Importance of the project?
There are clearly a large number of people with epilepsy that are excellent candidates for traditional open resective surgery to remove the area of brain responsible for seizure generation, but this type of procedure remains underutilized, owing largely to the invasive nature of the procedure. We believe a minimally invasive surgical option could increase the number of patients that qualify and seek out such a procedure.
What is hoped to be accomplished?
The goal of our Epilepsy Therapy Project-supported project was to complete pilot clinical studies using minimally invasive, MRI-guided laser ablation to thermally destroy epileptogenic seizure foci. Our work was aimed at determining whether this technique would provide results warranting more wide-spread use of this novel surgical tool.
How will this therapy be of help?
There are currently few treatment options between continued drug trials and highly invasive surgical procedures for people with epilepsy who don’t respond to initial drug therapies. If successful, our minimally invasive laser technology could fill that void and offer a new minimally invasive surgical tool for eliminating seizure foci.
When will it be available?
The Visualase Technology is already cleared by the U.S. Food and Drug Administration (FDA) as a surgical tool for soft tissue ablation (thermal destruction of tissue) in various medical specialties, including neurosurgery. Physicians are currently employing the system for procedures that previously would have been performed through a much larger opening in the skull (open craniotomy). Placement of our small (1.6mm, pencil lead size) fiber optic probes into target brain tissue requires only a 3.2mm diameter skull opening and has even been performed on awake patients using only local anesthetics. People undergoing minimally invasive laser ablation typically have much faster recoveries than traditional surgery with average hospital stays of only 24 to 48 hours and almost no signs of having gone through a surgical procedure at all.
Who will benefit from this new therapy?
Our pilot work investigated use of the system in both children and adults with well defined areas of the brain, typically visualized as lesions on imaging exams that were able to be safely targeted for ablation. Advances in imaging technology and diagnostic procedures are increasing the number of people in which the precise area of the brain responsible for initiating seizures can be determined, and therefore similar increases in the number of people which might be amenable to this procedure should emerge. Furthermore, many people with multiple lesions in the brain, which may have previously been excluded from standard surgeries, or those that wish to avoid more invasive “open” brain surgeries might now have a minimally invasive surgical option for destroying these lesions.
Why was it important that your project received funding?
During the course of our project, we exceeded our original goals of completing 10 procedures, and eventually enrolled 20 people into a pilot study at Texas Children’s Hospital. People with various lesions associated with epileptic foci were treated with the Visualase system, including Tuberous Sclerosis (n=2), Mesial Temporal Sclerosis (n=2), Hypothalamic Hamartoma (n=12), and Focal Cortical Dysplasia (n=4). To date people achieving seizure freedom from the laser procedure have compared favorably to traditional open surgical resection in similar patient populations. Our initial pilot results were critical in our ability to generate interest and support for adoption at additional sites. These exciting results were in large part enabled by the Epilepsy Therapy Project’s funding and support. To date, over 200 epileptic foci ablation procedures have been performed among more than 25 Visualase sites, with results that continue to show promise for minimally invasive laser surgery in patients with epileptic foci refractory to other therapies. Additional post-approval studies and expanded installations of the system are planned, which will build upon the great foundation we achieved through our early ETP funding.