Cell engraftment is a new strategy for the repair of ischemic myocardial lesions. The hemodynamic effectiveness of this strategy, however, is not completely elucidated yet. In a rat model of cryothermia-induced myocardial dysfunction, we investigated whether syngeneic transplantation of neonatal cardiomyocytes or satellite cells is able to improve left ventricular performance. Myocardial infarction was induced in female Lewis rats by a standardized cryolesion to the obtuse margin of the left ventricle. After 4 weeks, 5 × 10 6 genetically male neonatal cardiomyocytes (n = 16) or satellite cells (n = 16) were engrafted into the myocardial scar. Sham-transplanted animals (n = 15) received injections with cell-free medium. Sham-operated animals (n = 15) served as controls. Left ventricular performance was analyzed 4 months after cell engraftment. Chimerism after this sex-mismatched transplantation was evaluated by detection of PCR-amplified DNA of the Y chromosome. The average heart weight of the infarcted animals significantly exceeded that of controls (p < 0.05). In sham-transplanted animals, mean aortic pressure, left ventricular systolic pressure, aortic flow (indicator of cardiac output), and left ventricular systolic reserve were significantly lower (p < 0.05) compared with sham-operated controls. This was associated with deterioration of ventricular diastolic function (maximal negative dP/dt, time constants of isovolumic relaxation; p < 0.05). Transplantation of satellite cells was found more effective than transplantation of neonatal cardiomyocytes, resulting in i) normalization of mean aortic pressure compared with sham-operated controls, and ii) significantly improved left ventricular systolic pressure and aortic flow (p < 0.05) compared with sham-transplanted animals. Left ventricular systolic reserve and diastolic function, however, were improved by neither satellite cell nor neonatal cardiomyocyte transplantation. Analysis of male genomic DNA revealed 3.98 ± 2.70 ng in hearts after neonatal cardiomyocyte engraftment and 6.16 ± 4.05 ng in hearts after satellite cell engraftment, representing approximately 10 3 viable engrafted cells per heart. Our study demonstrates i) long-term survival of both neonatal cardiomyocytes and satellite cells after transplantation into cryoinfarcted rat hearts, ii) slight superiority of satellite cells over neonatal cardiomyocytes in improving global left ventricular pump performance, and iii) no effect of both transplant procedures on diastolic dysfunction.
Five-year results are comparable and encouraging for remodelling and reimplantation procedures. If the initial valve function and geometry is adequate, the chance of secondary failure beyond the first year is minimal.
Despite omental wrap and avoidance of prophylactic administration of corticosteroids in the early postoperative phase, ischemic bronchial complications still represent an important source of early morbidity and mortality following lung transplantation. In a retrospective analysis, the effect of pharmacological enhancement of pulmonary collateral flow on bronchial healing was investigated. Thirty-nine consecutive unilateral or bilateral transplant procedures (Tx) were analyzed. Immunosuppression consisted of rabbit antithymocyte globulin (RATG), cyclosporine A, and azathioprine. In group 1 (10 Tx, 12 anastomoses) routine immunosuppression was employed and the anastomoses wrapped with an omental or pericardial pedicle. In group 2 (29 Tx, 41 anastomoses) PGI2 (4 ng/kg per min x 48 h), heparin (200 U/kg per day), and prednisolone (0.5 mg/kg per day) were added to the therapeutic regimen. The 2 groups were comparable with respect to age and sex of the patients, primary diagnosis, type of transplant, intraoperative use of extracorporeal circulation, graft ischemia, duration of mechanical ventilation, and mortality. Bronchoscopic evidence of a significant bronchial ischemia (extending more than 1 cartilaginous ring beyond the anastomosis) was seen in 8 of 12 anastomoses in group 1 vs 14 of 53 anastomoses in group 2 (P = NS). In group 1, significant bronchial stenosis required implantation of an endobronchial silicone stent in 6 of 12 anastomoses, whereas in group 2, no significant bronchial stenosis occurred (P less than 0.01). No negative effects possibly related to the prophylactic administration of corticosteroids could be observed.(ABSTRACT TRUNCATED AT 250 WORDS)
Surgical removal continues to be the mainstay in the treatment of renal-cell carcinoma with neoplastic venous extension. The steady improvement of surgical and anesthesiological techniques and the introduction of complete circulatory arrest has dramatically improved the morbidity even of patients with extensive thrombi. If ultrasound or computerized tomography (CT) scanning suggests the presence of a venous extension in a patient with renal-cell carcinoma, cavography, magnetic resonance imaging (MRI), transesophageal color-coded ultrasound, and echocardiography may be needed to resolve the questions of cranial extension and vascular wall infiltration. Surgical stratification and, thus, classification of the venous extension depend on the potential need for complete circulatory arrest. Surgical removal is done en bloc for smaller venous extensions and in a two-step procedure (radical nephrectomy followed by thrombectomy) for more extensive thrombi. In patients with infiltration of the suprahepatic inferior vena cava, the hepatic veins or atrium, pending thrombotic embolism, or large masses of suprahepatic thrombotic material, the use of cardiopulmonary bypass and complete circulatory arrest is recommended.
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