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W J Kolff

Publications and source records attributed to W J Kolff.

At least 55 records · Page 3Linked to original sources
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

Membrane cascade plasmapheresis: theoretical analysis and in vitro studies.

As the donor plasma required in plasmapheresis therapy is not only expensive but may also cause side effects and transfer of infections, attempt was made in the present work to generate continuously autologous purified plasma. A membrane cascade plasmapheresis (MCP) system was developed which: 1. Separates plasma from blood using a membrane plasma separator 2. Fractionates this plasma into two fractions using a secondary filter, one fraction rich in albumin and the other rich in immunoglobulins 3. Returns to the patient filtered blood combined with albumin-rich plasma fraction Ringer solution was used to compensate for the loss of plasma volume rejected as immunoglobulins. The main problem is to maximize the clearance of IgG and recovery of albumin. Theoretical analysis of the system shows that the clearance of IgG increases with the increase in Ringer solution flow rate. However, this increase in clearance of IgG is accompanied by a decrease in albumin recovery. Theoretical analysis presents a relationship between the clearance of protein as a function of their sieving coefficients of the secondary filter, plasma separation rate, and the priming volume. In vitro evaluation of the system using patient's plasma and a Kuraray 2A filter (secondary filter) show that the relative clearances of IgG and albumin lie in the range of 65-70% and 40-45%, respectively. Further improvement in the selectivity of the secondary filter is necessary to minimize the clearance of albumin and to increase the clearance of IgG.

Humans↗
PubMed1983

Twin calves, total artificial heart, cardiac transplantation.

Numerous laboratories throughout the world are successful in sustaining life in calves, sheep, and goats implanted with total artificial hearts for 4-8 months. Very good reliability has been demonstrated with some of these devices, and all of the more successful devices are pneumatically driven. These pneumatic controllers are, for the most part, large and nonportable, and thus are criticized when considered for permanent tethering to a human recipient. The artificial hearts, however, have been developed to a stage where they could sustain the circulation for indeterminate periods of time, for 2-3 years. The pneumatic total artificial heart was used for a few weeks in calves, and then followed with cardiac transplantation. This format has been suggested for human application.

Animals↗
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↗
PubMed1982

A comprehensive elementary model of the mammalian circulatory system.

Beginning with a set of simplifying assumptions and the statements for the hydrodynamic and thermodynamic processes involved, a comprehensive mathematical model for the mammalian circulatory system is developed and evaluated. Analytical relationships are derived and examined for the circulatory component pressures, flow rates, blood volumes, flow resistances, pumping power and pumping rate. The essential circulatory model parameters are identified and inspected for their influence upon circulatory behavior. A complete and consistent set of circulatory model parameters is given for the adult human male and the model response is examined. In general, agreement of the model predictions for man with experimental data is good.

Adult↗
PubMed1982

Intraoperative and immediate postoperative management of calves undergoing valve or total artificial heart implantation.

The intraoperative and immediate postoperative management data were recorded in a series of twelve artificial device implantation operations in calves. Nine of these were valved conduit experiments not requiring cardiopulmonary bypass, and three were total artificial heart implantations in which bypass was needed. The intraoperative and immediate postoperative management procedures of this laboratory are described including anesthesia, respiratory and drug therapy, and cardiopulmonary bypass management. This paper shows how these procedures may aid in reducing the recovery times of research animals.

Animals↗
PubMed1981

A seven-month survival of a calf with an artificial heart designed for human use.

A Jarvik-7 type of pneumatic artificial heart, which was specifically designed to fit the anatomy and hemodynamic requirements of human patients, was implanted in a calf in an experiment to test the hemodynamic performance of the artificial heart. The experiment lasted for 221 days, longer than any animal had ever lived without its natural heart, despite the fact that the calf increased its body weight to 171 kg. The calf showed typical signs of low cardiac output before its death, but the direct cause of death was intestinal bleeding. At autopsy, it was discovered that the low cardiac output was due to severe pannus around the left inflow valve, as diagnosed earlier by changes in the pneumatic pressure wave form.

Animals↗
PubMed1981

Pressure control of ultrafiltration rate with high-flux dialysis membranes.

Control of ultrafiltration with high-flux dialysis membranes is normally achieved using complex, expensive, volumetric control methods. By using high-flux dialyzers with distensible membranes (parallel-plate dialyzers) in the cocurrent rather than in the countercurrent mode, ultrafiltration can be controlled simply and inexpensively by controlling the outlet pressure differential. Since this is the traditional method of ultrafiltration control, only minor, inexpensive equipment modifications are needed. As expected from transport theory, small molecule clearances are lower with cocurrent than with countercurrent flow. They are, however, adequate and superior to those achieved with post-dilutional hemofiltration (urea clearance greater than 110 ml/min with cocurrent single-pass, high-flux dialysis). Ultrafiltration control with this method is so simple and predictable that clearances at zero net ultrafiltration rates can easily be measured rather than extrapolated. Since dialysate pressure is always positive, no deaeration systems would be needed in dialysis equipment designed for use with cocurrent single-pass, high-flux dialysis.

Blood↗