Search PubMed⌕ Search

Biomedical subjects

W C DeVries

Publications and source records attributed to W C DeVries.

44 records · Page 3Linked to original sources
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↗
PubMedDate not supplied

Surgical positioning of the Jarvik-7 artificial heart.

The Jarvik-7 total artificial heart has been implanted in 18 patients at the time of this writing. Eleven patients received the 100 ml heart, and the remaining seven were treated with the 70 ml device. To date, five patients have been implanted for permanent use with an average survival in excess of 9 months, and the longest survival is more than 1 1/2 years following implantation of the heart. Complications related to positioning were a contributing factor in the death of one patient. Thirteen patients have received the Jarvik-7 heart as a bridge to transplant. Three died before transplant, and the remaining ten have been transplanted. To date, all are alive, several are home and in excellent condition, and several are still hospitalized but are expected to be released shortly. Three patients have experienced serious complications after transplantation. One patient rejected her heart transplant, was reimplanted with the artificial heart, and now has been sustained for more than 3 months. At this time she is in good condition awaiting a second donor. Selection of the appropriate size Jarvik-7 artificial heart for the individual patient can best be made based on measurements of thoracic dimensions obtained from a computed tomography scan and calculation of body surface area. The appropriate medial or lateral positioning can be determined and decisions concerning the lengths of the grafts and cuffs, excision or nonexcision of the left pericardium, and air drive line position can be made. The Jarvik-7 heart can be successfully used in patients from 50 kg. However, at the lower size limit in patients from approximately 50 to 65 kg, the risk of fit complications is the greatest and availability of an even smaller model heart would be desirable.

Adult↗
PubMedDate not supplied

Indexes of hemolysis in human recipients of the Jarvik-7 total artificial heart: a cooperative report of fifteen patients.

The degree of red cell destruction in human recipients of the total artificial heart has not previously been described. Fifteen patients implanted with a Jarvik-7 total artificial heart for either temporary or permanent heart replacement were reviewed. Clinically significant elevations of plasma free hemoglobin and serum lactate dehydrogenase were demonstrated in patients receiving the standard (100 ml) Jarvik-7 containing Medtronic-Hall valves and powered by pulses of compressed air delivered at a dP/dT of 6000 mm Hg/sec to 8000 mm Hg/sec. Reduction of the dP/dT by drive unit modification greatly reduced the plasma free hemoglobin and lactate dehydrogenase in subsequent patients. Introduction of the smaller (70 ml) total artificial heart was not associated with greater hemolysis once dP/dT had been reduced. With the current driver delivering systolic pulses at less than 4500 mm Hg/sec, both size hearts are free of clinically relevant hemolysis. In addition, it appears that attempts to eliminate hemolysis completely by lowering heart rates, cardiac outputs, or driving pressures are potentially dangerous. The eventual development of embolic cerebrovascular accidents is associated statistically with heart rates below 80 beats/min. These data reassure implanting physicians that the updated Jarvik-7 total artificial heart system does not induce worrisome hemolysis. In addition, this study has uncovered a link between eventual cerebrovascular accident and low heart rate, implying that purposeful application of heart rates around 100 beats/min may provide a significant margin of protection against cerebrovascular accident during implantation.

Adult↗