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Biomedical subjects

J F Keane

Publications and source records attributed to J F Keane.

At least 73 records · Page 4Linked to original sources
PubMed1990

Balloon dilation of branch pulmonary artery stenosis.

We consider balloon angioplasty to be an established, highly useful procedure in the management of branch pulmonary artery stenosis. It is successful in approximately 60% of cases. Current figures would indicate a low but significant mortality rate (1%) and a risk of aneurym formation (3%). Patients undergoing balloon angioplasty in the acute postpulmonary artery surgical period constitute a particularly high risk group for vessel rupture. Restenosis after branch pulmonary dilation is infrequent, but does occur. Further improvements in the use of this procedure should probably involve the use of expandable intravascular stents for patients with failed dilations or evidence of restenosis.

Aneurysm↗
PubMed1989

Balloon dilation of postoperative right ventricular outflow obstructions.

Balloon dilation was attempted in 16 patients, aged 5 months to 19.5 years, with right ventricular outflow obstruction after repair of congenital heart defects. Stenosis of a valved conduit between the pulmonary ventricle and pulmonary artery was present in nine patients with a mean transvalvular peak systolic ejection gradient of 61.6 +/- 21.0 mm Hg and a mean right ventricle to aorta pressure ratio of 0.9 +/- 0.2. Supravalvular pulmonary stenosis was present in seven patients; in five, stenosis was at the anastomotic site after the arterial switch operation with a mean peak systolic ejection gradient of 72.2 +/- 10.6 mm Hg and mean right ventricle to aorta pressure ratio of 0.93 +/- 0.05. The other two patients had stenosis at a previous pulmonary artery band site with a peak systolic ejection gradient of 60 and 65 mm Hg and right ventricle to aorta pressure ratio of 0.75 and 0.72, respectively. Balloon dilation was successful in three of nine patients with a valved conduit; two of them had additional successful balloon dilation of the right pulmonary artery. In five of the nine patients (including one with successful dilation) the conduit was replaced 5.7 +/- 4.5 months after balloon dilation. Balloon dilation was successful in only one of the five patients with supravalvular pulmonary stenosis after the arterial switch operation and partially successful in the two patients with supravalvular pulmonary stenosis at a previous band site. The success rate of balloon dilation of postoperative right ventricular outflow obstruction is much lower than that for other right heart obstructions.

Bioprosthesis↗
PubMed1989

Coil embolization to occlude aortopulmonary collateral vessels and shunts in patients with congenital heart disease.

Gianturco coils were used to embolize 77 vessels in 54 patients: 58 aortopulmonary collateral vessels, 14 Blalock-Taussig shunts, 3 arteries involved in pulmonary sequestrations and 2 venae cavae. Embolization resulted in total occlusion in 53 (69%), subtotal occlusion in 19 (25%) and partial occlusion in 3 (1 intentional). Two embolizations failed to reduce flow. Thus, 72 (95%) of 76 embolizations in which complete occlusion was the intended result resulted in total or subtotal occlusion. Analysis of the results demonstrates that completely occluded collateral vessels were longer and had a smaller diameter than did incompletely occluded vessels. Complications included six cases of inadvertent embolization to the pulmonary arteries (n = 5) or the aorta (n = 1); three were retrieved and three were left without symptoms. In addition, there was a case of severe hemolysis after intentional partial occlusion of a Blalock-Taussig shunt. The results demonstrate that coil embolization can be an effective procedure for managing a wide variety of aorto-pulmonary collateral vessels and shunts in children with congenital heart disease.

Adolescent↗
PubMed1989

Transcatheter closure of atrial septal defects. Experimental studies.

Recent experience with the spring-loaded patent ductus arteriosus (PDA) occluder has demonstrated several advantages of this device in the closure of intracardiac defects compared with previously described techniques. Pathologic and animal model studies were performed to identify which atrial septal defects (ASDs) might be suitable for device closure and to test a new septal closure double umbrella. Fifty specimens from the Cardiac Registry with unrepaired ASD secunda (2 degrees) were analyzed. Mean ASD size was 8 x 10 mm (range, 3 x 4 to 30 x 30 mm); 80% (n = 40) of ASDs were judged closable with the new device. ASD closure was attempted in four lambs with the Rashkind (hooked single umbrella) ASD occluder. One of four umbrellas was correctly positioned; no ASDs were closed. A new double-hinged ("clamshell") umbrella device was designed: eight ASD closures were attempted with this device (defects ranged from 8 to 20 mm in diameter). Six of eight umbrellas were correctly positioned; four of four animals observed more than 1 day appeared to have complete closure on postmortem examination with endothelialization of the device. We conclude that 1) most ASD 2 degrees are far enough from vital structures to permit closure, 2) initial placement of hooked umbrellas is often incorrect and cannot be altered, 3) clamshell double umbrellas were successfully placed in six of eight attempts, and 4) endothelialization of closed ASDs appears complete within weeks of implantation. These preliminary studies appear promising and support testing the clamshell ASD device in clinical trials.

Animals↗
PubMed1989

Neonatal critical valvar aortic stenosis. A comparison of surgical and balloon dilation therapy.

Balloon aortic valvotomy (BAV) is an alternative to surgical valvotomy in infants and children. We compared BAV in 16 consecutive neonates (1985-1988) to surgical valvotomy in a prior group of 16 consecutive neonates (1978-1984). Both groups were comparable in terms of age, weight, hemodynamic data, left ventricular size, and associated lesions. There were six early and one late deaths after surgery. Five out of six neonates requiring a second operation died. Left ventricular size (measured in 13 neonates) had some influence on survival after surgery: three of three with small or hypoplastic left ventricles and three of 10 with normal-sized left ventricles died. After BAV, there were three early deaths, two patients who underwent stage I palliation of hypoplastic left heart syndrome, and two late deaths. As with surgical valvotomy, left ventricular size seemed to influence survival after BAV: five of six with small or hypoplastic left ventricles died or underwent stage I palliation for hypoplastic left heart syndrome and two of nine with normal-sized left ventricles died. At follow-up (26 +/- 17 months) in six patients in the surgical group, the peak systolic ejection gradient (PSEG) was 52.2 +/- 23 mm Hg and left ventricular end-diastolic pressure (LVEDP) 18.2 +/- 5.2 mm Hg. Aortic regurgitation was mild in five and moderate in the sixth patient. At follow-up (17.6 +/- 7.8 months) in nine patients in the balloon dilation group, the PSEG was 45.6 +/- 11 mm Hg in five patients at catheterization and 43.8 +/- 22.9 mm Hg in four patients by echocardiography-Doppler. Aortic regurgitation was mild in three and absent in the other six patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aortic Valve↗
PubMed1989

Interventional catheterization of left heart lesions, including aortic and mitral valve stenosis and coarctation of the aorta.

The current status of percutaneous balloon valvotomy for aortic, subaortic, and mitral stenosis and angioplasty of aortic arch obstructions are reviewed. Results from the authors and other laboratories are discussed in relation to technique and other factors such as patient age and underlying pathology. Current indications for these procedures are reviewed.

Adolescent↗
PubMed1988

Echocardiographic and anatomic findings in atrioventricular discordance with ventriculoarterial concordance.

Atrioventricular (AV) discordance with ventriculoarterial (VA) concordance is a rare form of congenital heart disease that consists of 5 different anatomic types. The salient therapeutic consideration uniting these 5 different anatomic entities is that anatomic correction can be achieved by an atrial switch procedure with closure of any associated septal defect. Three patients who had AV discordance with VA concordance are presented, with emphasis upon 2-dimensional echocardiographic diagnosis and surgical management. One of these patients had ventricular inversion with inverted normally related great arteries in situs solitus (i.e., [S,L,I]), thus representing a form of congenital heart disease that until now has not been documented anatomically. Although these are complex defects, multiple-plane imaging with 2-dimensional echocardiography was found to be extremely reliable in ascertaining the anatomy when a comprehensive, segmental analysis is applied. This approach includes determination of visceroatrial situs, ventricular loop and great arterial position and alignment. A surgical approach to closure of the ventricular septal defect through the left-sided infundibulum in isolated ventricular inversion afforded excellent exposure of the defect and avoided AV conduction block.

Aorta↗
PubMed1988

Interventional catheterization in pediatric congenital and acquired heart disease.

The present status of catheter-directed therapy in pediatric congenital and acquired heart disease is reviewed. Balloon pulmonary valvotomy, established as the procedure of choice for children and adults with isolated pulmonary stenosis, has now been extended to neonates with critical pulmonary stenosis. Balloon mitral and aortic valvotomy are being performed for congenital and acquired stenoses, although indications and optimal techniques remain to be established. Balloon angioplasty of coarctation effectively relieves obstruction in native and post-operative aortic arch stenoses, but remains controversial due to late aneurysm formation. Balloon angioplasty of branch pulmonary artery hypoplasia and stenosis, despite a relatively low success rate and significant complications, remains the procedure of choice due to lack of better therapeutic options. Transcatheter closure of congenital and acquired vessels and defects is being performed with increasing frequency. Embolization of aortopulmonary collaterals and shunts using Gianturco coils is safe and effective in selected patients. Although Rash-kind umbrellas are most commonly used for closure of a patent ductus arteriosus, their use, especially in closing intracardiac defects, remains investigational.

Angioplasty, Balloon↗
PubMed1988

Balloon dilation of critical pulmonary stenosis in the first week of life.

Although balloon dilation of valvular pulmonary stenosis is established in infants and children, the techniques for and results of balloon dilation in neonates with critical pulmonary stenosis remain largely unreported. Since January 1, 1985, six successive neonates with critical pulmonary stenosis (aged 1 to 6 days) underwent attempted balloon dilation. Each was cyanotic and three of the six were on prostaglandin E1 therapy and three required tracheal intubation and ventilation. All had suprasystemic right ventricular pressures (mean 122.8 +/- 6.8 mm Hg). After hemodynamic evaluation and right ventricular angiography, the valve was crossed in five patients, and was first dilated with a low profile, 5 or 6 mm diameter, 2 cm long balloon. At least one more balloon was used in each patient, the largest being 95 to 133% of the diameter of the pulmonary valve anulus. The anulus size was 6.8 +/- 1.1 mm and the largest balloon size used was 6 to 10 mm. Right ventricular pressure decreased to nearly systemic level or less in five of five patients (58.8 +/- 6.7 mm Hg). Pressure gradients, measured in four infants, were 7, 12, 16 and 35 mm Hg, respectively, but were unreliable indicators of obstruction because of a patent ductus arteriosus. The five patients were discharged 3 to 8 days after balloon dilation. All are currently symptom free 10.6 +/- 11.7 months later, and all but one are believed clinically to have mild obstruction. Complications included iliac vein occlusion (n = 1) and complete right bundle branch block (n = 1). Although follow-up has been brief, neonates with critical pulmonary stenosis can safely undergo balloon dilation, usually with good short-term results.

Catheterization↗
PubMed1988

Noninvasive estimation of the left ventricular pressure waveform throughout ejection in young patients with aortic stenosis.

Validation of a totally noninvasive method for estimating instantaneous left ventricular pressure and constructing a pressure waveform throughout ejection in patients with aortic stenosis is reported. In 20 patients (aged 8.75 +/- 10 years) with congenital aortic stenosis (measured peak left ventricular pressure 120 to 260 mm Hg; transvalvular gradient 18 to 165 mm Hg), transaortic valve continuous wave Doppler ultrasound, indirect carotid pulse tracing, peripheral blood pressure and measured left ventricular pressure were recorded simultaneously at cardiac catheterization. Data were entered into a microcomputer using a digitizing tablet and the instantaneous Doppler gradient was calculated and added to instantaneous aortic pressure, derived from the time-corrected and calibrated carotid pulse tracing, to estimate instantaneous left ventricular pressure. Estimated left ventricular pressure waveforms reproduced measured left ventricular pressure closely. The mean error at peak left ventricular pressure was 0.2 +/- 4.8 mm Hg (r = 0.98, p = 0.001). The average error throughout ejection was 0.9 +/- 5.1 mm Hg. The error of estimated pressure was not related to age or the severity of aortic stenosis. The Doppler peak instantaneous gradient was observed to correlate closely (r = 0.97, p = 0.001) with peak to peak gradient. With this technique, the left ventricular pressure waveform throughout ejection can be accurately estimated noninvasively in patients with aortic stenosis. This methodology enables determination of mean, total and instantaneous systolic left ventricular pressure.

Adolescent↗
PubMed1988

Late results in patients with tetralogy of Fallot repaired during infancy.

Between 1973 and 1985, 220 infants (age 1 day to 18 months, mean = 7 months) underwent repair of tetralogy of Fallot (TOF) or TOF/pulmonary atresia with 17 early deaths. Follow-up status was ascertained for 184 of 203 survivors (91%) at a postoperative interval of 2 to 185 months (mean = 60 months). Significant residual hemodynamic lesions included ventricular septal defect in three, and right ventricular outflow gradient in excess of 40 mm Hg in 24. Reoperation or interventional catheter procedures were performed in 31 of 184 (17%) patients. All postoperative electrocardiograms were reviewed; only two of 184 patients had ventricular ectopy on any tracing. Holter data from 41 patients revealed one with sinus node dysfunction, 12 with Lown grade 1 ectopy, and one with Lown grade 2 or greater. Conduction defects, evaluated by electrocardiographic and electrophysiologic measurements, were not different from those reported for TOF patients undergoing repair at later ages. No study patient received antiarrhythmic medication, although one required a pacemaker for sinus node dysfunction. There were three late deaths, all unrelated to arrhythmia. TOF repair in infancy appears to be associated with an acceptable hemodynamic outcome, and a low incidence of ventricular ectopy and sudden death at 5 year follow-up.

Arrhythmias, Cardiac↗
PubMed1988

Outpatient closure of the patent ductus arteriosus.

We have modified and applied to selected outpatients the transvenous approach to correction of patent ductus arteriosus (PDA) with the Rashkind PDA Occluder. Modifications included establishing the diagnosis and PDA anatomy before catheterization with echocardiography. The sedation/anesthetic regimen was altered to meet the needs with respect to transcatheter PDA closure rather than diagnostic cardiac catheterization. Anticoagulation was avoided. A strategy for management of pin entrapment in the foam was devised. Residual trans-PDA flow after umbrella placement was temporarily occluded with balloon-tipped catheters. These modifications were used in 23 consecutive patients with uncomplicated PDA. Closure was successful in each child. Nineteen of 23 patients were discharged on the day of the procedure. No serious complications were encountered.

Adolescent↗
PubMed1988

Midterm results after the arterial switch operation for transposition of the great arteries with intact ventricular septum: clinical, hemodynamic, echocardiographic, and electrophysiologic data.

Although the short-term results of atrial level repair of transposition of the great arteries (TGA) are satisfactory, longer follow-up has disclosed a significant incidence of systemic right ventricular dysfunction and rhythm disturbances. The arterial switch operation (ASO) may represent a major improvement by restoring the left ventricle as the systemic ventricle and avoiding extensive atrial surgery. We have prospectively evaluated 49 consecutive survivors of ASO for TGA with intact ventricular septum (IVS) by clinical examination, echocardiography, cardiac catheterization, ambulatory electrocardiographic monitoring, and invasive electrophysiologic studies. The mean length of follow-up has been 29 +/- 14 (SD) months after surgery. All children are currently asymptomatic and on no medications. Severe supravalvular pulmonary stenosis (greater than 60 mm Hg) was present in five children, all of whom have undergone reoperation. No patient has severe supravalvular aortic obstruction. Mild degrees of supravalvular pulmonary or aortic obstruction have not progressed. Seven children (14%) have trivial or mild aortic regurgitation. Two children have proximal occlusion of the left anterior descending coronary artery with adequate retrograde collateral perfusion. One child had an electrocardiographic pattern of inferior myocardial infarction without evidence of ventricular dysfunction. Systemic (left) ventricular function is normal as measured by end-diastolic pressure (mean 7 +/- 6 mm Hg), ejection fraction (mean 68 +/- 6%), end-diastolic volume (mean 101 +/- 22% of predicted normal), and cardiac index (mean 4.7 +/- 1.3 liters/min/m2). Only one patient has sinus node dysfunction. There have been no late deaths. These early results are encouraging. We conclude that the arterial switch operation is currently the procedure of choice for neonates with TGA and IVS.

Cardiac Catheterization↗
PubMed1988

Balloon dilation of congenital aortic valve stenosis. Results and influence of technical and morphological features on outcome.

We evaluated dilation technique (n = 80) and aortic valve morphology by two-dimensional echocardiography (n = 58) in patients with congenital aortic valve stenosis to determine their influence on outcome. Patients' age (9 +/- 9 years; range, 1 day-39 years) and a history of surgical valvotomy did not influence outcome. The number of dilating balloons (one vs. two) and balloon: annulus ratio based on the largest balloon used in each case (97 +/- 12%; range, 71-133%) did not demonstrably influence the percent reduction in valvar gradient. In contrast, with a balloon: annulus ratio greater than 100%, the incidence (26%) of significant, dilation-induced aortic regurgitation was higher than occurred when the ratio was equal to or less than 100% (11%). Fifty bicommissural and eight unicommissural valves were identified echocardiographically. Relief of obstruction was associated with apparent commissural division in 24 of 32 patients with suitable postdilation studies. The sites of fusion and stenosis relief did not influence percent reduction in valvar gradient. Substantial increases in aortic regurgitation (greater than three of five grades) occurred in three of eight unicommissural and one of 50 bicommissural valves. The presence of a thick valve was associated with a slightly lower gradient reduction (53 +/- 12%) than thin and pliant valves (63 +/- 24%) (p greater than 0.05). Unlike all other congenital lesions we have studied, dilation technique and balloon size appeared to have a lesser influence on percent reduction in valvar gradient in congenital aortic stenosis, although balloon: annulus ratio influences the increase in aortic regurgitation. Valve morphology appears to assist with predicting the outcome of dilation.

Adolescent↗
PubMed1988

Transcatheter closure of ventricular septal defects.

Between January and October, 1987, we attempted percutaneous transcatheter closure of seven ventricular septal defects (VSD) in six patients; none of the patients was a candidate for operative management. Patients' ages ranged from 8 months to 82 years (6.0-70 kg); diagnoses included postinfarction VSD (n = 4), congenital VSD (n = 1), and postoperative congenital VSD (n = 2). Indications for VSD closure were shock or respiratory failure (n = 5) or multiple episodes of endocarditis (n = 1). Closure was attempted with a Rashkind double umbrella: VSDs were crossed via the left ventricle and a guide wire was advanced to the right heart, snared with a venous catheter, and used to direct a long sheath (and ultimately the double umbrella) across the VSD. We crossed the VSD in all seven attempts, and a 17-mm double umbrella was successfully placed in each VSD. In the first (postinfarction) patient with the largest (12 mm) VSD, the umbrella embolized after 20 seconds to the pulmonary artery (without reducing flow). The other six umbrellas remained in position, either diminishing or abolishing the left-to-right shunts. Postinfarction patients had increasing VSD shunting over the next several days and died; at postmortem, the umbrellas remained well positioned in the septum, with other VSDs present. All three congenital VSDs had absent or diminished shunts after umbrella closure. These preliminary data indicate that transcatheter VSD closure is feasible in selected cases.

Angiography↗
PubMed1988

Interventional cardiac procedures in neonates and infants: state of the art.

The currently available interventional cardiac procedures in neonates and infants are at various stages of development. We currently dilate neonates and infants with critical valvular pulmonary and aortic stenosis and postoperative aortic obstruction. We do not routinely dilate native coarctation of the aorta because of the possibility of aneurysm formation, unless the neonate is very sick and acidotic and an operative approach is considered to be high risk. Balloon and blade atrial septostomy are done routinely whenever indicated with a low incidence of morbidity. Coil embolization, endomyocardial biopsy, foreign body retrieval and percutaneous pericardial drainage are relatively safe, and with the currently available instruments these techniques can be performed safely in neonates and infants with the same indications as for older patients. We currently consider stenotic pulmonary veins to be an undilatable lesion and an optimal therapy remains to be defined. Transcatheter closure of PDA and intracardiac shunts is presently limited to older patients, due to the large size of the delivery system devices and cannot currently be used in neonates. Dilation of the pulmonary valve in cyanotic congenital heart disease appears useful, but further experience is needed.

Angioplasty, Balloon↗
PubMed1988

Anterior chest wall deformities and congenital heart disease.

Pectus excavatum and pectus carinatum usually exist as isolated abnormalities. Only 19 cases of associated congenital heart defects have been reported. Significant complications related to uncorrected pectus excavatum have been described either during or after cardiac operations. Therefore we reviewed our experience with these coexisting lesions to assess the risk of surgical repair of chest wall deformities before and after correction of congenital cardiac anomalies. Among 20,860 infants and children with congenital heart disease seen at our institution, 36 (0.17%) had associated anterior thoracic deformities, 22 of whom underwent surgical correction of pectus excavatum or pectus carinatum. Ten of these 22 patients had pectus repair after a cardiac operation. Pleural or pericardial entry was avoided in all and none required a blood transfusion. Ten other patients had pectus repair either before cardiac repair (five patients) or without a subsequent cardiac operation. Another patient had a cardiac operation performed through a median sternotomy both before and after pectus repair, and the remaining patient, early in the series, had simultaneous banding of the main pulmonary artery and repair of pectus excavatum complicated by chest wall instability and a lethal intrathoracic hemorrhage. The experience indicates that congenital chest wall deformities can be safely and effectively repaired after early correction of congenital heart defects through a median sternotomy, although repair of the chest wall deformity after cardiac surgery also gives good results. However, in children who require an extracardiac conduit for repair of their congenital heart defect, we recommend initial repair of the pectus excavatum followed at 6 weeks or later by repair of the cardiac lesion to eliminate possible extrinsic compression of the conduit by the depressed sternum. We avoid simultaneous cardiac and pectus excavatum repair because of potential associated major complications.

Adolescent↗