September Landmark first-in-human stroke trial reads blood clots from the inside

Scientists at University of Galway have taken part in a first-in-human study on stroke patients using a thin wire fitted with sensors to assess and map the clot they have experienced.

 The study involved the use of a guidewire called Clotild, which has been developed by medtech company Sensome. It can navigate arteries through a catheter, with tiny electrical sensors built into its tip, moving through a clot and continuously measuring how well different tissues conduct a small current. Red blood cells, platelets and arterial walls each have distinct electrical "fingerprints" which can be individually identified in real-time by the device’s prediction model.

 Some 41 people who had suffered a large vessel occlusion stroke were enrolled in the trial at hospitals in Australia and France to assess the performance of the device and how it reports the clot.

 The trial was led by Dr Andrew Cheung of Liverpool Hospital, NSW, Australia and Aymeric Rouchaud, France, with a device developed using clot analysis by Professor Karen Doyle, University of Galway and the Research Ireland funded Rinn Medical Devices Centre.

 Professor Karen Doyle said: "This first-in-human study represents an important step forward in how we understand and treat stroke patients. Being able to characterise clot composition in real time, during the procedure itself, has real potential to help clinicians tailor their approach to treating each patient and improve outcomes. It's been a privilege to contribute to the research underpinning this trial, and to see fundamental device research translated into a technology now being tested directly in patients."

 Every year, millions of people globally suffer a stroke caused by a blood clot blocking an artery in the brain. The gold standard treatment is a procedure called mechanical thrombectomy, where a tiny device is threaded through blood vessels to physically pull the clot out. Research has shown that removing a clot in a single pass dramatically improves a patient's chances of recovery. While this method can be successful, surgeons go in almost blind, knowing very little about the clot they are about to tackle, what it is made of, or where exactly it ends.

 The trial is the first time a potential solution to this issue has been tested in humans.

 The possibility of removing a clot in one pass depends partly on clot composition: clots rich in red blood cells behave differently to those packed with platelets. Until now, the only way to find this out was to analyse retrieved clot fragments under a microscope following a procedure - too late to change the surgical strategy.

 The results from the trial were unambiguous: not a single patient experienced a vessel perforation or dissection, the most feared complication of guidewire use in the brain.

 On performance, Clotild proved remarkably accurate. Its ability to distinguish red-blood-cell-rich clots from platelet-rich ones scored 0.97 and 0.94 respectively on a standard accuracy scale where 1.0 is perfect.

 The device was also able to detect the artery wall and the far end of the clot, information a surgeon could use to gauge clot length without injecting contrast dye.

 One of the most striking demonstrations came when the team reconstructed a full compositional "map" of a clot based on Clotild's continuous readings as it passed through. The map, showing which sections were red-blood-cell-rich and which were not, matched what histology later revealed about the retrieved clot fragments.

 Dr Cheung said: “This trial shows that impedance-based clot characterisation is not only feasible but can be integrated safely into standard procedure. It's the result of a genuinely international effort, and I want to thank our collaborators across Australia, France, USA and Ireland, for their contribution to the device development and data analysis that made these results possible."

 Dr Franz Bozsak, CEO of Sensome, said: "Bringing Clotild from concept to first-in-human trial has depended on close collaboration between industry and academic research partners. The expertise contributed by our academic partners across the globe has been invaluable in helping us validate and refine the science behind this technology. This kind of partnership is exactly how we believe medical devices should be developed, grounded in rigorous academic research and tested rapidly in clinical settings."

 Professor Doyle added: “As a proof of concept this is compelling. The vision is a future where, before a surgeon even selects a retrieval device, they already know exactly what kind of clot they are dealing with, giving stroke patients a meaningfully better chance of getting it out first time.”

 The research paper associated with the trial can be accessed on the Journal of NeuroInterventional Surgery https://jnis.bmj.com/content/early/2026/04/30/jnis-2025-024772

Ends