Hello there,
Welcome to HealthcareMagic. A failure of arterio-venous fistula for renal failures could be due to technical errors, hypotension, site of insertion, size of vessels, diabetes or even atherosclerosis.We can reduce failure rate of AVFs by monitoring and controlling the blood pressure during hemodialysis and prevent hypotension by salted regimen intake.Acute inflow stenosis is a rare cause, but can lead to acute inflow obstruction and cause sudden fistula failure and limb-threatening acute ischemia.As regards the cost, only surgical part would come to ~2000USD,but followed by that there is again chemotherapy too,the cost of which would vary from person to person.Wish your father good health.