Researchers have developed a lily-shaped stent to optimise drainage for patients recovering after weight-loss surgery.
By changing the shape of the stent itself, they believe they have found a better approach.
Their findings have been published in Advanced Healthcare Materials.
The prototype, called the Lily stent, is the first product of a design framework the researchers named PETALS, for Personalised Endoscopic Transmural Abscess Leak Solution. This framework takes a mathematical approach to optimising drain shape for complex biological fluids and the team says it could be applied beyond gastric leaks to other drainage challenges in the body.
Using computer simulations and mathematical modelling, the researchers found that length and inner diameter mattered most, while the curled anchoring ends had little effect on fluid flow.
Counterintuitively, a wider tube does not drain better. Increasing the inner diameter narrows the gap around the outside of the stent, where most of the fluid actually flows. That means exterior topography, not interior volume, is the primary driver of drainage performance.
That insight underpins the PETALS framework. By mathematically optimising the outer surface geometry for the viscosity and pressure of gastric fluid, the team developed their new stent, a six-part structure that creates more effective pathways for fluid to flow around the device.
Khalil Ramadi, an assistant professor at NYU Abu Dhabi and NYU Tandon School of Engineering and the study’s senior author, said: ‘The key insight is that the geometry of the tube’s cross-section, especially the exterior surface, fundamentally determines how fast fluid moves through and around it. We’re not just making it out of a different material. We’re changing the shape to make it work better.’
Faster drainage could shorten recovery and reduce the need for repeat procedures, easing the burden on patients and lowering the cost of care.
The Lily stent demonstrated greater flexibility than the commercial polyethylene device it aims to replace, a feature that surgeons believe leads to better patient tolerance and less tissue damage.
The researchers note that the Lily design’s constant cross-section geometry would allow it to be manufactured using conventional extrusion methods, without requiring hospitals to invest in 3D printing infrastructure.
