Blood-sucking robot could treat fatal brain haemorrhages

US researchers have built a robot that they claim could suck blood clots out of previously inoperable parts of the brain.

The device created at Vanderbilt University in Tennessee enables surgeons to use information from a CT scan to guide a steerable needle through a small hole in the skull and around important brain tissue to the site of the haemorrhage (bleeding).

The team of engineers and doctors behind the robot hope it could improve the survival chances of brain haemorrhage patients, 40 per cent of whom currently die within one month of the attack, partly because of the danger of existing surgical procedures that involve cutting large holes in the skull.

‘I think this can save a lot of lives,’ said project co-lead and assistant professor of neurological surgery Dr Kyle Weaver, in a statement. ‘There are a tremendous number of intracerebral hemorrhages and the number is certain to increase as the population ages.’

The robot is a hand-held device.

Surgeons currently avoid attempting to remove clots inside the brain because the agreed benefits of removing 25 to 50 per cent of a clot can be offset by the damage done to surrounding tissue. Instead doctors tend to hope that drugs reduce the swelling.

To solve this problem, Weaver and his colleague Robert Webster, assistant professor of mechanical engineering, have adapted a technology they originally designed for operating on brain tumours.

The system comprises a straight outer tube that the surgeon can angle through a small hole in the skull in a precise way to avoid damaging other tissue, and a curved inner tube that extends into the clot and moved around as a vacuum pump sucks out the blood. Several different inner tubes can be used depending on the clot’s size and shape.

‘The trickiest part of the operation comes after you have removed a substantial amount of the clot,’ said Webster. ‘External pressure can cause the edges of the clot to partially collapse making it difficult to keep track of the clot’s boundaries.’

From the left: Robert Webster, Kyle Weaver and graduate student Philip Swaney.

Using a gelatin model of the brain, the researchers have been able to remove up to 92 per cent of simulated blood clots. They now plan to add ultrasound imaging and a computer model of how brain tissue deforms to the system to ensure that all of the desired clot material can be removed.

Weaver and Webster adapted the single-needle system from technology they had developed to target brain tumours with a series of inner tubes, each with a different curvature, that could be extended, retracted and turned in order to follow a specific path through the body.

The research was supported by the National Science Foundation and a grant from the German Academic Exchange Service.