Prevention of calcification with TPEN in pericardial bioprosthetic heart valve material.

OBJECTIVE: Calcification is a frequent cause of the clinical failure of bioprosthetic heart valves fabricated from glutaraldehyde pretreated bovine pericardium. The major object of the present study is to prevent calcification of pericardial bioprosthetic heart valve materials with TPEN. METHODS: Bovine pericardium was cut into 2-cm 2 pieces, rinsed in phosphate-buffered saline solution, transferred into +4 degrees C phosphate-buffered saline containing 0.625% glutaraldehyde for initial fixation for 48 h, and allocated into two groups. Control samples were treated in an identical fresh solution for five more days. Others underwent additional fixation in phosphate-buffered saline 2microM TPEN for 48 h. They were then transferred into phosphate-buffered saline + 0.625% glutaraldehyde solution at 37 degrees C (pH 7.4) for three more days. Pericardial patches were inserted into the dorsal pouches of 18 juvenile male Wistar rats as control and study groups. Rats were divided into two groups and sacrificed consecutively by the end of 9th and 12th weeks. The biomechanical properties and calcium contents of explanted tissues were tested and were also assessed histopathologically. RESULTS: The difference in the calcium contents of the control and study groups' pericardial tissues at the 9th, and 12th weeks were statistically significant (p=0.0001, p=0.0001). The comparison of calcium contents between controls of 9th and 12th weeks and study groups' of the 9th and 12th weeks pericardial tissues were also significant (p=0.0001 and p=0.0001). Histopathologic and biomechanical assessment also supported these findings. CONCLUSION: Calcific degeneration of glutaraldehyde-fixed bovine pericardium can be reduced by using TPEN without any effect on durability.

Iloprost for the attenuation of ischaemia/reperfusion injury in a distant organ.

The objective of this study was to investigate antioxidant and cytoprotective properties of iloprost in a distant organ after ischaemia reperfusion injury. Male Wistar rats were divided into two groups. After application of anesthaesia both hindlimbs were occluded. A 2-h reperfusion procedure was carried out after 60 min of ischemia. Study group (STU) rats (n=10) received 10 microg kg(-1) iloprost in 1 ml of saline from the tail vein 10 min before reperfusion. Control (CON) group rats (n=10) received an equal amount of saline. The rats were sacrificed by injection of a high dose of thiopentone sodium. Blood and tissue samples (right kidneys) were taken for analysis. Differences in malondialdehyde (MDA), myeloperoxidase (MPO), Na+-K+ ATPase and total antioxidant capacity (TAC) between the groups were analysed. MPO, MDA and TAC levels in the sera of CON and STU groups were 1.60+/-0.26 U l(-1), 11.42+/-5.23 nmol ml(-1), 8.30 x 10(-2)+/- 3.93 x 10(-2) nmol ml(-1) h(-1) and 1.07+/-0.11 U l(-1), 7.60+/-1.81 nmol ml(-1) and 0.15+/-3.23 x 10(-2) nmol ml(-1) h(-1) (p=0.0001, p=0.043 and p=0.0001 respectively). MPO, ATPase and MDA levels in kidneys for CON and STU groups were 1.24+/-0.58 U g(-1), 85.70+/-52.05 nmol mg(-1), 17.90+/-7.40 nmol ml(-1) and 0.78+/-0.31 U g(-1), 195.90+/-56.13 nmol mg(-1) and 10.10+/-0.99 nmol ml(-1) (p=0.046, p=0.0001 and p=0.009 respectively). When given prior to reperfusion, the positive effect of iloprost in the attenuation of distant organ reperfusion injury has been demonstrated.

Hearing loss in patients undergoing coronary artery bypass grafting with or without extracorporeal circulation.

BACKGROUND: Our aim was to investigate the differences in postoperative hearing thresholds in patients undergoing coronary artery bypass grafting with (Group I, n=20) or without (Group II, n=17) extracorporeal circulation. MATERIAL/METHODS: 37 patients undergoing coronary artery bypass grafting with or without extracorporeal circulation were prospectively evaluated in terms of hearing threshold changes with the intention of documenting hearing losses postoperatively. The t-test for two independent variables was used for statistical analysis. RESULTS: Hearing threshold changes were detected in 9 Group I patients (45%) and 3 Group II patients (17.65%). The difference between the two groups was statistically significant (p=0.0426). CONCLUSIONS: Postoperative hearing threshold changes, not necessarily revealed by clinical examinations, are encountered after coronary artery bypass grafting operations. Extracorporeal circulation usage seems to bring an additional risk in terms of hearing loss.

Angiographic and clinical outcome following paclitaxel-eluting stent (taxus) implantation: a single center experience.

Coronary stents dramatically improve acute outcomes of percutaneous coronary interventions but also induce abundant intraluminal neointimal growth. Drug-eluting stents reduce intimal hyperplasia, the main cause of in-stent restenosis. The safety and beneficial effects of paclitaxel-eluting stents (Taxus) in patients treated in daily practice remains to be defined. The aim of this study was to report the late outcomes of Taxus implantation in patients with coronary artery disease. The study population consisted of 151 patients (202 stents) who had undergone coronary Taxus stent implantation between March 2003 and May 2005. Patients were eligible for enrollment if there was symptomatic coronary artery disease or positive functional testing, and angiographic evidence of single or multivessel disease with a target lesion stenosis of 70% in a 2.0 mm vessel. The control coronary angiographies were performed after stent deployment at 12 +/- 2.8 months, and approximately 2 years of follow-up was completed. The polymer-based paclitaxel-eluting stent has been shown to be effective in reducing restenosis. Patients were followed-up for 16.7 +/- 7.4 months. All patients survived after stent implantation, but 2 (1.3%) patients experienced acute myocardial infarction after 3 and 9 months following angioplasty. Recurrent angina pectoris was observed in 3 patients. Angiographic evidence of restenosis was observed in these 5 patients. Three patients underwent angioplasty because of re- stenosis, and coronary artery bypass grafting was conducted in the other 2 patients. The results indicate that Taxus stents can be implanted with a very high success rate and have encouraging long-term angiographic and clinical results.