Robot-assisted, real-time, MRI-guided laser interstitial thermal therapy for pediatric patients with hypothalamic hamartoma: surgical technique, pitfalls, and initial results

Abstract

OBJECTIVE Real-time, MRI-guided laser interstitial thermal therapy (MRgLITT) has been reported as a safe and effective technique for the treatment of epileptogenic foci in children and adults. After the recent approval of MRgLITT by the European Medicines Agency in April 2018, the authors began to use it for the treatment of hypothalamic hamartomas (HHs) in pediatric patients with the assistance of a robotic arm. In this study, the authors report their initial experience describing the surgical technique, accuracy of the robotic arm, safety, and efficacy. METHODS The laser fiber was placed with the assistance of the stereotactic robotic arm. The accuracy of the robotic arm for this procedure was calculated by comparing the intraoperative MRI to the preoperative plan. Common demographic and seizure characteristics of the patients, laser ablation details, complications, and short-term seizure outcomes were prospectively collected. RESULTS Sixteen procedures (11 first ablations and 5 reablations) were performed in 11 patients between 15 months and 17 years of age (mean age 6.4 years) with drug-resistant epilepsy related to HHs. The mean target point localization error was 1.69 mm. No laser fiber needed to be repositioned. The mean laser power used per procedure was 4.29 W. The trajectory of the laser fiber was accidentally ablated in 2 patients, provoking transient hemiparesis in one of these patients. One patient experienced postoperative somnolence and syndrome of inappropriate antidiuretic hormone secretion, and 2 patients had transient oculomotor (cranial nerve III) palsy. Fifty-four percent of the patients were seizure free after the first ablation (mean follow-up 22 months, range 15–33 months). All 5 patients who experienced an epilepsy relapse underwent a second treatment, and 4 remain seizure free at least 5 months after reablation. CONCLUSIONS In the authors’ experience, the robotic arm was sufficiently accurate for laser fiber insertion, even in very young patients. MRgLITT appears to be an effective treatment for selected cases of HH. MRgLITT for HH is a minimally invasive procedure with appealing safety features, as it allows delivery of energy precisely under real-time MRI control. Nonetheless, complications may occur, especially in voluminous HHs. The amount of delivered energy and the catheter cooling system must be closely monitored during the procedure. A larger sample size and longer follow-up duration are needed to judge the efficacy and safety of MRgLITT for HH more rigorously. This initial experience was very promising.

Completion of disconnective surgery for refractory epilepsy in pediatric patients using robot-assisted MRI-guided laser interstitial thermal therapy

“…The TPLE calculated for these patients was comparable to the TPLE described in our previous reports for other stereotactic techniques. 27,37,38 The major deviation was 4.2 mm in the second ablation in patient 4. This was a very long trajectory along the persisting connection in the uncinate fasciculus, and it passed through the postsurgical cavity.…”

“…We used the Neuromate robotic arm for laser fiber insertion; specific considerations for treating pediatric patients have been previously discussed. 27,37,38 In this cohort study, we were aware that the entry point did not coincide with the previous craniotomy performed.…”

“…The robot-assisted surgical workflow for laser fiber insertion has previously been described by the authors 27,37,39 and is shown in Fig. 1 and Video 1.…”

“…[17][18][19][20][21][22][23][24][25][26] This technology was initially incorporated into our hospital in 2019 to treat hypothalamic hamartomas (HHs) and had very promising outcomes. 27 Other authors have used it to perform partial or complete callosotomy [28][29][30][31][32][33] and even palliative hemispherotomy. 34 This previous experience prompted us to apply MRIgLITT to complete other disconnective surgeries.…”

Minimally invasive procedures for hypothalamic hamartoma–related epilepsy: a systematic review and meta-analysis

“…A patient from the study by Du et al 29 was excluded because of the absence of seizures at HH presentation. Finally, 15 studies 10,16,17,[26][27][28][29][30][31][32][33][34][35][36][37] enter the study. The study selection flowchart is presented in Fig.…”