Transplantation
-
This study was designed to examine the effects of both nitric oxide and milrinone on pulmonary hemodynamics and right ventricular function using a newly established model of monocrotaline pyrrole-induced chronic pulmonary hypertension. Sixteen mongrel dogs (23-25 kg) were used. All animals underwent percutanous pulmonary artery catheterization to measure right heart hemodynamics prior to and 8 weeks after a right atrial injection of either monocrotaline pyrrole (MCTP, n=8) or placebo (CTL, n=8). ⋯ Both nitric oxide and milrinone resulted in significant improvements in pulmonary vascular resistance, pulmonary blood flow, and right ventricular contractility. In addition, nitric oxide caused a significant improvement in pulmonary artery pressure and transpulmonary efficiency, while milrinone led to a significant increase in right ventricular hydraulic power. This study demonstrates the well-known clinical effects of nitric oxide and milrinone in improving pulmonary hypertension, which were also associated with an increase in pulmonary blood flow, transpulmonary efficiency, and right ventricular hydraulic power in the setting of monocrotaline pyrrole-induced chronic pulmonary hypertension.
-
A reliable method for determining the adequacy of immunosuppression of the lung allograft and the absence of rejection or infection does not exist. The purpose of this study is to evaluate the potential role of bronchoalveolar lavage (BAL) in monitoring the adequacy of immunosuppression of lung allografts and in identifying the possible presence of acute rejection (AR) or infection. Thirty-one consecutive lung transplant recipients were subjected to bronchoscopy, transbronchial biopsy, and BAL either as routine surveillance or for decline in lung function (n=68 episodes: 27 normal, 17 infections, six grade IAR, 10 grade II-III AR, and eight obliterative bronchiolitis). ⋯ Patients with obliterative bronchiolitis, on the other hand, had a mild elevation in the percentage of neutrophils and lymphocytes in BAL, which did not reach statistical significance. However, BAL T-cell LDCMC was significantly elevated (37.6+/-13.7%, P=0.019) compared with normal and infected allografts. We conclude that phenotypic and nonspecific cytotoxic T-cell analysis of BAL, when complimented with microbiological studies, may be useful in surveillance of lung transplant recipients and in determining whether allografts are likely to be quiescent, or possibly affected by acute/chronic rejection or infection, necessitating further definitive action.
-
Although bladder drainage of pancreatic exocrine secretions has been reported to decrease morbidity and improve pancreas allograft survival, significant complications remain associated with this technique. Furthermore, this technique requires systemic venous drainage of pancreas allografts. Evidence suggests that portal venous drainage of pancreas grafts prevents hyperinsulinemia and improves lipoprotein composition. ⋯ The incidence and outcome of allograft rejection were similar for the two techniques. These data suggest that combined pancreas/kidney transplantation with portal venous and enteric exocrine drainage is safe and results in outcomes similar to the standard technique, while eliminating many complications of bladder drainage. These findings should encourage additional studies to determine the consequences of portal venous drainage.
-
Comparative Study
Characterization of hypothermic intestinal ischemia-reperfusion injury in dogs. Effects of glycine.
The effects of 48 hr of hypothermic (4 degrees C ischemia) and short-term reperfusion. (I-R) on intestinal function and metabolism were studied in dogs utilizing Collins flush alone or with the putative cytoprotectant amino acid, glycine. Intestinal blood flow after hypothermic ischemia in Collins-flushed segments briefly rose at reperfusion, rapidly declined after 5 min, and plateaued over the 60-minute reperfusion period. Paired intestinal segments flushed with 5 mM glycine demonstrated parallel changes in blood flow over the reperfusion period, but the blood flow values were significantly higher (100-300%), relative to the Collins segments. ⋯ Glycine flush did not alter this pattern of NO synthesis. Light microscopic analysis in both Collins- and glycine-flushed segments revealed that intestinal hypothermic ischemia and reperfusion caused significant morphologic changes characterized by loss of villus epithelium, decreased villus height, and venous congestion. These data indicate that glycine significantly improve oxygenation after hypothermic ischemia and reperfusion and prevented the I-R-induced increase in tissue neutrophil infiltration and leukotriene synthesis.
-
Orthotopic liver transplantation is an established therapy for end-stage liver disease. This study evaluated the range of cardiovascular abnormalities in patients undergoing evaluation for orthotopic liver transplantation and determined the prognostic implications of abnormal echocardiographic features, including ischemia during dobutamine stress echocardiography, in predicting postoperative cardiac events. Two-dimensional echocardiography was performed in 190 patients for assessment of left ventricular function, valvular pathology, and pulmonary hypertension. ⋯ The majority of patients with end-stage liver disease, including those with alcoholic cirrhosis, have normal cardiac function on two-dimensional echocardiography. Severe intrapulmonary shunting portends a poor prognosis in patients awaiting transplantation. A negative dobutamine stress echocardiogram appears useful in excluding patients at risk for perioperative cardiac events related to obstructive coronary artery disease.