3 YEARS EXPERIENCE WITH BYPASS CANNULAE FOR CHRONIC HEMODIALYSIS

Abstract

In 14 patients over the past 3 yr., bypass cannulae were inserted to relieve obstruction in cannulae used for chronic hemodialyses. Experience with these patients has prompted changes resulting in improved technique. Clotting was the major cause of cannulae failure and infection was the 2nd most important cause. Other causes of failure included: venous atheroma, cannulae extrusion, aneurysms of the vessel at the cannulae tips, obstructive vegetation on the vessel wall, calcium deposits on the vessel wall, and thrombi on the vein walls. The mean survival time was improved from 1. 9 mo. in 1963-1964 to over 9. 0 mo. in 1965-1966. The longest surviving cannulae set was 2 yr. and the shortest 1 wk. It was considered that the most important factors contributing to increased cannulae survival are improved cannula care by patients and staff, the use of angiography for accurate diagnosis, and prompt anticoagulation if atheromatous stenosis of the venous component is encountered.