The rate of hemolysis and the behaviour of platelets were investigated during extracorporeal pig liver perfusions. In 8 animals whose iliac vessels had been cannulated and which were perfused for 6 hours in our circuit, packed cell volume, number of red blood cells and concentration of hemoglobin changed moderately after hemodilution with the machine's priming volume. Similiar results were obtained in 10 pigs which were perfused with homologous isolated pig livers up to 6 hours. The best parameter to determine hemolysis was the plasma hemoglobin. Its level was twice as high as the initial value after mixture of the blood with the machine's priming volume in the iliac bypass experiments. Instead it remained practically unchanged throughout 6 hours of extracorporeal liver perfusions. The liver seemed to act as a filter under these experimental conditions. It had similar filtration effects on the enzymes LDH and alpha-HBDG which are set free in hemolysis. The decrease of platelets was more pronounced in extracorporeal liver perfusions than in iliac bypass experiments. Especially the functioning platelets decreased significantly in extracorporeal liver perfusions after 4–5 hours. The filtration effect of the liver seemed to be due to its intact RES. Xenogenous immunreactions played a minor role.

The inferior epigastric artery (IEA) is a new arterial graft for myocardial revascularization. We examined the inferior epigastric artery, the internal thoracic artery (ITA) and representative sections of the coronary arteries in 45 postmortem examinations, for microscopic signs of atherosclerosis. In addition, a morphometric evaluation of the intima and media of both conduits was performed. The intima of the ITA is significantly thicker, but atherosclerosis is absent. There are fewer fenestrations/mm in the internal elastic lamina (IEL) (4.00 +/- 1.60 versus 4.62 +/- 1.46) of the IEA and the combined thickness of media and intima is lower (0.20 +/- 0.04 mm versus 0.30 +/- 0.06 mm). However, 24% of IEAs showed medial calcification of variable degrees. We conclude that the IEA should not be used routinely for myocardial revascularization until the long-term patency of this graft has been explored.

The incidence of infection among over 3,000 central venous catheters, placed over a period of 18 months, was analysed, 1,570 retrospectively and 1,581 prospectively. The Shaldon catheter had the highest infection rate of the various catheter types. Taking the findings of 983 catheters of one type, Cavafix, the infection rate was significantly higher when the internal jugular vein was the site of puncture instead of the cubital or subclavian veins. Signs of inflammation at the site of catheter entry were a further risk factor for infection. Although the clinical suspicion of catheter-induced sepsis proved groundless in nearly half the cases, early catheter removal is at present the most effective prophylactic means, while routine weekly catheter replacement did not reduce the infection rate. Catheter colonization and catheter sepsis are predominantly problems of nursing and hygiene. The infection rate was reduced through nursing and supervision by personnel specially trained in infectious precautions.