Epilepsy Surgery Advances at UPMC Children’s: Laser Thermal Ablation

Recent technological advances to arrive at UPMC Children’s Hospital of Pittsburgh Division of Pediatric Neurosurgery are allowing for significant advances in the epilepsy surgery program.

Among the advances are the deployment of a new laser thermal ablation (LTA) system in conjunction with an intraoperative magnetic resonance imaging (IMRI) system, and the newest generation of the ROSA^® robot that is used primarily for minimally invasive stereo electroencephalography (SEEG) to help identify epileptic networks in the brain in three dimensions, not just on the surface but also from deep inside the cerebral cortex and other deep brain structures.

“The combination of these technologies allows us to perform our epilepsy surgery cases with a much higher degree of precision and control, and they also allow us to treat some patients on whom it would otherwise be inadvisable to perform surgery because of the risk and origin of their epilepsy,” says Taylor Abel, MD, surgical director of the Epilepsy Surgery Program at UPMC Children’s.

Without these minimally invasive procedures, the standard method of performing epilepsy surgery generally requires a large incision and craniotomy, and with traditional tools, it can be very difficult, if not impossible to identify deep brain structures involved and work in areas that pose very high risk of complications, such as the insula.

Since the new technology has been available in the operating theatre, Dr. Abel has used these new tools to perform surgery on seven individuals.

“The ROSA robot allows us to place our ablation probe and our SEEG probes with submillimeter accuracy. To assist with the precision of our ablations, we employ MRI thermography, where we acquire real-time MRI images of the tissue temperatures in the brain during ablation. We can visualize exactly where the heat is and what the temperatures are, which allows us to know precisely which tissues we are destroying while sparing surrounding areas,” says Dr. Abel.

Laser Thermal Ablation and a Case of Insular Cortex Epilepsy

The insula is one of the most difficult areas of the brain in which to perform surgery of any kind. The deep location of the insular cortex and its plentiful supply of blood vessels brings with it, according to the most recent literature, an approximately 20% chance of the patient having a stroke during surgery using traditional epilepsy surgery techniques. The insula also can be difficult to pinpoint as an epileptic focus area because of its position. Temporal lobe epilepsy versus insular epilepsy can be difficult to disentangle (the ROSA robot and SEEG can help to precisely identify the affected regions of the brain).

In 2019, Dr. Abel performed surgery on a young female who has had epilepsy since birth. It was determined through examination, imaging, and SEEG that the focal point of this child’s epilepsy was the insula.

“For this case, we placed SEEG probes directly into the insula and surrounding areas to localize the focus of her seizure activity and then mapped out a plan of attack for the surgery. Again, this is an area of the brain that is difficult to explore with intracranial electrodes. Experienced centers use techniques that are well established regarding where to place the electrodes. However, if the surgeon is uncomfortable placing those electrodes, then it is possible to miss a seizure originating in the insula,” says Dr. Abel.

One aspect of operating in the insula with laser thermal ablation that Dr. Abel points to as a benefit has to do with the blood vessels in that area of the brain. Since the ablation technique uses heat to destroy tissue, the number and size of the blood vessels in the insula function as a heat sink, carrying away excess heat and decreasing the likelihood of iatrogenic injury to surrounding tissues and vessels that could cause serious complications.

“For this case, because the patient also had other medical problems in addition to her epilepsy, performing surgery on her with more traditional means and a large craniotomy would have been extremely dangerous. At some point, prior to surgery, she also suffered a stroke that affected both sides of her brain, which made it difficult to localize her seizure activity. Our minimally invasive technologies, however, made it a much simpler approach with, so far, a good outcome.

In a follow-up in the clinic after her procedure, the patient’s mother was overcome with emotion and explained to Dr. Abel that since the surgery, her daughter had had only one seizure and was able to go outside and play in the backyard, something she had not done in years.

“Before surgery, it was not uncommon for her to have eight or more seizures a day. It is a little early to say what the long-term outcome may be for this patient, but for some of our cases, a reduction in seizure burden of 50%, or 70%, and better control with medications post-surgery can be a life-changing experience. That is the reason I became a neurosurgeon. To be able to make that kind of difference in a patient’s life. Being at UPMC Children’s is facilitating that mission,” says Dr. Abel.

Research and Future Applications

While Dr. Abel and his collaborators are collecting data on their epilepsy surgery patients, investigating the institution’s outcomes to understand better how thermal ablation approaches to epilepsy surgery can be improved or expanded to other patient populations. The technique is beginning to be offered to patients who are candidates or likely can benefit from a corpus callosotomy to treat different kinds of epilepsy.

The LAANTERN Trial

UPMC Children’s is one of the sites in the multicenter Laser Ablation of Abnormal Neurological Tissue Using Robotic NeuroBlate System (LAANTERN) trial, and Dr. Abel is the site principal investigator at UPMC Children’s. LAANTERN is a prospective, multi-center registry that will include data collection to evaluate procedural success, local control failure rate, and Quality of Life (QoL) in up to 1,000 patients and up to 50 sites. The study is currently enrolling eligible patients who would like to participate.

Patients with either primary brain tumor or metastatic brain tumors and those with epileptic/seizure foci who choose thermal ablation surgery may be enrolled in the trial. Monteris Medical, the manufacturer of the NeuroBlate® system, is the sponsor of this trial. More information on the trial is available at ClinicalTrials.gov under identifier NCT02392078.

More About the Epilepsy Surgery Program at UPMC Children’s

The Epilepsy Surgery Program, part of the UPMC Children’s Brain Care Institute, comprises a team of pediatric specialists from Child Neurology, Pediatric Neurosurgery, Adult Neurology, Pediatric Neuroimaging, Pediatric Nuclear Medicine, and Pediatric Neurophysiology.

Doctors and Staff

• Christina Patterson, MD – Medical Director
• Taylor Abel, MD – Surgical Director
• Patricia Crumrine, MD
• Bilal Sitwat, MD
• Yoshimi Sogawa, MD
• Inna Vaisleib, MD
• Shelley Williams, MD
• Pat Lordeon, R.EEG.T – Supervisor, Neurodiagnostics
• Gerri vonHofen, RN – Supervisor, Patient Services

To make a referral, schedule an appointment, or request an evaluation for a patient, please call 412-692-6928. Learn more about the Division of Pediatric Neurosurgery at UPMC.