M de Leval

Early and late arrhythmias after the Fontan operation: predisposing factors and clinical consequences.

OBJECTIVE--To study the incidence, predisposing factors, and clinical significance of arrhythmias early and late after the Fontan operation for congenital heart disease. PATIENTS AND METHODS--All 104 consecutive patients undergoing Fontan repair from 1975 to 1988 were studied retrospectively. Hospital records were reviewed for perioperative arrhythmia. Clinical information and annual electrocardiograms were available for all 78 hospital survivors during a follow up of up to 13 years (mean 3.7 years). Ambulatory electrocardiographic monitoring was performed in 67 patients (81%). RESULTS--Eleven patients (10.6%) developed a perioperative tachycardia (eight, atrial flutter; three, His bundle tachycardia). Multivariate analysis showed that raised preoperative mean pulmonary artery pressure and low aortic saturation were significant risk factors for the development of atrial flutter (r2 = 0.32, p = 0.0001) but not for His bundle tachycardia. Despite intensive medical treatment 10 of these 11 patients died. At the last visit 72 (92%) of the 78 patients were in sinus rhythm on their standard 12 lead electrocardiogram. Junctional rhythm was present in three patients, two patients had atrial flutter, and one had a paced rhythm. Ambulatory monitoring did not show important bradycardia or ventricular arrhythmias. Actuarial survival free of supraventricular arrhythmia was 82% at eight years after operation. Multivariate analysis identified older age, increased right atrial size, and raised mean preoperative pulmonary artery pressure as risk factors for arrhythmia during intermediate follow-up (r2 = 0.46, p less than 0.001). Late tachycardias, in contrast to those occurring in the perioperative period, were not associated with an increased mortality. CONCLUSIONS--Except for his bundle tachycardia in the perioperative period, early and late arrhythmias after a Fontan operation seem to be a consequence of adverse preoperative and postoperative haemodynamic function. The perioperative outcome is therefore poor even when the patient can be restored to sinus rhythm. Medical and surgical modifications to improve the haemodynamic disturbances associated with arrhythmias are therefore indicated.

Cross-sectional echocardiographic diagnosis of systemic venous return.

To determine the sensitivity and specificity of cross-sectional echocardiography in diagnosing anomalous systemic venous return we used the technique in 800 consecutive children with congenital heart disease and whom the diagnosis was ultimately confirmed by angiography. Cross-sectional echocardiography was performed without prior knowledge of the diagnosis in all but 11 patients, who were recalled because of a known abnormality of atrial situs. The sensitivity of cross-sectional echocardiographic detection of various structures was as follows: right superior vena cava 792/792 (100%); left superior vena cava 46/48 (96%); bilateral superior vena cava 38/40 (95%); bridging innominate vein with bilateral superior vena cava 13/18 (72%); connection of superior caval segment to heart (coronary sinus or either atrium) (100%); absence of suprarenal inferior vena cava 23/23 (100%); azygos continuation of the inferior vena cava 31/33 (91%); downstream connection of azygos continuation, once seen, 21/21 (100%); partial anomalous hepatic venous connection (one hepatic vein not connected to the inferior vena cava) 1/1 (100%); total anomalous hepatic venous connection (invariably associated with left isomerism) 23/23 (100%). The specificity of each above diagnoses was 100% except in one infant with exomphalos in whom absence of the suprarenal inferior vena cava was incorrectly diagnosed. Thus cross-sectional echocardiography is an extremely specific and highly sensitive method of recognizing anomalous systemic venous return. It is therefore of great value of planning both cardiac catheterisation and cannulation for open heart surgery.

Cardiac ECMO for biventricular hearts after paediatric open heart surgery

Objective: To delineate predictors of hospital survival in a large series of children with biventricular physiology supported with extracorporeal membrane oxygenation (ECMO) after open heart surgery. Results: 81 children were placed on ECMO after open heart surgery. 58% (47 of 81) were transferred directly from cardiopulmonary bypass to ECMO. Hospital survival was 49% (40 of 81) but there were seven late deaths among these survivors (18%). Factors that improved the odds of survival were initiation of ECMO in theatre (64% survival (30 of 47)) rather than the cardiac intensive care unit (29% survival (10 of 34)) and initiation of ECMO for reactive pulmonary hypertension. Important adverse factors for hospital survival were serious mechanical ECMO circuit problems, renal support, residual lesions, and duration of ECMO. Conclusions: Hospital survival of children with biventricular physiology who require cardiac ECMO is similar to that found in series that include univentricular hearts, suggesting that successful cardiac ECMO is critically dependent on the identification of hearts with reversible ventricular dysfunction. In our experience of postoperative cardiac ECMO, the higher survival of patients cannulated in the operating room than in the cardiac intensive care unit is due to early effective support preventing prolonged hypoperfusion and the avoidance of a catastrophic cardiac arrest.

Absent or occult pulmonary artery.

Of 12 patients with angiographically absent pulmonary artery, 11 were investigated surgically. The previously occult pulmonary artery was found in 10 patients, in five of whom a vestige of an intrapericardial artery was present and in five the artery was patent only at the hilus, a gap existing between the main pulmonary artery and the hilar vessel, and no artery was found in one. All patients with an intrapericardial artery had right ventricular outflow tract obstruction and a ductus descending vertically from underneath the aortic arch. In those without an intrapericardial vessel the occult artery was on the side opposite the aortic arch, and there was evidence of a ductus coming from the innominate artery on the side of the interruption. The occult pulmonary artery, where identified at operation, was usually joined initially to the systemic circulation. Ultimately, continuity between the hilar and main pulmonary artery may be established surgically. Where no intrapericardial vessel exists, however, a conduit may be required to bridge the gap. It seems advisable to search for the occult artery as early in life as is feasible in the hope that providing a blood supply will ensure development of the vessel and normal lung growth.

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries. Effect of systemic pulmonary anastomosis.

In nine patients with pulmonary atresia, ventricular septal defect, and major aortopulmonary collateral arteries, the effect of a systemic-pulmonary anastomosis on the lung was studied by comparison of pre- and postoperative cine angiograms. Selective injections into the collateral arteries were performed in all patients and the source of blood supply to each bronchopulmonary segment was sought. Central pulmonary arteries were present in six children and absent in three, as confirmed at thoracotomy. After insertion of a shunt, central pulmonary arteries increased in size, but the intrapulmonary vessels with which they connected remained abnormally small and were frequently stenosed. In addition, in each case the central pulmonary arteries increased flow to only five to 11 segments of lung. In the absence of central pulmonary arteries, shunting to a hilar or a lobar pulmonary artery increased perfusion to five to nine segments of lung per case. In all these three cases the pulmonary arteries at lobar level showed aneurysmal dilatation proximal to a severe stenosis. Sixty-eight per cent of collateral arteries were stenosed. The findings suggest that in this anomaly, when the central pulmonary arteries are hypoplastic, the intrapulmonary branches are also hypoplastic, emphasising the need for early surgical intervention to increase blood flow while the lung still has growth potential. Further, one collateral artery may connect with at least as many bronchopulmonary segments as does a central pulmonary artery, and the peripheral intrapulmonary arteries with which it connects may appear at least as normal angiographically as do vessels connected to central pulmonary arteries. These observations suggest that segments of lung connected to collaterals alone should, and sometimes can, be connected to central pulmonary arteries, the aim being to produce a unifocal blood supply as a prelude to total correction.

Infective endocarditis in children with congenital heart disease: comparison of selected features in patients with surgical correction or palliation and those without.

The diagnostic and prognostic features of 44 episodes of infective endocarditis in 42 children with congenital heart disease were reviewed. Endocarditis occurred in 18 patients who had not had surgical correction or palliation of the defect (non-operated group). There were 26 episodes in 24 patients who had been treated surgically (operated group) (16 open and eight closed cardiac operations). Endocarditis occurred soon after open heart surgery in eight patients and as a late complication in the other 16. It recurred in two patients (operated group). Invasive monitoring and low cardiac output were consistent features in those patients who had endocarditis soon after open heart surgery whereas dental treatment was a common feature in non-operated cases and after closed cardiac operations. Late cases of endocarditis after open heart surgery had various microbiological features that were not typical of infection after dental problems. Gram positive infections occurred in non-operated patients and in those who had had closed cardiac operations. The group that had open heart surgery had infections caused by Gram positive, Gram negative, and anaerobic bacteria and fungi. Fever, anaemia, leucocytosis, and positive blood cultures were the only consistent findings. Vegetations were seen in nine of 12 patients at cross sectional echocardiography. All 12 (four non-operated, one closed, and seven open cases) needed acute surgical treatment. The mortality from infective endocarditis was 17% for non-operated cases, 0% for those who had had closed heart surgery, and 50% for those who had had open heart surgery. Infective endocarditis after open heart surgery differs from that in the other subgroups in terms of microbiology, source of infection, and outcome and its early diagnosis depends on a thorough investigation of minimal symptoms and signs.

Echocardiographic assessment of conjoined twins

Objective: To determine the accuracy of prenatal and postnatal echocardiography in delineating the degree of cardiac fusion, intracardiac anatomy (ICA), and ventricular function of 23 sets of conjoined twins with thoracic level fusion presenting to a single centre over a 20 year period. Methods: 13 thoracopagus, 5 thoraco-omphalopagus, and 5 parapagus pairs presenting to the authors’ institution between 1985 and 2004 inclusive were assessed. Echocardiographic data were analysed together with operative intervention and outcome. Twins were classified according to the degree of cardiac fusion: separate hearts and pericardium (group A, n  =  5), separate hearts and common pericardium (group B, n  =  7), fused atria and separate ventricles (group C, n  =  2), and fused atria and ventricles (group D, n  =  9). Results: The degree of cardiac fusion was correctly diagnosed in all but one set. ICA was correctly diagnosed in all cases, although the antenatal diagnosis was revised postnatally in three cases. Abnormal ICA was found in one twin only in two group A pairs, one group B pair, and both group C pairs. All group D twins had abnormal anatomy. Ventricular function was good in all twins scanned prenatally, and postnatally function correlated well with clinical condition. Thirteen sets of twins in groups A–C were surgically separated; 16 of 26 survived. None from groups C or D survived. Conclusions: Prenatal and postnatal echocardiography accurately delineates cardiac fusion, ICA, and ventricular function in the majority of twins with thoracic level fusion. It is integral in assessing feasibility of separation. The outcome in twins with fused hearts remains dismal.

Rastelli procedure for transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction. Early and late results in 41 patients (1971 to 1978).

Forty-one children with transposition of the great arteries, ventricular septal defect, and left ventricular outflow tract obstruction underwent a Rastelli operation between 1971 and 1978. A homograft valve preserved in an antibiotic solution and extended with A dacron tube was the conduit of choice. Alternatively, conduits with porcine heterografts or valves constructed from calf pericardium were used. They were positioned to the left of the aorta whenever possible. The intraventricular tunnel from the left ventricle to the aorta was constructed from Dacron velour. There were four early and seven late deaths. The last 13 consecutive patients have survived. Early deaths were related to unfavourable anatomy, conduit compression, and sepsis. Residual ventricular septal defects and postoperative infection were the main factors contributing to the late deaths.

Total anomalous pulmonary venous drainage in infancy.

Between May 1971 and December 1975, 39 infants had operations for correction of total anomalous pulmonary venous drainage. Fourteen of the 39 patients were under 1 month of age at the time of operation. Twenty-four patients had supracardiac, 7 intracardiac, and 6 infracardiac total anomalous pulmonary venous drainage, and 2 had a mixed type. The overall hospital mortality was 36 per cent. There have been no late deaths. The improvement in survival rate in this series is attributed to: (1) earlier recognition and prompt referral, (2) an aggressive approach to diagnosis involving complete cardiac catheterisation and angiocardiography, (3) vigorous preoperative care, (4) early complete correction including construction of a large anastomosis and enlargement of the left atrium when indicated, and (5) intensive postoperative management paying particular attention to fluid balance and treatment of pulmonary complications. Operative mortality was highest in patients with total anomalous pulmonary venous drainage directly to the superior vena cava, and in those with infradiaphragmatic drainage of whom all had pulmonary venous obstruction. Mortality was not closely related to age, body weight, or severity of pulmonary hypertension.

Surgical treatment of persistent truncus arteriosus in the first year of life.

Between October 1974 and December 1977, 17 infants with persistent truncus arteriosus were admitted to this unit. Four had gross heart failure and severe metabolic acidosis. Two of these also had an interrupted aortic arch. All 4 died without operation. An urgent or semi-urgent correction was performed in 12 infants. Operations were done on cardiopulmonary bypass with deep hypothermia and circulatory arrest or periods of reduced flow. Continuity between the right ventricle and the pulmonary artery was established with a valved conduit (either fresh aortic homograft or porcine xenograft). Seven infants (aged 28 days to 8 months, weight 2-4 to 5-7 kg) survived the operation and are progressing satisfactorily. The causes of death in 5 infants are analysed. In addition, an 1 1-month-old infant with raised pulmonary arteriolar resistance died after operation. The lung histology showed grade III pulmonary vascular obstructive disease. The policies of medical treatment alone, palliation followed by correction, and early primary repair, are analysed on the basis of published data and our own results. It is concluded that the chances of a child surviving with a normal or near normal pressure in the pul-