A simple method of maintaining cannula patency for repeated hemodialysis.

Hemodialysis requires repeated arterial and venous cut-downs unless Scribner's bypass technique is used. Infusion of large volumes of fluid causes further attrition of vessels; cardiac decompensation is a contraindication for an arteriovenous bypass. To overcome these problems a simple method of maintaining indwelling arterial and venous cannula patency by gravity infusion of 20 mg. heparin in 500 mg. of solution has been devised. The solution is suspended from a ceiling hook, the height being adjusted by pulley, according to the patient's blood pressure. A minimum infusion rate of 500 ml. per day keeps the cannula open indefinitely. In three patients dialyzed repeatedly the cannulae remained patent up to 13 days and were still open when removed. The method also facilitates connection of the patient to a dialyzer.