Endoscopic Stent Geometry for Bile Reflux After Bariatric Surgery
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Solution Overview
Problem
Existing bariatric stents used to treat leaks after sleeve gastrectomy or biliopancreatic diversion with duodenal switch are prone to migration and do not effectively prevent bile reflux due to their inadequate shape adaptation to the modified stomach geometry, leading to complications such as stricture and increased pressure in the upper part of the sleeve.
Innovation Solution
A stent with a flared proximal end, enlarged middle portion, and distal end portion, combined with a polymeric sleeve extending past the common bile duct, and optionally a one-way valve or elastomeric band, designed to prevent bile reflux by guiding bile into the small intestine and maintaining stent position within the stomach and duodenum.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing bariatric stents are used to treat leaks after sleeve gastrectomy, then leaks can be addressed, but the stents are prone to migration and do not effectively prevent bile reflux due to inadequate shape adaptation to modified stomach geometry
Solution Approach 1:
The stent incorporates different geometric features at different locations: a proximal flare portion (10-20 mm length, 5-15 mm flare angle) for esophageal anchoring, an enlarged middle portion (30-60 mm length, 10-30 mm diameter increase) for stomach body adaptation, and a distal tapered portion for duodenal positioning. This local differentiation of geometric properties enables the single stent to adapt to the complex three-dimensional anatomy of the modified stomach while maintaining stable positioning and preventing bile reflux.
2Object-affected harmful factors
If existing stents are used, then leak treatment is provided, but bile reflux prevention is inadequate leading to complications such as stricture and increased pressure in the upper part of the sleeve
Solution Approach 1:
The stent employs curved and tapered geometric transitions rather than abrupt angular changes. The proximal flare portion has a gradual 5-15 mm flare angle, the enlarged middle portion provides smooth radial expansion, and the distal portion tapers gradually. These curved transitions distribute mechanical stress evenly along the stent structure and surrounding tissue, preventing pressure concentration that would lead to stricture formation while effectively blocking bile reflux pathways.
3Adaptability or versatility
If the stent is designed with enlarged middle portion and flared ends, then adaptation to stomach geometry improves, but device complexity increases
Solution Approach 1:
The stent is divided into three distinct functional segments: a proximal flare portion for esophageal engagement and anchoring, an enlarged middle portion for adapting to the stomach body geometry, and a distal tapered portion for duodenal positioning. This segmentation allows each portion to be optimized for its specific anatomical location while maintaining overall structural integrity through continuous construction, balancing adaptability with manageable complexity.
Data Source
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AI summary
An endoscopic stent for implantation in a patient after sleeve gastrectomy or biliopancreatic diversion with duodenal switch or biliopancreatic diversion with duodenal switch comprising a stent portion, the stent portion comprising a proximal end portion, the proximal end portion defined by a length of about 50 mm to about 200 mm, an enlarged middle portion, a middle portion having an enlarged diameter relative to the proximal end portion and the distal end portion and defined by a length of about 20 mm to about 80 mm, and a distal end portion and a polymeric sleeve portion engaged to and extending distally from the distal end portion of the stent.