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Biomedical subjects

M R de Leval

Publications and source records attributed to M R de Leval.

At least 109 records · Page 6Linked to original sources

Pulmonary atresia and intact ventricular septum: a revised classification.

The dismal outlook for patients with pulmonary atresia with intact ventricular septum may be related to associated right ventricular hypoplasia. Study of 32 autopsy specimens and 46 angiocardiograms of neonates with this lesion suggested that the cavitary hypoplasia was related to massive hypertrophy of the right ventricular wall. This hypertrophy was sufficient to obliterate the trabecular and/or infundibular portion of the ventricular cavity entirely in one-third of the cases; this observation forms the basis for a revised classification of these hearts. Three autopsies and 14 angiograms of neonates with critical pulmonary stenosis were examined. Hearts with obliterated infundibular and trabecular cavities had thicker walls and smaller tricuspid valves, as estimated angiographically or at autopsy, than those in which the normal three portions of the ventricular cavity were represented.

Heart Defects, Congenital↗

Infradiaphragmatic total anomalous pulmonary venous drainage: surgical treatment and long-term results.

Since 1971, 20 infants (1 day to 3 months old) with infradiaphragmatic total anomalous pulmonary venous drainage (TAPVD) have undergone repair at The Hospital for Sick Children, Great Ormond Street, London. All patients were seen with severe cyanosis (mean partial pressure of arterial oxygen, 35.8 mm Hg) and pulmonary edema. All had a persistent ductus arteriosus. Right-sided pressures were equal to or greater than systemic in 17 patients. During surgical repair, the confluence of the pulmonary veins was anastomosed to the left atrium. The descending vein was ligated in 11, divided in 4, and left open in 5 patients. Atrial septal defects were closed with a patch in 6 and sutured in 14. Eight patients died (40%). Acidosis on admission was significantly greater among nonsurvivors (mean pH, 7.29 +/- 0.02) than survivors (mean ph, 7.37 +/- 0.02) (p less than 0.05). Twelve survivors are well four months to 8 years after operation. All are asymptomatic and none requires cardiac medication. Six have undergone repeat catheterization, demonstrating normal pressures and no shunts. We conclude that the mortality of patients with infradiaphragmatic TAPVD depends mainly on the condition of the child on admission.

Blood Pressure↗

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.

Adolescent↗

Surgical management of coarctation of aorta with ventricular septal defect. Multivariate analysis.

Optimal management of coarctation with ventricular septal defect is difficult. Should one treat the coarctation, the ventricular septal defect, or both? This dilemma was investigated by reviewing 39 successive patients, aged less than 4 months, undergoing coarctation repair without pulmonary artery banding. Twelve hospital deaths occurred. Ventricular septal defect size was graded "blind" according to preoperative angiocardiographic and haemodynamic findings. Of 14 patients classified as having a large ventricular septal defect, necropsy and operative findings in eight showed defects 7 to 12 mm in diameter. Factors associated univariately with significantly increased mortality were young age, raised atrial and ventricular end-diastolic pressures, low weight, high admission blood urea, preoperative ventilation, and a large ventricular septal defect. All but the last two were also closely associated with each other. A jack-knifed discriminant function based upon ventricular septal defect size, blood urea, pulmonary venous oxygen content, and inferior caval oxygen saturation correctly predicted outcome in 78.9% of patients. Combinations of these four giving a probability greater than 0.9 of survival were rare with blood ureas above 8 mmol/litre. Raised blood urea was associated with low descending aortic pressure and subsequent dialysis. Only patients with a large ventricular septal defect stand to benefit from pulmonary artery banding at initial operation. Preoperative treatment to increase renal blood flow (prostaglandins, dopamine) may improve overall survival.

Analysis of Variance↗

Modified Blalock-Taussig shunt. Use of subclavian artery orifice as flow regulator in prosthetic systemic-pulmonary artery shunts.

Between April, 1975, and December, 1979, 99 modified Blalock-Taussig shunts (MBTSs) were carried out at The Hospital for Sick Children, Great Ormond Street. The operation consists of interposing between the subclavian artery and the pulmonary artery a prosthesis of greater diameter than that of the subclavian artery. The first 13 operations were performed with a prosthesis of woven Dacron. Conduits of expanded polytetrafluorethylene (PTFE) were used for 86 MBTSs, and these form the basis of this report. Forty-four (51.1%) shunts were performed in infancy, 25 in patients under the age of 1 month (29.0%). Prostheses of 4 mm were used in 34 cases, 5 mm in 14, and 6 mm in 38. There were five shunt failures (5.8%) documented at postmortem or angiocardiographic investigation. Including two late deaths for which postmortem examinations were not obtained, the overall failure rate was 8.1% (seven patients). All these patients were operated upon in infancy, four of them in the neonatal period. Although a longer follow-up is necessary to assess the validity of these shunts, the early results are encouraging. We believe we can now recommend MBTS as an alternative when the classical Blalock-Taussig shunt is considered unsuitable.

Blood Vessel Prosthesis↗

Postoperative angiographic assessment of modified Blalock-Taussig shunts using expanded polytetrafluoroethylene (Gore-Tex).

Thirty-six of 87 modified Blalock-Taussig shunts done with expanded polytetrafluoroethylene (Gore-Tex) were restudied angiocardiographically. In 7 patients the study was carried out within 1 month of the shunt operation because the patients failed to make satisfactory clinical progress. Two shunts were occluded and 1 ws stenosed; all 3 were in neonates. The remaining 29 patients were reinvestigated electively between 5 and 29 months postoperatively and had a 97% shunt patency rate. Because of the rather high incidence of irregular or stenosed shunts among neonates with 4 mm conduits, we now prefer to use a larger conduit even in this age group.

Arteriovenous Shunt, Surgical↗

Early and late results of surgical correction of pulmonary artery sling.

Since 1976, we have operated on 4 children with pulmonary vascular sling. They were 5, 12, 19, and 54 months old. All patients were seen initially with severe stridor. Diagnosis was made by barium swallow in all 4. Each child was operated on through a left thoracotomy; the left pulmonary artery was dissected deep between the trachea and esophagus. Systemic heparinization and microsurgical techniques were used. All patients improved after operation. Radioisotope pulmonary ventilation/perfusion scans were performed 9, 9, 14, and 21 months after operation. Decreased ventilation was noted in the right upper lobe of one scan; the other three ventilation scans were normal. Perfusion scans showed good patency of both pulmonary arteries in all 4 patients. It is concluded that pulmonary vascular slings should be treated surgically as soon as diagnosed. Delayed operation can lead to severe tracheomalacia, as demonstrated in our 54-month-old patient.

Child, Preschool↗

Surgical technique to reduce the risks of heart block following closure of ventricular septal defect in atrioventricular discordance.

Traumatic heart block remains a major concern after ventricular septal defect (VSD) closure in patients with atrioventricular discordance. A technique of closing the VSD, placing the suture line on the morphologically right side of the septum without opening the systemic ventricle, is described. This was used in 13 consecutive patients. The VSD was closed through the right atrium in eight patients, the left ventricle in three patients, the right atrium and the left ventricle in one patient, and through the right ventricle in one patient with atrioventricular disordance and ventriculo-arterial concordance. All patients were in sinus rhythm preoperatively, two exhibited atrioventricular dissociation before intracardiac manipulation began, and 11 patients were in sinus rhythm postoperatively. No major arrhythmia could be attributed to the closure of the VSD.

Adolescent↗

Left ventriculotomy for closure of muscular ventricular septal defects. Treatment of choice.

Closure of muscular ventricular septal defects (VSDs) through the right atriotomy or right ventriculotomy may be difficult. These VSDs are often located behind the hypertrophied trabeculae carnae or papillary muscle. Residual or recurrent VSD may result from the difficult approach. Between March 1971 and December 1975, we have used the left ventriculotomy near the apex for closure of muscular VSDs in ten children. The patients' ages ranged from five months to eight years and three months. The diagnosis was established by cardiac catheterisation and left ventricular angiocardiogram in all patients. Six patients had multiple VSDs; in four patients VSD in the muscular septum was present (three apical, one midseptal). Operations were performed on cardiopulmonary bypass with moderate hypothermia and intermittent anoxic arrest. VSDs in the membranous septum were closed through the right atrium. Muscular VSDs were approached through a small vertical incision in the left ventricle near the apex. The postoperative course was uneventful in eight patients. Two patients, aged 16 months and eight years, died; histology showed grade IV pulmonary vascular disease in both. All survivors are well four months to five years after the operation, without clinical evidence of residual or recurrent VSD.

Angiocardiography↗

Mustard operation and creation of ventricular septal defect in two patients with transposition of the great arteries, intact ventricular septum and pulmonary vascular disease.

The condition of patients with transposition of the great arteries, intact ventricular septum and severe pulmonary vascular disease is inoperable with present techniques. In a series of 260 surgically treated patients with transposition of the great arteries and intact ventricular spetum, 5 had severely increased pulmonary vascular resistance, and all 5 died; postmortem examination confirmed the presence of severe pulmonary vascular disease. The concept of the "palliative Mustard" procedure was applied in two children with transposition of the great arteries, intact ventricular spetum and pulmonary vascular disease who underwent the Mustard operation with creation of a ventricular septal defect. The postoperative course was uneventful in both patients. Thirteen and 5 months, respectively, after operation, both are physically active and have respective arterial oxygen saturation levels of 94 and 92 percent.

Aneurysm↗

Blood platelets and extracorporeal circulation; kinetic studies on dogs on cardiopulmonary bypass.

Platelet kinetics and functions were studied in dogs during extracorporeal circulation. A transient platelet sequestration in the liver occurs during the bypass. This reversible disappearance is accompanied by a loss of the ability of platelets to adhere or aggregate. The platelets which return to the circulation have normal functions and a normal life span. The irreversible damage is mainly due to the direct blood-gas interface. Impairment of lung function by platelet aggregates is discussed and the importance of an in vivo model to study the factors which affect the platelets, such as antiaggregating agents, is pointed out.

Animals↗