Arteriovenous aneurysms in patients on hemodialysis.
ABSTRACT Realization of vascular access for patients with chronic renal failure on chronic hemodialysis sometimes proves to be a difficult task. Problems arise when these routes start creating complications and technical difficulties after longterm hemodialysis. A similar problem arises in dealing with arteriovenous aneurysms in patients on chronic hemodialysis. Along with technical difficulties, there also are a number of problems related to hemodynamics and hemostasis. In the present study, 32 patients were analyzed. These patients had advanced arteriovenous aneurysmal dilatations which necessitated surgical intervention. The state of advancement, the causes and the possible types of aneurysms were taken into account. Serious surgical aneurysmal complications were observed in more than 40 percent of the cases. After surgical removal of the arteriovenous aneurysms, the problem of creating new routes for continuing hemodialysis always arose and frequently led to atypical and nonconventional solutions. Suggestions are made for prolongation of life and maximal avoidance of aneurysmal dilatation development in the vascular accesses of patients on chronic hemodialysis.
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ABSTRACT: Complications in arteriovenous fistula (AVF) occur in up to 35% of renal failure patients on hemodialysis. The most frequent complication is thrombosis, usually from stenotic lesions in the venous outflow system. To study the pre-existing smooth muscle changes in the cephalic vein of these patients, we prospectively collected a total of 17 cephalic vein specimens from 3 normal controls and 14 renal failure patients undergoing primary AVF construction on the chosen limb. After preparation, ultrathin sections were stained with uranyl and lead acetate and were examined under the transmission electron microscope (TEM). Compared with the normal controls, abnormal fibrous infiltration of the intima and the media and varying degrees of smooth muscle degenerative changes were observed in all the cephalic vein sections of renal failure patients. Smooth muscle cells (SMCs) lost their normal fusiform shape and were widely separated by increased amount of irregularly disposed, extracellular collagen fibers. Other cellular abnormalities included irregular cell membrane, granular cytoplasm, Peri- and Paranuclear vacuoles and mega mitochondria. SMCs also showed morphological expression of phagocytosis of collagen and elastic fibers as a sign of remodeling of the vein wall. In conclusion, pre-existing wall and smooth muscle changes were observed in all the cephalic vein sections of renal failure patients, which may contribute to the later complications of AVFs.Journal of Smooth Muscle Research 07/2002; 38(3):75-85.