Endoscopic Approaches to Pediatric Epilepsy Surgery: Pediatric Endoscopic...

Recurrent seizures and long-term anti-epileptic drug therapy have detrimental effects on the developing brain in children.

The International League Against Epilepsy has a consensus for recommending early surgical intervention in pediatric epilepsy when it is safe to do so.

Minimally invasive approaches for epilepsy surgery must achieve complete disconnection and offer outcomes similar to maximally invasive approaches.

At Texas Children's Hospital, Dan Curry has been a pioneer in stereotactic laser ablation for epilepsy surgery.

Cost comparison using national databases showed that minimally invasive laser ablation for hamartomas had lower hospitalization costs compared to open surgery.

In a comparison of approximately 10 corpus callosotomies, laser ablation versus open craniotomy showed no difference in length of stay or discharge destination.

With laser ablation for corpus callosotomy, most children needed to go to rehabilitation, three children needed re-operations, and one had transient hemiparesis.

Laser ablation for corpus callosotomy requires multiple trajectories because the anatomy of the corpus callosum is curved, making it difficult to control straight-line catheters.

Endoscopic corpus callosotomy has been described in cadaveric studies and clinical series by groups including Matt Smith in Saint Louis.

The endoscopic-assisted approach for corpus callosotomy uses three hands, similar to transsphenoidal surgery, which reduces the learning curve compared to fully endoscopic techniques.

For endoscopic corpus callosotomy, navigation is performed in real time using a straight endoscope, and the surgical steps include interhemispheric approach, identification of pericallosal arteries and ACAs, and white matter disconnection from rostrum to splenium.

Postoperative DTI imaging was used initially to confirm complete disconnection after endoscopic corpus callosotomy.

Hemispherectomy techniques have evolved over time from anatomical to functional hemispherectomy to functional hemispherotomy, with approaches varying from lateral to paramedian vertical.

Al Cohen described cadaveric studies for endoscopic hemispherectomy using two burr holes (frontal and occipital), with the frontal approach providing a view at the foramen of Monro and the occipital approach into the atrium providing a view of the temporal horn.

The Texas Children's Hospital team developed a single-burr-hole paramedian vertical approach for endoscopic hemispherectomy, with a fallback plan to convert to open approach or middle temporal gyrus approach if needed.

Dr. Sood and Dr. Chandra have described small series of endoscopic approaches for both callosotomies and hemispherectomies.

In cadaveric studies, the single-burr-hole approach allowed visualization of the corpus callosum, lateral ventricle body, anterior corpus callosum, splenium, choroid plexus, atrium, temporal horn after insular cut, and enabled hippocampectomy.

Case selection is very important when developing new endoscopic techniques, and surgeons must have extensive experience and comfort with open surgeries and be very familiar with the anatomy before attempting to minimize the access corridor.

The first endoscopic hemispherectomy patient at Texas Children's Hospital was a post-stroke epilepsy patient with significant tissue loss, providing good initial conditions for the new technique.

Preliminary results from the small case series show that children undergoing endoscopic hemispherectomy mobilize quicker, have less soft tissue edema, and recover faster than with open craniotomy.

Anesthesia colleagues did not see the need to transfuse blood during endoscopic hemispherectomy cases, and blood loss was much less than with open craniotomies for hemispherectomies.

Seizure outcomes with endoscopic hemispherectomy have been comparable to open craniotomy so far, though long-term follow-up and more patients are needed.

Operative time for endoscopic hemispherectomy has been comparable to open craniotomy.