The early stage study 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 humans, the platform could simplify and reduce the risks associated with diagnosing and treating diseases in the deep, delicate reaches of the brain.
It could help surgeons look deeper into the brain to diagnose disease, more accurately administer treatments such as drugs and laser ablation to tumors, and better utilize electrodes for deep brain stimulation in conditions such as Parkinson’s and epilepsy.
Senior author Professor Ferdinando Rodriguez y Baena, from Imperial’s Department of Mechanical Engineering, led the European effort, saying: “The brain is a fragile, complex web of tightly packed nerve cells, each playing its part. When a disease occurs, we want to being able to navigate this delicate environment to precisely target those areas without harming healthy cells.
“Our new accurate, minimally invasive platform improves upon currently available technology and could improve our ability to safely and effectively diagnose and treat disease in humans, 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 PLUS ONE.
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 prevent damage to brain tissue during treatment delivery, and an artificial intelligence (AI)-compatible robotic arm to help surgeons navigate the catheter through brain tissue.
Inspired by the organs that parasitic wasps use to covertly lay eggs in tree bark, the catheter consists of four interlocking segments that slide over each other to allow flexible navigation.
It connects to a robotic platform that combines human input and machine learning to carefully guide the catheter to the site of disease. Surgeons then deliver optical fibers through 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 in brain tissue to guide the catheter with pinpoint accuracy.
Compared to traditional ‘open’ surgical techniques, the new approach could ultimately help to reduce tissue damage during surgery and improve patient recovery times and the length of postoperative hospital stays.
While performing minimally invasive surgery on the brain, surgeons use deep penetrating catheters to diagnose and treat disease. However, the catheters currently in use are stiff and difficult to position precisely without the aid of navigation robots. The inflexibility of the catheters combined with the intricate, delicate structure of the brain means that catheters are difficult to place precisely, which poses risks for this type of surgery.
To test their platform, the researchers used the catheter in the brains of two live sheep at the University of Milan’s Veterinary Medicine Campus. The sheep were given pain medication and monitored 24 hours a day for a week for signs of pain or distress before being euthanized so that researchers could examine the structural impact of the catheter on brain tissue.
They found no signs of suffering, tissue damage or infection after 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 to bring this platform to life.” four years in the clinic.
“Our findings may have major implications for minimally invasive, robotic brain surgery. We hope it will help to improve the safety and effectiveness of current neurosurgical procedures that require precise deployment of treatment and diagnostic systems, for example in the context of localized gene therapy.”
Professor Lorenzo Bello, co-author of the study from the University of Milan, said: “One of the main limitations of the current MID is that if you want to go through a borehole in the skull to a deep-seated site, you are forced to rectilinear trajectory. The limitation of the rigid catheter is its accuracy in 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.