Determination of Survival of Various Types of Vascular Accesses in Patients with End Stage Renal Disease

There are profound challenges in relation to the development of end stage renal disease (ESRD) against communities around the world [1,2] More than 1.5 million people worldwide have end stage renal disease, and this figure is rising steadily. Patients with acute renal failure or end stage renal disease require renal replacement therapy, which includes peritoneal dialysis (PD), hemodialysis (HD), or kidney transplantation [3]. Transplantation is a good treatment for patients with end stage renal disease. But in a group of patients, Received: February 18, 2019


Introduction
There are profound challenges in relation to the development of end stage renal disease (ESRD) against communities around the world [1,2] More than 1.5 million people worldwide have end stage renal disease, and this figure is rising steadily. Patients with acute renal failure or end stage renal disease require renal replacement therapy, which includes peritoneal dialysis (PD), hemodialysis (HD), or kidney transplantation [3]. Transplantation is a good treatment for patients with end stage renal disease. But in a group of patients, with failure of peritoneal dialysis, failure in the transplant or low socioeconomic status, continuous hemodialysis remains the only choice [4]. Broad access to dialysis has caused the lives of hundreds of thousands of patients with long-term end stage renal disease (ESRD) [5] Hemodialysis has become a safe and high tolerance treatment for patients with end-stage renal disease [6].
Patients with end-stage renal disease require permanent vascular access to hemodialysis treatment and care and maintenance of vascular access to these patients is one of the important issues for them [7] There are three primary vascular accesses for hemodialysis: Arteriovenous-fistula, Arteriovenousgraft and Venous-Intravenous catheter ( Figure 1). Any vascular access has distinct advantages and disadvantages. The ideal vascular access after placement can be quickly applied and has a low initial failure rate and low mechanical and infectious effects [8]. Factors that have a significant effect on vascular access selection include age, associated illness, vascular quality, prognosis, urgency of dialysis and surgeon's preference. The care of vascular access should be centered around the patient, with the goal of maximizing patient survival without loss of vascular access, not just focusing on the longevity of vascular access [9]. AVF is caused by anastomosis of the patient's artery and vein [10] as a subcutaneous anastomosis of an organ artery to an adjacent vein [11]. Graft, used in the manufacture of synthetic materials or animal veins [12], and subcutaneously, a tube graft between an arteriovenous graft and the artery [11] One quarter of the cost of care for patients with end stage renal disease is vascular access. On the other hand, dialysis by artificial graft increases the rate of disability and associated costs compared with normal arterial-venous fistula [13,14]. The most important principle in any type of vascular access is its duration of survival as an effective method for dialysis [15]. Also, vascular access problems account for about 16-25% of hospital admissions [16]. Failure in vascular access increases the efficacy and usefulness of treatment, quality of life, disease, hospitalization and mortality among hemodialysis patients in the world [17][18][19].
Accidents and thrombotic problems in AVF and graft (poly tetra fluoroethylene) often lead to failure and loss of vascular access [20]. Also, thrombosis and vascular access infection lead to 20 to 40% hospitalization in hemodialysis patients [21].

Materials and Methods
This cross-sectional descriptive-analytic study was performed with survival analysis. Using a simple sampling method, two hemodialysis centers in Gorgan (north west of Iran) were selected and the vascular access of all patients in this study was collected from the time of using vascular access until August. We counted all endstage renal transplant patients undergoing chronic hemodialysis from 2015 to 2017, who entered the study.160 patients were enrolled and their case was studied. One patient was excluded from our study due to kidney transplants due to death and other illness.  Table 2 shows the frequency of patients on the basis of diabetes in the studied population. Table 3 shows the frequency of patients based on high blood pressure in the study population. Four patients could not be weighed due to pneumonia,The BMI of patients was calculated and categorized in three groups of 18, 18, and 30 and> 30, which were 8.2% and 77.8%, respectively, and 11.9% of patients in these groups. Table 4 shows the frequency of patients based on BMI groups in the studied population. Table   5 shows the frequency of vascular access types in terms of BMI groups in the population under study.  The average survival rate of all types of permanent vascular access was 42.65 months with a standard deviation of 41.83 months.
The minimum survival was 3 months and the highest survival was 249 months. Table 6 shows the survival of a variety of vascular access methods. Table 7 shows the survival of a variety of vascular access approaches based on age groupsBased on the results of ANOVA, there is no significant relationship between different age groups and survival rates of vascular access. (P = 0.064). Table 8 shows

Discussion and Conclusion
In a retrospective study conducted by Arhuidese et al. [22] In In our study, the highest prevalence of vascular access is related to AVF, as opposed to the study by Dr. Arhuidese et al. [22] with the highest incidence of permanent catheter.
But in both studies, the prevalence of AVF use is greater than that of AVG, and the survival of arterial venous fistula is more than graft but in our study, contrary to the study, AVF survival is significantly higher than AVG In a systematic review and meta-analysis study conducted by (95% CI, 56% -73%, 6 studies, 11 cohorts, 1,939 AVFs) [23][24][25][26]. In our study, the survival rate of one-year-old AVF was 92.1%, which is higher than that of Ahmed A. Al-Jaishi and colleagues.

Research limitations
The study also had some limitations. In this study, the effect of cigarette smoking and coagulation problems and vascular access and peripheral vascular disease in survival of vascular access is not considered. Also, the results of survival are different from global studies, which may be due to insufficient sample size. It is also not possible to mention the exact time of insertion of vascular access due to patient defect and memory. Therefore, it is recommended that future studies should be conducted with a larger sample size and the effects of factors such as smoking and vascular access, and peripheral vascular disease and coagulation problems will be measured on the survival of vascular access techniques. It is also advisable to accurately record the exact history of the creation and failure of vascular access and substitution or interventions to open vascular access in a country's system in order to more accurately study the survival of vascular access in the future.