Donor brain death mechanisms and outcomes after heart transplantation.

We sought to explore whether the cause of donor brain death influenced recipient outcomes after cardiac transplantation. In retrospect, 358 consecutive donors provided cardiac allografts to adult patients undergoing orthotopic heart transplantation at a single urban US medical center from January 2000 through December 2005. Alternate recipients were excluded. Mechanism and cause of donor brain injury and death were divided into five categories: anoxia (nontraumatic) (n=36), blunt head trauma (n=220), penetrating head trauma (n=83), brain tumor/infection (n=7), and cerebrovascular event (n=12). The five subgroups were categorized as traumatic or nontraumatic. The end points of the study were causes of early and late mortality, survival, and rejection rate. There were 59 deaths in the 6-year period. Total and short-term recipient mortality were found to be statistically higher among heart transplant recipients when the donors suffered from traumatic brain death compared to those whose brain death etiology was nontraumatic (P=.045, P=.033, respectively). Rejection rate was similar in all groups (P=.497). In conclusion, donor traumatic brain death was found to be a valid risk factor for recipient mortality after heart transplantation. Caution should be used when evaluating such donors, particularly in the presence of other risk factors.

Ethnicity as a predictor of graft longevity and recipient mortality in heart transplantation.

BACKGROUND: There is a dearth of data about the effect of donor and recipient ethnicity on survival and rejection rate after clinical heart transplantation, although the subject had been partly studied before. We compared the mortality and rejection rate among different ethnic groups at our institution. METHODS: In retrospect, 525 consecutive donors provided cardiac allografts to adult and pediatric patients undergoing orthotropic heart transplantation at a single, urban US medical center between 2000 and 2005. Donors and recipients were categorized according to ethnicity: African American, Asian, Caucasian, Hispanic, and Others (Indian, Mediterranean/Arabic, Afghans). Donor and recipient ethnicity-as an independent factor and the interaction between them-were examined as a risk factor for mortality and rejection after heart transplantation. Mean follow-up period was 3.2+/-1.9 years (range, 0.1 to 6.6). All recipients received triple immunosuppression consisting of a calcineurin inhibitor, an antiproliferative agent, and steroids. No patients received induction immunotherapy. The end points of the study were early and late mortality, rejection rate, and rejection-free survival time. RESULTS: The overall mortality was 17.3% (91 patients). Recipient mortality rate according to donor race was: African American, 23.1%; Asian, 11.1%; Caucasian, 18.7%; and Hispanic, 14.6%. No statistical significance was found, although the mortality differences presented. Recipient mortality with regard to recipients ethnicity was: African American, 22.2%; Asian, 6.3%; Caucasian, 18%; Hispanic, 18.9%; and others 40% (P=.048). Donor-recipient race match was not found as a risk factor influencing mortality as the matched group mortality was 17.5% comparing with the mismatched group mortality of 17.8% (P=.874). The overall rejection rate was 3.8% (20 rejection events). Rejection rate according donor race was: African American, 7.7%; Asian, 10.7%; Caucasian, 4%; and Hispanic, 1.3% (P=.027). Rejection rate with respect to recipients ethnicity was: African American, 0; Asian, 3.2%; Caucasian, 4.4%; Hispanic, 2.7%; and others, 20% with no statistical significance (P=.236). Donor recipient race match was not found as a risk factor influencing rejection rate (P=.58). CONCLUSIONS: Recipients' ethnicity was found as a significant risk factor for mortality. Rejection rate were found higher among the African American donors and significantly lower in the Hispanic donors. Significantly lower mortality rate was found among Asian recipients. Donor-recipient race match did not influence the mortality or rejection rate.

Expression of cardiomyocytic markers on adipose tissue-derived cells in a murine model of acute myocardial injury.

Animal and early clinical studies have provided evidence suggesting that intracoronary administration of autologous bone marrow-derived cells results in improved outcome following myocardial infarction. Animal studies with cultured marrow stromal cells (MSC) have provided similar data. Cells with properties that are similar to MSC have been identified in adipose tissue. Other groups have demonstrated in vivo differentiation of adipose tissue-derived cells (ADC) into cells exhibiting biochemical and functional markers of cardiac myocytes, including spontaneous beating. Based on these observations, the objective of the present study was to determine whether ADC might undergo similar differentiation in vivo in the context of myocardial injury.ADC were isolated from subcutaneous adipose tissue of Rosa26 mice (which express the beta-galactosidase transgene in almost every tissue) and injected into the intraventricular chamber of B6129S recipient mice immediately following induction of myocardial cryoinjury. Groups of recipients were euthanized at 24 hours, 7 and 14 days post surgery and examined for the presence of donor-derived cells within the heart.Beta-gal positive cells were identified in the infarcts of ADC-treated animals. No staining was observed in uninjured myocardium or in infarcts of control animals. Immunohistochemical analysis revealed co-expression of beta-gal with Myosin Heavy Chain, Nkx2.5 and with Troponin I. Co-expression of beta-galactosidase with Connexin 43, CD31, von Willebrand factor, MyoD or CD45 was not detected.Thus, these data indicate that adipose tissue contains a population of cells that has the ability to engraft injured myocardium and that this engraftment is associated with expression of cardiomyocytic markers by donor-derived cells.

Prevention of spinal cord ischemia in an ovine model of abdominal aortic aneurysm treated with a self-expanding stent-graft.

PURPOSE: To present novel techniques to prevent spinal ischemia during aneurysm creation and chronic bifurcated stent-graft implantation in an ovine model of abdominal aortic aneurysm (AAA). METHOD: Experimental AAAs were created in 38 sheep. To prevent spinal ischemia, an internal aortic shunt was used during aneurysm creation. In the animals designated to receive bifurcated stent-grafts, a left external iliac-to-internal iliac bypass was performed to revascularize the caudal artery and prevent postdeployment spinal cord ischemia. Specimens were harvested at 1 week, 1, 3, and 6 months, and 1 year. RESULTS: Aneurysms were successfully created without paralysis in 35 animals. Two died due to aspiration pneumonia. Of the 33 animals implanted with endografts, 16 (94%) of 17 with straight devices and 15 (94%) of 16 with bifurcated stent-grafts survived with well-functioning, patent stent-grafts. Paralysis developed in 2 animals after endografting due to technical failures. CONCLUSIONS: The use of an internal shunt during aneurysm creation and internal iliac-to-external iliac transposition prior to bifurcated stent-graft deployment prevented spinal ischemia in an ovine AAA model. Chronically deployed stent-grafts were well tolerated.

Subclavian vein thrombosis: outcome analysis based on etiology and modality of treatment.

Therapeutic options for subclavian vein thrombosis (SVT) include anticoagulation, thrombolysis, endovascular repair, and direct surgical intervention. The most effective method of treatment remains undetermined. We reviewed our institutional experience over 7 years with SVT patients to compare the results of treatment based on etiology of thrombosis. Nineteen patients suffered SVT secondary to malignancy, catheter placement, radiation, or hypercoagulability. Thirteen were Paget-Schroetter (PSS), or primary effort-related SVT. Patients with dialysis access procedures were excluded. Thrombolysis was initiated in 31/32 patients. Success was defined as complete obliteration of clot. Adjunctive treatment to relieve external compression or improve lumenal contour was performed on 16/32 patients (eight PSS, eight secondary SVT). Success of adjunctive treatment was defined as return to baseline activity without symptoms. Objective follow up (venography or duplex scanning) was included when available. Adjunctive treatment included balloon angioplasty (6), stent placement (5), first rib resection and scalenectomy (4), and vein reconstruction (4). Initial treatment success with thrombolysis was achieved in 26/31 patients (84%). Angioplasty failed in three PSS and three secondary SVT patients. Stent placement was successful in 2/5 patients (both secondary SVT). Surgery was performed only on PSS patients: first rib resection and scalenectomy succeeded 4/4 times, vein reconstruction 2/4. Twenty-eight patients were given long-term therapy with oral anticoagulation with good long-term results. Seven patients experienced complications, including one death. Results of SVT therapy including thrombolysis and oral anticoagulation are very good. Angioplasty and stent placement in secondary SVT patients appears to add little long term benefit. Surgery may improve outcome in selected PSS patients, although the additional benefit could not be determined by the design of this study. Evaluation and treatment limited only to PSS excludes the majority of SVT patients.

Etiology of aortic aneurysm.

Inthe past three decades, the prevalence of aortic aneurysms has increased threefold. Incidence of aortic aneurysms increases with age and as the population ages, the prevalence increases. Population-based stud- ies have shown that 10% of men over the age of 70 have abdominal aortic aneurysms. After many years of research, the exact pathogenesis of degenerative aneurysms-the most common form of aneurysm-is still unknown, although a number of factors including genetic, protelytic enzymes, hemodynamics, inflammation, and infection have been implicated.