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Biomedical subjects

M R de Leval

Publications and source records attributed to M R de Leval.

At least 73 records · Page 4Linked to original sources
PubMed1994

Comparison of single- and multi-dose crystalloid cardioplegia to protect the immature myocardium.

The primary objective of this study was to compare the protective effects of single-dose and multi-dose St. Thomas' Hospital cardioplegic solution number 1 in the ischemic and reperfused neonatal rabbit heart. In addition, the effect of including bicarbonate (a component of St. Thomas' Hospital cardioplegic solution number 2) was also studied. Hearts (n = 8 per group) were excised from rabbits (7-10 days old) and aerobically perfused in the working mode with crystalloid media for 20 min (37 degrees C). After assessing cardiac function, the hearts were arrested by an infusion of cold cardioplegic solution (2 min at 15 degrees C) with or without the addition of bicarbonate (10 mmol). The hearts were then subjected to 6 h of hypothermic ischemia (15 degrees C) and, during this period, some hearts received multiple infusions (2 min/h at 15 degrees C) of cardioplegic solution. All hearts were reperfused for 35 min (15 min Langendorff plus 20 min working), cardiac function was then re-assessed and expressed as a percent of the preischemic value. The coronary effluent, collected during the first 15 min of reperfusion, was assayed for creatine kinase activity. At the end of the reperfusion period, the hearts were freeze clamped and taken for metabolic analysis. With multi-dose cardioplegia (without bicarbonate) the postischemic recovery of cardiac output was 67.0 +/- 6.5% and with single-dose the value was 39.3 +/- 10.0% (NS). The same pattern of postischemic recovery (that varied between 30% and 60%) for aortic flow, stroke volume and stroke work was observed with both multi-dose and single-dose infusion.(ABSTRACT TRUNCATED AT 250 WORDS)

Analysis of Variance↗
PubMed1994

Mycotic pulmonary artery aneurysm following pulmonary artery banding.

A neonate with situs inversus, transposition of the great arteries, ventricular septal defect, criss-cross ventricles and hypoplastic right ventricle underwent pulmonary artery banding at the age of 7 days. The course was complicated by septicaemia and subsequently the development of an aneurysm of the pulmonary artery. Serratia marcessans was grown from the band site. The pulmonary artery aneurysm was resected and the pulmonary artery was repaired. The literature is reviewed with the emphasis on diagnosis, natural history and surgical management.

Aneurysm, Infected↗
PubMed1994

Analysis of a cluster of surgical failures. Application to a series of neonatal arterial switch operations.

A pediatric cardiac surgeon performed 104 neonatal arterial switch operations for transposition of the great arteries with or without ventricular septal defect between June 1987 and February 1993. Initial euphoria on having only one death in the first 52 patients gave way to increasing concern when patients 53, 55, 59, 63, 64, 67, and 68 died. Sensing a problem, the surgeon visited a low-risk institution after patients 55 and 64 had died and then decided to re-train after patient 68 died. One death has occurred since. To find out whether the cluster of failures could have been related to chance alone, to variability of risk factors across time, or to suboptimal performance, we conducted the following analyses: First, identification of trends with the cumulative sum procedure was undertaken and actual mortality compared with the mortality predicted from an equation derived from a multi-institutional study. Second, logistic regression analysis of risk factors was done. If a mechanism of continuous monitoring had been in place, unfavorable trends and a need for change in protocol would have been detected earlier. Retrospective risk factor analysis suggested an excessive risk for patients with origin of the circumflex or left anterior descending coronary arteries from sinus 2 and a protective effect of phenoxybenzamine. However, about half of the risk associated with the cluster of failures was not accounted for by the variables analyzed. There was therefore an indication of suboptimal performance that appears to have been neutralized by retraining.

Cardiac Surgical Procedures↗
PubMed1994

Surgical treatment of aortic coarctation in infants younger than three months: 1985 to 1990. Success of extended end-to-end arch aortoplasty.

There remains controversy regarding the appropriate surgical treatment of coarctation of the aorta in infants. In 1985 we introduced the extended end-to-end repair into our practice and now wish to present a review of our recent experience. One hundred fifty-one infants younger than 3 months of age underwent repair of coarctation between 1985 and 1990. In 25% and 33% of the patients, there was hypoplasia of the isthmus and of the transverse arch, respectively. Surgical procedures were as follows: subclavian flap angioplasty in 15 patients, resection with a traditional end-to-end anastomosis in 43, and resection with an extended end-to-end anastomosis into the arch in 77. In 30 patients, the extension was proximal to the origin of the left carotid artery (radically extended end-to-end anastomosis). Other procedures were used in 16 patients. Mortality (13 early and 12 late deaths) was related on multivariate analysis to the presence of an associated major heart defect, preoperative resuscitation, and direct postoperative gradient over the arch. This immediate postoperative gradient was significantly lower after both extended and radically extended end-to-end anastomosis if there was a hypoplastic isthmus, and after radically extended end-to-end anastomosis if the transverse arch was hypoplastic. Actuarial freedom from recoarctation at 4 years was 57% (confidence limits 28% to 78%) after subclavian flap angioplasty, 77% (confidence limits 60% to 87%) after end-to-end anastomosis, 83% (confidence limits 66% to 92%) after extended end-to-end anastomosis and 96% (confidence limits 77% to 100%) after radically extended end-to-end anastomosis. We conclude that the extended end-to-end anastomosis and radical end-to-end anastomosis appear to offer the best prognosis for all infants with coarctation. The technique can be applied successfully to almost all types of arch anomalies.

Age Factors↗
PubMed1993

[Combination heart-lung transplantation in children: 4-year experience in London].

Since 1987, 21 children under 16 years of age have undergone combined heart and lung transplantation at Great Ormond Street Hospital, London. All children had terminal pulmonary or cardiopulmonary disease. Eight children died one day to 21 months after operation. Actuarial survival was 76% (SEM 10) at 1 year and 60% (SEM 12) at 3 and 4 years after transplantation. 13 children were alive, and all took part in all age-appropriate activities.

Adolescent↗
PubMed1993

An unusual case of cor triatriatum: clinical presentation and the haemodynamics of a rare anomaly.

The case of a 24-year-old woman with cor triatriatum sinister and a persistent left superior vena cava connected to the junction of the left upper pulmonary vein and left atrium is reported. A diagnosis of partial anomalous pulmonary venous return had been made and the patient underwent surgery. Inspection of the left atrium revealed a complex form of left triatrial heart. The general haemodynamics of the malformation are discussed, with particular emphasis on the features accounting for variation in the clinical presentation. This rare anomaly often remains undiagnosed before surgery and should be considered whenever obstruction of pulmonary venous flow above the mitral valve is not explained by pulmonary vein stenosis, mitral or mitral valve-linked abnormalities, atrial tumours or anomalous pulmonary venous drainage with high resistance to flow.

Adult↗
PubMed1993

Increased plasma levels of endothelin-1 after cardiopulmonary bypass in patients with pulmonary hypertension and congenital heart disease.

The plasma level of the potent vasoconstrictor endothelin-1 was measured in children who underwent cardiac operations. Forty-five patients were divided into two groups, those with a high pulmonary blood flow (HF group; n = 23) and those with a normal or low flow (NF group; n = 22). Seven blood samples were taken: immediately before cardiopulmonary bypass, immediately after removing the aortic cross-clamps, immediately after discontinuing bypass, and at 20 minutes and 3, 6, and 24 hours after termination of bypass. The plasma levels of endothelin-1 were similar in both groups before bypass. From the time the aortic crossclamps were removed, the plasma endothelin-1 levels in both groups increased significantly, to reach a peak level at 3 to 6 hours. The increase was significantly greater in the HF than in the NF group, and the maximum values in the two groups were 12.6 +/- 1.1 and 9.6 +/- 0.8 fmol/ml, respectively (mean +/- standard error of the mean, p < 0.05). The value 20 minutes after bypass showed a positive correlation with the mean pulmonary arterial pressure measured at the preoperative cardiac catheterization study (r = 0.41, p < 0.05). In addition, a significant positive correlation was obtained between endothelin-1 3 hours after bypass and the maximum pulmonary/systemic arterial pressure ratio during the first 12 hours after operation (r = 0.86, p < 0.05). These results suggest that cardiopulmonary bypass is associated with an immediate postoperative increase in circulating endothelin and that patients who had a high pulmonary blood flow before the operation are particularly vulnerable, bypass having a more injurious effect on a lung with preexisting endothelial dysfunction. A high level of circulating endothelin may predispose to pulmonary vascular lability and pulmonary hypertensive crises in the postoperative period.

Adolescent↗
PubMed1992

Pulmonary artery sling.

Eighteen patients who underwent surgical treatment of pulmonary artery sling at this institution since 1969 were reviewed. Four of them had associated tracheal stenoses produced by complete cartilaginous rings (stovepipe trachea). All patients underwent operation. The median age at operation was 180 days (range, 27 days to 54 months). In the 14 patients with isolated pulmonary sling, the operation consisted of division of left pulmonary artery and reimplantation into the main pulmonary artery anterior to the trachea. In the 4 patients with stovepipe trachea, the stenotic tracheal segment was resected on cardiopulmonary bypass and the left pulmonary artery was brought anterior to the trachea before the latter was reanastomosed to the main pulmonary artery. There were no early deaths. One patient died late. The pulmonary artery anastomosis was patent in all 14 patients investigated postoperatively. Three patients have residual tracheobronchial problems. One patient is mentally retarded and is institutionalized. All other patients are symptom-free and growing normally and have normal chest radiographs.

Child, Preschool↗
PubMed1992

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.

Analysis of Variance↗
PubMed1991

Current surgical technique to repair Fallot's tetralogy with absent pulmonary valve syndrome.

The experience with surgical repair of Fallot's tetralogy and absent pulmonary valve syndrome is reviewed. Twenty-two patients aged 1 day to 8 years were treated between 1982 and 1989 using one surgical technique. This consisted of resection of the main pulmonary artery and large parts of the anterior wall of the right and left pulmonary artery. The ventricular septal defect was closed with a patch, and an aortic or pulmonary homograft (size, 8 to 24 mm) was interposed between the right ventricle and the pulmonary artery. Two of the 8 infants operated on died; there was one late death. All 14 older children survived the operation. All survivors are well up to 7 years follow-up (mean follow-up, 3.6 years). We recommend early treatment of infants; older children can be treated electively. The technique used in our series gives excellent results.

Child↗
PubMed1991

Pulmonary hypertensive crises following surgery for congenital heart defects in young children.

In this clinical study, 20 high risk infants and neonates were monitored to identify and characterize pulmonary hypertensive crises following surgery for congenital cardiac defects. Monitoring included right ventricular or pulmonary artery pressure catheters and transcutaneous oximetry. Eleven patients also had continuous analog recording of hemodynamic data so that antecedents of crises and the sequence of events following treatment could be reconstructed. Eleven of the 20 patients had one or more crises. Six of these ultimately died whereas 5 patients survived with aggressive vasodilator therapy. Four patients without crises but with episodic pulmonary hypertension benefitted from pulmonary vasodilator therapy to ease weaning from ventilatory support. Typically, each crisis was associated with a stress event. Crises were difficult to ablate if not rapidly treated and multiple crises would often cluster following an initial event. High dose narcotic (fentanyl) analgesia was found to be important in the postoperative management. Tolazoline and oxygen were the most consistently useful vasodilators, but isoproterenol and nitrates also played a role. Five of the children who died were examined post mortem: histologically, there was increased pulmonary arterial muscularization in 2, in none were there changes of fixed pulmonary vascular disease. The postoperative management must be individualized on the basis of monitored responses of pulmonary circulation.

Biopsy↗
PubMed1991

Surgical treatment of aortico-left ventricular tunnel.

Thirteen children (age range 6 h-11 years, median 4 months) operated upon for aortico-left ventricular tunnel since 1971 are reported. All patients had systolic and diastolic murmurs, 4 of 5 neonates were in severe congestive heart failure. Twelve children had left ventricular hypertrophy on ECG with an ischaemic pattern in the neonates. Chest X-ray revealed cardiomegaly with a broad upper mediastinal shadow from the enlarged aorta. Echocardiography (2DE) revealed a tubular communication between the aorta and the left ventricle bypassing the aortic valve and massive regurgitation through this tunnel demonstrated by Doppler sonography. In 8 patients, the diagnosis was confirmed by angiography. The tunnel arose from the right coronary sinus in 12 and from the left coronary sinus in 1 patient. The tunnel was closed at both ends in 8, at the aortic end only in 3 and at the ventricular end in the remaining 2 cases. One 6-day-old infant, operated upon in 1971 died postoperatively. There was 1 non-cardiac related late death due to a brain tumour. Echocardiographic analysis of left ventricular size and function was carried out in 9 children up to 39 months after surgery. Mild to moderate aortic incompetence was detected during the follow-up period in 2 of 12 patients. All surviving children are leading normal lives.

Aorta↗
PubMed1991

Arrhythmias after the Fontan procedure. Comparison of total cavopulmonary connection and atriopulmonary connection.

Arrhythmia was compared between 40 consecutive patients (pts) undergoing atriopulmonary connection (APC) and 40 undergoing total cavopulmonary connection (TCPC), between 1986 and 1990. Patients were not randomized, and those undergoing APC predominantly had tricuspid atresia (57.5% versus 15%) compared with pts undergoing TCPC who had more varied and complex cardiac defects. Before surgery there was no significant arrhythmia in either group. Hospital mortality was 15/40 and 6/40 for APC and TCPC, respectively (p less than 0.05). Early after APC nine pts developed atrial flutter (AFL) and eight died, while after TCPC only two developed AFL, and neither died (p less than 0.01). Fatal junctional ectopic tachycardia occurred in one pt in each group. During follow-up (38 +/- 8.5 months after APC versus 20 +/- 10 months after TCPC), new arrhythmia was uncommon (two AFL after APC with one death versus two AFL and one supraventricular tachycardia after TCPC with no deaths). Ambulatory ECG during follow-up showed arrhythmia in two APC and six TCPC pts (p = NS). The incidence of early arrhythmia and mortality associated with early arrhythmia appears to be less after TCPC compared with APC.

Arrhythmias, Cardiac↗
PubMed1991

Heart and lung transplantation for terminal cystic fibrosis. A 4 1/2-year experience.

From among 112 patients with cystic fibrosis who were assessed for heart-lung transplantation, 83 were accepted. Twenty-six died while awaiting heart-lung transplantation and 32 had the operation. The management and the outcome of these 32 patients is reported. Survival, infection, and rejection rates among these patients were compared with those of 61 patients without cystic fibrosis who underwent heart-lung transplantation between 1984 and 1990. The cumulative survival rate was 72.29% +/- 94.91% at 1 year and 55.59% +/- 7.50% at 3 years. The mortality rate was slightly higher in the group with cystic fibrosis during the first year after the operation but it was lower at 3 years. The difference, however, could have been due to chance alone (p = 0.308). The same was true for the prevalence of rejection (up to 6 months: chi 2 = 1.8141, p = 0.17), and infection (up to 6 months: chi 2 = 2.20, p = 0.14), between the two groups. It is concluded that cystic fibrosis does not constitute an additional risk in terms of survival and morbidity after heart-lung transplantation.

Adolescent↗
PubMed1989

Long-term results of homograft valves in extracardiac conduits.

Between 1971 and 1986, 335 patients received various extracardiac valved conduits between one of the heart chambers and the pulmonary arteries. The group of patients who received aortic homograft conduits and survived the operation were analysed in detail. The age varied between 9 days and 18 years (mean 7.1 +/- 0.7 years), weight 2.4 kg-63.5 kg (mean 17.8 +/- 10.8 kg). The diameter of the conduit used was 10-30 mm (mean 20.8 mm). Multivariate analysis revealed a highly significant model (P less than 0.005) which showed that the time interval between harvesting and use of the homograft (P less than 0.02) and the earlier date of operation (P less than 0.05) were the major risk factors for obstruction. Homografts used within 3 weeks of harvesting had freedom from obstruction of 79% at 8 years; homografts used between 3-6 weeks had freedom from obstruction of only 55% at 8 years. Homografts used alone performed significantly better than those extended with woven Dacron tubes. At 10 years, 93% of homografts used alone were free of obstruction compared to 52% of homografts extended with a Dacron tube. We conclude that aortic homografts used within 3 weeks of harvesting provide a reasonably durable conduit for a period of 12 years. Longer storage, and extension of the homograft with a woven Dacron tube should be avoided.

Adolescent↗