Endovascular Management for Salvage of Failing Arteriovenous Fistula

Background: Failure of arteriovenous access for hemodialysis is a challenging problem. Maintaining the patency of this access is one of the most important corner stones in the care of patients with chronic renal failure. Recently, percutaneous transluminal balloon angioplasty (PTA) is considered the first line of treatment for dealing with this issue. Aim: The purpose of this retrospective observational study was to evaluate the primary and secondary patency rates after initial endovascular intervention to restore and preserve the patency of failing autogenous arteriovenous fistulae and to identify the potential factors that affect the durability of the procedure. Methods:The results of 56 patients with failing autogenous arteriovenous fistulae were retrospectively analyzed after being treated with percutaneous transluminal balloon angioplasty from November 2014 to December 2018. Technical & clinical success rates were reported. The variables, including patients’ demographics, co-morbidities, medications, fistula age, fistula type, site, number of lesions and degree of stenosis were analyzed and correlated with primary and secondary patency rates. Results: The mean age of the fistulae included in the study since their creation was 17.4 ± 9.6 months, most of which were radiocephalic fistulas (64.3%). The most common cause of autogenous access dysfunction was 90-99% stenosis while the most common site of stenosis was juxta-anastomotic. Technical and clinical success rates of the study population were 92.9% and 89.3%, respectively. The mean primary and secondary patency were 12.3 and 19.9 months, respectively. Primary patency rates at 6,12,18 and 24 months were 79%, 64%, 57% and 44% respectively. Secondary patency rates at 6,12,18 and 24 months were 85%, 76%, 68% and 52% respectively. Patient age ≥ 60 years old was associated with reduced post-PTA primary patency (P < 0.001) and secondary patency (P = 0.018). Dyslipidemia showed marked decrease in both primary and secondary patency rates (P < 0.001). Insulin intake (P < 0.001) was a predictor of primary patency decrease while use of antiplatlets was to a less extent predictor of secondary patency loss (P = 0.004). Radiocephalic fistulae had short primary patency (P = 0.016), while stenotic lesions > 90% showed a significant decrease (P < 0.001) in primary patency more obvious than with secondary patency (P = 0.006). Lesions at arteriovenous anastomosis were significantly associated with decrease in primary patency (P < 0.001). Statins were the only medications associated with longer primary patency (P < 0.001). Age of fistula and number of lesions were independent factors. Conclusion: Endovascular treatment is both safe and effective in managing failing autogenous arteriovenous fistulas. Although its technical and success rates are high, primary and secondary patency rates are still questionable. Dyslipidemia, insulin, statin and antiplatelet intake together with age of patient, degree and site of stenosis are potential risk factors that affect these rates.