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Biomedical subjects

K Turley

Publications and source records attributed to K Turley.

At least 55 records · Page 3Linked to original sources
PubMed1985

The effects of coronary angioplasty and reperfusion on distribution of myocardial flow.

To assess the effects of angioplasty (PTCA) and intracoronary streptokinase (ICSK) on relative myocardial perfusion, we administered 99mTc-macroaggregated albumin (MAA) to the uninvolved coronary artery before successful PTCA in 33 patients and before successful infusion of ICSK in eight patients and of 111In-MAA into the same vessel after the intervention. In 10 patients who underwent PTCA, MAA was injected into the involved, instrumented coronary artery. Computer-processed images were acquired in registry and compared. Similar scintigraphic studies were performed in six control patients and in 11 in whom planned interventions were not performed or were unsuccessful. Distribution of MAA was also compared with angiographic results and with the distribution of 201Tl on images obtained in patients at rest or on redistribution images obtained before and soon after intervention in 22 patients. In control patients and those studied after aborted or unsuccessful intervention, scintigraphic results showed excellent correlation with the angiographic anatomy and were without serial change. When MAA was injected into the uninvolved vessel, the scintigram revealed evidence of collateral perfusion with retraction of the perfusion zone from that of the involved coronary in 19 of 33 patients undergoing PTCA and in three of eight of those receiving ICSK. When MAA was injected into the involved artery, a relative increase in perfusion was seen in eight of 10 patients after PTCA. Although 30 patients demonstrated scintigraphic evidence of collateral vessels, only 10 patients had angiographic evidence of collateral circulation before intervention. The distribution of 201Tl demonstrated little change in its global pattern and regions previously supplied by collaterals were generally well perfused after intervention. Coronary collateral perfusion may be inapparent angiographically and regress rapidly after angioplasty or reperfusion. Native perfusion is generally and quickly restored after successful PTCA or ICSK infusion, which obviates the need for collaterals. After intervention, the distribution of total perfusion may not change, but its regional source may demonstrate beneficial alterations, shifting from collateral to native circulation.

Angioplasty, Balloon↗
PubMed1984

Synthetic patch aortoplasty. A simplified approach for coarctation in repairs during early infancy and thereafter.

Synthetic patch aortoplasty is an expedient, safe technique for coarctation repairs during early infancy and thereafter for reoperation since it affords both an immediate hemodynamic result and potential for late growth while avoiding sacrifice of a major arch vessel. The surgical advantages include minimization of the total cross-clamp time (10 minutes in infants and 12 minutes in older patients) and elimination of the need to sacrifice collateral vessels and the need for extensive dissection for proximal and distal control. Hence, this technique has minimized the associated severe complications of coarctation repair, even in emergency cases. In our study, there were no operative deaths, spinal cord injuries or recoarctation, and intraoperative cardiac arrest occurred in only 3 percent of the patients.

Abnormalities, Multiple↗
PubMed1984

Graft patency in patients with coronary artery bypass operation complicated by perioperative myocardial infarction.

Coronary artery bypass graft patency was examined by contrast-enhanced computed tomography in 18 patients with perioperative myocardial infarction soon after surgery to determine the role of graft occlusion. Preoperative coronary angiograms were reviewed to assess native coronary disease and visible collateral channels in the distribution of the myocardial infarction. Perioperative myocardial infarction was diagnosed if creatine kinase-MB was elevated, characteristic electrocardiographic changes occurred and, in the majority of cases, the pyrophosphate scan was positive. Fourteen patients (78%) had patent grafts and perioperative myocardial infarction in the distribution of the grafted vessel. Four patients had an occluded graft with infarction in the distribution of the grafted vessel. Among the 14 patients with patent grafts, there was a significant difference (p less than 0.0005) in the degree of the mean (+/- standard deviation) diameter stenosis of 80 +/- 11% in native coronary vessels supplying the perioperatively infarcted myocardium versus a 55 +/- 12% mean diameter stenosis in the 23 bypassed native coronary vessels supplying noninfarcted myocardium. It is concluded that the majority of perioperative myocardial infarcts associated with coronary artery bypass operations are not caused by graft occlusion. The severity of coronary obstruction in the grafted vessel and the lack of collateral vessels to the region of perioperative infarction in patients with patent grafts suggests that an island of jeopardized myocardium exists that is subject to inadequate intraoperative preservation.

Adult↗
PubMed1984

Surgical treatment of truncus arteriosus in the first 6 months of life.

One hundred six infants were seen at the University of California Medical Center between 1974 and 1981 with the diagnosis of truncus arteriosus. One hundred of these underwent physiologic correction prior to 6 months of age. Six infants died prior to operation while undergoing intense medical therapy to improve their basic condition. There were 11 operative deaths with a mortality rate of 11%. Of the 86 long-term survivors, 55 have returned for conduit change because of either body growth or pseudointima proliferation of the conduit. There had been no mortalities at the time of conduit change, and 29 of these were repaired using a straight tube between the ventricle and pulmonary trunk, while 26 had valve conduits placed. Physiologic correction in the first 6 months of life has been accomplished with a low mortality rate and apparent good long-term results with none of the survivors having evidence of elevated pulmonary vascular resistance.

Blood Vessel Prosthesis↗
PubMed1984

The total repair of interrupted arch complex in infants: the anterior approach.

Results of repair of the interrupted arch complex have remained poor despite advances in operative technique. Palliative prosthetic grafts to form a transverse arch through the lateral approach have been advocated, but a need for both subsequent closure of the ventricular septal defect and replacement of the prosthetic conduit makes this approach undesirable. The total experience with this lesion at the University of California San Francisco (29 patients) is presented. Since January 1982, 10 patients, eight with type B and two with type A interrupted arch, underwent total repair. Ages ranged from 3 to 150 days (median 11 days). An anterior approach to total repair with single atrial-to-ascending aortic and transductal descending aortic bypass was used. Deep hypothermia to less than 18 degrees C was used, and during total circulatory arrest the cannula was removed from the descending aorta and direct anastomosis of the descending and ascending aorta was performed. Total circulatory arrest time was a mean of 12 min. During rewarming of the infant, the ventricular septal defect was closed. Mean pump time was 52 min. Operative mortality was 20% (two of 10 patients) at 17 and 32 days after surgery. Our results demonstrate that the anterior approach to total repair of interrupted arch complex in early infancy can be achieved with a lower mortality than palliation followed by subsequent closure of ventricular septal defect and also obviates the need for prosthetic replacement of the transverse arch. The anterior approach is the method of choice for repair of interrupted arch complex.

Aorta, Thoracic↗
PubMed1984

The effects of cardiopulmonary bypass on coronary blood flow in the dog.

The effects of cardiopulmonary bypass on autoregulation, maximum coronary flow, and regional blood flow in the heart were investigated in 25 dogs. A Gregg cannula was inserted into the left main coronary artery, and pressure-flow relations were then measured in the autoregulating state or with vasodilation produced by intracoronary adenosine infusion before, during, and after cardiopulmonary bypass. Seventeen of the dogs had radioactive microspheres injected to investigate regional blood flow changes at the same times. (1) Autoregulation was not present after bypass for at least 3 hours. (2) Blood flow was shifted toward the subendocardium on bypass (increased subendocardial/subepicardial ratio) and tended to return to prebypass distribution following bypass. (3) Blood flow after bypass was not significantly different to the subendocardium and subepicardium. (4) Response to a coronary vasodilator (maximum coronary flow) was significantly affected by cardiopulmonary bypass: blood flow to all layers of the heart could be increased with adenosine after bypass. (5) Global lactate and oxygen metabolism were not adversely affected by bypass. We conclude that cardiopulmonary bypass abolished the normal autoregulation of coronary flow; this may predispose the incompletely revascularized patient to a "coronary steal" syndrome. However, the heart with normal coronary arteries is not underperfused in any layer after bypass. Thus, the bypass technique is not the cause of the subendocardial ischemia that sometimes complicates cardiac operations.

Adenosine↗
PubMed1984

Successful aortic valvotomy for severe congenital valvular aortic stenosis in the newborn infant.

The preoperative evaluation, surgical course, and early follow-up results of 11 newborn infants less than 30 days of age who underwent aortic valvotomy for severe valvular aortic stenosis between 1976 and 1983 were reviewed to determine our current surgical mortality and the early prognosis of these neonates. Ten of the 11 patients had severe congestive heart failure and dyspnea. Preoperative cardiac catheterization and angiography detected features characteristic of congenital aortic valvular stenosis in newborn infants. Emergency aortic valvotomy was performed in all during cardiopulmonary bypass, for which a cold (4 degrees C) blood prime and moderate systemic hypothermia were used. An effort was made to achieve maximal relief of the stenosis without causing aortic insufficiency. Mean cardiopulmonary bypass time was 21 minutes and mean cross-clamp time was 6.4 minutes. There was a single operative death, and there have been no late deaths during a mean follow-up period of 2.2 years. All patients are currently free of heart failure. Four patients underwent postoperative cardiac catheterization for clinical suspicion of severe residual stenosis. However, three had only mild or moderate residual stenosis. The fourth had a large gradient, 70 mm Hg, and has since undergone successful repeat valvotomy. These results indicate that neonates with severe valvular aortic stenosis can undergo valvotomy safely and have a favorable early prognosis. The factors responsible for the low mortality appear to include prompt recognition and diagnosis followed by emergency operation, use of a 4 degree C cold pump prime, brief cross-clamp times, and conservative valvotomy to avoid the development of significant aortic insufficiency.

Aortic Valve↗
PubMed1983

Severe aortic insufficiency in juvenile chronic arthritis.

Valvular heart disease is rare in patients with juvenile chronic arthritis. We describe a 27-year-old woman with the systemic-onset form of juvenile chronic arthritis in whom aortic insufficiency necessitated valve replacement. Nodules were seen on both the aortic and anterior mitral leaflets at surgery, and histopathologic evaluation of the excised aortic leaflets demonstrated nonspecific changes similar to those described in rheumatoid valve disease causing aortic insufficiency in adults with rheumatoid arthritis. We believe that this is the first reported case of aortic insufficiency in systemic-onset juvenile chronic arthritis in which the pathologic condition of the valve can be attributed to the underlying disease.

Adult↗
PubMed1983

Pulmonary valve replacement for regurgitation after repair of tetralogy of Fallot.

In general, it has been thought that pulmonary valve insufficiency is well tolerated when the valve is excised or when the pulmonary annulus has been widened with an outflow patch during repair of tetralogy of Fallot. However, when pulmonary regurgitation is massive or when it is combined with other causes of right ventricular failure, progressive right ventricular dilation may occur in some patients. Pulmonary valve replacement has not been commonly used in the past. From January, 1980, to August, 1982, 12 patients, 11 months to 17 years old, had pulmonary regurgitation treated by insertion of a valve in the pulmonary position 4 1/2 months to 11 years after initial repair of tetralogy of Fallot. All patients had progressive right ventricular failure not responsive to medical management. There were no major outflow tract obstructions, residual ventricular septal defects, or persistent aortopulmonary shunts. All 12 patients underwent patch reconstruction of the right ventricular outflow tract that allowed placement of a larger valve. There have been no operative or late deaths, and each patient has had improvement in functional status. One patient required tricuspid valve replacement 1 1/2 years after pulmonary valve replacement to achieve sustained relief of symptoms. Only 1 other patient required subsequent operation; this was for pacemaker lead changes. These early results suggest that in patients with right ventricular failure, attention should be directed to pulmonary regurgitation since this is a component of failure that is reversible; pulmonary valve replacement carries a low risk, and it can relieve symptoms and prevent further deterioration of right ventricular function.

Adolescent↗
PubMed1983

Surgery for cyanotic heart disease in the first year of life.

Data are reviewed on 248 patients less than 1 year old who presented with a diagnosis of cyanotic heart disease between January 1976 and January 1982. No infant had had prior surgical treatment. The patients were classified according to diagnosis: tetralogy of Fallot, transposition of the great arteries, pulmonary atresia and anomalies of the tricuspid atresia or single ventricle type. Other remote forms of cyanotic heart disease were excluded from the analysis. Management of these patient groups is discussed in relation to their potential for corrective surgery early in infancy or later. The proper selection of palliative procedures that will permit bilateral growth and development of pulmonary arteries and equal distribution of pulmonary blood flow is emphasized. Morbidity and mortality in each patient group are discussed.

Heart Defects, Congenital↗
PubMed1983

Evaluation of early postoperative coronary artery bypass graft patency by contrast-enhanced computed tomography.

Fifty patients with 117 coronary bypass grafts were studied by contrast-enhanced computed tomography at an average of 5 +/- 4 days after surgery to determine if this technique was a feasible method for detecting early postoperative graft occlusion. The study was limited in only three patients because of incisional chest pain (one patient) or multiple metal clips attached to the graft (two patients). The distal patency of sequential grafts cannot be determined by current techniques. There was a lower graft patency rate (70%) in the 10 patients with perioperative myocardial infarction than in the 40 (95%) without (p less than 0.025), but most regions of infarcted myocardium were perfused by patent grafts. There were eight graft occlusions in eight patients. The graft occlusion rate (30%) was significantly higher (p less than 0.025) in grafts with intraoperative flows less than 45 ml/min. The postoperative complications of myocardial dysfunction, arrhythmia and coronary artery spasm did not correlate with graft occlusion. Early graft occlusion is uncommon (7%) and usually occurs in grafts with low flows or severe distal disease (seven of eight grafts), or both. Thus, the need for early reoperation is very infrequent. It is concluded that contrast-enhanced computed tomography is feasible for the assessment of coronary bypass graft patency. Because early graft occlusion is unusual the technique may be an ideal noninvasive screening method.

Aged↗
PubMed1982

Intrauterine cardiothoracic surgery: the fetal lamb model.

We have developed fetal lamb models of congenital cardiothoracic lesions that have been allowed to progress through birth for physiological study. Simulated lesions, simulated repairs, actual lesions, and actual repairs have been performed in this model. Sixty-two fetal lambs comprised the study group, including 48 in which models were created and 14 controls. Models included pulmonary stenosis, aortic stenosis, and diaphragmatic hernia. Gestational age ranged from 90 to 120 days (0.6 of normal gestation). In each pregnant ewe, laparotomy and hysterotomy were performed under general anesthesia, with care taken to avoid placental vessels. The foreleg was exposed, the appropriate anterior chest wall was isolated, and a thoracotomy was done. Thoracic or cardiac procedures then were performed under controlled transplacental anesthesia and perfusion. Following completion of the procedure, the fetal thoracotomy was closed, sterile antibiotic solution was placed in the amniotic sac, and the hysterotomy and laparotomy were closed. Subsequently the fetus either was allowed to progress to birth and infant study or underwent subsequent intrauterine repair and then was allowed to progress to birth and neonatal study. This fetal lamb model provides reproducible anatomical and pathophysiological lesions to facilitate the development of techniques for repair of such lesions in early infancy. Further, it offers the potential for developing methods of intrauterine cardiothoracic surgical repair.

Animals↗
PubMed1982

Long-term results after atrial repair of transposition of the great arteries in early infancy.

Fifty-two patients younger than age 100 days who had an intact interventricular septum or a small ventricular septal defect underwent atrial repair of d-transposition of the great arteries (d-TGA). No patient died. To assess long-term results, we evaluated all 36 patients who had been followed for at least 1.5 years (mean 2.7 years) after surgery. The physical findings, chest roentgenograms, ECGs and echocardiograms were reviewed. Catheterization was done 6-60 months (mean 15 months) after surgery in 28 patients. Growth was normal in all but three patients. Neurologic development was abnormal in six patients (delayed speech in one patient, learning disability in three patients and preoperative cerebral infarction in two patients). The ECG showed sinus rhythm in 24 patients, minor abnormalities in nine and major dysrhythmias in three. Catheterization showed a normal cardiac index in all 28 patients. No intracardiac shunt was detected in 19 of 24 patients in whom complete oximetry data were available. One patient required reoperation for persistent atrial shunt and subsequent pacemaker placement. Two patients required baffle revision for symptoms related to superior vena caval obstruction. Right ventricular end-diastolic pressure was less than 15 mm Hg in all of 18 patients evaluated. We conclude that atrial repair of d-TGA in early infancy can be performed with a low mortality rate and a low incidence of late complications.

Arteries↗
PubMed1982

Evaluation of infradiaphragmatic total anomalous pulmonary venous connection with two-dimensional echocardiography.

In three newborn infants with infradiaphragmatic total anomalous pulmonary venous connection, the common pulmonary vein was visualized with two-dimensional echocardiography and validated with saline contrast injections. The transducer was placed in the subcostal region in a sagittal body plane so as to image the descending aorta and the vertebral column. The common pulmonary vein, which connected the pulmonary veins to a systemic vein in the abdomen, was seen lying parallel and anterior to the descending aorta and to the left of the inferior vena cava. With peripheral venous contrast injections, contrast echoes first filled the inferior vena cava and then the descending aorta because of obligatory right-to-left atrial shunting. The common pulmonary vein was the only structure that remained free of contrast echoes. Thus, contrast echocardiography provided a method for identifying the site of pulmonary venous drainage and for distinguishing the common pulmonary vein from other structures such as the inferior vena cava. In cyanotic infants with respiratory distress, two-dimensional contrast echocardiography permits a rapid diagnosis of infradiaphragmatic total anomalous pulmonary venous connection.

Diaphragm↗
PubMed1982

Left ventricular outflow enlargement by the Konno procedure.

The optimal management of patients with small aortic anulus or left ventricular outflow tract obstruction remains unclear. Between 1976 and March, 1982; 18 patients have undergone enlargement of their left ventricular outflow tract by means of the Konno or a modification of the Konno procedure. Fourteen of these 18 patients had previous operations for aortic stenosis or tunnel left ventricular outflow tract, and two patients had undergone three previous operations. All 18 patients had symptoms of either heart failure of chest pain, or had electrocardiographic evidence of strain. They ranged in age from 4 years to 58 years, with 13 of the 18 patients being less than 20 years of age. A Dacron patch was used to enlarge the left ventricular outflow tract after incising down the ventricular septum. In all patients, at least a 21 mm valve could be placed, with between 50% and 65% of the valve anulus being made up of natural tissue. The remaining portion of the valve anulus was constructed from the Dacron patch. The patch was extended up to enlarge the ascending aorta, and a pericardial patch was used to close the defect in the right ventricular outflow tract. In all 18 patients the gradient was obliterated at the time of operation. There was one early death in a patient who had previous insertion of a left ventricular apical-aortic conduit in which the heterograft valve had degenerated. There has been one late death because of bacterial endocarditis in a child who also had a parachute mitral valve and evidence of pulmonary hypertension. The remaining 16 patients are functioning well after the Konno procedure. Three are receiving warfarin sodium, and 13 are receiving aspirin. These results suggest that this is an acceptable method of treating patients with small aortic anulus or left ventricular outflow tract obstructions and would appear to have advantages over a left ventricular apical-aortic conduit.

Adolescent↗
PubMed1982

Assessment of saphenous vein graft patency by contrast-enhanced computed tomography.

Early saphenous vein coronary bypass graft patency has been found to range from 82% to 94%. Recent advances in computed tomography have led to the development of a safe, effective, and "relatively noninvasive" means of assessing early graft patency. We designed a prospective study using contrast-enhanced computed tomography (CECT), postulating that selected grafts might be redone prior to the development of pericardial adhesions if early closure was demonstrated. Forty-three random patients undergoing elective coronary artery bypass comprise the study group. All patients underwent CECT study of graft patency an average of 6 days postoperatively (range 1 to 17 days). Ninety of 96 grafts were open, for an early patency rate of 94%. Three of the grafts were closed because of poor run-off or extensive distal coronary atherosclerosis. Two additional grafts were closed, one in a patient with severe atherosclerosis of the ascending aorta and one in a patient having triple vessel bypass using cephalic vein because of limited conduit material. Only one graft was closed without apparent cause and judged potentially suitable for reoperation. CECT was found to be a safe and potentially useful means of assessing early graft patency, particularly in patients sustaining untoward clinical events.

Aged↗