NYU's 3D-Printed Lily Stent Could Make Gastric Leak Recovery Less Miserable

A research team at NYU has redesigned the lowly stent from a simple tube into a six-segmented drainage device shaped like a lily. The goal is not aesthetics. It is to speed up fluid drainage after weight-loss surgery complications, reducing the pain and repeat procedures that come with gastric leaks.

About 250,000 Americans a year get sleeve gastrectomy. Most recover without issue. But 1% to 3% of routine cases, and up to 10% of revision surgeries, end with a gastric leak: fluid escaping the stomach and forming an abscess. Doctors treat it by threading a double-pigtail stent through the stomach wall to drain the fluid. The stents available today were designed for bile ducts, not the oddly shaped pockets left by gastric leaks. They slip, drain slowly, and often need replacing.

The NYU team, led by assistant professor Khalil Ramadi, built a mathematical framework they call PETALS: Personalized Endoscopic Transmural Abscess Leak Solution. It optimizes the outer geometry of the stent for the viscosity and pressure of gastric fluid. The result is the Lily stent, a 3D-printed prototype with longitudinal fins that create more effective routes for fluid to move around the device.

In benchtop tests, the Lily design cut hydraulic resistance by 32% and increased flow rate by 30% compared with a commercial double-pigtail stent. It also proved more flexible than the polyethylene device it is meant to replace, which surgeons associate with better patient tolerance and less tissue damage. Short-term animal studies showed no significant difference in tissue response, an early sign of biocompatibility.

The researchers are quick to note that this is still a lab prototype. It has not been tested in human trials, and the regulatory path to approval is long. But the design insight matters beyond this one device. The team found that the exterior shape of a stent, not its interior bore, is what controls drainage speed. That is counterintuitive. Most stent design assumes a bigger hole moves more fluid. In reality, fluid travels in the gap around the outside of the tube, so the outer topography does the real work.

There is also a manufacturing caveat. The Lily stent's constant cross-section means it could be made by conventional extrusion, not just 3D printing. Hospitals would not need to buy SLA machines to adopt it. That makes the path to scale simpler, and it means 3D printing here is an enabler, not a bottleneck.

If the Lily stent clears animal studies and moves toward clinical use, it could meaningfully shorten hospital stays for the roughly 2,500 U.S. patients who need gastric leak treatment each year. Faster drainage means fewer repeat endoscopies, less patient suffering, and lower costs. For a technology that started as a geometry problem on a computer, that is a practical outcome worth watching.