From lab to market: IISc team, surgeon develop dissolving stent to cut 2nd surgeries

BENGALURU: A small, dissolving tube developed in a Bengaluru lab is moving a step closer to hospital use, offering a way to avoid repeat procedures after major abdominal surgeries.

The device, called the “Asthana Stent”, is the result of a collaboration between liver transplant surgeon Sonal Asthana of Aster CMI Hospital and researchers led by Kaushik Chatterjee at IISc, spanning its Departments of Materials Engineering and Bioengineering.

It has now been licensed to Advanced Medtech Solutions Private Limited under an Indian Patent, marking a shift from laboratory prototype to a product that could reach operating rooms.

The idea began with a recurring problem seen after liver transplants. Surgeons must join bile ducts, a delicate connection that can later leak or narrow. These complications affect 11% to 40% of patients and often require another procedure to fix.

Existing solutions rely on plastic tubes, or stents, to keep the duct open while it heals. But these come with trade-offs. Some protrude outside the body and need careful management. Others stay inside but must be removed later through an additional procedure, adding cost and risk.

“The new stent takes a different approach. It is made from polydioxanone (PDS), a biodegradable polymer already used in dissolvable surgical stitches. Once placed inside the body, it holds the duct open for about six weeks, then gradually breaks down and is absorbed. No removal is needed,” the research team said.

Turning that idea into a working device required engineering work by Thaseeb Rehman of the Department of Materials Engineering and Saswat Choudhury of the Department of Bioengineering at IISc. The team designed the tube to stay open under pressure and resist migration using surface ridges and velcro-like hooks, while a flexible mid-section allows placement even when duct openings are misaligned. Tiny radiopaque markers allow doctors to track it using X-rays.

“Tests showed the stent could withstand more than 16 Newtons of pressure, well above what bile ducts experience. It also held its structure over six weeks in both lab conditions and human bile, covering the critical healing window,” the researchers said.

With the technology now licensed, the focus shifts to manufacturing and approvals.

The firm will take it through regulatory checks set by the Central Drugs Standard Control Organisation (CDSCO). The project has also received support from the Indian Council of Medical Research (ICMR).
If approved, the stent would be used during surgery itself, and will be available in multiple sizes. For patients, the benefit is straightforward: one operation instead of two, and fewer chances of complications after going home.