Name:
10.3171/2024.4.FOCVID2415
Description:
10.3171/2024.4.FOCVID2415
Thumbnail URL:
https://cadmoremediastorage.blob.core.windows.net/1ebe4154-a449-4d8c-a7fd-73391c7923aa/videoscrubberimages/Scrubber_389.jpg
Duration:
T00H08M36S
Embed URL:
https://stream.cadmore.media/player/1ebe4154-a449-4d8c-a7fd-73391c7923aa
Content URL:
https://cadmoreoriginalmedia.blob.core.windows.net/1ebe4154-a449-4d8c-a7fd-73391c7923aa/16. 24-15.mp4?sv=2019-02-02&sr=c&sig=q1lxQ%2FC5X5aI5wuLuDUfAS%2B%2FBHyzV46Qaynuxi0Asm4%3D&st=2026-04-29T03%3A48%3A03Z&se=2026-04-29T05%3A53%3A03Z&sp=r
Upload Date:
2024-05-30T00:00:00.0000000
Transcript:
Language: EN.
Segment:0 .
[UPBEAT MUSIC]
SPEAKER: In this video, we highlight the operative steps for a robot-assisted laser interstitial thermal therapy and the treatment of drug-resistant epilepsy caused by a hypothalamic hamartoma with concurrent use of a stereotactic biopsy needle. A hypothalamic hamartoma is a congenital, nonprogressive lesion of the hypothalamus formed during fetal development. There are two anatomic variants of these lesions, parahypothalamic hamartomas, which are often associated with precocious puberty, and intrahypothalamic hamartomas, which are often associated with gelastic seizures, other forms of epilepsy, cognitive impairment, and psychiatric symptoms.
SPEAKER: Up to 40% of patients, however, will present with symptoms from both anatomic variations. Stereotactic laser interstitial thermal therapy, also known as LITT therapy, is an emerging, minimally invasive neurosurgical technique primarily used in the treatment of brain tumors, radiation necrosis, and epileptic foci. Despite first being introduced in 1983, its initial use was limited due to an inability to monitor tissue temperature and control the extent of ablation.
SPEAKER: Recent advancements in intraoperative MRI, however, have allowed for improved thermal monitoring and, thus, increased treatment accuracy. Previous studies have shown LITT therapy to be an effective treatment for drug-resistant epilepsy and hypothalamic hamartomas, with as high as 80% of patients reporting seizure-free outcomes 6 months after their procedure. There currently exists limited data on risk and potential complications.
SPEAKER: However, previous studies have shown a rate of severe complications requiring medical interventions to be approximately 3%. Of these complications, weakness is reported to be the most common. Other reported complications noted to be aware of have been a worsening of diabetes insipidus and potential gadolinium extravasation into nearby ventricles.
SPEAKER: A 24-year-old female was referred to our clinic for potential resection of her known hypothalamic mass, causing a long-standing history of epileptic episodes. She reported approximately three gelastic seizures every month, despite being on maximum antiepileptic drug therapy. These episodes typically last 30 seconds and are associated with oral automatisms and postictal confusion. Additionally, she reported being diagnosed with central precocious puberty around the age of one, which was suppressed until the age of 12 with leuprolide.
SPEAKER: Her neurological exam was fully intact. Given these findings and context of her known hypothalamic mass, we determined that she was an appropriate candidate for LITT therapy. Preoperative T1-weighted MRI was completed, which showed a demonstration of her known nonenhancing mass arising from her right hypothalamus. This mass measured approximately 8 x 8 x 8 mm. Within this mass, there were no areas of restricted diffusion seen and no abnormal contrast enhancement.
SPEAKER: There was no mass effect on surrounding structures, no extra-axial fluid collections, and all major blood vessels demonstrated adequate flow related signal. In total, there were no significant changes seen when compared to her previous images. Once in the operating room and anesthetized, the patient was positioned supine and penned with the Mayfield skull clamp.
SPEAKER: For this procedure, we used the Globus ExcelsiusGPS Robotic Navigation System with concurrent C-arm fluoroscopy registration. After the robot was registered with fluoroscopy, the patient is prepped, draped, and the area is marked. Using the patient's images, a trajectory is planned with the goal of taking the most direct path towards the hypothalamus. Being sure to avoid the fornices, optic apparatus, and sulci, which may contain easily damaged blood vessels.
SPEAKER: The sterile reference arc is positioned adjacent to the patient's head, and the robot is then brought into the field and guided to its planned trajectory. A stab incision is then made on trajectory through the end effector arm of the robot. The reducing tube was then placed, and a hole was drilled on trajectory with high speed burr.
SPEAKER: Opening the dura can then be confirmed using a sharp stylet. If the dura was not opened during the drilling, it can now be done. An anchor bolt is placed through the burr hole and on trajectory. The bolt is then turned seven to eight full turns.
SPEAKER: It may be beneficial, however, to perform 16 half-turns. You will know you remained on trajectory if the bolt is easily removed without resistance at the end. As an alternative to using a measured stylet, we chose to use a stereotactic navigated biopsy needle to ensure the proper trajectory. At this point, if biopsy were needed, this navigated biopsy needle can be used to sample specimen.
SPEAKER: The biopsy needle is then placed on trajectory using real-time navigation. If the trajectory is correct, the needle should be able to pass through the bolt without any resistance. The robot is then removed from the field. A navigated probe is placed at the top of the bolt to measure the distance from the target. A sterile paper ruler can be placed over the opening of the anchor bolt to provide a flat surface for measurement.
SPEAKER: A cap is then placed on top of the anchor bolt to ensure sterility and conserve cerebral spinal fluid. A snap cover drape is then placed and stapled to the patient's scalp that can be opened steadily once in the MRI suite. Once the patient is in the MRI suite, the laser is measured to length, passed through the machine, and attached to the anchoring bolt. A T1-weighted noncontrast sequence MRI with the laser in place is obtained to be identified by the laser software and ensure proper location. Under MRI thermography, the laser is heated to 43°C, and the lesion is ablated. For this particular hematoma, only one pass of the laser was needed. If the lesion is larger, however, multiple trajectories may be planned.
SPEAKER: Alternatively, we may choose to reposition the laser along the length of the lesion, taking particular care not to injure any vital hypothalamic structures. Once treatment is complete, a post-op MRI is obtained, the laser and bolt are removed, and the small stab incision is closed with a single nylon figure-of-eight stitch. After ablation, a T1-weighted gadolinium MRI was obtained to demonstrate the postoperative changes of LiTT therapy.
SPEAKER: At this point, the probe tip was still within the right hypothalamus. Two weeks post-op, the patient denied any seizure-like activity and her neurological exam continued to be unremarkable. To assess her endocrine function, we measured her ACTH, LH, FSH, prolactin, insulin-like growth factor, TSH, free T3 and free T4 levels, all of which came back within normal limits.
SPEAKER: This video demonstrates the use of LITT therapy as a minimally invasive method for definitive treatment of hypothalamic hamartoma. This technique, combined with recent advancements in robotic systems, can allow for a highly accurate, expedited approach to epilepsy surgery that maintains high efficacy. Thank you for listening. Presented here are our references.
SPEAKER:
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