Arteriovenous fistula (AVF) is now the optimal method of obtaining vascular access for dialysis. Measures such as systemic anticoagulation have been proposed as means of increasing patency rates but enough evidence does not exist to support their use. The investigators aimed to evaluate the efficacy of preoperative heparin injection on patency of AVF during the first 24 hours after surgery and to determine whether such measure can be used to prevent early thrombosis of the vascular access.

The study was carried out on patients admitted to Shohada-e-Tajrish hospital for permanent vascular access placement since April 2011 through September 2012. The exclusion criteria consisted of having a contraindication of administration of anticuagulant agent. 150 patients were enrolled in the study.

All patients were operated on by a single surgeon (Dr Mozafar. The non dominant upper extremity (mostly the left arm) was generally used unless unfavorable vasculature or previous fistula placement changed the preference. The anastomosis technique was either end-to-side or side-to-side using a number 6.0 prolene suture. 75 patients were randomly assigned to receive 100units/kg of heparin after dissection prior to anastomosis while the other 75 received no intraoperative heparin injection. Auscultation of bruit and palpation of thrill was used to assess arteriovenous fistula patency in the first 24 hours after AVF placement.

Data analysis was performed using SPSS v.20. A p-value of less than 0.05 was considered as statistically significant. Bivariate analysis in the form of Chi-square tests, T-test and Fischer's exact test were calculated.

Patient enrollment was voluntary and no costs were imposed on the patients. The study protocol was in accordance with 1975 Declaration of Helsinki.

Inclusion Criteria:

• Chronic Kidney Disease, In need of AVF placement

Exclusion Criteria:

• Contraindications for anticoagulant therapy