New flexible, steerable device placed in live brains by minimally invasive robot
Imperial College London
The early-stage research tested the delivery and safety of the new implantable catheter design in two sheep to determine its potential for use in diagnosing and treating diseases in the brain.
If
proven effective and safe for use in people, the platform could simplify and
reduce the risks associated with diagnosing and treating disease in the deep,
delicate recesses of the brain.
It
could help surgeons to see deeper into the brain to diagnose disease, deliver
treatment like drugs and laser ablation more precisely to tumours, and better
deploy electrodes for deep brain stimulation in conditions such as Parkinson's
and epilepsy.
Senior author Professor Ferdinando Rodriguez y Baena, of Imperial's Department of Mechanical Engineering, led the European effort and said: "The brain is a fragile, complex web of tightly packed nerve cells that each have their part to play. When disease arises, we want to be able to navigate this delicate environment to precisely target those areas without harming healthy cells.
"Our
new precise, minimally invasive platform improves on currently available technology
and could enhance our ability to safely and effectively diagnose and treat
diseases in people, if proven to be safe and effective."
Developed
as part of the Enhanced Delivery Ecosystem for Neurosurgery in 2020 (EDEN2020)
project, the findings are published in PLOS ONE.
Stealth
surgery
The
platform improves on existing minimally invasive, or 'keyhole', surgery, where
surgeons deploy tiny cameras and catheters through small incisions in the body.
It
includes a soft, flexible catheter to avoid damaging brain tissue while
delivering treatment, and an artificial intelligence (AI)-enabled robotic arm
to help surgeons navigate the catheter through brain tissue.
Inspired
by the organs used by parasitic wasps to stealthily lay eggs in tree bark, the
catheter consists of four interlocking segments that slide over one another to
allow for flexible navigation.
It
connects to a robotic platform that combines human input and machine learning
to carefully steer the catheter to the disease site. Surgeons then deliver optical
fibres via the catheter so they can see and navigate the tip along brain tissue
via joystick control.
The
AI platform learns from the surgeon's input and contact forces within brain
tissues to guide the catheter with pinpoint accuracy.
Compared
to traditional 'open' surgical techniques, the new approach could eventually
help to reduce tissue damage during surgery, and improve patient recovery times
and length of post-operative hospital stays.
While
performing minimally invasive surgery on the brain, surgeons use deeply
penetrating catheters to diagnose and treat disease. However, currently used
catheters are rigid and difficult to place precisely without the aid of robotic
navigational tools. The inflexibility of the catheters combined with the intricate,
delicate structure of the brain means catheters can be difficult to place
precisely, which brings risks to this type of surgery.
To
test their platform, the researchers deployed the catheter in the brains of two
live sheep at the University of Milan's Veterinary Medicine Campus. The sheep
were given pain relief and monitored for 24 hours a day over a week for signs
of pain or distress before being euthanised so that researchers could examine
the structural impact of the catheter on brain tissue.
They
found no signs of suffering, tissue damage, or infection following catheter
implantation.
Lead
author Dr Riccardo Secoli, also from Imperial's Department of Mechanical
Engineering, said: "Our analysis showed that we implanted these new
catheters safely, without damage, infection, or suffering. If we achieve
equally promising results in humans, we hope we may be able to see this
platform in the clinic within four years.
"Our
findings could have major implications for minimally invasive, robotically
delivered brain surgery. We hope it will help to improve the safety and
effectiveness of current neurosurgical procedures where precise deployment of
treatment and diagnostic systems is required, for instance in the context of
localised gene therapy."
Professor
Lorenzo Bello, study co-author from the University of Milan, said: "One of
the key limitations of current MIS is that if you want to get to a deep-seated
site through a burr hole in the skull, you are constrained to a straight-line
trajectory. The limitation of the rigid catheter is its accuracy within the
shifting tissues of the brain, and the tissue deformation it can cause. We have
now found that our steerable catheter can overcome most of these
limitations."
This study was funded by the EU Horizon 2020 programme.