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 the diagnosis and treatment of brain diseases.
If proven effective and safe for human use, the platform could simplify and reduce the risks associated with diagnosing and treating diseases in the deep, delicate recesses of the brain.
It could help surgeons look deeper into the brain to diagnose diseases, apply treatments like drugs and laser ablation more precisely to tumors, and make better use of deep-brain stimulation electrodes for conditions like Parkinson’s and epilepsy.
Lead author Professor Ferdinando Rodriguez y Baena of the Imperial Department of Mechanical Engineering led the European effort and said: “The brain is a fragile, complex web of densely packed neurons, each with a role to play. When diseases appear, we want to be able to navigate in this delicate environment, to precisely target these areas without damaging healthy cells.
“Our new precise, minimally invasive platform improves on currently available technology and, if proven safe and effective, could improve our ability to safely and effectively diagnose and treat disease in humans.”
The results were developed as part of the Enhanced Delivery Ecosystem for Neurosurgery in 2020 (EDEN2020) project and published in PLUS ONE.
The platform improves on existing minimally invasive, or “keyhole” surgery, in which surgeons insert tiny cameras and catheters through small incisions in the body.
It includes a soft, flexible catheter to avoid damaging brain tissue during treatment and an artificial intelligence (AI) robotic arm to help surgeons navigate the catheter through brain tissue.
Inspired by the organs parasitic wasps use to secretly lay eggs in tree bark, the catheter consists of four interlocking segments that slide over one another to allow for flexible navigation.
It’s connected to a robotic platform that combines human input and machine learning to gently steer the catheter to the disease site. Surgeons then insert optical fibers over the catheter so they can see the tip along the brain tissue and navigate using joystick controls.
The AI platform learns from the surgeon’s inputs and the contact forces in the brain tissue to guide the catheter with pinpoint accuracy.
Finally, compared to traditional “open” surgical techniques, the new approach could help reduce tissue damage during surgery and improve patient recovery times and postoperative hospital stay length.
During minimally invasive brain surgery, surgeons use deep penetrating catheters to diagnose and treat diseases. However, currently used catheters are rigid and difficult to place accurately without the aid of robotic navigation tools. The inflexibility of catheters combined with the intricate, delicate structure of the brain means it can be difficult to place catheters accurately, creating risks for this type of surgery.
To test their platform, the researchers inserted the catheter into the brains of two live sheep at the University of Milan’s Veterinary Campus. The sheep received pain relief and were monitored 24 hours a day for signs of pain or stress for a week before being euthanized so the researchers could study the structural effects of the catheter on brain tissue.
They found no evidence of distress, tissue damage, or infection after catheter implantation.
lead author dr Riccardo Secoli, also from the Imperial Department of Mechanical Engineering, said: “Our analysis showed that we safely implanted these new catheters without damage, infection or suffering. If we get equally promising results in humans, we hope to be able to see this platform in the clinic within four years.
“Our results could have major implications for minimally invasive, robot-guided brain surgery. We hope they will help improve the safety and effectiveness of current neurosurgical procedures when precise use of treatment and diagnostic systems is required, 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 MIS is that you are forced to go through a burr hole in the skull to a deep seated location in 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 program Horizon 2020.