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J M Parsons

Publications and source records attributed to J M Parsons.

At least 37 records · Page 2Linked to original sources
PubMed1994

Influence of anatomic correction for transposition of the great arteries on myocardial perfusion: radionuclide imaging with technetium-99m 2-methoxy isobutyl isonitrile.

OBJECTIVES: We sought to determine the incidence of late perfusion defects attributable to coronary artery mobilization in patients undergoing anatomic correction for complete transposition of the great arteries. BACKGROUND: Anatomic correction (arterial switch procedure) is currently the surgical treatment of choice for complete transposition. From its conception, there has been concern about the impact on myocardial perfusion of the coronary artery mobilization and reimplantation involved in the correction. Previous studies have demonstrated myocardial perfusion defects in patients after correction, although a causal relation between coronary mobilization, and perfusion abnormality has not been established. METHODS: In a case-comparison study designed to test this hypothesis, 29 children underwent imaging with technetium-99m 2-methoxy isobutyl isonitrile (technetium-99m mibi). Ten had undergone anatomic correction (arterial switch group; interval from operation 6.9 +/- 1.42 years [range 4.9 to 9.1]); 9 had required noncoronary open heart surgery for other cardiac lesions (post-bypass group; interval from operation 5.6 +/- 3.6 years [range 1.0 to 13.25]); and 10 had had no surgical procedure (control group). The latter group comprised children with atrial or ventricular septal defects who required a radionuclide study for shunt calculation. Planar studies were performed in all 29 children, and additional tomographic acquisition was achieved in 25. To assess reversibility of perfusion defects both an exercise and a rest planar study were performed in the arterial switch group. RESULTS: Perfusion abnormalities were observed in seven of the nine children in the postbypass group and in all 10 children in the arterial switch group. The frequency of perfusion defects in these two groups was similar, with at least 25% of the tomographic segments reported being abnormal. The control group had significantly fewer defects than the other two groups (p = 0.02), with only 8% of the tomographic segments judged to be abnormal. In all except one patient in the arterial switch group, the segments reported as abnormal on the planar exercise study were either abnormal or equivocal on the rest study, indicating a fixed abnormality. CONCLUSIONS: Although the precise etiology of these perfusion abnormalities cannot be defined from this study, these data suggest that their origin is related more to the insult of open heart surgery itself than to the coronary manipulation involved in the arterial switch procedure. The functional importance requires further study.

Cardiac Surgical Procedures↗
PubMed1992

Anaemia in children following cardiac transplantation: treatment with low dose human recombinant erythropoietin.

Anaemia is common in children following cardiac transplantation. In a series of 5 children with anaemia beyond the immediate post-operative period one had a hypochromic, microcytic anaemia which corrected with oral iron. The other four had normochromic, normocytic anaemias unresponsive to iron or folate supplementation and associated with inappropriately low levels of erythropoietin. Subcutaneous administration of low dose human recombinant erythropoietin to these four patients resulted in correction of their anaemia. Our findings suggest that erythropoietin deficiency is an important cause of anaemia in transplant recipients and should be sought in cases of anaemia refractory to conventional haematinic therapy. In cases of proven erythropoietin deficiency, treatment with erythropoietin is effective, acceptable to patients and preferable to repeated blood transfusion.

Adolescent↗
PubMed1992

Stenting of the arterial duct: a new approach to palliation for pulmonary atresia.

OBJECTIVE: To assess the possibility of maintaining ductal patency in neonates with complex pulmonary atresia by percutaneous implantation of balloon expandable stents. PATIENTS: Two duct-dependent neonates with long segment pulmonary atresia, right sided aortic arch, and left sided arterial duct. RESULTS: Stents with final diameter of 3.5 or 4 mm and initial length of 7 or 15 mm were successfully positioned in the arterial duct. Two stents were required in one child and four in the other in order to stent the entire length of the duct. After the procedures the ducts remained widely patent and arterial oxygen saturations remained above 80%. Complications of the procedures included perforation of a peripheral pulmonary artery and cardiac perforation, both caused by guide wire manipulation. Both babies died suddenly, one at five weeks, and the other at nine days after successful stenting of the duct. Both ducts were patent at necropsy; the exact cause of one death was not clearly defined, but the second seemed to be caused by pneumococcal septicaemia. CONCLUSIONS: Stenting of the arterial duct is technically feasible. It provides adequate palliation for neonates with pulmonary atresia at least in the short term and it seems to result in balanced, central perfusion of both pulmonary arteries. This preliminary report suggests that this previously untried technique may prove to be a promising and attractive alternative to neonatal aortopulmonary shunt operation.

Dinoprostone↗
PubMed1991

Spontaneous hyphaema in childhood.

Between January 1987 and September 1989 three children presented to the childrens' casualty department with spontaneous hyphaema. Physical examination and haematological investigations were sufficient to determine their cause in two cases (sickle cell disease and acute lymphoblastic leukaemia). In the third child an ophthalmological examination under general anaesthesia revealed a granulomatous lesion of the iris consistent with the diagnosis of juvenile xanthogranuloma.

Anemia, Sickle Cell↗
PubMed1991

Balloon dilatation of a stenosed aortic homograft conduit following repair of the common arterial trunk.

An 8-year-old boy, who underwent surgical correction of a common arterial trunk at the age of 10 months, developed stenosis of the 15-mm aortic homograft. Chest x-ray demonstrated calcification of the homograft, and at cardiac catheterization there was a 57 mmHg gradient across the conduit. He underwent balloon dilatation using a 15-mm balloon catheter. After four inflations at a pressure of 5.5 atm, the gradient decreased to 34 mmHg. Six months later he had a Doppler-estimated gradient of 38 mmHg.

Angiography↗
PubMed1991

Double-outlet right ventricle: morphologic demonstration using nuclear magnetic resonance imaging.

Sixteen patients with double-outlet right ventricle, aged 1 week to 29 years (median 5 months), were studied with a 1.5 tesla nuclear magnetic resonance (NMR) imaging scanner. Two-dimensional echocardiography was performed in all patients. Thirteen patients underwent angiography, including nine who underwent subsequent surgical correction. Three patients underwent postmortem examination. Small children and infants were scanned inside a 32 cm diameter proton head coil. Multiple 5 mm thick sections separated by 0.5 mm and gated to the patient's electrocardiogram were acquired with a spin-echo sequence and an echo time of 30 ms. A combination of standard and oblique imaging planes was used. Imaging times were less than 90 min. The NMR images were technically unsuitable in one patient because of excessive motion artifact. In the remaining patients, the diagnosis of double outlet right ventricle was confirmed and correlated with surgical and postmortem findings. The NMR images were particularly valuable in demonstrating the interrelations between the great arteries and the anatomy of the outlet septum and the spatial relations between the ventricular septal defect and the great arteries. Although the atrioventricular (AV) valves were not consistently demonstrated, NMR imaging in two patients identified abnormalities of the mitral valve that were not seen with two-dimensional echocardiography. In one patient who had a superoinferior arrangement of the ventricles, NMR imaging was the most useful imaging technique for demonstrating the anatomy. In patients with double-outlet right ventricle, NMR imaging can provide clinically relevant and accurate morphologic information that may contribute to future improvement in patient management.

Angiography↗
PubMed1991

Percutaneous laser valvotomy with balloon dilatation of the pulmonary valve as primary treatment for pulmonary atresia.

A neonate with pulmonary atresia and an intact ventricular septum with a tripartite right ventricle was successfully treated by percutaneous balloon dilatation of the pulmonary valve. This was facilitated by previous laser valvotomy with a hot tip Trimedyne laser wire. There were no major complications. Four weeks later the patient was discharged home on no medication with peripheral oxygen saturations of 70% in air.

Catheterization↗
PubMed1990

Magnetic resonance imaging of the great arteries in infants.

Sixty infants, aged 1-48 (median 8) weeks, with suspected congenital heart disease underwent a morphological evaluation of the great arteries using magnetic resonance imaging at 1.5 Tesla. Cross-sectional echocardiography was performed in all infants, angiography in 33 and surgery in 44. Multiple sections, 5 mm thick and gated to the patients' electrocardiogram were acquired in standard and oblique imaging planes. Ventriculo-arterial connexions were correctly identified in 54 infants (6 did not have intracardiac imaging performed) and an accurate description of the relationships of the great arteries was made in all. Magnetic resonance imaging clearly demonstrated normal and hypoplastic pulmonary arteries to the level of the first hilar branches and was better than echocardiography at confirming the presence or absence of central intrapericardial pulmonary arteries in 4 infants with pulmonary atresia. All parts of the thoracic aorta were accurately demonstrated and, in 23 infants with clinical suspicion of aortic coarctation, magnetic resonance images provided more information than echocardiography. Magnetic resonance imaging accurately demonstrates great arteries non-invasively supplementing echocardiographic and angiographic findings. In many cases, it replaces the need for invasive investigations.

Aorta, Thoracic↗
PubMed1990

Doppler evaluation of superior caval venous pathways after Mustard and Senning operations.

Doppler waveforms from the superior caval vein were analysed to evaluate the patency of superior caval venous pathways following venous redirection (Mustard and Senning) operations for complete transposition. The group consisted of 26 unselected survivors of Mustard (9 patients) and Senning operations (17 patients). Patients were examined a mean of 5.9 (range 0.1-15.3) years following operation and their age at study ranged from 0.4-25.3 years, mean 7.3 years. Doppler waveforms were correlated with digital subtraction angiograms, which were performed in every patient within 24 hours of the Doppler study. Totally occluded superior caval venous pathways were identified in 3 patients with digital subtraction angiography. The remaining patients had angiographically patent pathways. In the 23 patients with patent pathways, Doppler waveforms demonstrated an initial systolic peak smaller than a second diastolic peak. In the 3 patients with totally occluded pathways, the pattern of the waveform was reversed, with the systolic larger than the diastolic peak. Doppler examination of the superior caval vein is a quick and simple bedside method of accurately determining patency of superior caval venous pathways after atrial redirection procedures for complete transposition.

Adolescent↗
PubMed1990

Balloon dilatation of critical stenosis of the pulmonary valve in neonates.

Percutaneous balloon dilatation was attempted in 15 consecutive neonates (mean age 7.3 (range 1-27) days and weight 3.2 (range 2.5-4.1) kg) with critical stenosis of the pulmonary valve. Dilatation was successful in 11 (73%) patients. The mean balloon to annulus ratio was 1.1 (range 0.6-1.77). The ratio of right ventricle to femoral artery systolic pressure decreased from a mean (1 SD) of 1.4 (0.32) before to 0.8 (0.24) after dilatation and the transvalvar gradient decreased from 81 (29.7) mm Hg before to 33 (27.7) mm Hg after dilatation. All four (27%) patients in whom dilatation was unsuccessful underwent surgical valvotomy. Complications of balloon dilatation occurred in three (20%) patients; these included retroperitoneal haematoma (one) and iliofemoral venous occlusion (two). In one (7%) patient severe hypoxia and hypotension developed when the valve was crossed with a guide wire and balloon catheter. Despite successful dilatation he died 7 days after the procedure. During a mean (1 SD) follow up of 2 (1.7) years, seven (64%) of the 11 patients remained free of important restenosis. One patient required repeat dilatation three weeks after the initial procedure. In three (27%) patients restenosis developed 4-9 months after dilatation and all three had surgical valvotomy. Of the four patients initially referred for surgery three required a second operation and one required balloon dilatation. Percutaneous balloon dilatation gave effective relief of critical pulmonary stenosis in most neonates but complications and restenosis requiring surgery were common.

Blood Pressure↗
PubMed1990

Morphological evaluation of atrioventricular septal defects by magnetic resonance imaging.

Twelve patients aged between 2 weeks and 22 months (median 6 weeks) with atrioventricular septal defects were examined with a 1.5 T, whole body, magnetic resonance imaging system. Ten patients had a common atrioventricular orifice (complete defect) while two patients had separate right and left valve orifices (partial defect). Associated cardiac malformations included the tetralogy of Fallot in two, isomerism of the right atrial appendages and pulmonary atresia in two, and right isomerism and double outlet right ventricle in one. All had previously been examined by cross sectional echocardiography. Eight subsequently had angiography and six underwent surgical correction. There was one operative death and three other deaths. Three of these patients underwent postmortem examinations. Small children and infants were scanned inside a 32 cm diameter head coil. Multiple electrocardiographically gated sections 5 mm thick, separated by 0.5 mm, were acquired using a spin echo sequence with echo time of 30 ms. A combination of standard and oblique imaging planes was used. Magnetic resonance imaging was more accurate than echocardiography in predicting the size of the ventricular component of the defect. It was also better than either echocardiography and angiography in identifying the presence of ventricular hypoplasia. All these findings were confirmed by surgical or postmortem examinations or both. Magnetic resonance imaging is capable of providing detailed morphological information in children with atrioventricular septal defects which is likely to be of value in their management.

Abnormalities, Multiple↗
PubMed1990

Percutaneous transcatheter myectomy of subvalvar pulmonary stenosis in tetralogy of Fallot: a new palliative technique with an atherectomy catheter.

A male infant with tetralogy of Fallot was given a modified left Blalock-Taussig shunt at 11 days of age because of duct dependence. Twenty months later, because of increasing cyanosis and polycythaemia, he was given palliative treatment with balloon dilatation of the right ventricular outflow tract. Seven months later a right ventricular angiogram showed further progression of the infundibular stenosis with poor anterograde opacification of the pulmonary arteries. He underwent percutaneous transcatheter myectomy of the infundibulum with an atherectomy catheter. One month later he was well and less cyanosed.

Cardiac Catheterization↗
PubMed1989

Growth of the pulmonary artery after neonatal balloon dilatation of the right ventricular outflow tract in an infant with the tetralogy of Fallot and atrioventricular septal defect.

A two week old girl with tetralogy of Fallot and atrioventricular septal defect underwent palliation, for severe hypoxaemia, by balloon dilatation to the right ventricular outflow tract. This procedure was repeated once over the next eight months without complications. Serial right ventricular angiograms showed growth of the hypoplastic pulmonary ring ("annulus"), trunk, and arteries. Balloon dilatation is an alternative palliative procedure for patients with the tetralogy of Fallot which may promote growth of the pulmonary ring, trunk, and arteries.

Catheterization↗
PubMed1989

Magnetic resonance imaging of coarctation of the aorta in infants: use of a high field strength.

Nineteen infants with suspected coarctation of the aorta were studied with electrocardiographically gated magnetic resonance imaging on a 1.5 T whole body imaging system. In all cases imaging was successful and produced diagnostic images of high resolution. Coarctation was shown in 12 cases. The position and shape of the coarctation were well displayed by the magnetic resonance images. In addition, they clearly showed the relation of the coarctation to arteries arising from the aortic arch and to the length and diameter of the aortic isthmus and the distal aortic arch. The anatomy was confirmed at operation in all 12 patients, except for two with a small ductus arteriosus (arterial duct), which was not seen in the magnetic resonance images. In the seven remaining patients, coarctation was excluded. Magnetic resonance imaging produced high quality images that showed the anatomy better than other non-invasive methods. It provided all the anatomical information required for surgical correction.

Aorta, Thoracic↗