Biomedical subjects
Publications and source records attributed to Ismaïl El-Hamamsy.
A left ventricular (LV) assist device was implanted in a 53-year-old woman in cardiogenic shock secondary to fulminant myocarditis. LV function recovered to normal after one week of support from an LV assist device. The device was explanted and the patient is showing a good outcome with a normalized LV function.
A primary cardiac lymphoma was encountered in a patient with prosthetic mitral valve dysfunction. Although rare, this tumor could be related to the presence of prosthetic material and specifically that of Dacron. Primary cardiac tumors have to be considered in the differential diagnosis of prosthetic valve dysfunction.
Aspergillus species infections are an increasingly common occurrence in hospital wards. Aspergillus endocarditis constitutes one of the manifestations of the disease, which bears a poor prognosis in cardiac surgery patients. A review of the literature on fungal and Aspergillus endocarditis was undertaken. Valvular risk factors, indwelling intravenous catheters, prolonged antibiotics, malignancy, and intravenous drug use increase the risk. Clinical presentation is insidious, with embolic complications often representing the first manifestation of the disease. Blood cultures are typically negative. The mortality rate is almost 100%. Amphotericin B represents the mainstay of medical therapy with several possible adjuncts. Surgery is an essential part of therapy in Aspergillus endocarditis after cardiac surgery and should be undertaken as soon as the diagnosis is made. Aspergillus endocarditis is an ominous complication after cardiac surgery. A high suspicion index, early administration of appropriate antibiotics, and prompt surgical intervention should improve the prognosis, which remains dismal.
BACKGROUND: Coronary endothelial dysfunction occurs early after heart transplantation and predicts the development of intimal thickening characteristic of cardiac allograft vasculopathy. OBJECTIVES: To assess the effects of removal of the endothelium by balloon injury of coronary arteries of allografts without rupture of the internal elastic lamina at the time of implantation and on coronary endothelial dysfunction, and to assess the development of accelerated atherosclerosis after heart transplantation. METHODS: A porcine model of heterotopic heart transplantation with preoperative immunologic typing, enabling progressive rejection without immunosuppression, was used to study the effect of endothelial removal on these 2 end points. Endothelium-dependent relaxations of epicardial coronary arteries from allografts submitted to endothelial denudation after harvest, arteries from allografts not undergoing denudation, and native coronary arteries were compared 30 days after graft implantation by using standard organ chamber experiments. Intimal thickening was measured by light microscopy with a semiquantitative scale (0 to 4+ grading). RESULTS: Relaxations to serotonin and to bradykinin were significantly decreased in denuded arteries compared with nondenuded allograft arteries. There was a significant increase in the incidence of severe intimal hyperplasia in denuded arteries compared with nondenuded arteries, which were both significantly increased compared to native coronary arteries. CONCLUSIONS: Endothelial injury at implantation worsens the endothelial dysfunction as a result of rejection after heart transplantation and compounds the intimal thickening leading to cardic allograft vasculopathy. All efforts should be deployed to maintain a morphologically intact and functional endothelium at the time of graft implantation.
BACKGROUND: Coronary endothelial dysfunction occurs early after heart transplantation and predicts the development of cardiac allograft vasculopathy. Cardioplegic solutions may cause endothelial injury. The present study aimed to assess the effects of cardioplegic solutions (crystalloid, blood and Celsior) used at the time of graft harvesting on endothelial function and intimal hyperplasia 1 month after heart transplantation. METHODS: A porcine heterotopic heart transplantation model was used. Three experimental groups were studied: crystalloid, blood and Celsior solutions were used for induction of cardiac arrest. Epicardial coronary arteries of native and allograft hearts were studied 1 month after transplantation in organ chambers. Endothelium-dependent relaxations to serotonin, bradykinin and calcium ionophore were assessed. Coronary neointimal proliferation was evaluated using histomorphometric studies. RESULTS: Endothelium-dependent relaxations to serotonin and to calcium ionophore were significantly decreased in all 3 experimental groups vs controls (p<0.05). Endothelium-dependent relaxations to bradykinin were significantly reduced in the crystalloid group compared with the Celsior and blood groups and controls (p<0.05). There was a significantly lower rate of severe intimal hyperplasia in the Celsior group compared to the crystalloid and blood groups (p<0.05). CONCLUSION: Celsior cardioplegic solution represents the solution of choice in terms of preservation of endothelial function and lower incidence of severe coronary intimal hyperplasia following transplantation compared with crystalloid and blood cardioplegia solutions. These early results could translate into a reduction of the long-term incidence of cardiac allograft vasculopathy and improve graft survival.
Cancer limits survival following heart transplantation. The study's objectives were to evaluate the incidence and risk factors for cancers after heart transplantation and to assess the association between i.v. thymoglobuline induction therapy [rabbit antithymocyte immunoglobulin, (RATG)] and neoplasia. From 1982 to 2002, prospective data were gathered for 207 heart transplant recipients. Except from 1982 to 1987, all patients received a 3-day course of i.v. RATG following transplantation. Forty-three malignant neoplasms (21%) were diagnosed. The most common were: skin (42%), lung (12%), prostate (9%), genitourinary (9%) and lymphoma (5%). Mean length of follow-up after transplantation was 99 +/- 57 months. Mean survival after diagnosis was 52 +/- 44 months. Multivariate analysis showed no significant increase in the incidence of cancer with recipient age, sex, number of rejection episodes, the type of immunosuppression or the use of RATG. Patients receiving RATG developed their malignancies significantly earlier after transplantation (P =0.007) and succumbed faster after the diagnosis (P = 0.06). Cancer is a limiting event for long-term survival after heart transplantation. No individual risk factors allow predicting its development. In the present cohort, RATG does not have carcinogenic effects following transplantation, but is associated with a more precocious development of malignancies.
BACKGROUND: Renal failure following heart transplantation carries a poor prognosis. The objectives of this study were to determine risk factors for renal failure requiring continuous renal replacement therapy (CRRT), to describe the management strategies regarding immunosuppressive therapy and to examine the short-term prognosis. METHODS: Fifty-six patients who underwent heart transplantation from 1998 to 2002 at the Montreal Heart Institute were retrospectively analyzed. RESULTS: Six of 56 patients (11%) underwent CRRT after heart transplantation. Patients who underwent CRRT had lower preoperative creatinine clearance than those who did not (median 44 versus 59 mL/min, P=0.04) and lower first two-week postoperative creatinine clearance (median 23 versus 42 mL/min, P<0.01) compared with patients without CRRT. The total duration of CRRT ranged between two and 60 days (median 15 days). Cyclosporine was withheld for 12 days versus two days (P<0.01) and the time to achieve therapeutic levels of cyclosporine averaged 18 days versus nine days (P=0.01) among CRRT versus non-CRRT patients. Patients were administered thymoglobulin or basiliximab during cyclosporine withholding. The time to discharge from hospital after transplantation was longer in patients with CRRT (median 47 days versus 17 days, P<0.01). There was no mortality at three months in the CRRT group. CONCLUSION: Creatinine clearance is an important predictor of renal failure requiring renal replacement therapy. Although renal failure remains a serious complication after transplantation, the use of CRRT and antilymphocyte agents during cyclosporine A withholding is associated with a favourable short-term prognosis following heart transplantation.
BACKGROUND: Radial artery infections secondary to catheterization for blood pressure monitoring are rare but potentially serious complications. The objective of the study was to evaluate the incidence, the risk factors and the evolution of radial artery infections following cardiac surgery. METHODS: A retrospective review of 8300 patients undergoing cardiac surgery between 1998 and 2002 at the Montreal Heart Institute (MHI) was undertaken. All patients with superficial radial artery infections, infected radial artery pseudoaneurysms, and arterial catheter-related bacteremia were considered using prospective global surveillance of all nosocomial infections over the study period by an infection control nurse. RESULTS: Thirteen patients with radial infections were encountered (0.2%) with bacteremia occurring in 9 patients (0.15%). Five patients developed infected radial artery pseudoaneurysms (0.05%) and 5 patients developed subsequent sternal wound infections. Two patients died in their early postoperative evolution. Mean patient age was 67 years old and mean duration of cannulation was 5.8 days. Only 1 patient had diabetes. Seven of 13 patients were positive for Staphylococcus aureus (54%). All patients had undergone cardiopulmonary bypass (CPB) for various procedures. All superficial infections responded well to antibiotic therapy. Early surgical intervention is essential in cases of infected radial artery pseudoaneurysms. CONCLUSIONS: The postoperative state and cardiopulmonary bypass put patients at risk for infectious complications. Strict systematic changing of arterial lines on a timely basis is unwarranted in our opinion. A high suspicion index, aggressive surgical treatment of bacterial arteritis and appropriate intravenous antibiotics are essential to improve the prognosis.