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Biomedical subjects

W C DeVries

Publications and source records attributed to W C DeVries.

At least 37 records · Page 2Linked to original sources
PubMed1984

Evaluation of total artificial heart performance in man.

This report describes the method whereby total artificial heart (TAH) performance was evaluated in the first human implantation, the operating characteristics of the TAH and the accompanying circulatory response. The patient survived for 112 days. Weekly averages (+/- standard deviation) for left-heart drive pressure ranged from 146 +/- 5 to 171 +/- 10 mm Hg, right-heart drive pressure from 46 +/- 4 to 79 +/- 17 mm Hg, heart rate from 77 +/- 8 to 98 +/- 3 beats/min, diastolic vacuum from 0 to 7 +/- 0.5 mm Hg and percent systole 40 +/- 1 to 44 +/- 0. Left-sided cardiac output ranged from 3.0 +/- 0.4 to 3.9 +/- 0.2 liters/min/m2, and was consistently greater than right-sided cardiac output, which ranged from 2.6 +/- 0.4 to 3.6 +/- 0.1 liters/min/m2. Drive line air pressure and flow signals and cineradiography of the TAH demonstrated complete filling and ejection for the left ventricle and complete filling but partial ejection for the right ventricle. There was no significant change in cardiac index during variation in right atrial pressure between 4 and 14 mm Hg. During 21 days of invasive hemodynamic monitoring, daily average of mean systemic arterial pressure ranged from 81 +/- 5 to 107 +/- 11 mm Hg, pulmonary artery pressure from 22 +/- 2 to 28 +/- 8 mm Hg and left atrial pressure from 8 +/- 2 to 22 +/- 4 mm Hg. Prominent V waves on the left atrial pressure tracing suggested mitral regurgitation as a cause of the difference between the outputs of the 2 ventricles.(ABSTRACT TRUNCATED AT 250 WORDS)

Air Pressure↗
PubMed1984

Clinical use of the total artificial heart.

We report here our first experience with the use of a total artificial heart in a human being. The heart was developed at the University of Utah, and the patient was a 61-year-old man with chronic congestive heart failure due to primary cardiomyopathy, who also had chronic obstructive pulmonary disease. Except for dysfunction of the prosthetic mitral valve, which required replacement of the left-heart prosthesis on the 13th postoperative day, the artificial heart functioned well for the entire postoperative course of 112 days. The mean blood pressure was 84 +/- 8 mm Hg, and cardiac output was generally maintained at 6.7 +/- 0.8 liters per minute for the right heart and 7.5 +/- 0.8 for the left, resulting in postoperative diuresis and relief of congestive failure. The postoperative course was complicated by recurrent pulmonary insufficiency, several episodes of acute renal failure, episodes of fever of unidentified cause (necessitating multiple courses of antibiotics), hemorrhagic complications of anticoagulation, and one generalized seizure of uncertain cause. On the 92nd postoperative day, the patient had diarrhea and vomiting, leading to aspiration pneumonia and sepsis. Death occurred on the 112th day, preceded by progressive renal failure and refractory hypotension, despite maintenance of cardiac output. Autopsy revealed extensive pseudomembranous colitis, acute tubular necrosis, peritoneal and pleural effusion, centrilobular emphysema, and chronic bronchitis with fibrosis and bronchiectasis. The artificial heart system was intact and uninvolved by thrombosis or infectious processes. This experience should encourage further clinical trials with the artificial heart, but we emphasize that the procedure is still highly experimental. Further experience, development, and discussion will be required before more general application of the device can be recommended.

Blood Pressure↗
PubMed1984

Nutrition for the first Total Artificial Heart patient: implications for future patients.

Since the mid-1960s, millions of dollars in federal funds have been used for research in the development of the Total Artificial Heart (TAH). Significant advances in bio-materials and pump and energy systems, as well as animal experimentations, have led to the clinical reality of the TAH's use in man. On December 2, 1982, Dr. Barney Clark became the first recipient of a permanent TAH. He had been suffering from terminal congestive heart failure secondary to idiopathic cardiomyopathy. No other treatment was available, since, at the age of 61, he was too old for heart transplant. Dr. Clark's 112-day hospitalization was complicated by pulmonary problems, renal insufficiency, seizures, nosebleeds, and a broken heart valve. Dr. Clark appeared malnourished before surgery, and his numerous postoperative complications confounded attempts at nutritional support. Standard nutritional assessment techniques were inadequate or inappropriate in the face of severe edema, renal failure, and multiple transfusions. Although nitrogen balance was achieved intermittently, for the majority of his hospitalization Dr. Clark remained in negative nitrogen balance, due mainly to renal insufficiency. Some of the nutritional complications seen in the first TAH patient might have been preventable with early nutritional assessment and more aggressive support. The Artificial Heart Management Team at the University of Utah now includes a nutritionist, and future protocols outline detailed nutrition monitoring.

Forecasting↗
PubMed1983

Impact of regulations on artificial organs research.

From a research perspective, some of the primary problems created by the FDA regulations include: the amount of time necessary to comply with the regulations and to obtain FDA and IRB review of the studies. The cost of such delays may be great in terms of statistical death. Lack of understanding of the regulations on the part of investigators. Escalated costs and extra restrictions on the use of animals. Benefits of the regulations appear to be: better preclinical testing performed prior to initiating clinical trials, and improved testing protocols, both of which may result in lower risks to patients.

Artificial Organs↗
PubMed1983

Response of the human body to the first permanent implant of the Jarvik-7 Total Artificial Heart.

The success of the first permanent total artificial heart implant would have been more obvious had the patient been able to be transferred from the hospital to an outlying home care setting. Nevertheless, several major achievements were realized. First, we were able to demonstrate that the total artificial heart will fit within an adult male chest without causing obstruction to inflow or outflow channels. Second, we were able to demonstrate that the total artificial heart would sustain life on a long-term basis (at least up to 112 days) without any evidence of systemic or local infection and without any untoward systemic effects. Third, we were able to demonstrate that the patient was able to tolerate a total artificial heart without complaint of the noise or the bulk of the drive system to which he required permanent attachment and that the patient could be comfortable and totally free of pain. An additional finding, which could not be assessed in the animal experimentations, was the fact that the patient was able to maintain higher CNS activity on an undisturbed basis following the implant of the total artificial heart. It is for these reasons that the entire University of Utah Medical Center staff feel great indebtedness to the patient and his family for demonstrating to the world the feasibility and the necessity for pursuing this device as a new therapy for end-stage heart disease.

Adolescent↗
PubMed1981

Determinants of pannus formation in long-surviving artificial heart calves, and its prevention.

In a group of 76 calves maintained with Jarvik-5 and Jarvik-7 artificial hearts, pannus formation in the atrial location was evaluated retrospectively using a grading system based on measurement of the pannus tissue. Pannus was present in 87% of the calves surviving one to 7 mos with an old-style inflow quick-connect design utilizing polyester felt surfaces. This design had a suboptimal hemodynamic flow path. Using a new design of quick-connect with an improved hemodynamic flow path and a Biomer blood-contacting surface, pannus occurred only in 17% of calves surviving one to 9 mos. Furthermore, the pannus formation with the new design was mild in the 2 cases where it occurred, whereas the pannus formation in animals with the old cuffs was frequently severe. One calf survived 9 mos with no pannus formation utilizing our new quick-connect system, and we conclude that pannus is no longer a problem in our experiments. We also reviewed the relation of pannus to anticoagulant regimens and found that Persantine, Coumadin, and aspirin were not effective in preventing pannus when the inflow cuff design was conducive to its development.

Animals↗
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.

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Animals↗