Magic slippers to stop blood clots

HigH-tecH slippers could lower the risk of deep vein thrombosis (DVT) or blood clots in the leg after surgery. the slippers, which are on trial in Japan, are connected to a pump that applies pulses of pressure to the bottom of the foot.

this is thought to mimic the effects of walking — stimulating blood flow and stopping blood collecting in the legs.

this pooling of blood is what causes the dangerous clotting, or DVTS, that affect one in 1,000 people in the UK,

A DVT is a blood clot in a vein deep in the body, commonly in the lower legs or thighs.

it is usually associated with immobility for extended periods, such as long hospital stays after surgery and long-haul flights.

When we walk, the added pressure from the push on the ground flattens the arch of the foot, which in turn narrows and squeezes the blood vessels — forcing blood upwards, back up the legs towards the heart.

Without this action, blood starts to pool in the legs.

clots can form and parts break off and travel through the bloodstream, sometimes becoming lodged in small blood vessels in the lungs, causing pulmonary embolism, which can be fatal.

to prevent DVTS, patients at risk are given blood-thinning drugs or told to wear compression stockings that fit tightly around the legs and squeeze the blood vessels to encourage blood flow around the body.

However, drugs can increase the risk of bleeding, while compression stockings can be uncomfortable.

the latest innovation, foot pump slippers, could offer a more convenient alternative. they are connected to a pump that releases pulses of pressurised air into the hard sole of the slippers.

this in turn puts pressure on the sole of the foot, mimicking the effects of walking, say the researchers at the nagasaki Medical centre.

in a 2009 study of hip surgery patients, those who wore the slippers had no side-effects and reported no DVTS, despite not being on anti-clotting medication, according to a report in the Journal of Arthroplasty. in a new trial, around 70 patients at nagasaki University Hospital in Japan who are undergoing knee surgery will be given the anti-clotting drug edoxaban daily or the slippers to wear whenever they are sitting or lying down.

Patients will be checked for DVTS for a month after surgery.

commenting on the technology, Stella Vig, a consultant vascular surgeon at croydon University Hospital, says: ‘Devices are available that encompass the lower leg, but this is cumbersome.

‘this technology allows the wearer increased comfort, making it more likely that patients use the therapy. We need widespread application of prevention policies rather than the high cost of treatment of complications.’

MEANWHILE, Russian scientists say they have developed a way to make injectable drugs dissolve clots up to 4,000 times more effectively than current drugs and with fewer side-effects.

the problem with available drugs is that they must be injected in very high doses to ensure enough reaches the blood clot to break it down, but this can cause sideeffects such as bleeding.

Writing in the journal Scientific Reports, the scientists explained how they had developed a magnetic ball structure, which carries the drugs and only dissolves when it reaches a clot.

in a laboratory study, these balls were filled with the clot-busting chemicals used in conventional therapy — and none of the drugs leaked out until they reached the blood clot.