Jens J. Thiis

AUTOLOGOUS FIBRIN GLUE--PREPARATION AND CLINICAL USE IN THORACIC SURGERY

Autologous fibrin glue was used in 20 patients undergoing lung resection to reduce pulmonary air leaks and improve hemostasis. The fibrinogen in the glue was prepared by ethanol precipitation of plasma separated from 88 ml of the patients blood. The mean volume of fibrinogen concentrate +/- SD was 4.9 +/- 0.5 ml with a fibrinogen concentration of 28 +/- 5 mg/ml. The yield obtained by the separation was 81% +/- 9%. One part of fibrinogen concentrate was converted to solid fibrin by means of 0.3 parts of thrombin solution. The outcome was 6.4 ml of two-component fibrin glue. The preparation was performed in a closed system to ensure sterility, and was completed within 90 min. Pulmonary air leak decreased following sealing of the resection lines with autologous fibrin glue and the hemostasis was effective. No adverse effects were observed, and all cultures from the glue were negative. Autologous fibrin glue has the obvious advantages of safety from transmission of viral diseases and from immunological reactions. In summary, we report a new technique for preparing autologous fibrin glue with a high concentration of fibrinogen making it a safe and effective sealant of pulmonary air leak and hemostatic agent in thoracic surgery.

Chest pain after coronary artery bypass: relation to coping capacity and quality of life.

Objective - To investigate relations between chest pain after coronary artery bypass grafting (CABG), quality of life (QoL), and coping capacity. Design - Two groups were included, Group I ( n = 111) was evaluated before and 1 year postoperatively, and Group II ( n = 102) once, at 3 years. The questionnaire included parts of the Seattle angina questionnaire, one question concerning chest pain, coping capacity (sense of coherence), emotional state, the Psychological general well-being index, and a global QoL question. Results - Chest pain was significantly related to lower coping capacity (at 1 year) and lower QoL scores (at 1 and 3 years). Changes of coping capacity and emotional state from before to 1 year after the CABG did not reach statistical significance in the chest pain group while the no chest pain patients had significantly better emotional state. The relation between chest pain and worse QoL was significantly reduced by high coping capacity. Conclusion - Independent of the direction of causality, the patients coping capacity and experienced chest pain is highly related.

Effects of large conductance Ca2+-activated K+ channels on nitroglycerin-mediated vasorelaxation in humans

Nitric oxide (NO)-induced vasorelaxation and the regulation of endothelial superoxide anion levels is partly mediated by vascular large conductance Ca(2+)-activated K(+) (BK(Ca)) channels. Nitroglycerin acts through the release of NO and its effect is modulated by changes in endothelial superoxide levels. This study examines the effect of BK(Ca) channel blockade on nitroglycerin-induced vasorelaxation in human arterial and venous vascular segments and whether responses to BK(Ca) channel blockade are influenced by the development of venous nitroglycerin tolerance. Dose-relaxation curves to nitroglycerin (10(-10)-10(-4) M) were obtained in segments of the saphenous vein and the left mammary artery. Studies were performed with and without pre-incubation with the BK(Ca) channel blocker iberiotoxin (10(-7) M) and venous tolerance to nitroglycerin were induced by a 24-h i.v. infusion (0.5 microg/kg/min). Iberiotoxin reduced the vasorelaxant effect of nitroglycerin (E(max)) by 60% in endothelium-intact arteries and 13% in endothelium-denuded arteries (P<0.05). Development of nitroglycerin tolerance did not affect the response to iberiotoxin in the venous vascular segments (P>0.05) and (compared to arterial segments) veins were less sensitive to BK(Ca) channel blockade (30% reduction in E(max)) or endothelial removal. The results suggest that primarily arterial effects of nitroglycerin are significantly inhibited by changes in the activity of the endothelial BK(Ca) channels. Although endothelial BK(Ca) are likely regulators of mechanisms underlying arterial tolerance development to nitroglycerin, they do not appear to play a role in human venous nitroglycerin tolerance development.

Antibiotic Prophylaxis in Non-Cardiac Thoracic Surgery: A Double-blind Study of Penicillin vs. Cefuroxime

Patients referred for elective pulmonary surgery were enrolled in a prospective, randomized, double-blind study comparing the prophylactic efficacy of four-dose regimens of penicillin-G 5 million IU and cefuroxime 1.5 g. the first dose given immediately preoperatively. The treatment groups were comparable preoperatively with regard to all tested demographic factors. No significant intergroup difference was found concerning postoperative empyema, wound infection, septicaemia, pneumonia or fever of unknown origin, or any other complication or parameter tested in connection with pulmonary surgery. No side effects were observed, and no effects on the patients normal bacterial flora. Penicillin is recommended as prophylaxis in this type of surgery.

Brugada syndrome risk loci seem protective against atrial fibrillation.

Several studies have shown an overlap between genes involved in the pathophysiological mechanisms of atrial fibrillation (AF) and Brugada Syndrome (BrS). We investigated whether three single-nucleotide polymorphisms (SNPs) (rs11708996; G>C located intronic to SCN5A, rs10428132; T>G located in SCN10A, and rs9388451; T>C located downstream to HEY2) at loci associated with BrS in a recent genome-wide association study (GWAS) also were associated with AF. A total of 657 patients diagnosed with AF and a control group comprising 741 individuals free of AF were included. The three SNPs were genotyped using TaqMan assays. The frequencies of risk alleles in the AF population and the control population were compared in two-by-two models. One variant, rs10428132 at SCN10A, was associated with a statistically significant decreased risk of AF (odds ratio (OR)=0.77, P=0.001). A meta-analysis was performed by enriching the control population with allele frequencies from controls in the recently published BrS GWAS (2230 alleles). In this meta-analysis, both rs10428132 at SCN10A (OR=0.73, P=5.7 × 10−6) and rs11708996 at SCN5A (OR=0.80, P=0.02) showed a statistically significant decreased risk of AF. When assessing the additive effect of the three loci, we found that the risk of AF decreased in a dose-responsive manner with increasing numbers of risk alleles (OR=0.50, P=0.001 for individuals carrying ≥4 risk alleles vs ≤1 allele). In conclusion, the prevalence of three risk alleles previously associated with BrS was lower in AF patients than in patients free of AF, suggesting a protective role of these loci in developing AF.

Autologous Fibrin Glue—Clinical Use and Sealing of High-Porosity Vascular Prostheses

Autologous fibrin glue was prepared in a new way by means of ethanol. From 42 patients 44 mL of blood with a mean plasma fibrinogen concentration of 3.7 mg/mL was drawn. The product of the preparation was a mean of 2.5 mL of fibrinogen concentrate with a concentration of 28 mg/mL. After addition of 0.3 part of thrombin solution containing calcium chloride and aprotinin, an antifibrinolytic agent, the total volume of two-component fibrin glue was 3.3 mL. The preparation was done in a closed system to ensure sterility and com pleted within ninety minutes. Twenty high-porosity double-velour vascular prostheses were sealed with autologous fibrin glue in the laboratory. The pro stheses were tight for blood up to a pressure higher than 300 mmHg, which was comparable to vascular prostheses impregnated with collagen, but to more than twice the pressure of 130 mmHg, where vascular prostheses preclotted with blood started leaking. Autologous fibrin glue imparts a nice white vascular graft with superior handling characteristics, since it is nonsticky compared with blood-clotted grafts and softer and more pliable than the vascular prostheses impregnated with collagen from the manufacturer. In addition autologous fi brin glue has the obvious advantages of safety from transmission of viral dis eases and from immunologic reactions.

Composite Graft Replacement of the Aortic Valve and Ascending Aorta with Cabrol Technique

Replacement of the aortic valve, root and ascending aorta with the technique first described by Cabrol was performed on 17 patients. In five cases the aortic arch was also replaced. The indications were type A aortic dissection with aortic insufficiency (8 cases, with acute dissection in 7), native endocarditis with severe aortic insufficiency and aortic root abscess (3 cases), prosthetic endocarditis (3), and true aneurysm of the ascending aorta with aortic insufficiency (3). Acute surgery was performed in 15 cases (88%). The overall operative mortality was 41%. For the patients discharged from hospital the mean observation time was 30 months. None died, but in one case the right leg of the interposition graft became occluded and reoperation was required 40 months after the primary operation for acute type A dissection. The described technique of aortic valve and root displacement can be used in all cases in which use of a composite graft is indicated, except in situations where the coronary ostia and arteries are damaged by acute dissection.