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M Zenati

Publications and source records attributed to M Zenati.

At least 37 records · Page 2Linked to original sources
PubMed1994

Results of heart transplantation by extending recipient selection criteria.

From November 1985 to July 1993, 29 out of 241 patients (12%) who underwent heart transplantation (HTx) at our institution had one or more "classical" contraindications to HTx: age > or = 60 years (20 patients); insulin-dependent diabetes mellitus (5 patients); irreversible renal failure requiring combined heart-kidney transplantation (2 patients); previous surgery for malignancy (1 patient); familial hypercholesterolemia (1 patient) and active systemic infection (1 patient). The main indication for HTx was ischemic cardiomyopathy (21 patients, 61%). Immunosuppression regimen consisted of Cyclosporine and Azathioprine, oral prednisone being subsequently added in 6 patients because of persistent rejection. There were 2 perioperative deaths and one late death. Follow-up ranged from 1 to 88 months (mean, 28 +/- 20) with an actuarial survival at 5 years of 85 +/- 8%. Annual cardiac catheterization demonstrated normal graft function and coronary arteries in all. No significant differences in survival, incidence of rejection and infection, renal function and duration of hospitalization were found when these patients were compared with those with no contraindications to HTx. In conclusion, HTx can be performed with good early clinical results in selected patients with "classical" contraindications to HTx; longer follow-up, however, is needed to confirm whether extension of the recipient selection criteria justified.

Adult↗
PubMed1992

Improved immunosuppression with aerosolized cyclosporine in experimental pulmonary transplantation.

Rejection remains a major obstacle to long-term success of pulmonary transplantation. Direct delivery of cyclosporine to lung allografts may produce better control of rejection by generating high intragraft concentrations of drug with decreased systemic delivery and toxicity. The efficacy of inhaled cyclosporine in preventing allograft rejection was compared with systemic delivery by intramuscular injections in a rat model of lung transplantation (Brown-Norway to Lewis). Group 1 animals were given no immunosuppression. Group 2 received a single i.m. injection of 25 mg/kg CsA on the day of operation while group 3 received daily doses on postoperative days 0-3. Groups 4-7 received aerosolized CsA daily for seven days. The aerosol generator produced an airborne concentration of CsA of 180 mg/m3 with a mean particle size of 0.7 mu and estimated pulmonary depositions of CsA of 0.98-3.6 mg/kg/day. Animals were killed on POD 7, and the transplanted lungs graded histologically in a blinded fashion. All control animals showed destructive grade 4 changes by POD 7. Animals receiving high-dose aerosolized CsA (groups 6 and 7) showed minimal changes with a mean rejection grade of 1.3. A single i.m. dose of CsA (group 2) failed to prevent rejection; the mean grade was 2.2. Animals given four i.m. doses of CsA had a mean grade of 1.8. Aerosolized CsA provided significantly better control of rejection than did systemic CsA (groups 6 and 7 vs. groups 2 and 3; P less than 0.0002 and less than 0.0054, respectively). Local delivery of CsA by aerosol inhalation is effective in limiting acute rejection of the rat lung allograft.

Aerosols↗
PubMed1992

Donor-transmitted pneumonia in experimental lung allografts. Successful prevention with donor antibiotic therapy.

Bacterial pneumonia is the most common cause of early morbidity and mortality (less than 2 weeks) after heart-lung transplantation. The majority (76%) of cultures taken from human donor tracheas at the time of explant grew bacteria. The abnormal immune response of the lung allograft and the common finding of bacterial contamination of lung donors led us to hypothesize that clinically silent bacterial contamination of the donor lung progresses to pneumonia in the recipient and that antibiotic treatment of donors will prevent the development of pneumonia in the recipient. Inocula of Streptococcus pneumoniae were instilled into the left middle lobe of normal and donor dogs to identify the number of bacteria that would result in pneumonia in a normal animal and the amount that, when given to a donor, would result in pneumonia in the recipient. Initial studies established that inocula of 10(4) colony-forming units of S. pneumoniae did not result in pneumonia in normal or immunosuppressed animals. When 10(4) colony-forming units or as few as 10(2) were instilled into the left middle lobe of donors 24 hours before explantation and use of the lung for transplantation, severe acute bronchopneumonia developed in all 18 recipients. Treatment of donors with aerosol and intravenous antibiotics, but not with either alone, prevented pneumonia in the recipients. We conclude that bacterial contamination of the donor lung leads to pneumonia in recipients. Intravenous and aerosol antibiotic treatment of donors with bacterial contamination prevents pneumonia in canine lung recipients. Treatment of human donors with this antibiotic regimen may decrease the prevalence of early bacterial pneumonia.

Administration, Inhalation↗
PubMed1991

Immunosuppression with aerosolized cyclosporine for prevention of lung rejection in a rat model.

The efficacy of local delivery of aerosol cyclosporine (CsA) for prevention of lung rejection was compared with the intramuscular route (IM) in a fully allogeneic rat model (BN/LEW) of lung transplantation (LTx). Control rats (group 1, n = 6) received no CsA after LTx. Rats in group 2 (n = 10) received 4 doses of CsA in olive oil (25 mg/kg) intramuscularly starting on postoperative day (POD) 0. Group 3 (n = 9) was treated with aerosolized CsA for 3 h/day for 7 days starting on POD 0. All animals were sacrificed on POD 6. Transplanted lungs were graded histologically in a blind manner on a 0-4 scale. Control animals all showed grade 4 rejection. i.m. CsA therapy reduced lung rejection with a rejection grade of 1.8 +/- 0.35 (mean +/- SD) but was associated with a 50% incidence of pneumonia. Aerosol CsA provided better control of rejection with a rejection grade of 1.2 +/- 0.4 (group 3 vs. group 2: P less than 0.05 Wilcoxon) and none of these animals had penumonia. Trough blood levels of CsA were significantly lower in the group treated with aerosolized CsA when compared with the IM group (P less than 0.05). Therefore we conclude that: (1) aerosol CsA is effective in preventing lung allograft rejection following lung transplantation in rats, and (2) local delivery of aerosol CsA is superior to the i.m. route because better control of rejection is achieved with a lower systemic delivery of CsA.

Aerosols↗
PubMed1990

Disruption of the aortic anastomosis after heart-lung transplantation.

Disruption of the aorta at the anastomotic site occurred in 4 of 66 consecutive heart-lung transplant recipients and was associated with a 100% mortality. In 3 of these patients, Candida either was cultured from the suture line or was seen in the wall of the aorta at postmortem examination. In 2 of these 3 patients, cultures of material from the donor trachea taken at the time of explanation grew Candida species. Two patients were seen with sudden massive hemorrhage on postoperative day 26 and postoperative day 28. One patient experienced acute decompensation due to right ventricular outflow tract obstruction on postoperative day 30, and the remaining patient was seen 7 months postoperatively with obstruction of both the left main bronchus and the right pulmonary artery caused by extrinsic compression by an aortic pseudoaneurysm. A high index of suspicion should be maintained when transplanting lungs containing Candida species, as we believe there is substantial evidence of donor transmission of the fungal agents. We now include amphotericin B in our antibiotic prophylactic regimen in an attempt to prevent fungal infection because previous treatment has been uniformly unsuccessful. Furthermore, we wrap both the trachea and the aorta with omentum to lessen the likelihood of mediastinal spread of infection to the aortic suture line.

Adolescent↗
PubMed1990

HLA-class II antigen expression in human heart-lung allografts.

Long-term survival in heart-lung transplantation has ben hindered by the development of bronchiolitis obliterans (OB), which is believed to be a manifestation of chronic rejection of the lung. Since HLA-class II antigens are involved in the rejection response, the distribution of the class II products HLA-DR, HLA-DQ, and HLA-DP were studied in normal lung, and in transplanted lung with and without OB, utilizing frozen-section immunohistochemical techniques. All three allelic products are usually expressed on the epithelial, endothelial, and mesenchymal components of the lung. Sequential transbronchial biopsies from 4 recipients before and concurrent with the diagnosis of OB were stained with serial dilutions of monoclonal antibodies to assess the level of expression of the above class II products. Increased levels of HLA-DR and HLA-DP antigens may be seen on the bronchial and bronchiolar epithelium during OB, but the changes are subtle and complicated by many other variables. Additional studies are needed to confirm these preliminary results.

Bronchiolitis Obliterans↗
PubMed1990

The pulmonary donor.

This article discusses the Pittsburgh experience with the pulmonary donor and provides guidelines for the maintenance and selection of appropriate donor lungs. Criteria for the selection of the pulmonary donor include absence of radiographic abnormality, minimal ventilation-perfusion mismatch, and an absence of identifiable infection. Because early thoracic infections result in a high mortality, donors are excluded if white cells, fungi, or bacteria are noted in samples obtained from tracheal aspirates or bronchoscopic examination. A number of techniques for the procurement of donor lungs are currently satisfactory and include core cooling with the use of cardiopulmonary bypass and different hypothermic pulmonary artery flush solutions. Other clinical preservation techniques are discussed, including autoperfusion and the use of blood-based pulmoplegia and University of Wisconsin storage solution. Because so much of the outcome following pulmonary allografting is based on the quality of the donor lungs, much of the future direction in pulmonary transplantation must be directed toward a continuing investigation of better methods for selection and maintenance of the donor and ex vivo preservation.

Adult↗
PubMed1990

Aerosolized cyclosporine as single-agent immunotherapy in canine lung allografts.

Current systemic immunosuppressive regimens are unable to prevent lung allograft rejection consistently and are associated with significant morbidity and death. Acute rejection has occurred in 40% and chronic rejection in 50% of our lung recipients. We hypothesized that regional immunotherapy with aerosolized cyclosporine would prevent or reduce lung allograft rejection while allowing for low systemic drug delivery. In a canine model of unilateral lung allotransplantation, aerosolized cyclosporine was delivered directly to the allograft. Acute rejection was prevented or reduced in all treated recipients. All control animals had severe acute rejection. Intragraft cyclosporine concentration was high and systemic drug delivery was low, as evidenced by low whole-blood cyclosporine levels and low tissue cyclosporine levels in skeletal muscle. Ninety-five percent of whole-blood trough cyclosporine levels were less than 150 ng/ml. Aerosolized cyclosporine was able to prevent or reduce acute pulmonary rejection and resulted in minimal systemic drug delivery.

Aerosols↗
PubMed1989

Organ procurement for pulmonary transplantation.

Selection of suitable donors is critical to the success of clinical pulmonary transplantation. Requirements for lung donors, management before explantation, and methods of preservation were reviewed for the 70 heart-lung, eight double-lung, and two single-lung transplantations performed at the University of Pittsburgh since 1982. Careful observation of trends of hyperoxygenation studies, chest roentgenograms, and Gram stain and culture results of tracheal secretions, as well as findings on bronchoscopy, can help identify which lungs not only have adequate function but are acceptable for transplantation. In spite of the rigid criteria used, 76% of tracheal cultures from donors deemed acceptable grew organisms. The presence of oropharyngeal flora has been shown to correlate with the development of early intrathoracic infections in the recipient. Prophylactic broad-spectrum antibiotic treatment of the donor is desirable to treat microbial contamination that could cause focal injury to the donor lung and predispose to infection in the recipient. Acceptance of less than ideal donors is ill-advised even though rejection of such donors conflicts with the current shortage of organs.

Graft Survival↗
PubMed1989

Infections in mortally ill cardiac transplant recipients.

A total of 351 cardiac transplantations performed between June 1, 1980, and Sept. 30, 1987, were reviewed to determine if infectious complications were more frequent in those patients requiring preoperative intravenous inotropic support, placement of an intraaortic balloon pump, or mechanical support with a left ventricular assist device or total artificial heart. One hundred forty-nine transplants (45%) were performed in these mortally ill patients. There was no statistically significant difference between patients with and without infection within each support group for the following: the number of in-patient days awaiting a donor heart, the number of days receiving support, the percent of patients with preoperative tracheal intubation, the length of the operation, and the percent of patients requiring reoperation for bleeding. The need for invasive methods of support (intraaortic balloon pump, left ventricular assist device, or total artificial heart) in patients awaiting heart transplantation increases the prevalence of perioperative nonviral infection. Preoperative mechanical support with a left ventricular assist device or total artificial heart significantly increases the risk of infection-related mortality.

Adult↗
PubMed1989

[New trends in combined transplantation of the heart and lungs].

Heart-lung transplantation is a surgical alternative for patients with end-stage lung disease with associated right heart failure. While the procedure is very promising, the morbidity and mortality remain high. The current understanding of the proper selection of candidates, procurement and preservation of donor organs, operative procedure and postoperative care continues to evolve. At the University of Pittsburgh, 70 heart-lung transplantations have been performed since 1982. Early infection and chronic rejection are the major factors influencing survival. Early (less than 2 weeks) intrathoracic infection occurred in 43% of heart-lung transplant recipients, with pneumonia being the most frequent infection. The incidence of pneumonia in heart-lung transplant recipients is twice that in a comparable group of heart recipients. Subclinical pneumonitis in the donor lung, abnormal muco-ciliary clearance and altered allogenic response in the transplanted lung are significant factors associated with the increased incidence of early infections. Chronic rejection, manifested as bronchiolitis obliterans, has occurred in 54% of heart-lung transplantation recipients. Infection caused by cytomegalovirus, Epstein-Barr virus and Pneumocystis carinii have been shown to increase the incidence of bronchiolitis obliterans, as have episodes of acute rejection. Recent reports of a 61% 2-year survival rate represent a substantial improvement over earlier trials. With a better understanding of the pathogenesis of infection in the transplanted lung as well as improved immunosuppressive agents, further improvements in survival can be expected.

Heart-Lung Transplantation↗
PubMed1988

[Elements for an analysis of psychosocial indicators and psychological intervention in heart transplantation].

It is now accepted that cardiac transplantation is a viable therapeutic alternative for patients with end-stage heart disease. The most recent data offer a favourable short and medium term prognosis. Retrospective studies suggest that transplantation is associated with a good quality of life and tolerance of the side effects of the medication. Even if cardiac transplantation does not appear to be associated with serious psychological morbidity, it is important to assess the recipient's anxiety, depression, body image and his subjective quality of life, including satisfaction with his family and marital life, to prevent postoperative psychologic distress and enhance the patient's coping abilities. The family is the patient's chief buffer against stress but it is also under stress and needs to be aided through this process. The psychosocial themes that appear prominently at the different stages of the transplant process are somewhat predictable. These can be used to help the patient and family anticipate stress and deal with these issues in a way that enhances mastery of a difficult situation. The heart transplant team faces difficult ethical issues regarding patient selection and informed consent. Public input on these issues is needed, especially since more patients elect to receive heart transplants and the donor supply is likely to remain the same, thereby making donor hearts less available to those who could derive benefit from them.

Family↗
PubMed1985

[Cardiac failure due to isolated pulmonary sequestration. Description of a clinical case in the neonatal period].

Pulmonary Sequestration is a congenital anomaly rarely seen in the pediatric age. Clinical manifestations commonly appear with a respiratory symptomatology and less frequently with cardiac signs especially in the case of an associated congenital heart disease. In the presented case, isolated Pulmonary Sequestration manifested itself as a congestive heart failure, and a diastolic overloading of the left ventricle. After surgical removal of the Sequestration was demonstrated a normalization of both clinical and haemodynamic findings.

Bronchopulmonary Sequestration↗
PubMedDate not supplied

Minimally invasive coronary artery bypass grafting: a kinder cut.

Minimally invasive coronary artery bypass graft (CABG) surgery is a promising variation on traditional CABG, avoiding the risks of sternotomy and cardiopulmonary bypass. This article describes the procedure, patient-selection criteria, and postoperative care.

Coronary Artery Bypass↗