From the Research
Rectosigmoid stents are held in place primarily through their self-expanding design and the mechanical forces they exert against the bowel wall, as well as features like flared ends and tissue integration, which prevent migration and ensure luminal patency. The self-expanding design of these stents allows them to expand radially and press against the surrounding tissue, creating friction that prevents migration. Most rectosigmoid stents have flared ends (also called flanges) that are wider than the central portion, which helps anchor the stent at both ends of the stricture or obstruction. The stent's mesh structure allows it to embed slightly into the mucosal tissue over time, further securing its position. Some stents also incorporate specific design features like barbs or hooks that enhance fixation by gently gripping the bowel wall. The body's natural response to the stent as a foreign object includes tissue ingrowth through the mesh openings, which provides additional stabilization within 1-2 weeks after placement, as noted in studies such as 1.
Key Features of Rectosigmoid Stents
- Self-expanding design for radial expansion and friction against the bowel wall
- Flared ends for anchoring at the stricture or obstruction sites
- Mesh structure for tissue embedding and integration
- Optional design features like barbs or hooks for enhanced fixation
Clinical Evidence
Studies such as 1 and 2 support the use of rectosigmoid stents for palliation of obstructing rectosigmoid cancer, highlighting their effectiveness in maintaining luminal patency and reducing the need for colostomies. However, the most recent and highest quality study, 1, is prioritized for its comprehensive analysis of postoperative complications, mortality, and colostomy formation rates, demonstrating the benefits of preoperative stent placement.
Stent Placement and Patient Outcomes
The placement of rectosigmoid stents has been associated with lower postoperative complications and a lower rate of colostomy formation, as shown in 1. This study characterized the national incidence of preoperative placement of a colonic stent in the setting of malignant obstruction, supporting the hypothesis that stenting as a bridge to surgery may benefit patients by converting an emergent surgery into an elective one.