Stereo-Electro-Encephalo-Graphy (SEEG) With Robotic Assistance in the Presurgical Evaluation of Medical Refractory Epilepsy: A Technical Note

The overall goal of this surgical intervention is to localize the patient's epileptogenic focus, potentially allowing further intervention for the ultimate goal of seizure freedom. Stereo-electro-encephalo-graphy, also known as SEEG, it's a method and technique designed to better localize the epileptogenic zone, which is the minimal area in the brain that is responsible for the generation of seizures. The main advantages of SEEG, compared to subdurals, is that SEEG, it's a minimally invasive method that does not require craniotomy.

It carries minimal complication rate, and allows the three-dimensional mapping of the epileptogenic brain. After developing an implantation strategy based upon the hypothesized epileptogenic zone, select new patient on the robotic assistance device to create a new encounter. Then, click on create trajectory, and select the appropriate entry and end-points that correspond with the desired trajectory.

When the device is ready, arrange the patient on the surgical table in the supine position. After prepping the patient, select register on the robotic assistance device, and follow the prompts to complete the registration process using the surface landmark registration based on the facial features. When the registration is complete, use guidance assistance from the robotic stereotactic system to bore the first bolt-hole in the skull with a 2.5 millimeter drill bit.

Then, insert the monopolar coagulator probe to open the dura mater, and use the robotic stereotactic system to screw the first implantation bolt into the skull. Use the implanted bolt to guide the insertion of the stylet probe to create the initial trajectory, and insert the first electrode. Then, secure the electrode to the bolt to prevent further displacement and cerebrospinal fluid leakage.

After inserting and connecting the rest of the electrodes in the same manner, place the iodine solution soaked gauze around each of the bolt caps. Then connect the electrodes to the EEG recording machine to confirm their proper function and obtain intraoperative x-rays in the lateral and anterior/posterior skull to confirm that the electrodes have been placed with the correct trajectories. Now, transfer the patient to the epilepsy monitoring unit, and monitor the patient for seizure activity both clinically and electrographically via the stereo-electro-encephalo-graphy electrode recording, administering analgesia as appropriate.

Wrap the head. When sufficient ictal data has been recorded, return the patient to the operating room for removal of the stereo-electro-encephalo-graphy electrodes under conscious sedation. Then, after removing the head wrap, and cutting the electrode wires, prep the remaining bolts and tails of the electrodes with iodinated gel, and remove the first bolt cap with twisting.

Next, gently pull the corresponding electrode out along the axis of its insertion, and twist out the bolt. Before moving on to the next electrode, close the defect left by the bolt with one stitch of nylon suture. Then, repeat the removal procedure for each of the other electrodes.

After all of the electrodes have been removed, cover the stitch areas with antibiotic ointment and a loose head wrap. Finally, image the patient to confirm the absence of any residual hardware. Here, temporal, temporal-occipital, temporo-parietal-occipital, fronto-temporal, fronto-parietal-insular, perisylvian, and bi-temporal and right frontal insertion plans are shown.

The black dots represent the entry points of the electrodes implanted in an orthogonal fashion, and the black lines represent the electrodes in oblique trajectories. Recent results indicate that in one consecutive series of 78 patients who underwent stereo-electro-encephalo-graphy insertion via robotic assistance, successful localization of the epileptogenic zone was achieved in 76.2%of patients. In the same study, surgical resection of the epilepogenic zone was demonstrated to impart Grade 1 Engel seizure freedom in 67.8%of patients.

Note that the observed morbidity rate of the procedure is 2.5%with a permanent morbidity notice of one patient, or 1.2%Per electrode, wound infection and intracranial hematoma rates of 0.08%were also observed. The SEEG procedure, it should take approximately two to three hours. Although it's considered to be a minimally invasive procedure, it does carry some risks, which are approximately 1%The main risks are intracranial bleedings.

While you are watching this movie, you will be able to understand how to perform a robotic SEEG implantation.