Risk factors associated with vascular access steal syndrome in renal replacement therapy patients with chronic kidney disease. A multicenter study

Introduction: Symptomatic decrease in perfusion distal to the vascular access is a severe complication in patients with chronic kidney disease (CKD) in hemodialysis programs. This study aimed to identify the risk factors associated with vascular access steal syndrome (VASS) in patients with CKD undergoing renal replacement therapy in hemodialysis units. Methods: This case-control study was carried out in Santo Domingo and Portoviejo (Ecuador) hemodialysis units from January to December 2015. Patients with CKD 5-d with arteriovenous fistulae, with VASS (Cases) and without VASS (controls). The variables were demographic, type of arteriovenous fistula, the severity of the steal syndrome, comorbidities, size of the anastomosis, place of implantation of the vascular access, and etiology of kidney disease. The sample was probabilistic of 42 patients in each group. The association with the Odds ratio and 95% confidence interval is presented. Results: The average age was 56 ±15 years. In patients with VASS 33 cases (78.57%) were in the elbow forearm, 6 cases (14.29%) were in the arm, and 3 cases (7.14%) were in the wrist. The severity of VASS was Grade I, 10 cases (23.81%); grade II, 19 cases (45.24%); grade III, 6 cases (14.29%); grade IV, 7 cases (16.67%). Overweight/obese had an OR 3.1 (95% CI 1.24-7.75) P=0.01. The implantation of the fistula was different from the wrist OR 11.81 (95% CI 1.24-7.75) P=0.01. Type 2 diabetes and high blood pressure were not factors associated with the presence of VASS. The anastomosis size > 5 mm OR 0.20 (95% CI 0.07-0.52) was established as a protective factor. Conclusions: In the present study, overweight or obesity are established as risk factors for the presence of VASS at the implantation site other than the wrist.