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Biomedical subjects

M L Rigby

Publications and source records attributed to M L Rigby.

At least 19 recordsLinked to original sources
PubMed1995

Contemporary results of balloon valvuloplasty and surgical valvotomy for congenital aortic stenosis.

The purpose of this study was to compare contemporary results of balloon dilatation and surgery for valvar aortic stenosis in infants and children in the five years between August 1988 and October 1993. Thirty four children underwent attempted balloon valvuloplasty (age 1 day-16 years, weight 1720 g-68 kg) (group 1), eight of whom were neonates with critical aortic stenosis. During the same period, 17 children underwent direct surgical valvotomy (group 2) (seven neonates). Successful balloon valvuloplasty was achieved in 33 (97%) with immediate reduction in the instantaneous systolic pressure gradient from 82 to 34 mm Hg (mean). There were two deaths in this group (both neonates), the second in a preterm neonate from necrotising enterocolitis. Complications requiring intervention in group 1 were aortic regurgitation in one and femoral artery injury in two. Follow up from four months to five years showed sustained results in most cases. There were two neonatal deaths in the surgical group. When the two groups were compared there was no significant difference in mortality, morbidity, or need for reintervention within 12 months. Deaths from both groups were attributed to small left ventricles. Hospital stay was significantly shorter in group 1. It is concluded that balloon dilatation for valvar aortic stenosis is effective and safe for the entire paediatric population. The results compare favourably with those of surgery.

Adolescent↗
PubMed1995

Increasing cyanosis early after cavopulmonary connection caused by abnormal systemic venous channels.

OBJECTIVE: To show that abnormal systemic venous channels in patients who undergo cavopulmonary anastomoses can become manifest and haemodynamically important only after surgery despite detailed preoperative investigation. DESIGN: Descriptive study of patients fulfilling the above criteria selected from hospital records over the past three years. SETTING: A tertiary referral centre. PATIENTS: Of the three cases identified, two were isomeric, one with left atrial isomerism and hemiazygos continuation of the inferior vena cava who underwent bilateral bidirectional Glenn anastomoses and one with right isomerism who underwent total cavopulmonary anastomosis. Case 3 had absent left atrioventricular connection with a hypoplastic left lung and underwent a classic right Glenn procedure. All three cases presented with progressive cyanosis in the early postoperative period. INTERVENTIONS AND RESULTS: Postoperative angiography in case 1 showed a remnant of a left inferior vena cava draining to the atrium to have become grossly dilated causing cyanosis, which resolved after redirection of this vessel and of the hepatic veins into the right pulmonary artery with an intra-atrial baffle. Cyanosis in case 2 was caused by intra-hepatic shunting to a hepatic vein draining to the left of the intra-atrial baffle. The diagnosis was made at necropsy, being overlooked on postoperative angiography. Repeat angiography in case 3 showed progressive dilatation of a small left superior vena cava to coronary sinus. Test occlusion with a view to embolisation revealed hitherto an undemonstrated hemiazygos continuation of inferior caval to brachiocephalic vein. The patient underwent surgical ligation of these two venous channels. CONCLUSIONS: Despite appropriate investigation some "abnormal" venous pathways manifest themselves, dilate, and become haemodynamically important only after surgical cavopulmonary anastomoses. In the presence of early postoperative cyanosis "new" systemic venous collateral channels should be considered as a possible cause, which may require reintervention.

Child↗
PubMed1995

Closure of Blalock-Taussig shunts using a new detachable coil device.

Two children underwent interventional closure of a modified Blalock-Taussig shunt using a new detachable coil system (Duct-Occlud). This procedure has advantages over currently available materials to occlude these and other communications between the systemic and pulmonary circulations.

Arteriovenous Shunt, Surgical↗
PubMed1994

Transcatheter closure of interatrial communications with a modified umbrella device.

OBJECTIVE: To show the institutional experience of closure of interatrial communications with a modified umbrella device. DESIGN: Descriptive study of all patients in whom transcatheter umbrella closure of interatrial communications has been attempted. SETTING: A tertiary referral centre. PATIENTS: 16 patients with 17 interatrial communications of various types. INTERVENTIONS: Transcatheter placement of a modified Rashkind umbrella occluder. RESULTS: Two procedural failures due to venous access problems. Two placement failures needing early surgical repair. 13 successful placements in 12 patients. CONCLUSIONS: The modified Rashkind umbrella can successfully be used to close both iatrogenic and naturally occurring interatrial communications, particularly those present after the Fontan procedure.

Adolescent↗
PubMed1992

Right ventricular outflow obstruction by anomalies of the tricuspid valve: report of a windsock diverticulum.

A 9-month-old infant with a clinical diagnosis of double outlet from the right ventricle, subaortic ventricular septal defect, and muscular subpulmonary obstruction underwent surgical repair. The defect was corrected and the right ventricular infundibulum enlarged with a patch. Eight hours after the operation there was a sudden collapse which rapidly progressed to cardiac arrest and death. Postmortem examination of the heart confirmed the clinical diagnosis but noted that the subpulmonary obstruction was caused by a "windsock" deformity of the tricuspid valve which was not identified at operation. The variants of malformations of the tricuspid valve causing subpulmonary obstruction are reviewed.

Heart Septal Defects, Ventricular↗
PubMed1992

Exercise capacity after complete repair of tetralogy of Fallot: deleterious effects of residual pulmonary regurgitation.

OBJECTIVE: To determine the effects of residual pulmonary regurgitation on exercise tolerance after complete repair of tetralogy of Fallot. DESIGN: Prospective study of symptom free patients more than five years after complete repair. Graded exercise performance was measured with standard Bruce protocol. Maximal oxygen uptake and ventilatory anaerobic threshold were measured by respiratory mass spectrometry. Measurement of pulmonary regurgitant fraction was from pressure-volume loops constructed from measurements of right ventricular volume obtained from biplane angiograms and simultaneous pressures measured with a micromanometer. SETTING: Tertiary referral centre. PATIENTS: 16 patients were studied. Two patients had been excluded because of residual cardiac lesions or inadequate data from cardiac catheterisation. Four were later excluded because they failed to reach a respiratory quotient of greater than 1.0 during graded exercise. RESULTS: There was a significant negative correlation between the degree of residual regurgitation and both total duration of exercise and maximal heart rate achieved. Maximal heart rate and total duration of exercise were significantly lower in the patients than in normal controls. Patients with an abnormal maximal oxygen uptake (less than 85% of the predicted normal value) had significantly greater residual pulmonary regurgitation than those in whom oxygen uptake was normal. CONCLUSIONS: Impaired exercise capacity after complete repair of tetralogy of Fallot is directly related to the degree of residual pulmonary regurgitation. These data should be taken into account when deciding the optimal timing and nature of corrective surgery.

Adolescent↗
PubMed1992

Left ventricular performance in children: transthoracic versus transoesophageal measurement of M mode derived indices.

OBJECTIVE: To compare M mode derived indices of left ventricular performance obtained with transthoracic and transoesophageal echocardiography in children with congenital heart disease. DESIGN: Transthoracic and transoesophageal M mode echocardiograms were obtained under general anaesthesia before cardiac catheterisation. Recordings were digitised by dedicated software. Indices of cavity dimension and left ventricular wall dynamics were compared. PATIENTS: 16 unselected patients with congenital heart disease. RESULTS: Group data for simple measurements of ventricular dimension and wall thickness were similar with the two techniques and had acceptable coefficients of repeatability, but there were considerable individual differences. Correlation was poor with unacceptable repeatability for derived indices of cavity and ventricular wall dynamics. CONCLUSION: Both transthoracic and transoesophageal echocardiography can be used to obtain M mode derived indices of left ventricular performance but the resultant measurements are not directly comparable, presumably because of regional non-uniformity of function.

Adolescent↗
PubMed1991

Aortic atresia with aortopulmonary window and interruption of the aortic arch.

The cross-sectional echocardiographic and postmortem appearances of the heart from a patient with the rare association of aortic valve atresia, aortopulmonary window, and interrupted aortic arch are described. Differentiation of this anomaly from truncus arteriosus with interrupted aortic arch is important.

Aorta, Thoracic↗
PubMed1991

Familial aneurysms of the interventricular septum.

Congenital aneurysms of the interventricular septum were found in a 29 year old man and his four year old son. Both were symptom free. In both, M mode and cross sectional echocardiography showed an aneurysm in the mid-muscular trabecular portion of the ventricular septum with considerable paradoxical motion of the aneurysmal segment. Otherwise the chamber dimensions, intracardiac structures, and cardiac function were normal for age. Congenital aneurysm of the interventricular septum is rare and these familial cases may be unique.

Adult↗
PubMed1991

Early complications of interventional balloon catheterisation in infants and children.

Interventional balloon catheterisation is now the recommended procedure for several congenital heart defects. The overall complication rate in the first 160 children (median age 3 years) to undergo balloon intervention (excluding balloon atrial septostomy) at the Brompton Hospital was 24% (14% excluding haemorrhage and including three deaths (1.9%]. Most complications were related to vascular problems at the site of cardiac catheterisation. Complications were more common in the younger patient, especially neonates, and also in procedures that were ultimately unsuccessful. Most complications were transient and usually had no long term effects. Improvements in equipment design and technical expertise may reduce morbidity from these procedures.

Adolescent↗
PubMed1991

Cardiac function after surgery for subaortic stenosis: non-invasive assessment of left ventricular performance.

OBJECTIVE: To examine left ventricular function after surgical resection of subaortic stenosis during childhood. DESIGN: Left ventricular performance was measured non-invasively in all patients who responded to an invitation for formal assessment. SETTING: Outpatient study, tertiary referral centre. PATIENTS: Twenty three (12 male and 11 female) patients (age range 3 to 31 years) of 43 consecutive patients with fixed subaortic stenosis undergoing surgical resection between 1975 and 1989 reattended for formal assessment 16 months to 15 years (median 4 years 4 months) after operation. MAIN OUTCOME MEASURES: Left ventricular dimension, left ventricular wall thickness, left ventricular Doppler inflow velocities, and left ventricular diastolic pressure (measured from apexcardiograms). Results were compared with those in controls individually matched for age and sex. RESULTS: All patients were symptom free. Left ventricular cavity dimensions were normal, as was the mean fractional shortening. Posterior wall thickness tended to be greater in the patients and there was a significant increase in septal thickness. Normalised peak rate of posterior wall thinning was significantly lower in the patients and the isovolumic relaxation time was significantly shorter. Doppler inflow velocity measurements showed that early diastolic mitral flow acceleration time was normal but deceleration time was significantly shorter in the patients. The ratio of mitral flow in early diastole (E) to E plus mitral flow in late diastole (A) was significantly higher in the patients and in two patients there was complete absence of A wave flow despite large A waves on the apexcardiogram. CONCLUSIONS: Systolic function was well preserved in patients after operation for subaortic stenosis. A restrictive pattern of left ventricular filling was common, however, and presumably reflected a response to the chronic pressure load and to surgery in the paediatric heart.

Adolescent↗
PubMed1991

Abnormal patterns of intraventricular flow and diastolic filling after the Fontan operation: evidence for incoordinate ventricular wall motion.

OBJECTIVE: To assess whether regional abnormalities of ventricular function are present in patients after the Fontan operation and to explore the implications of any such abnormalities for ventricular filling. DESIGN AND PATIENTS: Prospective study in which 25 patients after the Fontan operation were compared with 25 healthy controls and 12 patients with a univentricular atrioventricular connection, before the Fontan operation. INTERVENTIONS: Doppler echocardiography, with simultaneous electrocardiogram, phonocardiogram, and respirometer. RESULTS: Isovolumic relaxation time was significantly longer in patients after the Fontan operation than in normal children (p less than 0.001) or the preoperative patients (p = 0.001). Systolic intraventricular flow was detected in 60% of patients after the Fontan operation and in 42% of preoperative patients. After the Fontan operation 80% of patients showed intraventricular flow during isovolumic relaxation compared with 8% of normal children and none of the preoperative patients. CONCLUSIONS: Incoordinate ventricular relaxation is common after the Fontan operation. This may have important implications for ventricular diastolic filling, pulmonary blood flow, and cardiac output in these patients.

Adolescent↗
PubMed1991

Double-inlet ventricle presenting in infancy. II. Results of palliative operations.

The influence of palliation on survival was studied in 191 consecutive infants, presenting at under 1 year of age, with double-inlet ventricle (1973 to 1988, median follow-up 8.5 years). Palliative operations were performed on 154 occasions in 121 patients (63%). Survival after a systemic-pulmonary arterial shunt (n = 57) and banding of the pulmonary trunk (n = 35) was comparable (84% and 77% at 1 year, 62% and 45% at 5 years), but those who underwent repair of aortic arch obstruction fared worse (n = 18, 44% and 22% at 1 and 5 years, p less than 0.001). The remainder did not undergo an operation because of balanced physiology (n = 17, 9% of entire group), complex anatomy (n = 32, 15%), or irreversible low output (n = 19, 12%). Palliative surgery, overall, had a deleterious effect on immediate survival (greater than 1 month relative risk 6.6, p less than 0.001), but, in the survivors, medium-term outcome was improved (greater than 6 months, 0.68, p less than 0.05). This effect was most marked for those undergoing a systemic-pulmonary artery shunt (less than 1 month, 2.52; greater than 6 months, 0.43); by contrast, after banding of the pulmonary trunk, with or without additional repair of the aortic arch repair, medium-term risk was not altered (greater than 6 months, 1.13 and 0.91, respectively). These data will assist the clinician in making decisions concerning the management of infants with double-inlet ventricle and in the judicious use of palliative surgery.

Anastomosis, Surgical↗
PubMed1991

Morphologic-echocardiographic correlates of Ebstein's malformation.

The cross-sectional echocardiographic findings were analysed retrospectively in 26 patients with Ebstein's malformation in the light of studies of autopsied specimens from different patients showing this lesion. The salient anatomical feature in diagnosis is the finding of the hinge point of the septal and mural leaflets of the valve within the inlet component of the right ventricle rather than at the atrioventricular junction. The other important feature is the nature of the distal attachment of the leaflets, particularly the anterosuperior one, which can either be in focal or linear fashion. The hinge point of the septal leaflet was noted echocardiographically to be displaced in 19 patients but, significantly, the leaflet was absent in the other seven. Also significant was that the hinge point of the mural leaflet at the crux had been visualized in only 15 of the patients. The anterosuperior leaflet had a distal linear attachment in 20 of the patients, with the anteroseptal commissure becoming a keyhole in six of these through which blood passed to the functional right ventricle. The valve remained a competent structure, even though closing at the junction of atrialized and functional components of the right ventricle rather than at the atrioventricular junction. Cross-sectional echocardiography is the technique of choice with which to display the salient morphological features of Ebstein's malformation.

Adolescent↗
PubMed1991

Double-inlet ventricle presenting in infancy. I. Survival without definitive repair.

Survival before definitive operations was studied in 191 infants with double-inlet ventricle presenting before 1 year of age (1973 to 1988, median follow-up 8.5 years). The morphologic spectrum was broad, with a great prevalence of associated lesions. The actuarial survival rate before definitive repair was 57% at 1 year, 43% at 5 years, and 42% at 10 years, worse than prior reports because of the younger age at entry into our series. Analysis of univariate risk factors established that right atrial isomerism (18% of the group, relative risk 2.9), common atrioventricular orifice (42%, 2.0), pulmonary atresia (20%, 3.4), obstruction of the systemic outflow tract (18%, 2.5), and extracardiac anomalous pulmonary venous connection (13%, 3.1) were strongly associated with poorer survival. Pulmonary stenosis (40%, 0.35), balanced pulmonary blood flow (9%, 0.40), and presentation at an older age (3%, 0.42 to 0.18) were beneficial (p less than 0.05 to 0.0001). Multivariate analysis allowed the creation of patient-specific curves for prediction of survival for different anatomic and physiologic variants of double-inlet ventricle. A simple additive index was then derived from the multivariate Cox coefficients to enable stratification of risk for these morphologic subgroups of patients and so assist in the making of clinical decisions in infancy.

Follow-Up Studies↗
PubMed1991

Double-inlet ventricle presenting in infancy. III. Outcome and potential for definitive repair.

The fate of 191 infants with double-inlet ventricle was studied to determine the influence of morphologic characteristics at presentation and subsequent management on the potential for, and timing of, definitive repair by the Fontan operation or ventricular septation. At presentation, 136 patients (71%) were potential candidates for a Fontan procedure. Actuarial survival was better than for those deemed unsuitable for either definitive option (n = 55; 68% versus 28% at 1 year; p less than 0.001), but still, only 78 patients (57%) were known to be alive and suitable candidates at 2 years of age. This was largely due to death after presentation with low cardiac output (n = 19) and at palliative operation (20 of 98 surgically treated patients). The adverse events of late sudden death (n = 14) and the development of new features precluding a Fontan operation (n = 18) mostly occurred before 4 years of age (n = 22). Patients requiring no operation and those who underwent a systemic-pulmonary arterial shunt fared better than those who underwent isolated banding of the pulmonary trunk (9/13 and 25/42 alive and suitable versus 14/33; p less than 0.05), and than those who required aortic arch repair together with banding (1/12; p less than 0.01), because of the development of subaortic stenosis in the latter group. In contrast, only 43 patients (23% of all 191 patients) had morphologic features that were additionally compatible with future ventricular septation. Actuarial survival free of adverse events for these 43 patients was similar to that of the 136 patients considered suitable for a Fontan operation. Thus management in infancy must be aimed at maintaining potential for a future Fontan operation, which itself should not be delayed, for most patients, beyond 3 years of age, because of the prevalence of adverse events with increasing age.

Follow-Up Studies↗