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Biomedical subjects

K Turley

Publications and source records attributed to K Turley.

At least 19 recordsLinked to original sources
PubMed1992

Intraoperative echocardiography for evaluation of congenital heart defects in infants and children.

To determine the accuracy, utility, and limitations of intraoperative transesophageal echocardiography (TEE) in infants and children, we performed prebypass and postbypass TEE in 90 children undergoing surgical repair of congenital heart lesions, comparing the results to those obtained using intraoperative epicardial echocardiography and pre- and postoperative precordial echocardiography. Patients ranged in age from 4 days to 21 yr (mean 4.1 yr) and in weight from 3 to 68 kg (mean 15.4 kg). Prebypass, we obtained high-quality, two-dimensional TEE images in 86 patients, with correction of the preoperative precordial diagnosis in 3 and confirmation of the preoperative diagnosis in the rest. Adequate epicardial images were obtained in 78 patients, with confirmation of the preoperative diagnosis in all. Shunt lesions that were well delineated prebypass by both TEE and epicardial imaging included interatrial, interventricular, and atrioventricular septal defect lesions. TEE failed to detect the exact size and location of lesions involving the right ventricular outflow tract, i.e., doubly committed subarterial (supracristal) ventricular septal defects. Regurgitant lesions (n = 30) were identified and their severity evaluated in all patients by both TEE and epicardial imaging. Obstructive lesions (n = 33), excluding those involving the right ventricular outflow tract, were well defined by both echocardiographic approaches. Postbypass, we obtained high-quality, two-dimensional, color and Doppler TEE images in 86 patients and epicardial images in 78 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Current method of repair of truncus arteriosus.

Surgical treatment of truncus arteriosus has been demonstrated to be optimized when approached in early infancy. In the past, the materials available, namely the 12-mm porcine valve Dacron conduit, restricted the size of the patient in whom early repair could be performed with increasing risk associated with decreasing age and size. The availability of homografts for reconstruction of right ventricular pulmonary artery continuity has allowed repair even in the neonatal period. Two hundred forty-four patients with truncus arteriosus have been operated on at the University of California San Francisco since 1975. In the past 5 years, 49 have been repaired using homograft reconstruction. The method of repair differs markedly from that of Dacron conduits, and specific points concerning homograft insertion including orientation, method of proximal anastomosis, and sizing are discussed in detail and the difference in insertion from the Dacron bovine heterograft conduit are discussed.

Age Factors↗
PubMed1991

Growth of the hypoplastic ascending aorta after radical palliation.

Surgical treatment of hypoplasia of the ascending aorta is a difficult problem. An approach using proximal pulmonary artery to distal aorta bypass with distal pulmonary artery banding was employed in 19 patients with an ascending aorta less than 6 mm in diameter but a patent aortic outflow. There were 11 male and 8 female neonates and infants, and weight ranged from 2 to 4.5 kg (median weight, 3.5 kg). Four patients had transposition of the great arteries, 12 had subaortic stenosis, and 5 had interrupted aortic arch. There was one operative death. Cerebral cyanosis developed in 3 of the 4 patients with transposition of the great arteries and necessitated additional operations within the first year postoperatively. Therefore, palliation with a pulmonary artery to descending aorta conduit and banding was abandoned in such patients. All 14 surviving patients with normally related great arteries had successful palliation and growth of left heart structures. Subsequent procedures included a Fontan/Damus procedure in 1 patient, patch aortoplasty and pulmonary arterioplasty in 5 patients, arch reconstruction with aortic valvulotomy and pulmonary arterioplasty in 2, double arch reconstruction in 2, and simple patch aortoplasty with plans for subsequent pulmonary arterioplasty and ventricular septal defect closure in 1. Results demonstrate that in patients with a hypoplastic ascending aorta, this radical method of palliation can result in growth of right and left heart structures and thus provides the possibility of biventricular repair.

Anastomosis, Surgical↗
PubMed1991

Intraoperative transesophageal echocardiography of atrioventricular septal defect.

To determine the accuracy and utility of single-plane transesophageal echocardiography in analyzing atrioventricular (AV) septal defect, intraoperative transesophageal echocardiography was performed before and after institution of cardiopulmonary bypass in 16 patients (age 24 days to 14 years, weight 3 to 47 kg). Prebypass transesophageal echocardiography (including two-dimensional echocardiography, Doppler color flow mapping and pulsed wave Doppler ultrasound) correctly diagnosed divided AV valve, common AV valve and unbalanced AV valve, as well as atrial or ventricular septal defect, or both, in all cases. It correctly analyzed AV valve regurgitation in all 10 patients with right and all 14 with left AV valve regurgitation and correctly analyzed 30 of 33 additional cardiac anomalies. Transesophageal echocardiography was able to detect the absence of normal pulmonary venous connections but failed to demonstrate all of the complex anomalous pulmonary venous connections in three patients with atrial isomerism. Postbypass transesophageal echocardiography documented the absence of a significant residual shunt in 11 of 11 patients undergoing corrective surgery and verified residual AV valve regurgitation in 7 of 9 patients with tricuspid regurgitation and 11 of 13 with mitral regurgitation. Transesophageal echocardiographic information that altered or refined the surgical treatment was obtained in 5 (31%) of 16 patients. Epicardial and transesophageal echocardiography results were concordant in all 13 patients in whom both were performed. Transesophageal echocardiography provides useful and accurate imaging of the important two-dimensional, pulsed wave Doppler ultrasound and Doppler color flow mapping features in AV septal defect.

Adolescent↗
PubMed1990

Iodine toxicity secondary to continuous povidone-iodine mediastinal irrigation in dogs.

Mediastinitis is a devastating complication following median sternotomy. Continuous povidone-iodine (PVP-I) irrigation has been advocated as therapy because of its broad antimicrobial spectrum and its apparent safety. However, several recent clinical reports have warned of suspected local and systemic iodine toxicity. The purpose of this study is to determine if significant amounts of iodine can be absorbed systemically via the mediastinum, and if so, what toxicity (local and/or systemic) may result. PVP-I (0.5%) was continuously irrigated into the pericardial sacs of three dogs via catheters for 48 hr. Serial serum and urine iodine levels were determined. The serum steady-state concentration (Css), the rate elimination constant (k), the urinary clearance (Cl), and the serum half-life (t 1/2) for iodine were assessed. Serum electrolytes, Bun, Cr, and arterial pH were measured to assess systemic iodine toxicity. Tissue samples of the heart, pericardium, liver, and kidney were examined histologically for evidence of local or end-organ iodine toxicity. This study demonstrated that the absorption of iodine during continuous mediastinal irrigation with PVP-I follows zero-order pharmacokinetics, just as if it were being given by continuous intravenous infusion. The baseline serum iodine concentration was 145.9 +/- 64.3 micrograms/dl, Css was 29,290 +/- 101.4 micrograms/dl, k was 0.0996 +/- 0.009/hr, Cl was 872.4 +/- 119.3 ml/hr, and t1/2 was 6.22 hr. Urinary excretion of iodine increased in proportion to the serum iodine. Measured serum chloride increased in a linear manner (r = 0.949), while serum Na, K, Bun, Cr, and pH were unchanged.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorption↗
PubMed1990

Intraoperative echocardiography in infants and children with congenital cardiac shunt lesions: transesophageal versus epicardial echocardiography.

To determine the utility and limitations of intraoperative transesophageal echocardiography in infants and children with congenital intracardiac shunts, intraoperative transesophageal (n = 50) and epicardial (n = 49) echocardiograms were performed before and after cardiopulmonary bypass in children from 4 days to 16 years old and 3 to 45 kg in body weight. A miniaturized transesophageal probe (6.9 mm maximal diameter) was used in 36 patients weighting less than or equal to 20 kg. Epicardial imaging was performed with a 5 MHz precordial probe. The intraoperative transesophageal echocardiographic findings before and after cardiopulmonary bypass were correct and complete in 94% of patients. Transesophageal echocardiography correctly identified atrial septal defects, most types of ventricular septal defects, anomalous pulmonary veins, atrioventricular septal defects, tetralogy of Fallot, truncus arteriosus and double inlet ventricles. It failed to provide a correct diagnosis in only three patients, all of whom had doubly committed subarterial ventricular septal defects. Epicardial echocardiography identified all cases that had a doubly committed subarterial ventricular septal defect. A correct and complete intraoperative diagnosis was obtained with the use of epicardial imaging in 92% before and after cardiopulmonary bypass, but this technique required interruption of surgery and could not be completed in three patients because of induced arrhythmias and hypotension. These results demonstrated that intraoperative transesophageal echocardiography consistently defined important morphologic, color and pulsed Doppler ultrasound features of most congenital shunt lesions. Lesions that involved the right ventricular outflow tract are sometimes difficult to image with uniplane transesophageal echocardiography. There were no complications in any of the 50 subjects.

Cardiopulmonary Bypass↗
PubMed1990

Neonatal aortic stenosis.

Aortic stenosis in the neonate has been associated in the past with a high operative mortality. As a result, in the current era of percutaneous balloon dilatation, the optimal mode of therapy remains controversial. An approach of stabilization with cardiopulmonary bypass, followed by relief of left ventricular outflow tract obstruction, was used at three institutions, and the results are presented. During the period 1983 to 1989, 40 neonates with isolated aortic stenosis and patent ductus arteriosus or coarctation of the aorta, or both, underwent operative therapy. Ages ranged from 1 to 30 days, median of 12 days, including 17 patients in the first week of life. There were 30 boys and 10 girls; weights ranged from 2.5 to 5.5 kg with a mean of 3.6 kg. Perioperative conditions included congestive heart failure in 38 and mitral regurgitation in 16; left ventricular-aortic gradients ranged from 15 to 130 mm Hg, with a mean of 67 mm Hg. There were 30 open valvotomies and 10 transventricular dilatations. The hospital survival rate was 87.5% (35/40) with no significant difference between the methods of valvotomy (9/10 in the transventricular dilatation group, 90%; 26/30 in the open valvotomy group, 87%). Although multiple methods of perfusion and valvotomy were used, the single unifying factor of cardiopulmonary bypass stabilization was present in all 40 patients. No significant difference in survival was noted between institutions, methods of cardiopulmonary bypass, cardiopulmonary bypass times, crossclamp times, or method of valvotomy. There have been five reoperations, with one late death in a patient requiring mitral valve replacement and an apical-aortic conduit. One sudden death occurred; autopsy revealed endocardial fibroelastosis. Results demonstrate that in the three institutions using the methods described, a high operative and late survival rate is possible. The results of this technique, against which percutaneous dilatation should be compared, are standard in the current era.

Aortic Valve↗
PubMed1989

Effect of surgical blood loss and volume replacement on antibiotic pharmacokinetics.

Antibiotic prophylaxis is used widely to prevent postoperative infection associated with cardiac operations. The influence of perioperative blood loss on antibiotic pharmacokinetics has not been well studied. Plasma cefazolin sodium samples from 8 patients undergoing a cardiac operation were collected postoperatively and analyzed. The results suggest that blood loss has a minimal effect on the elimination of cefazolin and that therapeutic concentrations are maintained without altering the dosage regimen.

Aged↗
PubMed1989

Aortic allografts: reconstruction of right ventricle-pulmonary artery continuity.

The use of aortic allografts in the repair of congenital cardiac lesions has increased as a result of both the advent of cryopreservation and the effects of increased donor availability secondary to infant transplantation. During the period 1986 through 1987, 38 cryopreserved aortic allografts were placed for right ventricle-pulmonary artery discontinuity. Size of the allografts ranged from 11 to 26 mm (mean size, 19 mm), and age of the patients ranged from 6 weeks to 26 years (mean age, 5 years). Twenty-one patients had primary placement of aortic allografts, and 17 underwent replacement of previous conduits. There were 5 hospital deaths (13%) overall, only 1 among the 10 patients younger than 6 months of age with truncus arteriosus, and none among the 17 patients having conduit replacement. A large conduit could be placed with a low incidence (10.5%) of postoperative hemorrhage related to the conduit. The aortic allograft is our conduit of choice for both conduit replacement and primary repair of right ventricle-pulmonary artery discontinuity.

Adolescent↗
PubMed1989

Systemic-to-pulmonary artery shunt using the internal mammary artery.

Systemic-to-pulmonary artery shunts may be useful for palliation of cyanotic congenital heart disease. We report the case of a 5-year-old boy in whom the internal mammary artery was used to create a systemic-to-pulmonary artery shunt after failure of a previous Blalock-Taussig shunt. This technique may have distinct advantages in selected cases and should be considered as an alternative during investigation of the older child who requires a systemic-to-pulmonary artery shunt.

Anastomosis, Surgical↗
PubMed1989

Lord Brock--the direct approach.

The contributions of Sir Russell Brock to the early development of cardiac surgery are multiple. However, one of the most telling was his description of 3 cases of pulmonary stenosis in 1948 treated by direct transventricular valvulotomy. His subsequent treatise, The Anatomy of Congenital Pulmonary Stenosis, published in 1957, outlined this direct approach to cardiac lesions, a philosophy commonly adopted in modern care of cardiac lesions and a major contribution to cardiac surgical thinking.

Cardiac Surgical Procedures↗
PubMed1989

Diagnosis of coronary artery fistula by two-dimensional echocardiography, pulsed Doppler ultrasound and color flow imaging.

Ten consecutive patients with a coronary artery fistula, aged 1 day to 4 years, were studied by two-dimensional echocardiography, pulsed Doppler ultrasound and color flow imaging. All patients underwent cardiac catheterization, and seven patients had surgical closure of the fistula. The origin, course and site of drainage of the coronary artery fistula were correctly identified prospectively by echocardiographic examination in all patients. Color flow imaging was particularly helpful in visualizing the site of drainage of the fistula. Diameters of the right and left coronary arteries at their origin and of the aortic root were measured from two-dimensional echocardiographic frames and compared with measurements obtained in normal children. The ratio of coronary artery diameter to aortic root diameter in normal children was 0.14 +/- 0.03 (mean +/- SD) for the right coronary artery and 0.17 +/- 0.03 for the left coronary artery. These normal ratios were greatly exceeded for coronary arteries feeding the fistula, and ranged from 0.68 to 0.84 for the right coronary artery and from 0.34 to 0.52 for the left coronary artery. All anatomic information needed for surgical treatment of coronary artery fistula was consistently obtained by echocardiography with color flow imaging. The fistula was closed from within the heart in five patients and by ligation from the epicardial surface in two patients. In these latter patients, intraoperative color flow imaging at the time of ligation proved to be extremely valuable in achieving complete closure.

Cardiac Catheterization↗
PubMed1989

Surgery of right-sided endocarditis: valve preservation versus replacement.

Surgical treatment of right-sided endocarditis has in the past been centered on valve resection or resection with valve replacement. From 1981 to 1989, we attempted tricuspid valve repair in 19 patients with right-sided endocarditis. Fourteen of these were successful. The methods of valve repair and classification of the lesions that allow evaluation for repair are discussed, including the use of transesophageal echo and a hand-held color Doppler unit for intraoperative assessment.

Echocardiography↗
PubMed1988

The fate of the 12 mm porcine valved conduit from the right ventricle to the pulmonary artery. A ten-year experience.

The 12 mm Dacron conduit containing a porcine valve is the smallest valved conduit manufactured and is used in the youngest infants with the most diminutive pulmonary arterial system. The outcome of patients with such a conduit is unknown. Between 1975 and 1985 there were 49 hospital survivors after placement of a 12 mm extracardiac valved conduit from the right ventricle to the pulmonary artery. Follow-up is available in 42 patients, aged 1 to 16 months (mean 3.5) and weighing 2.5 to 8.7 kg (mean 3.8). Twenty-eight patients (67%) have undergone subsequent conduit replacement, and 11 (26%) are alive and asymptomatic with a mean follow-up of 56 months. There were three late deaths. The interval between implantation and conduit change was 4.5 to 101 months (mean 44), allowing a weight gain of 2.7 to 23 kg (mean 10.4) before reoperation at age 12 to 117 months (mean 49). Despite elevated right ventricular pressures equaling systemic values, 37% of these patients were clinically asymptomatic. The gradient across the 12 mm valved conduit before explantation ranged from 30 to 173 torr (mean 83) with an almost equal predilection for stenosis at the proximal anastomosis, valve, conduit, distal anastomosis, and main pulmonary artery. The intervening pulmonary artery growth determined the size of the replacement conduit, 14 to 25 mm (mean 16), and was the main factor influencing the results of reoperation. This study demonstrates that the 12 mm porcine valve-containing conduit affords palliation in this difficult subset of patients with the smallest pulmonary arterial tree.

Bioprosthesis↗
PubMed1985

Changes in the respiratory gas tensions of a pneumonectomy space and their application to the diagnosis of bronchopleural fistula.

The oxygen (pO2) and carbon dioxide (pCO2) gas tensions of a pneumonectomy space were studied in an animal model. The 2 gases were measured in a standard blood gas analyser. The space gas pO2 and pCO2 equilibrated to a steady state within 48 hours of thoracotomy (pO2 mean 53.9 +/- 9.3 SD torr; pCO2 mean 44.8 +/- 9.9 SD torr). In the presence of a bronchopleural fistula (BPF), the pO2 rose significantly (mean pO2 118.4 +/- 13.2 SD torr; p less than 0.001). The space pCO2 usually fell, but the response was inconsistent (mean pCO2 33.6 +/- 16.4 SD; p = NS). A further rise in space pO2 could sometimes be induced by allowing the animals to breathe 100% oxygen by face mask. Data from 4 clinical cases of BPF support the concept that measurement f the space gas pO2 could be used as a bedside test for BPF.

Animals↗