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Biomedical subjects

B Radovancevic

Publications and source records attributed to B Radovancevic.

At least 73 records · Page 4Linked to original sources
PubMed1990

Rapid placement of the Hemopump and hemofiltration cannula.

Hypervolemia, a potential complication in patients on ventricular assist device support, can be managed by use of continuous arteriovenous hemofiltration. The Hemopump, a new catheter-mounted, transaortic axial-flow ventricular assist device, and the vascular access catheter for the Diafilter-30 Hemofilter system, used in continuous arteriovenous hemofiltration, are both usually inserted by way of the femoral artery. Because placing two large catheters in the femoral artery of a patient with peripheral vascular disease can compromise circulation, a technique for placing them in the abdominal aorta was developed. Two patients have undergone combined Hemopump and hemofiltration treatment, and neither experienced complications. Such techniques may benefit more patients in the future, as the usefulness of the Hemopump is proved.

Aorta, Abdominal↗
PubMed1990

Use of potentially infected donor hearts for cardiac transplantation.

Despite the nationwide shortage of heart donors, more patients, some of whom are critically ill, are being accepted as candidates for transplantation. Thus, on occasion, we have liberalized our donor criteria to meet the demand. We have recently transplanted 16 potentially infected donor hearts into critically ill recipients. Of these 16 donors, 7 had multiple positive blood cultures as follows: Streptococcus pneumoniae (3), Staphylococcus aureus (2), Klebsiella pneumoniae (1), and Enterobacter sp (1). Seven other donors were accepted despite high fevers (rectal temperature greater than 38.9 degrees C), leukocytosis (greater than 18 x 10(9)/L [greater than 18,000 cells/microL]), and pulmonary infiltrates with positive sputa (Enterobacter [3], Klebsiella pneumoniae [2], and Staphylococcus [2]). Two other donors with hepatitis B surface antigen positivity were deemed at high risk but were used because the recipients were in immediate need. Early mortality (less than or equal to 30 days) among the recipients was 3/16 (18.7%) with 1 patient dying of uncontrolled allograft rejection, 1 of hepatic failure, and 1 of Pseudomonas septicemia. Late mortality (greater than 30 days after operation) occurred in 6 patients: 2 patients died of hepatic failure, 3 died of graft atherosclerosis, and 1 died of iatrogenic hemorrhage after a liver biopsy. Only 1 patient died of infection unrelated to that of the donor, and the other patients had no infectious complications resulting from the organisms identified in their respective donors. Use of potentially infected donor hearts resulted in surprisingly few infectious complications in this group of recipients. This practice can be safe and should be considered when other options are unavailable.

Adult↗
PubMed1990

Risk factors for development of accelerated coronary artery disease in cardiac transplant recipients.

Allograft coronary artery disease (CAD) is the major determinant of long-term survival following heart transplantation (HTx). In a group of 210 heart transplant recipients, we diagnosed CAD in 54 (27.1%) by coronary angiography, postmortem examination or examination of the transplanted heart at the time of retransplantation. Retrospective analysis of potential risk factors for the development of CAD was performed for both immunological (rejection pattern, immunosuppressive therapy, cytomegalovirus [CMV] infection), and nonimmunological (hyperlipidemia, smoking, hypertension, diabetes mellitus, obesity) risk factors. The total number of rejection episodes correlated significantly with the occurrence of CAD (P less than 0.05), showing that patients who experienced two or more rejection episodes had an incidence of CAD of 40%, as opposed to a 23% incidence in patients who experienced no rejection. A composite rejection score derived from multivariate regression analysis of the severity, frequency, and timing of acute cardiac rejection episodes was found to correlate with the development of CAD (P less than 0.05). Postoperative arterial hypertension also correlated significantly with the onset of CAD (P less than 0.01), with a 92.6% incidence of hypertension in the group with CAD versus 76.3% in the group without CAD. Smoking after transplantation correlated significantly with the occurrence of CAD (P less than 0.05). There was no significant correlation with other analyzed factors in this group of patients. In this review, the development of CAD after heart transplantation correlated with treated allograft rejection. Aggressive treatment of hypertension and cessation of smoking may contribute to alleviation of this serious complication.

Coronary Disease↗
PubMed1989

Anastomosis of bypass grafts using a low-powered CO2 laser.

The purpose of this study was to evaluate the feasibility of using a low-powered CO2 laser to perform end-to-side anastomoses of bypass grafts. The internal jugular veins of 13 domestic swine were removed and used as grafts to bypass their ligated carotid arteries. Each end of the vein graft was apposed to the artery with four to six temporary stay sutures, and a waveguide delivery CO2 laser with a power density of 900 mW/mm2 was used to perform the anastomoses, after which the sutures were removed. The animals were sacrificed postoperatively at five time intervals: 2 to 4 hours, 5 days, 1 month, 3 months, and 5 months. Of the 10 anastomoses studied at 2 to 4 hours, 70% were fully patent, none thrombosed, and 30% disrupted. Of the 16 anastomoses studied between 5 days and 5 months postoperatively, 88% were patent, 12% thrombosed, and none disrupted. None of the animals developed aneurysms at any stage of this investigation. Histologic analysis of acute studies revealed thermal damage such as charring of tissue, unraveling of the collagen fibrils, and the formation of microvacuoles. Within 3 months, the anastomotic sites showed localized healing with intimal fibromuscular proliferation and dense fibrous tissue. Good apposition of tissue was found to be of great importance in achieving patency of vessels in this procedure.

Animals↗
PubMed1989

Implantation techniques for the Hemopump.

Techniques for implantation of the Hemopump, an intraarterial, axial-flow circulatory assist device, are described. The Hemopump, which is currently undergoing clinical investigation, has been used successfully to treat patients experiencing profound left ventricular failure in a variety of clinical situations, including postcardiotomy shock, acute myocardial infarction, cardiac allograft rejection, and cardiac allograft failure.

Cardiopulmonary Bypass↗
PubMed1989

The older cardiac transplant donor. Relation to graft function and recipient survival longer than 6 years.

A donor age of less than 35 years has long been considered crucial for heart transplantation. Because of limited donor heart supply and increasing demand for cardiac transplants, we attempted to expand the donor pool by using hearts from older individuals. This study was designed to determine if older donor hearts adversely affected cardiac transplant patient prognosis by predisposing them to graft failure from coronary artery disease, ventricular dysfunction, or death. Since 1982, 314 heart transplants have been performed at our institutions. Potential donors were deemed fit if there was no history of heart disease, the chest x-ray film was normal, the electrocardiogram showed nonspecific changes only, and blood pressure was maintained without major pharmacological support. In 47 (15%), donor age was 35 years or greater (group 1: mean age, 39 years; range, 35-49 years). In 267 (85%), donor age was less than 35 years (group 2: mean age, 23 years; range, 2-34 years). Mean group 1 recipient age was 55 years (range, 39-68 years) compared with 46 years (range, 0.7-66 years) in group 2 (p less than 0.01). Pretransplant inotropic support, mechanical support, or both were required in 15 (33%) group 1 patients and in 41 (16%) group 2 patients (p less than 0.01). Group 1 and 2 follow-up intervals were 1.1 +/- 1.0 and 1.8 +/- 1.4 years (mean +/- SD), respectively (p less than 0.0001). Overall survival was 64% versus 65%, group 1 versus group 2, and life table analysis showed no significant difference between the groups. There were three of 17 (18%) deaths due to coronary artery disease in group 1 and 20 of 87 (23%) in group 2 (p = NS). Seven patients in group 2 and none in group 1 required retransplant because of coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

Complications in cardiac transplant patients requiring general surgery.

With the advent of cyclosporine A, heart transplantation has become a widely accepted treatment for patients with end-stage cardiac disease that is not amenable to medical or surgical treatment. Between July 1982 and December 1985, 86 heart transplantations were performed at the Texas Heart Institute with cyclosporine A and prednisone used for immunosuppression. Thirty patients had complications requiring general surgical consultation. The pancreas and biliary tracts were most commonly affected. Pancreatitis developed in sixteen patients; five patients required operative intervention, resulting in a 40% mortality rate. Five of nine patients with cholecystitis required cholecystectomy. All patients survived the procedures. Other gastrointestinal complications included colonic ileus, bowel perforation, gastrointestinal bleeding, gastric outlet obstruction, and perirectal abscess. Patients who have undergone cardiac transplantation are susceptible to life-threatening infections and are at risk of serious complications requiring general surgical intervention. Better results can be obtained in these complex clinical situations when complications are identified early and managed aggressively through the adjustment of immunosuppression, adequate selection of antimicrobial agents, and proper timing of surgical intervention.

Cholecystitis↗
PubMed1987

Occlusive coronary arteritis: a cause of early death in a cardiac transplant patient.

A patient died 5 months after undergoing cardiac transplantation. Endomyocardial biopsies performed prior to death showed no evidence of severe rejection. At autopsy, nonnecrotizing occlusive coronary arteritis was present. The intima of the coronary arteries contained numerous lymphocytes and plasma cells. Chronic rejection appeared to be responsible for the arteritis. The onset of coronary occlusive disease is insidious, and recognition depends on the performance of coronary arteriography, which is usually not done until the one-year follow-up. Early coronary arteriography is suggested to rule out occlusive coronary arteritis when cardiac allograft function is not satisfactory, even when the endomyocardial biopsy shows no evidence of rejection.

Arteritis↗
PubMed1986

Cardiac transplantation in an 8-month-old female infant with subendocardial fibroelastosis.

On Nov 1, 1984, an orthotopic cardiac transplantation was performed in an 8-month-old female infant with subendocardial fibroelastosis. Because of the advanced state of cardiac failure, the operation was done despite a positive tissue crossmatch for antitoxic donor-specific antibodies. Immunosuppression consisted of high doses of cyclosporine (up to 550 mg/m2 or 30 mg/kg) and steroids. Hypertension and tremor of the extremities, which were attributed to cyclosporine, occurred during the first week but resolved after seven days. No signs of nephrotoxic effects have been noted; however, a severe episode of allograft rejection was detected by endomyocardial biopsy on the seventh postoperative day, and a moderate rejection episode was noted on the 22nd postoperative day. Histologic improvement was seen after treatment with conventional steroid pulses. The patient was discharged on Nov 29, 1984. Complications consisted of four episodes of otitis media caused by Staphylococcus aureus and one rejection episode that was treated on an outpatient basis with an intravenous methylprednisolone sodium succinate pulse. Our experience emphasizes both the feasibility and importance of performing endomyocardial biopsies in infant recipients. Through biopsy, episodes of rejection can be discovered when clinical signs are not yet apparent. Eighteen months after transplantation, the child was developing and growing normally.

Cyclosporins↗
PubMed1985

Heterotopic heart transplantation in three patients at the Texas Heart Institute.

Seventy-three orthotopic and three heterotopic transplantations have been done in our institution, and in this report, we describe the procedure and outcome of those who underwent heterotopic transplantation. Three patients were in critical condition while awaiting donors for heart transplantation, and in each case, a suitable donor could not be found. Smaller donor hearts became available, and knowing that these patients would die without some kind of immediate action, we performed heterotopic heart transplantations. Patient Number 1 was a 53-year-old diabetic man who was in the last stages of heart disease when a small donor heart became available. Because of his rapidly deteriorating condition, we did a heterotopic transplantation. The patient is presently well and functioning normally. Patient Number 2 was a 26-year-old woman who received the heart of a 13-year-old donor after it became obvious that she could not wait for a suitable donor. We performed a heterotopic transplantation, after which the patient continues to function well. Patient Number 3 was a 53-year-old man who weighed 260 lbs. When a suitable donor could not be found, the heart of a 170-lb man became available and was used in a heterotopic transplantation. This patient also continues to be active and well. After considering the various advantages and disadvantages of heterotopic transplantation, we are convinced that there is a definite place for this procedure in some patients with end-stage cardiac failure, although we still believe that orthotopic transplantation should be offered to most recipients.

Journal Article↗
PubMed1985

Successful treatment of invasive aspergillosis in a heart transplant patient.

Infection continues to be a major cause of mortality in cardiac transplant patients, and even though there has been significant progress in diagnosing and treating many infectious disease problems, invasive aspergillosis in the transplant patient represents a serious and usually fatal complication. Even with successful early diagnosis, the use of free amphotericin B (a polyene antibiotic) has failed to cure disseminated infection. We report the case of a 46-year-old transplant patient who failed to respond to treatment with free amphotericin B after a 7-day period of treatment for biopsy-proven pulmonary aspergillosis. However, a subsequent substitution of a liposomal form of amphotericin B was used, and the patient responded well to a total dose of 1.5 mg. After 7 months, the patient continues free of infection. This experience suggests that the introduction of liposomal amphotericin B may give new hope for treating an otherwise lethal infection.

Journal Article↗
PubMed1985

Legionella infections in cyclosporine-immunosuppressed cardiac transplants.

Pulmonary infections from bacterial or viral agents, as well as rare infectious agents, such as Toxoplasma gondii, Aspergillus, and Pneumocystis carinii, have been a bane to the clinician in charge of the care of transplant patients. One such opportunistic Organism, Legionella pneumophila, was responsible for four episodes of infection in three of our patients who survived due to better management of immunosuppression, together with aggressive therapy and early diagnosis of the infectious complications.

Journal Article↗