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Biomedical subjects

T B Kinney

Publications and source records attributed to T B Kinney.

At least 37 records · Page 2Linked to original sources
PubMed1991

Idiopathic hemochromatosis.

Hemochromatosis is a rare disorder in which about four times the normal amount of iron is absorbed in the intestine, resulting in the accumulation of iron in the skin, liver, pancreas and heart. Radiographic features may include a small liver on plain abdominal films, increased hepatic density on computed tomographic imaging, and loss of liver signal on magnetic resonance imaging as a result of the strong paramagnetic effect of iron. Management includes phlebotomy and supportive treatment of damaged organs.

Bloodletting↗
PubMed1991

Parathyroid hyperplasia as a cause of recurrent hyperparathyroidism.

Parathyroid hyperplasia is second only to adenoma as the most common cause of hyperparathyroidism. Symptoms are most likely to result from elevated serum calcium levels. Symptoms include nephrocalcinosis and nephrolithiasis. Studies that may help confirm a suspected diagnosis include ultrasonography, computed tomography, radionuclide scanning with thallium and/or technetium, and magnetic resonance imaging. Surgical treatment consists of excision of all but part of one parathyroid gland if all of the glands are enlarged.

Humans↗
PubMed1991

Kartagener's syndrome.

Kartagener's syndrome is characterized by situs inversus, chronic paranasal sinusitis and bronchiectasis. The pathogenesis of this rare condition is an ultrastructural defect that results in immotile cilia. Radiologic features may include findings consistent with bronchiectasis.

Abnormalities, Multiple↗
PubMed1990

Agricultural production systems and environmental health.

By the turn of the century, American farmers and ranchers will be producing food and fiber through the application of highly sophisticated systems that involve a broad spectrum of relevant factors--from soil type, to options for fertilizer and pesticide use, to markets and other economic information. These systems will help farmers and ranchers better match land use to land capability, apply needed conservation practices, make environmentally sound production choices, and lower production costs. Most importantly, they will aid in selecting the best combinations of chemical and the biological means for producing and protecting plants and animals. The systems will also help complement currently available and new classes of chemicals with biological control mechanisms such as natural predators and naturally occurring protective phenomena such as allelopathy and other forms of resistance to insects, weeds, and disease. Additionally, they will incorporate the use of biodegradable, slow-release, or timed-release natural and synthetic pest control materials. Also, scientists will increasingly emphasize nutrition and food safety in the development of plant and animal germplasm and production and processing methods.

Agriculture↗
PubMed1987

Clinical comparisons of methods of myocardial protection.

Currently, numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operations. During cardiac ischemia we have compared myocardial surface cooling with topical cold saline (Group I, N = 9), crystalloid cardioplegia plus topical cold saline (Group II, N = 8) and cardioplegia with a specially designed cooling jacket (Group III, N = 8) in patients undergoing aortic or mitral valve replacement, or both. Temperatures were assessed and recorded continuously in standardized locations for the right and left ventricular epicardium and endocardium. In Group I the rate of cooling was significantly slower than in the other two groups. Also, excessive gradients were developed across the left and right ventricular walls. In Group II the rate and depth of cooling were adequate and initial temperature gradients were eliminated. However, over the period of ischemia, significant rewarming occurred. In Group III temperatures were reduced rapidly and uniformly and maintained at or below 10 degrees C for the duration of the ischemic period. These differences are statistically significant (p less than 0.05). For optimal myocardial hypothermia, we recommend the following: separate cannulation of the superior and inferior venae cavae with caval snares; venting of the pulmonary artery (if inadequate, pulmonary vein occlusion or direct left atrial venting); induction of myocardial hypothermia with crystalloid or cold blood cardioplegia; and maintenance of hypothermia by the cooling jacket described herein. It is also desirable to continuously monitor temperatures of the right and left ventricular endocardial and epicardial surfaces.

Heart Arrest, Induced↗
PubMed1985

Shear force in angioplasty: its relation to catheter design and function.

The inability to successfully position angioplasty catheters and the occurrence of complications during angioplasty procedures can, in part, be related to the shear forces generated during catheter introduction. Shear forces are the axial contact forces that the catheter system exerts on the inner arterial surfaces during advancement. The shear forces exerted by three different catheter designs (coaxial dilator, coaxial balloon, and linear extrusion) were measured in normal and atherosclerotic arteries; in modeled stenoses of variable severity, length, and compliance; and in modeled vessel angulations. The results with modeled vessels show that the linear extrusion catheter reduces the level of shear forces, particularly in narrow, long, noncompliant stenoses and in tortuous vessels. The stenotic artery results also show that the linear extrusion catheter minimizes these forces in tight lesions. The relative differences in forces are explained by the mechanism of action for each catheter. The reported occurrences of technical difficulties, complications, and long-term patency rates are then interpreted on the basis of the relative differences in measured shear forces. The results of this study combined with preliminary clinical data indicate that linear extrusion should facilitate placement and reduce associated complications.

Angioplasty, Balloon↗
PubMed1985

A new vascular clamp.

A new vascular clamp called the occluder pad is described. It has significant utility when used in a variety of anatomic sites in either normal or diseased vessels. It possesses suitable tractive and occlusive forces while minimizing the mechanical forces applied to the vessel walls.

Constriction↗
PubMed1984

Current status of dilatation catheters and guiding systems.

New transluminal angioplasty catheters based upon the linear extrusion of the dilating element have been developed to facilitate placement of the dilating balloon within the arterial narrowing. In a multicenter study, the use of linear extrusion catheters has been shown to be safe and effective in adjunctive intraoperative peripheral dilatations. Physical measurements of the frictional forces exerted on the inner arterial surfaces during advancement of 3 angioplasty catheter designs show that the linear extrusion catheter consistently minimizes these forces. The use of a secondary guiding sheath in conjunction with a linear extrusion catheter provides additional directional capability. A secondary guiding sheath with a side port has recently been developed that allows access to difficult-to-cannulate vessels. The favorable results of the clinical studies and research data justify an ongoing evaluation of these concepts in percutaneous dilatation procedures and in intraoperative coronary procedures.

Angioplasty, Balloon↗
PubMed1984

Intraoperative coronary artery balloon-catheter dilatation.

A new transluminal angioplasty catheter based on linear extrusion of the dilating element has been specifically designed and developed for the cardiac surgeon. This catheter facilitates placement of the dilating balloon within the arterial narrowing without the routine use of fluoroscopy in the operating room. Physical measurements of the frictional forces exerted on the inner arterial surfaces by three different angioplasty catheter designs during advancement show that the linear extrusion catheter consistently minimizes these forces. The linear extrusion catheters have now been used in over 64 coronary adjunctive intraoperative dilatations. The results of these clinical studies and our research data indicate that the linear extrusion balloon catheter is a safe and effective adjunct to primary coronary artery bypass procedures.

Angioplasty, Balloon↗
PubMed1984

Coaxial balloon dilation and calibration of urethral strictures.

New coaxial balloon dilators with standard urologic tip configurations have been designed for use in urethral strictures. Balloon dilatation provides several advantages over conventional dilatation of strictures including improved access and decreased mucosal trauma due to a low silhouette, adjustability of diameter and rigidity, decreased instrumentation, and facilitation of intermittent self-dilation by the patient. The instruments were evaluated in 51 strictures (41 patients) as both a dilator and a calibrator. All catheters were located across the stricture easily (although two required filiform attachments). All clinical goals were achieved, and no complications were identified. Two patients were started on a program of intermittent self-dilation after internal urethrotomy with good results. It is our initial clinical impression that slow, gradual dilation of strictures is superior to rapid, abrupt dilation. This can only be practically achieved with balloon dilators.

Adult↗
PubMed1984

Transluminal angioplasty: a mechanical-pathophysiological correlation of its physical mechanisms.

We quantitatively determined the relative contribution of various factors leading to arterial lumen enlargement during transluminal angioplasty. Mechanical tests were conducted on both normal and atherosclerotic artery necropsy specimens. In our range of dilating pressures (0-3.4 atm or 0-50 lb/in2), content extrusion of fluid from the plaque accounted for 6-12% of the overall lumen area increase, while compaction of the plaque accounted for only 1-1.5%. The majority of the increase, 86.8-93%, was due to plaque and arterial wall disruption. The mechanism of disruption began with shearing of the plaque from the underlying artery at relatively low dilating pressures and continued with longitudinal tearing and stretching of the arterial wall at higher pressures. Diseased arteries dilated significantly more than nondiseased arteries at dilating pressures greater than or equal to 1.36 atm or 20 lb/in2 (P less than .05). In the range of stenoses that were tested (10-50%), the mean dilating pressure required to increase the lumen cross-sectional area by 50% was approximately 1.5 atm or 22 lb/in2.

Angioplasty, Balloon↗
PubMed1984

A physical measurement of the mechanisms of transluminal angioplasty.

We report a quantitative determination of the relative contribution of various factors leading to arterial lumen enlargement during transluminal angioplasty. Mechanical tests were conducted on both normal and atherosclerotic artery necropsy specimens. In the range of dilating pressures tested (0 to 3.4 atm or 0 to 50 lb/in2), content extrusion of fluid from the plaque accounted for 6% to 12% of the overall lumen area increase, while compaction of the plaque accounted for only 1% to 1.5%. Most of the increase (86.8% to 93%) was due to plaque and arterial wall disruption. The mechanism of disruption involved shearing of the plaque from the underlying artery at relatively low dilating pressures, followed by longitudinal tearing in the arterial wall at higher pressures. Diseased arteries were observed to dilate significantly more than nondiseased arteries at dilating pressures greater than or equal to 1.36 atm or 20 lb/in2 (P less than 0.05). In the range of stenoses tested (10% to 50% based on diameter reduction), the mean dilating pressure required to increase the lumen cross-sectional area by 50% was approximately 1.5 atm or 22 lb/in2. Based on these studies, we conclude that balloon dilatation results arise mainly from plaque and arterial wall disruption.

Angioplasty, Balloon↗
PubMedDate not supplied

Treatment of postoperative lymphoceles with percutaneous drainage and alcohol sclerotherapy.

PURPOSE: To assess the efficacy and safety of percutaneous catheter drainage combined with alcohol sclerosis in the treatment of postoperative lymphoceles. PATIENTS AND METHODS: Thirteen patients with 14 postoperative symptomatic lymphoceles were treated. Drainage catheters were inserted under ultrasound (n = 13) or computed tomographic (n = 1) guidance. Lymphocele sclerosis was performed by instilling 10-100 mL of absolute alcohol into the lymphocele cavity and aspirating the alcohol after 30 minutes. Sclerosis sessions were carried out one to three times per day, usually three times per week. Catheter sinograms were obtained and prophylactic antibiotics administered. Imaging was repeated if symptoms or signs of recurrence developed. RESULTS: Successful drainage and sclerosis were achieved in all 13 patients. One patient with a recurrence was successfully treated with repeated drainage and alcohol ablation. No adverse effects of alcohol instillation were seen. The mean duration of catheterization was 36 days (range, 17-65 days; median, 30 days). CONCLUSION: Percutaneous drainage combined with alcohol ablation is a safe and effective treatment of postoperative lymphoceles.

Adult↗
PubMedDate not supplied

Does cervical spinal cord injury induce a higher incidence of complications after prophylactic Greenfield inferior vena cava filter usage?

PURPOSE: To determine whether acute cervical spine injury represents a risk factor for complications from prophylactic placement of current generation Greenfield inferior vena cava (IVC) filters. MATERIALS AND METHODS: A retrospective chart review performed during a 7-year period identified 11 patients with acute cervical spinal cord injuries who underwent prophylactic Greenfield IVC filter insertion. Specific complications evaluated included symptomatic pulmonary embolism (PE), migration, filter base diameter changes, caval perforation, and thrombosis. The amount of migration and changes in filter base dimension were compared statistically with a control population of IVC filter patients (n = 16) without cervical spine injuries. RESULTS: Filter migration (> 10 mm) was the most common complication (46%). Migration usually is caudally directed (64%), may occur early (36% moved > 10 mm within a 30-day period), and is often asymptomatic. The prevalence of filter migration greater than 30 mm was 27%. The average amount of migration for the subpopulation under study was greater than that seen with the control population (P < .05). No statistically significant change in filter base size occurred. The study population also had rates of PE (9%-18%), caval perforation (9%), and IVC thrombus formation (18%) that were higher than the rates in historical controls. The majority of patients with these complications received vigorous pulmonary toilet (46%), including "quad coughs" or cardiopulmonary resuscitation (18%). CONCLUSIONS: Acute cervical spinal cord injury and the associated supportive care may be associated with an increased risk for caudal IVC filter migration, IVC perforation, caval thrombosis, and PE.

Adult↗