two postoperative days) and late. Azari and colleagues25 reported arrhythmias as the most common postoperative complication in the children they studied, occurring in 28.4% of the children.25 Other immediate complications noted among these children were pneumonia sepsis, hypomagnesaemia, urinary tract infection and seizure. Among the immediate postoperative complications observed on echocardiography in our patients, pleural and pericardial effusion along with free pulmonary regurgitation were the most common, each occurring with a prevalence of 58.1, 48.4 and 48.4%, respectively. The patients with pleural effusion had the effusions drained without sequelae. The pericardial effusions were not life-threatening and resolved spontaneously over time. This was monitored using echocardiography. The group of children with free pulmonary regurgitation had a trans-annular patch without valve replacement during corrective surgery. Pulmonary regurgitation is a common sequela following corrective surgery for TOF and may be well tolerated for many years after surgery.29 Relief of the obstruction to the RVOT in TOF often impairs the integrity of the pulmonary valve, which results in pulmonary regurgitation. About a decade after repair, 40 to 85% of patients have moderate to severe pulmonary regurgitation.2 Over time, it results in progressive dilation of the right ventricle and biventricular dysfunction, with progressively worsening intolerance to exercise, heart failure, tachyarrhythmia, and later sudden death.2,29 Pulmonary regurgitation very often requires surgical intervention.29 More than half of our patients (54.2%) did not have surgery and were on palliative medical care. The mortality rate among these patients was more than twice the rate among the children who had corrective surgery. The cause of death included right heart failure, infective endocarditis and cerebrovascular accidents. The most common complication occurring in all but one of the patients was polycythaemia (haematocrit ≥ 65%). This was managed by partial exchange transfusion with normal saline. The highest recorded haematocrit among these children was 84%. The procedure was done as often as it was required to minimise the risk for stroke. Unfortunately, among this group, one-fifth of the children suffered a stroke, with only partial recovery in most of them. A tenth of these patients developed cerebral abscesses. Right ventricular dysfunction was noted in a quarter of the patients. This was identified by echocardiography. Further investigations such as CMRI are yet to be done for these patients because of the cost implications of such investigation. More than a third of these patients had right coronary cusp prolapse, half of whom had concomitant aortic regurgitation. Corrective surgery for TOF significantly reduces morbidity and mortality among children with TOF. Corrective surgery in infancy is desirable but is not readily accessible due to the cost of the procedure in this part of the world. Many patients find the cost of surgery prohibitive. In most cases, parents enlist the
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