Stanford's milli-spinner reduces blood clots by 95% in tests

A significant breakthrough in stroke treatment has been achieved with the development of a new device called the milli-spinner. This tiny, rotating hollow tube, equipped with fins and slits, has shown remarkable potential in compacting and shrinking blood clots, making their removal quicker and more effective. The device, created by researchers at Stanford University, addresses a longstanding challenge in stroke treatment: the need to swiftly and reliably remove dense blood clots that block oxygen flow to the brain.

The milli-spinner's effectiveness was demonstrated in both lab and swine tests, where it successfully reduced the size of blood clots by up to 95%. This dramatic reduction in clot size allows for easier and faster removal, often on the first attempt. The device works by exerting both compression and shear forces to release red blood cells from the dense fibrin that binds them together. This process, which was initially observed as a somewhat unexpected phenomenon, has been described as "magic" by the researchers involved.

Current thrombectomy methods, which involve aspirating clots via a catheter or using a stent to grab and remove them, are not primarily designed to reduce the size of blood clots. The milli-spinner, however, appears to do so routinely and very quickly, sometimes in a matter of seconds. This could significantly improve the outcomes for stroke patients, as current devices successfully remove clots less than 50% of the time on the first try, and in about 15% of cases, they fail altogether.

Strokes are a leading cause of death, with ischemic strokes, which are caused by blood clots, accounting for roughly nine in 10 cases. Patients with ischemic strokes are often treated with clot-busting drugs like tPA or thrombectomy, but mechanical techniques still encounter failures. The milli-spinner's ability to prevent clot fragmentation and its high success rate in restoring blood flow make it a promising new tool in stroke treatment.

The development of the milli-spinner was not initially aimed at solving the issue of blood clot removal. Instead, the researchers were working on millirobots—tiny, origami-based spinning devices capable of swimming untethered through the bloodstream. The spinning millirobots generate a highly localized, very strong suction, which the researchers realized could be used to suck a clot. This simple yet effective approach led to the creation of the milli-spinner.

Human clinical trials are the next step in evaluating the milli-spinner's effectiveness and safety. Areas to watch include how human brain tissue is affected by the new thrombectomy method and how the cells and debris behave once they’re liberated from the fibrin by the milli-spinner. If the device performs in people as well as it does in these models, it will improve recanalization rates—how frequently blocked arteries in the brain, heart, or lung can be opened. This will lead to better outcomes in patients with stroke, heart attack, and pulmonary embolism.

The milli-spinner's potential extends beyond stroke treatment. The untethered, robotic version of the device could be used to treat a range of conditions, including brain aneurysms and kidney stones. The team has formed a company to proceed with clinical trials on the milli-spinner, with the goal of bringing this promising technology to patients as soon as possible. The development of the milli-spinner represents a significant advancement in stroke treatment and has the potential to save tens of thousands of lives and substantially reduce disability in treated patients.