NiTi based stent for the treatment of acute urinary retention due to benign prostatic hyperplasia: a preliminary study on NiTi wires and tubes under pure bending

Benign prostatic hyperplasia (BPH) remains an incompletely understood disease, mostly striking old men. As an alternative to catheterization, an innovative NiTi shape memory alloy (SMA) based stent, made of a helical wire inserted into a helical tube was developed. In particular, this stent presents at least two distinct successive shape memories during heating, allowing an extension phase to release the urethra, and a contraction phase for an easy removal. This paper presents the stent mechanism, and the first mechanical characterization of the NiTi wires and tubes, under pure bending.