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Biomedical subjects

W C DeVries

Publications and source records attributed to W C DeVries.

18 recordsLinked to original sources
PubMed1990

Cardiorespiratory interactions in patients with an artificial heart.

A retrospective analysis of the influence of respiration was carried out in three patients with artificial hearts. During spontaneous ventilation, large swings in intrathoracic pressure can produce a pattern reminiscent of pulsus paradoxus in the systemic arterial pressure. A decrease in intrathoracic pressure decreased biventricular filling and enhanced biventricular emptying. An increase in intrathoracic pressure increased biventricular filling, but acting as an increased afterload, impeded biventricular emptying. The influence of respiration on the artificial heart can be considered the result of the artificial ventricles' functioning effectively as extrathoracic pumps, such that changes in intrathoracic pressure produce gradients for biventricular filling and ejection relative to atmospheric pressure (which serves as the reference pressure for the artificial ventricles). Respiratory-induced variation in ventricular performance is clearly present with the artificial heart, but the mechanisms producing these changes appear to be markedly different from normal conditions, in which the ventricles are functionally within the thorax and have a compliant common septum allowing ventricular interaction.

Atrial Function↗
PubMed1988

Postmortem microbiological findings of two total artificial heart recipients.

This report describes the postmortem microbiological findings and related gross pathology from two patients who had the longest survival after implantation of the Jarvik-7-100 total artificial heart. We documented extensive polymicrobial colonization at the site of the device and adjacent structures; however, the internal drive lines were remarkably free of bacterial colonization despite evidence of infection at the skin junction and in close proximity to the artificial heart. The polyurethane polymer (Biomer) on the external surface of the device was discolored and pitted in appearance and the Velcro material that attaches the two ventricles together was eroded. A nonspecific mass of tissue that was adherent to the device and to portions of the drive lines contained inflammatory cells, fibrinous debris, and colonies of microorganisms.

Autopsy↗
PubMed1988

The permanent artificial heart. Four case reports.

This article describes the clinical course of four patients in whom the Jarvik-7-100 total artificial heart was implanted as a permanent device. Details of their preoperative assessment and comprehensive summaries of their postoperative course are presented. The neurological, hematological, renal, and infectious complications they experienced and the interventions initiated to achieve resolution of these problems are described. Finally, revisions in the treatment protocols as a consequence of the experience and knowledge gained are examined.

Acute Kidney Injury↗
PubMed1988

Biomaterial-centered sepsis and the total artificial heart. Microbial adhesion vs tissue integration.

The principal barrier to the extended use of the total artificial heart is infection that is centered on the biomaterial constituting the prosthetic device and exacerbated by the surrounding damaged tissue. Ultrastructural studies of total artificial hearts removed from two patients indicate a failure of true tissue integration and diffuse, adhesive bacterial colonization of biomaterial surfaces. Biomaterials are, in part, susceptible to infection because, at the present state of the art, they are usually not well integrated with host tissue or, if hemodynamic, not optimally biocompatible or antiadhesive.

Aorta↗
PubMed1988

Immunologic complications of long-term implantation of a total artificial heart.

Bacterial infections are a significant complication of long-term total artificial heart implantation. We evaluated the functional capabilities of host defense mechanisms in two patients sustained long-term by a total artificial heart. Although serum complement and polymorphonuclear leukocyte function remained intact, both patients became B and T lymphopenic and there was an initial decrease in the ratio of helper/inducer to suppressor/cytotoxic cells. Histologic examination of their lymphoidal tissue at autopsy further revealed reduced numbers of germinal centers and atrophy of the T lymphocyte-dependent areas. In addition, the reticuloendothelial system was engorged with degenerate erythrocytes. We hypothesize that blockade of the reticuloendothelial system was induced by multiple blood transfusions necessitated by device-associated hemolysis and coagulopathy. This blockade may have led to a progressive loss of content of the antigen-specific lymphoidal elements and, perhaps, to a reduced ability to ingest microbe-antibody complexes.

Bacterial Infections↗
PubMed1988

The role of nuclear medicine in three permanent total artificial heart recipients.

A total of 13 nuclear medicine studies were performed on three permanent total artificial heart (TAH) recipients at Humana Hospital-Audubon. Preoperative radionuclide studies were performed to evaluate left ventricular function for all three patients. Contrast studies were contraindicated because of impaired renal function. Two of the patients had renograms to assess renal function. The two patients who had strokes received 111In Oxine-labeled platelet scans to determine the presence of thrombi in the atria or TAH. No thrombi were evidenced. At autopsy, several septic thrombi were found, none of which contained a detectable amount of platelets.

Heart↗
PubMed1979

Unilateral pulmonary emphysema created by ligation of the left pulmonary artery in newborn puppies.

The left pulmonary artery was ligated in 7 puppies 12 to 24 hours after birth. All were followed by periodic chest roentgenograms. At 6 months of age, ventilatory spaces, split-lung function, and static compliances were determined. Bronchograms and arteriograms were obtained, and histopathology was studied. All animals demonstrated a decrease in left lung size with gross and microscopic changes typical of chronic emphysema. There was impressive bronchial artery hypertrophy. Oxygen consumption and static compliances in the left lungs were depressed. These marked alterations in maturation, as well as the degenerative changes, are believed to be related to an impairment in the nutritive circulation of the lung.

Animals↗
PubMed1975

Oxygen toxicity.

Explore the source record for details and available documents.

Animals↗
PubMedDate not supplied

Nine year experience with the clinical use of total artificial hearts as cardiac support devices.

One hundred sixteen total artificial hearts (TAH) were implanted in 113 patients by 29 centers between April 4, 1969 and March 1, 1988. Five were permanent and 111 were temporary implants (3 patients received second implants). Eight different types of TAHs have been used. The ages ranged from 15 to 62 (mean age: permanent 57, temporary 42). Sixty-seven percent (72/108) of patients receiving the TAH for temporary support were transplanted; 6 patients were waiting for a transplant. Forty-seven percent (34/72) were alive after transplantation. Of the 92 patients receiving the Jarvik TAH (the most frequently used device) as a temporary device, 67% (62/92) were transplanted (6 currently supported) and 55% were alive after transplantation; 85% were back to work, with a normal life-style. The thromboembolic rate for patients who received the device as a temporary support was 10%, with 3 patients having residual sequellae. No deaths resulted from mechanical failure. Experience to date suggests that the use of the TAH as a temporary device can be beneficial if patients are carefully selected.

Adolescent↗
PubMedDate not supplied

Summary of the world experience with clinical use of total artificial hearts as heart support devices.

A review of the world experience with the implantation of total artificial hearts has been carried out. Thirteen centers throughout the world have implanted 27 total artificial hearts in 26 patients. Eight different types of total artificial hearts have been employed. As of June 1, 1986, five of these individuals have had implants for permanent support. Of the other twenty-one patients, three patients died while on a total artificial heart, seven patients died following transplantation, two patients are waiting for transplant, and nine patients have successfully been transplanted and are presently alive. Various clinical preoperative and postoperative parameters are analyzed in this investigation.

Adult↗