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Biomedical subjects

K E Fellows

Publications and source records attributed to K E Fellows.

At least 55 records · Page 3Linked to original sources

Balloon dilation angioplasty of postoperative aortic obstructions.

Balloon dilation angioplasty (BDA) was attempted 29 times in 27 patients, aged 3 months to 22 years, with postoperative aortic obstructions. Previous operations included end-to-end anastomosis (n = 10), subclavian flap angioplasty (n = 7) and patch angioplasty (n = 3) for aortic coarctation, end-to-end anastomosis for interrupted aortic arch type B (n = 4) and aortic arch reconstruction for hypoplastic left heart syndrome (n = 3). Two of the patients with interrupted arch had multiple areas of obstruction. Balloon sizes were between 2 and 6 times the diameter of the lesion and up to twice the diameter of the proximal transverse arch (mean 1.1). BDA was at least partially successful (more than 50% decrease in gradient and more than 30% increase in diameter) in 26 of the 29 procedures (90%). BDA failed in the 2 lesions with an initial diameter of more than 8 mm. No differences were apparent in the success rate among any of the clinical groups. Peak systolic gradient decreased from 42 +/- 14 to 14 +/- 15 mm Hg (p less than 0.01) and mean diameter increased from 4.1 +/- 2.6 to 6.8 +/- 3.2 mm (p less than 0.01). There was no mortality or significant acute morbidity associated with the procedure. After 1 to 24 months of follow-up, restenosis has occurred in only 1 patient. Aneurysm formation was found in 2 of 5 patients who had undergone repeat catheterization; both aneurysms occurred in patients with repaired interruption of the aortic arch.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗

The treatment of post-operative and peptic esophageal strictures after esophageal atresia repair. A program including dilatation with balloon catheters.

Nine patients, 6 weeks to 17 years of age with esophageal atresia (EA), developed esophageal strictures and were treated with 26 balloon catheter dilatations over a period of 3 years; 6 are now asymptomatic. Five of the 9 patients had suspected reflux esophagitis, confirmed in 3 by biopsy and treated medically prior to dilatation. Seven of the 9 patients had a primary anastomosis, 1 a gastric tube, and 1 a colonic interposition. Most dilatations in the group of 7 were performed with balloon (B) greater than or equal to the diameter of the distal esophagus (E) (B/E greater than or equal to 1). The 3 residually symptomatic patients include an infant dilated conservatively (B/E less than 1) to facilitate later bouginage, 1 patient with a recurrent stricture after stopping medical therapy and home bouginage, and 1 infant who had a persistent anastomotic stricture, suspected but untreated reflux esophagitis, and a perforation during the second balloon dilatation. Balloon catheter esophageal dilatation, as an alternative to bouginage, is usually a safe and effective procedure when reflux esophagitis is diagnosed and treated prior to dilatation.

Adolescent↗

Stability of coil emboli: an in vitro study.

Gianturco stainless steel coils were discharged into clear plastic tubes of varying sizes and subjected to pulsatile flow in order to study their behavior in a controlled, in vitro environment. When coils are too small for a given vessel, they tend to migrate distally or even proximally. Coils that are too large tend not to reform completely, limiting their cross-sectional area and potentially affecting their occlusive potential. Thus, each coil was tested in tubes of varying sizes and evaluated with regard to positional stability and extent of reformation.

Embolization, Therapeutic↗

Balloon dilation of the aortic valve: studies in normal lambs and in children with aortic stenosis.

To evaluate the risks of and optimal method for valve dilation in aortic stenosis, balloons of different sizes were used to dilate the normal aortic root in 16 lambs and then stenotic valves in 15 children. In the lambs, inflated balloon to aortic anulus diameter ratios ranged from 0.9 to 1.5. These hearts were examined immediately after the procedure. Ratios of 0.9 to 1.1 did not produce significant damage to the left ventricular outflow tract, whereas those of 1.2 to 1.5 produced tears or hematomas, or both, of the aortic valve leaflets (n = 3), mitral valve leaflets (n = 4) and interventricular septum (n = 4). The 15 patients, aged 10 days to 15 years, underwent 16 balloon aortic valvotomy procedures. The balloon-aortic anulus ratio ranged from 0.67 to 1.1 (mean 0.90). The average pressure gradient decreased 69% and, overall, the peak systolic gradient decreased from 86 +/- 21 to 28 +/- 14 mm Hg (p less than 0.01) and the aortic valve area increased from 0.44 +/- 0.11 to 0.73 +/- 0.22 cm2/m2 (p less than 0.01). Immediately after the procedure an increase in aortic regurgitation was noted in 8 (57%) of 14 patients, but was never greater than 3+ and has been well tolerated. Other early complications encountered consisted of transient left bundle branch block in two patients, temporary femoral artery occlusion in three and femoral artery rupture requiring operative management in one infant. Balloon valvotomy can reduce the transvalvular gradient in most patients with valvular aortic stenosis when a balloon less than 1.1 times the aortic root diameter is used.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Transcatheter umbrella closure of congenital heart defects.

Between October 1984 and September 1986, we attempted transcatheter umbrella closure, using the Rashkind PDA occluder, of 12 congenital or postoperative cardiovascular defects (other than patent ductus arteriosus [PDA]) in 11 patients. In each, we used the umbrella for closure because the defect was too short and/or too large to close with conventional transcatheter methods. The defects included three post-Glenn venous communications (superior vena cava-right atrium, n = 2; azygos vein to inferior vena cava), four congenital "interatrial defects" producing cyanosis ("coronary sinus" septal defect, left superior vena cava to left atrium, patent foramen ovale, left inferior vena cava to left atrium), and five non-PDA systemic-to-pulmonary arterial communications (two congenital and three postoperative). Ten of 12 defects were embolized successfully; nine had complete or subtotal closure, and one was partially closed. The first attempted closure resulted in embolization of a 12 mm device to a lower-lobe pulmonary artery, without clinical sequelae. No other complications occurred. Clinical improvement was most dramatic in those patients whose cyanosis was relieved and less obvious when pulmonary blood flow was reduced. The Rashkind umbrella device, originally designed for closure of PDA, considerably expands the list of congenital or operative defects that can be closed nonsurgically.

Cardiac Catheterization↗

Fibrinolytic therapy for femoral arterial thrombosis after cardiac catheterization in infants and children.

The charts of 79 patients who required femoral arterial (FA) thrombectomy after cardiac catheterization were reviewed. Fifteen patients (19%) had poor pulses after thrombectomy and 2 had an extremity amputated. One thousand consecutive patients undergoing cardiac catheterization were also studied to prospectively determine the safety and efficacy of systemic fibrinolytic therapy for treatment of FA thrombosis. Among these, 771 patients underwent retrograde arterial catheterization, including 31 patients with left-sided obstructive lesions who had undergone transarterial balloon dilation procedures with large catheters. All patients were given heparin at the time of arterial cannulation. Patients who had a pulseless extremity 4 hours after catheterization continued to receive heparin therapy for 24 to 48 hours. If the extremity continued to have no palpable pulse and the systolic blood pressure was less than 50% of that in the contralateral leg, intravenous streptokinase infusion was begun. The overall incidence of FA thrombosis was 3.6% (28 of 771), including 39% (12 of 31) of all patients undergoing transarterial balloon dilation procedures; 97% (27 of 28) of patients weighed less than 14 kg and the majority weighed less than 10 kg. After an average treatment period of 33 hours, 16 patients continued to have a pulseless extremity and were treated with streptokinase for an average duration of 13 hours. Normal pulses and systolic blood pressure returned in 14 (88%) and were nearly normal in 1 other patient (6%). The incidence of bleeding at the arterial puncture site was 25% and was highest in the patients who had a transarterial balloon dilation procedure. No serious complications occurred.

Adolescent↗

Maintenance of vascular access patency in pediatrics.

The patency of vascular access shunts and fistulae has been prolonged by a combined surgical and radiological approach that includes percutaneous transluminal angioplasty (PTA), surgical revision, thrombectomy, and thrombolysis. Over the last 3 years, 35 vascular accesses in 27 patients were found to have angiographic abnormality. PTA was performed 32 times on 19 accesses and 7 PTAs resulted in patent accesses by the end of the study. Surgical revision was performed 9 times on 8 accesses and 2 of the surgical revisions resulted in a patent access by the end of the study. Concerning Thomas femoral shunts, PTA prolonged the patency by 2.2 months and surgical revision by 3.8 months per procedure. Concerning arteriovenous (AV) fistulae, PTA prolonged the patency by 4.3 months and surgical revision by 3.5 months per procedure. A combination of procedures effectively doubles the duration of patency of Thomas femoral shunts and almost triples the duration of patency of AV fistulae in children. Forty-one percent of these accesses remain open 1 year following the initiation of these procedures.

Adolescent↗

Percutaneous balloon valvotomy of congenital pulmonary stenosis using oversized balloons.

Percutaneous balloon valvotomy was attempted in 27 patients (aged 6 days to 19 years, median 2 years, 11 months) with unoperated typical valvular pulmonary stenosis using a balloon 7 to 60% (mean 30%) larger than the valve anulus. One patient had undergone a previous balloon valvotomy elsewhere. To achieve an oversized dilation diameter in three larger patients, two balloons were inflated side by side. Their "effective dilation diameter" was determined by the diameter of the circle with the same area as that of the oval enveloping the two balloons. A significant reduction of the transvalvular gradient occurred in all patients (mean +/- SD = 74.3 +/- 14.7%, range 33 to 100%). The average gradient of 65.0 +/- 19.0 mm Hg (mean +/- SD) fell to 15.9 +/- 7.6 mm Hg (0 to 30 mm Hg). Twenty-five of 27 patients had a residual transvalvular gradient of less than 25 mm Hg. The calculated valve orifice area increased by an average of 183 +/- 80%. No significant complications occurred. It is concluded that percutaneous balloon valvotomy with a balloon 20 to 40% larger than the valve anulus is the treatment of choice for typical congenital valvular pulmonary stenosis.

Adolescent↗

Therapeutic catheter procedures in pediatrics.

There is a large spectrum of interventional catheter procedures being performed presently in children. The procedures that offer a greater advantage than surgical techniques and that will continue to be established procedures include percutaneous angioplasty of the pulmonary valve, peripheral pulmonary artery and caval stenosis, embolizations of pulmonary collaterals and pulmonary arteriovenous malformations, angioplasty of vascular access shunt, embolization of bronchial arteries for hemoptysis, and percutaneous nephrostomy and abscess drainage procedures. Others that have been successful but not yet routinely established in children include thrombolysis, renal artery angioplasty, embolization of peripheral arteriovenous malformations, dilatation of the urinary and gastrointestinal tract stenosis, and percutaneous biopsy.

Angioplasty, Balloon↗

Measurement of extravascular lung water in infants and children after cardiac surgery.

Extravascular lung water (EVLW) was measured in 17 patients with congenital heart disease by the cold-green-dye, double indicator-dilution technique. In 5 control patients, EVLW was 4.7 +/- 0.5 ml/kg (111 +/- 13 ml/m2) (mean +/- standard deviation). Twelve patients were studied immediately after correction of their heart defects. In 6 patients with normal or decreased pulmonary blood flow preoperatively (Group I), EVLW was 6.2 +/- 1.9 ml/kg (122 +/- 46 ml/m2). This value is not significantly different from that of the control patients. In 6 patients with increased pulmonary blood flow and congestive heart failure preoperatively (Group II), EVLW was 15.7 +/- 3.8 ml/kg (270 +/- 60 ml/m2), which is significantly different from both control and Group I patients (p less than 0.01). There was no correlation of EVLW with pre- or postoperative left atrial pressure, length of cardiopulmonary bypass or deep hypothermic circulatory arrest, postoperative serum protein, albumin, hematocrit or cardiac index. Thus, EVLW in the immediate postoperative period is determined by preoperative pathophysiologic characteristics rather than by intraoperative management, and patients with congestive heart failure resulting from left-to-right shunts have increased EVLW despite normal left atrial pressures.

Blood Pressure↗

Therapeutic catheter procedures in congenital heart disease: current status and future prospects.

Advancing technology in catheterization techniques have allowed the development of several therapeutic procedures in patients with congenital heart disease. Some of these, such as atrial balloon septostomy, are well established. Others, such as pulmonary valve dilatation, patent ductus closure, and systemic-pulmonary collateral obliteration are currently being tried with success in many institutions. In the future, certain forms of coarctation, some intracardiac shunts and perhaps other anomalies may be suitable for therapy by catheter techniques.

Adolescent↗

Typhlitis: a cause of gastrointestinal hemorrhage in children.

Three children with typhilitis complicating acute leukemia and presenting with severe intestinal hemorrhage are described. The arteriographic findings were hypervascularity of the cecum with intense mucosal staining, opacification of superficial ulcers, and arteriovenous shunting into dilated mesenteric veins. The three children were managed successfully with medical, surgical, and embolic therapies, respectively.

Cecal Diseases↗