Case Report Nitinol stenting and an unsuccessful surgical operation

Stent implantation in vascular access for haemodialysis has grown up in the last few years. Nine percent of percutaneous transluminal angioplasties (PTA) performed in 2001 on haemodialysis accesses was associated with stent implantation, according to the United States Renal Data System 2003 annual data report [1]. Furthermore, graft longevity is improved when stenoses are treated with stents in selected cases [2,3]. Among several materials, nitinol is one of the most used: it is a non-magnetic alloy of nickel (ni) and titanium (ti) (þ nol, from Naval Ordinary Laboratory, where it was created in 1968) [4]. We report here the case of a haemodialysis patient bearing a native arteriovenous fistula (AVF), in whom nitinol stents behaved as a two-faced Janus: initially, nitinol stent implantation in a stenotic vein enabled the patient to overcome a syndrome of venous hypertension; after 1 year, when surgical ligation of the AVF was decided upon because of the relapse of the syndrome, the same nitinol stents represented an unexpected trap.