الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Hemodialysis is still the most common RRT modality in ESRD patients. The first problem to be faced when choosing hemodialysis for patients with ESRD is the vascular access.
In diabetic ESRD patients there is advanced calcified atherosclerosis which leads to frequently inadequate arterial inflow and eventually also to venous run-off problems. So ESRD patients with diabetes have worse access survival rates and hemodialysis adequacy.
Dia¬lysis delivery should be adequate not only to improve quality of life but also to prolong sur¬vival; one method of assessing dialysis adequacy is cal¬culation of kt/v. This index reflects the effi¬ciency of dialysis and correlates with mortality and morbidity rate of patients. Quality of life adjusted for life expectancy defined kt/v of 1.2 as the optimal cost-effective dialysis dose.
An ideal access delivers a flow rate to the dialyzer adequate for the dialysis prescription, has a long use-life, and has a low rate of complications (e.g., infection, stenosis, thrombosis, aneurysm, and limb ischemia). Of available accesses, the surgically created fistula comes closest to fulfilling these criteria.
In general, a working fistula must have all the following characteristics; blood flow adequate to support dialysis which usually equates to blood flow greater than 600 ml/min, a diameter greater than 0.6 cm, with a location accessible for cannulation and a depth of approximately 0.6 cm (ideally between 0.5 and 1cm) from the skin surface.
In hemodialysis patients with an AVF, access failure is primarily due to fistula stenosis, which predisposes to thrombosis and subsequent access loss. The risk for access failure differs individually, an observation that is independent from vascular anatomy in a significant number of patients. Fistula stenosis is histologically characterized by intimal hyperplasia, which is induced by released TNF-α from leukocytes, which could induce proliferation of vascular smooth muscles leading to subsequent intimal hyperplasia.
Vascular access dysfunction is a well-known cause for a reduction in delivered dialysis, although the prevalence of this problem as a cause for a fall in Kt/v is not known, Inadequate vascular access flow rate due to stenosis leads to mixing of blood from the venous side of the dialysis circuit into the arterial inflow line. This reduces the concentration gradient and reduces net removal for dialyzable solutes.
The aim of this work is to study the relation between serum TNF- α and hemodialysis adequacy in diabetic and non-diabetic maintenance HD patients.
The study will be conducted on 75 subjects divided to 3 main groups:
1. 30 diabetic patients with ESRD on maintenance hemodialysis with functioning native arteriovenous fistula at Armed Forces Hospital & Police Hospital, Alexandria
Then the group will be subdivided to 2 subgroups according to duration of AVF to:
• 15 patients with AVF between 3 months and 6 months.
• 15 patients with AVF more than 1 year
2. 30 Non-diabetic patients with ESRD on maintenance hemodialysis with functioning native arteriovenous fistula.
Then the group will be subdivided