Improving Bypass Durability with Spiral-Flow Graft Design

Spiral-Flow Graft Design

Improving the durability of arterial bypass grafts is the focus of an innovative 18-month research project at Manchester Metropolitan University, where a team led by Dr Amir Keshmiri, Founder and Technical Director of Mansim, is working alongside Professor Mark Slevin from the Department of Life Sciences. Their aim is to develop spiral-flow blood grafts that reduce wear and failure at the critical junction between natural arteries and synthetic grafts.

More than 20,000 coronary artery bypass operations take place in England each year, yet many grafts last only 8–15 years before deterioration begins. By re-engineering graft geometry to recreate the natural swirling motion found in healthy arteries, the researchers hope to improve blood-flow behaviour, reduce stagnation and hotspots, and ultimately extend the functional lifespan of these life-saving devices.

“The impact could be huge,” said Dr Amir Keshmiri, Founder of Mansim and Senior Lecturer in Fluid Dynamics. “If it works, it will improve the fluid dynamics of the blood and delay the failure of the graft. It could save millions of pounds and a lot of time for health services.”

Inspired by techniques used in industrial fluid systems, including spiral flow optimisation from nuclear cooling applications, Dr Keshmiri’s approach introduces subtle helical features into synthetic grafts—helping blood transition smoothly through junctions, avoiding stagnation zones and blockages.

“In many cases, the graft junction fails and blocks the blood flow. We want to be able to avoid these hotspots by inducing a spiral flow,” added Dr Keshmiri. “If you can get the blood to swirl before joining the junction it will help accelerate flow and improve graft longevity. The body is already familiar with spiral flow—it’s how our arteries naturally work.”

The technique could eventually be extended to arterio-venous access grafts used in haemodialysis treatment for kidney-failure patients, with potential to enhance safety and durability across multiple vascular procedures.

This research embodies Mansim’s mission to translate advanced simulation and fluid-dynamics expertise into real-world engineering and biomedical solutions that deliver measurable impact.

Spiral-Flow Graft Design Media Coverage