Abstract
Pathological examinations of internal arterio venous fistulae were done in 7 regular hemodialysis patients. The vascular wall of fistula vessel was stained with hematoxylin eosin, azan, Elastic-Van Gieson, aldehyde fuchsin, HE·Kossa reaction double staining, and immunohistochemical staining with mouse anti-α actin monoclonal antibody. Fistula-vessel wall was characterized with both arterial structural change and thrombotic phlebitis. Severe fibrous hypertrophy of the medial layer was common finding. Foamy cell, which play an important role in pathogenesis of arteriosclerosis, was not found in the intima. In the medial layer, elastic lamina was severely broken and atrophic or proliferative smooth muscle cells were seen, and the adventitia showed severe hemorrhagic adventitis with fibrous sclerosis. Moreover many polymorphic leukocytes appeared, especially around vessels in the adventia. It is suggested that the direct injury caused by repeated direct injuries with needle punctures, migration-prolifilation of smooth muscle cells and the continuos immunoreaction of chronic panangitis are the most important pathogenetic factors of fistula lesions in regular hemodialysis patients. The DD genotype of the angiotensin-converting enzyme was not found in the seven patients.
