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BioMed Research International
Volume 2013 (2013), Article ID 370582, 10 pages
http://dx.doi.org/10.1155/2013/370582
Research Article

Study of the Behavior of a Bell-Shaped Colonic Self-Expandable NiTi Stent under Peristaltic Movements

1Department of Mechanical Engineering, University of Zaragoza, Maria de Luna 3, 50018 Zaragoza, Spain
2Department of Gastroenterology, Miguel Servet University Hospital, Paseo Isabel la Católica 1, 50009 Zaragoza, Spain
3Department of Material Science, University of Zaragoza, Maria de Luna 3, 50018 Zaragoza, Spain
4Department of Manufacturing Engineering, University of Zaragoza, Maria de Luna 3, 50018 Zaragoza, Spain
5Department of Surgery, University of Zaragoza, Domingo Miral, 50009 Zaragoza, Spain
6Department of Orthopaedic Surgery and Traumatology, Miguel Servet University Hospital, Paseo Isabel la Católica 1, 50009 Zaragoza, Spain

Received 23 January 2013; Revised 6 May 2013; Accepted 21 May 2013

Academic Editor: Xin-yuan Guan

Copyright © 2013 Sergio Puértolas et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Managing bowel obstruction produced by colon cancer requires an emergency intervention to patients usually in poor conditions, and it requires creating an intestinal stoma in most cases. Regardless of that the tumor may be resectable, a two-stage surgery is mandatory. To avoid these disadvantages, endoscopic placement of self-expanding stents has been introduced more than 10 years ago, as an alternative to relieve colonic obstruction. It can be used as a bridge to elective single-stage surgery avoiding a stoma or as a definitive palliative solution in patients with irresectable tumor or poor estimated survival. Stents must be capable of exerting an adequate radial pressure on the stenosed wall, keeping in mind that stent must not move or be crushed, guaranteeing an adequate lumen when affected by peristaltic waves. A finite element simulation of bell-shaped nitinol stent functionality has been done. Catheter introduction, releasing at position, and the effect of peristaltic wave were simulated. To check the reliability of the simulation, a clinical experimentation with porcine specimens was carried out. The stent presented a good deployment and flexibility. Stent behavior was excellent, expanding from the very narrow lumen corresponding to the maximum peristaltic pressure to the complete recovery of operative lumen when the pressure disappears.