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

Santiago Candela-CantóDepartments of Neurosurgery,
Epilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain

Search for other papers by Santiago Candela-Cantó in
jns
Google Scholar
PubMed
Close
 MD, PhD
,
Jordi MuchartEpilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain
Diagnostic Imaging,

Search for other papers by Jordi Muchart in
jns
Google Scholar
PubMed
Close
 MD
,
Carlos ValeraEpilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain

Search for other papers by Carlos Valera in
jns
Google Scholar
PubMed
Close
 MD
,
Cristina JouEpilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain
Pathology, and

Search for other papers by Cristina Jou in
jns
Google Scholar
PubMed
Close
 MD
,
Diego CulebrasDepartments of Neurosurgery,
Epilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain

Search for other papers by Diego Culebras in
jns
Google Scholar
PubMed
Close
 MD
,
Mariana AlamarDepartments of Neurosurgery,

Search for other papers by Mariana Alamar in
jns
Google Scholar
PubMed
Close
 MD
,
Victoria BecerraDepartments of Neurosurgery,

Search for other papers by Victoria Becerra in
jns
Google Scholar
PubMed
Close
 MD, PhD
,
David ArtésAnesthesiology, and

Search for other papers by David Artés in
jns
Google Scholar
PubMed
Close
 MD
,
Georgina ArmeroDepartments of Neurosurgery,

Search for other papers by Georgina Armero in
jns
Google Scholar
PubMed
Close
 MD
,
Javier AparicioEpilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain

Search for other papers by Javier Aparicio in
jns
Google Scholar
PubMed
Close
 MD, PhD
,
José HinojosaDepartments of Neurosurgery,
Epilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain

Search for other papers by José Hinojosa in
jns
Google Scholar
PubMed
Close
 MD, PhD
, and
Jordi RumiàDepartments of Neurosurgery,
Epilepsy Surgery Unit, full member of the ERN EpiCARE, Sant Joan de Déu Barcelona Children’s Hospital, University of Barcelona, Spain

Search for other papers by Jordi Rumià in
jns
Google Scholar
PubMed
Close
 MD, PhD
Free access

OBJECTIVE

Since 2007, the authors have performed 34 hemispherotomies and 17 posterior quadrant disconnections (temporoparietooccipital [TPO] disconnections) for refractory epilepsy at Sant Joan de Déu Barcelona Children’s Hospital. Incomplete disconnection is the main cause of surgical failure in disconnective surgery, and reoperation is the treatment of choice. In this study, 6 patients previously treated with hemispherotomy required reoperation through open surgery. After the authors’ initial experience with real-time MRI-guided laser interstitial thermal therapy (MRIgLITT) for hypothalamic hamartomas, they decided to use this technique instead of open surgery to complete disconnective surgeries. The objective was to report the feasibility, safety, and efficacy of MRIgLITT to complete hemispherotomies and TPO disconnections for refractory epilepsy in pediatric patients.

METHODS

Eight procedures were performed on 6 patients with drug-resistant epilepsy. Patient ages ranged between 4 and 18 years (mean 10 ± 4.4 years). The patients had previously undergone hemispherotomy (4 patients) and TPO disconnection (2 patients) at the hospital. The Visualase system assisted by a Neuromate robotic arm was used. The ablation trajectory was planned along the residual connection. The demographic and epilepsy characteristics of the patients, precision of the robot, details of the laser ablation, complications, and results were prospectively collected.

RESULTS

Four patients underwent hemispherotomy and 2 underwent TPO disconnection. Two patients, including 1 who underwent hemispherotomy and 1 who underwent TPO disconnection, received a second laser ablation because of persistent seizures and connections after the first treatment. The average precision of the system (target point localization error) was 1.7 ± 1.4 mm. The average power used was 6.58 ± 1.53 J. No complications were noted. Currently, 5 of the 6 patients are seizure free (Engel class I) after a mean follow-up of 20.2 ± 5.6 months.

CONCLUSIONS

According to this preliminary experience, laser ablation is a safe method for complete disconnective surgeries and allowed epilepsy control in 5 of the 6 patients treated. A larger sample size and longer follow-up periods are necessary to better assess the efficacy of MRIgLITT to complete hemispherotomy and TPO disconnection, but the initial results are encouraging.

ABBREVIATIONS

AED = antiepileptic drug; DWI = diffusion-weighted imaging; HH = hypothalamic hamartoma; ILAE = International League Against Epilepsy; LITT = laser interstitial thermal therapy; MRIgLITT = MRI-guided LITT; SWI = susceptibility weighted imaging; TPLE = target point localization error; TPO = temporoparietooccipital; VEEG = video-electroencephalogram.

OBJECTIVE

Since 2007, the authors have performed 34 hemispherotomies and 17 posterior quadrant disconnections (temporoparietooccipital [TPO] disconnections) for refractory epilepsy at Sant Joan de Déu Barcelona Children’s Hospital. Incomplete disconnection is the main cause of surgical failure in disconnective surgery, and reoperation is the treatment of choice. In this study, 6 patients previously treated with hemispherotomy required reoperation through open surgery. After the authors’ initial experience with real-time MRI-guided laser interstitial thermal therapy (MRIgLITT) for hypothalamic hamartomas, they decided to use this technique instead of open surgery to complete disconnective surgeries. The objective was to report the feasibility, safety, and efficacy of MRIgLITT to complete hemispherotomies and TPO disconnections for refractory epilepsy in pediatric patients.

METHODS

Eight procedures were performed on 6 patients with drug-resistant epilepsy. Patient ages ranged between 4 and 18 years (mean 10 ± 4.4 years). The patients had previously undergone hemispherotomy (4 patients) and TPO disconnection (2 patients) at the hospital. The Visualase system assisted by a Neuromate robotic arm was used. The ablation trajectory was planned along the residual connection. The demographic and epilepsy characteristics of the patients, precision of the robot, details of the laser ablation, complications, and results were prospectively collected.

RESULTS

Four patients underwent hemispherotomy and 2 underwent TPO disconnection. Two patients, including 1 who underwent hemispherotomy and 1 who underwent TPO disconnection, received a second laser ablation because of persistent seizures and connections after the first treatment. The average precision of the system (target point localization error) was 1.7 ± 1.4 mm. The average power used was 6.58 ± 1.53 J. No complications were noted. Currently, 5 of the 6 patients are seizure free (Engel class I) after a mean follow-up of 20.2 ± 5.6 months.

CONCLUSIONS

According to this preliminary experience, laser ablation is a safe method for complete disconnective surgeries and allowed epilepsy control in 5 of the 6 patients treated. A larger sample size and longer follow-up periods are necessary to better assess the efficacy of MRIgLITT to complete hemispherotomy and TPO disconnection, but the initial results are encouraging.

In Brief

The authors report their initial experience with MRI-guided laser interstitial thermal therapy (MRIgLITT) to complete hemispherotomy and temporoparietooccipital (TPO) disconnections. Six pediatric patients with seizure persistence or recurrence due to an incomplete hemispherotomy (4 patients) or TPO (2 patients) underwent 8 surgical procedures with MRIgLITT. Five patients achieved successful seizure control after MRIgLITT. This technique has been proven to be safe and will become a good technical option to complete disconnective surgeries in select cases.

In most pediatric surgical cases, epilepsy is caused by malformations of cortical development, perinatal insults, and encephalitis.13 When the epileptogenic area is large, the techniques of choice are disconnective surgeries (such as hemispherotomy) if the entire cerebral hemisphere is affected,48 or temporoparietooccipital (TPO) disconnection if the epileptogenic area affects only the posterior quadrant of the hemisphere and motor function is preserved.913

Our hospital is a national and European reference center (EpiCARE Network) for the treatment of pediatric patients with refractory epilepsy. Every year, 170 patients are evaluated and 60 patients are surgically treated in our epilepsy unit. Since 2007, 34 hemispherotomies and 17 TPO disconnections have been performed for refractory epilepsy in our pediatric hospital. Until 2019, our cohort of patients reached an ILAE class 1/Engel class I in 88% of hemispherotomies and 75% of TPO disconnections.35,36 Prior to this study, 6 of the patients who underwent hemispherotomy required reintervention due to incomplete disconnection to allow drug withdrawal or for persistent seizures. Reoperation is the most effective treatment for failed disconnective surgeries, although it is technically challenging and can result in severe complications.1416

The technique of MRI-guided laser interstitial thermal therapy (MRIgLITT) has previously been used successfully in the treatment of epilepsy.1726 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 callosotomy2833 and even palliative hemispherotomy.34 This previous experience prompted us to apply MRIgLITT to complete other disconnective surgeries.

In this paper, we report our initial experience with laser ablation to complete hemispherotomy and TPO disconnection in pediatric patients, aiming to describe the surgical technique assisted by the robotic arm and its accuracy, safety, and efficacy.

Methods

Approval by the Research and Ethics Committees of the Sant Joan de Déu Barcelona Hospital was obtained before starting this study.

Patient Selection Criteria

Laser interstitial thermal therapy (LITT) was suggested for patients in whom reoperation was indicated to complete a hemispherotomy or TPO disconnection for seizure recurrence or persistence, or to allow antiepileptic drug (AED) withdrawal. After the initial disconnective surgery, patients were evaluated in the epilepsy surgery unit at 3, 6, and 12 months. The study included a video-electroencephalogram (VEEG), 3-T MRI with a specific epilepsy protocol, and neuropsychological assessments. In cases of seizure recurrence, seizure semiology, extended interictal and ictal VEEGs, and postoperative MRI were discussed. If the study findings were considered coherent, the team established a working hypothesis of which remnant connections were the most probable culprit of seizure propagation; therefore, those areas were defined as the MRIgLITT target.

Imaging Studies

Preoperative studies were performed using a 3-T MRI machine (Philips Healthcare). They included diffusion-weighted imaging (DWI), susceptibility weighted imaging (SWI), T2-weighted imaging, time-of-flight 3D volumetric FLAIR, and volumetric T1-weighted (1 mm3 isotropic) pre- and postcontrast images for neurosurgical navigation. Intraoperative MRIgLITT studies were performed using a 1.5-T MRI machine (Philips Ingenia, Philips Healthcare) located in the surgical area beside the neurosurgical theater. This equipment was used for spatial coregistration, intraoperative monitoring during laser ablation, and immediate postoperative imaging control.

Presurgical Plan

Preoperative 3D isotropic T1-weighted pre- and postcontrast MRI data sets were loaded into the planning workstation. The fiber trajectory was planned using Voxim software (Renishaw). The treatment aim was to ablate the connection or connections along its long axis, but in some cases a transverse trajectory was planned if it was considered safer. More than one laser fiber was planned if multiple connections were not included in one trajectory. Vessels were avoided during presurgical planning. Because of the size of the therapeutic window of the laser fiber, several pullouts were planned beforehand.

Laser Fiber Insertion

The robot-assisted surgical workflow for laser fiber insertion has previously been described by the authors27,37,39 and is shown in Fig. 1 and Video 1.

VIDEO 1. Clip showing completion of the disconnective surgical technique using MRIgLITT in a pediatric patient. © Santiago Candela-Cantó, published with permission. Click here to view.

FIG. 1.
FIG. 1.

Implantation of the laser fiber assisted by the Neuromate robotic arm. A: Preoperative MRI for coregistration and laser ablation are performed in the MRI facility located next door to the operating room. Spatial patient coregistration is performed through ultrasounds. The fiducial star-shaped array, with which the preoperative MRI is performed, is replaced by an ultrasound emitter, and an ultrasound receiver is attached to the robotic arm. In this way, the robot is able to locate the patient in the operating room space and achieve very precise coregistration. B: The drill bit is guided by the robotic arm through the 3.2-mm instrument holder. C: Fixation of the anchoring screw with a 1.7-mm stylet held by the robotic arm. D: Patient positioning in the MRI machine, using the soft coils to allow connection of the cooling catheter and laser fiber (or fibers) with the Visualase system without bending them. Figure is available in color online only.

Patients were transferred to the intraoperative MRI machine after fixation of a fiducial support to the skull for stereotactic spatial registration of the preoperative MRI. In the operating room, coregistration was based on fiducial location through ultrasound, and accuracy was checked by pointing a laser beam attached to the robotic arm at facial anatomical landmarks. The Medtronic 10-mm Visualase laser fiber was inserted with the Neuromate (Renishaw) robotic arm, and the skull was drilled with a 3.1-mm drill bit.

Transfer to the MRI Facility

After fiber insertion, an MRI safety checklist was reviewed and the patients were transferred to the MRI room. First, a standard MRI was performed to assess any possible complications, check the correct fiber placement, and determine which two planes would be more useful for treatment execution and monitoring.

Accuracy of the Laser Fiber Insertion Calculation

The accuracy of fiber insertion was calculated postoperatively using Voxim software, as reported previously in deep brain stimulation,37 stereo-electroencephalography,38 and laser ablation of HHs27 by the authors. The preoperative plan and initial intraoperative T1-weighted MRI localization were combined. Voxim measuring tools were used to calculate the distance between the tip of the laser fiber and the planned target point in different Cartesian planes. The “in-line” view of the trajectory was also used to calculate the total deviation.

Laser Ablation

The ablation was performed using the Visualase system, with the laser fiber connected to a 15-W, 980-nm laser diode and the cooling system. The procedure was performed using an intraoperative 1.5-T Philips Ingenia MRI machine.

The therapy was continuously monitored by real-time MRI thermography.40,41 We defined low-temperature markers (45°C) to protect the contralateral hemisphere, internal capsule, middle cerebral artery branches, insula, or basal ganglia, depending on the location of the laser ablation. During the cooling time after each treatment, real ablation extension was checked with DWI, FLAIR, and T2-weighted MRI. The laser fiber was pulled out as many times as needed to ablate the planned length. At the end of the procedure after removing the laser catheter, complete final MRI including volumetric T1-weighted, FLAIR, DWI, T2-weighted, and SWI was performed.

The Visualase system provided detailed power and time logs for every patient. The postoperative volume of the lesion was calculated with the “Smartbrush” tool of the Elements software (Brainlab) on the postoperative 3D FLAIR images.

Epilepsy Outcome

Epilepsy outcomes were evaluated using the International League Against Epilepsy (ILAE) and Engel (epilepsy surgery outcome) scales at 3, 6, and 12 months.35,36 Furthermore, all patients were contacted prior to manuscript submission to check the epilepsy outcomes. Intra- and postoperative complications were prospectively recorded during the hospital stay and outpatient follow-up.

In the 1 case with treatment failure, pathological analysis of the excised tissue was performed after the anatomical hemispherectomy was completed. Brain samples were processed following standard histological protocols.42

Results

Patient Demographics

Six patients with drug-resistant epilepsy, between 4 and 18 years of age (mean age 10 ± 4.4 years), who had previously undergone hemispherotomy (4 patients) or TPO disconnection (2 patients), were treated at our hospital. Seizures persisted in 5 of the 6 patients after open disconnective surgery. One patient relapsed and experienced seizures after the withdrawal of the AEDs, 4 years after hemispherotomy.

All patients in whom the initial disconnective surgery failed through persisting connections during the study period could be included in this series and only an open reoperation was performed in 1 patient after failed MRIgLITT. Persisting connections were identified through MRI in the posterior insula (2 cases), uncinate fasciculus (2 cases), superior temporal gyrus (2 cases), parietal and fronto-orbital cortices, and anterior corpus callosum. Figure 2 shows examples of the pre- and postoperative MR images. Table 1 summarizes the patient data.

FIG. 2.
FIG. 2.

Examples of planned trajectories (left column) and ablations (right column) using Voxim software: A: In-line coronal T1-weighted enhanced MR image showing a trajectory longitudinal to the posterior insular connection in patient 2. B: Postoperative in-line coronal FLAIR image showing complete ablation of the connection. C: Preoperative in-line sagittal T1-weighted enhanced trajectory including posterior insular and uncinate fasciculus connections in patient 3. D: Postoperative sagittal in-line FLAIR image in patient 3 corresponding to the insular trajectory, in which uncinate fasciculus ablation can also be seen. E: Preoperative in-line sagittal T1-weighted enhanced trajectory along the superior temporal gyrus in patient 5. F: Postoperative sagittal in-line FLAIR imaging in patient 5 showing the laser ablation of the superior temporal gyrus. G: Preoperative in-line coronal T1-weighted enhanced MR image showing a trajectory to complete a frontoorbital disconnection in patient 6. H: Postoperative in-line coronal FLAIR image showing the frontoorbital disconnection. Figure is available in color online only.

TABLE 1.

Patient description

Pt No.Disconnective SurgeryEtiologyAge (yrs)Time Btwn Open Surgery & LITTSeizureTx ReceivedPersisting Connections
At AblationAt OnsetAt Previous SurgeriesTypeFrequency
1Lt hemiMeningitis40.583 & 46 mosTonic-clonic, atonicDailyLEV, LEV + CLB, LEV + CLB + VGB, VPA + CLB + LCM, VPA + CLB + TPM, VPA + CLB + VGB, OXC + PER, VGB + CLB + BRV + VPA, VGB + CLBPosterior insula
2Rt hemiRasmussen encephalitis1058 & 910 mosNonmotor, tonicDailyOXC, OXC + VPA, OXC + VPA + steroids + IGS, OXC + VPA + RITAB, OXC + LCM, OXC + ZNS + steroids + IGS + RITAB, OXC + ZNS + IGS ± CLB, PER, OXC + ZNS, OXC + TPM, OXC + TPM + CLB + ADAB, OXC + CLB + ADAB, OXC + BRV, OXC + CLB, OXC + LTG, OXC + ESL
3Rt TPOCortical dysplasia8 & 92718 mosBlinking, impaired awarenessDailyVGB, VPA, VPA + LEV, VPA + LEV + CBZ, VPA + LEV + CBZ + steroids, LEV + LCMUF, posterior insula/T1, parietal parisaggital
4Lt hemiPerinatal stroke18101720 mosTonic, hypermotorDailyPHT + PB + MDZ, PB + VPA, OXC, LEV, CZP, TPM + LCM + PER, LCM + CBZ, LCM + ESL + ZNS, LCM + ESL + VPAUF
5Rt TPOPerinatal stroke71.6665 mosMotor, CSWSSubclinicalOXC, OXC + VPA, OXC + VPA + LEV, VPA + LEV + CLB, VPA + LEV + CLB + steroids, OSP + CLB + BRV, OSP + CLB + ETOUF, posterior insula
6Lt hemiPerinatal stroke154105 yrsMotorOccasionalVPA + CBZ, LEV + CBZ, CBZ, TPM + CBZ, CBZ + LTG, LTG + CLB, CLB + PER, CLB + CBZ, CLB + CBZ + LCM, CBZ + LCM, ESL + LCM, ESL + LTGFrontoorbital cortex, anterior corpus callosum
Mean103.881.6 yrs

ADAB = adalimumab; BRV = brivaracetam; CBZ = carbazepine; CLB = clobazam; CSWS = epileptic encephalopathy with continuous spike and wave during sleep; CZP = clonazepam; ESL = eslicarbamazepine; ETO = etosuximide; hemi = hemispherotomy; IGS = immunoglobulins; LCM = lacosamide; LEV = levetiracetam; LTG = lamotrigine; MDZ = midazolam; OSP = ospolot; OXC = oxcarbazepine; PB = phenobarbital; PER = perampanel; PHT = phenytoin; pt = patient; RITAB = rituximab; TPM = topiromate; Tx = treatment; UF = uncinate fasciculus; VGB = vigabatrin; VPA = valproic acid; ZNS = zonisamide.

Presurgical Plan

We intended to plan trajectories longitudinally along the persisting connections: a longitudinal transparietal trajectory was planned for the posterior insula and the posterior part of the superior temporal gyrus, and a longitudinal transoccipital trajectory for the superior temporal gyrus. However, in 2 cases (for the uncinate fasciculus and to disconnect the frontoorbital cortex), a perpendicular trajectory was considered safer. In all cases, the entry point was planned through the disconnected brain tissue. Examples of planned trajectories are shown in Fig. 2.

Laser Ablation

The mean laser fiber deviation at the target point (target point localization error [TPLE]) was 1.7 ± 1.4 mm. This accuracy was adequate for performing all surgeries without replacing any laser fiber. The mean amount of energy delivered in the ablations was 16,075 ± 6746 J over 2391 ± 963 seconds. The mean power used was 6.58 ± 1.53 W. The ablated volume was 4840 ± 2108 mm3. The maximum ablation diameter was 19.4 ± 4.2 mm. Table 2 summarizes the ablation data. Table 3 summarizes the descriptive and outcome statistics. The most relevant thermography images have been included in Video 2.

VIDEO 2. Clip showing real-time MRI thermographies of disconnective surgery using MRIgLITT. CSWS = continuous spike and wave during sleep; sz = seizures. © Santiago Candela-Cantó, published with permission. Click here to view.

TABLE 2.

Ablation details and seizure outcome

Pt No.Ablated AreaTrajectoryTPLE (mm)Mean Power (W)Time (sec)Energy Delivered (J)Vol Ablated (mm3)Max Ablation Diameter (mm)Surgical Time (hrs)Postop Hospital Stay (days)Seizure OutcomeFU
Engel ClassILAE Class
1Post insulaLong02.939082658660148.54IA129 mos
2Post insulaLong0.46.19408525,2775555236.73IA122 mos
31st LITT
  F19.5IA13 mos* 
   UFPerp36.58256716,885632021 
  F2 
   Post T1Long2.35.71227913,024667020 
2nd LITT
  F16.93IA119 mos
   Post insulaLong07.42220016,330309025
  F2
   ParietalLong1.57.50148811,166505023
41st LITTIVA5
  UFPerp37.04265818,7124350186.7534 days*
2nd LITT
  UFLong4.28.67248021,5098130226.520 days*
5Temporal pole–T1Long1.756.40367023,5005220137.53IA116 mos
6Frontoorbital cortexPerp1.27.43157411,6943360155.53IA115 mos
Mean1.76.58239116,075484019.47.23.1

FU = follow-up; Long = longitudinal; Perp = perpendicular.

There were no complications in any patient.

Time to epilepsy relapse.

TABLE 3.

Summary of descriptive and outcome statistics

VariableMeanSDMinQ1MedianQ3Max
Age at laser ablation (yrs)10.144.4147.5912.518
Age at epilepsy onset (yrs)3.873.400.581.7434.7510
Age at previous open surgeries (yrs)84.3435.57.69.2517
Time btwn open surgery & LITT (mos)19.8320.6157419.560
TPLE (mm)1.731.4000.61.622.824.2
Mean power (W)6.581.532.936.246.817.428.67
Duration of ablation (sec)2390.9963.039081730.52379.52635.254085
Energy delivered (J)16,075.56746.11265812,026.516,607.520,809.7525,277
Surgical time (hrs)7.231.255.56.656.827.759.5
Vol ablated (mm3)4840.52108.946603607.551356128.758130
Max diameter ablated (mm)19.44.191315.7520.522.7525
FU (mos)20.25.61516192223

Q1, Q3 = quartile 1, quartile 3.

Five (83%) of 6 patients attained seizure freedom after LITT: 4 (66%) of 6 after the first LITT, and 1 (50%) of 2 after the second LITT.

Duration of Surgical Procedure and Hospital Stay

The mean duration of the complete procedure was 7 hours 15 minutes (range 5 hours 30 minutes to 9 hours 30 minutes), from the fiducial support insertion to the final MRI control (both included). The mean postoperative hospital stay was 3 days, including 1 night in the intensive care unit.

Epilepsy Outcome

Five (83%) of the 6 patients were seizure free (ILAE class 1, Engel class IA) after a mean of 20.2 ± 5.6 months of follow-up. Four patients (66%) were seizure free after a first MRIgLITT; 2 patients with initial MRIgLITT failure (1 TPO disconnection and 1 hemispherotomy) underwent reoperation.

Patient 3 (TPO disconnection) did not present with clinical seizures after the first MRIgLITT, but the VEEG showed a pseudoperiodic pattern originating in the disconnected parenchyma and diffusing to the rest of the cerebral hemisphere, which improved after the second laser ablation. The VEEG changes are shown in Fig. 3. The seizures persisted in patient 4 (hemispherotomy) after two MRIgLITT procedures. The patient underwent an open reintervention (anatomical hemispherectomy) 8 months after the initial procedure without improvement (ILAE class 5, Engel class IVB). Figure 4 shows the MR images corresponding to the first and second MRIgLITT, the MR image after hemispherectomy, and current VEEG.

FIG. 3.
FIG. 3.

Pre- and postoperative VEEGs 6 months after the second MRIgLITT in patient 3 (bipolar; high-pass filter 0.4 Hz, low-pass filter 70 Hz, gain 150 μV/cm). A: Preoperative awake VEEG showing asymmetrical basal activity and subcontinuous slowing over the right cerebral hemisphere due to interference of the anomalies (spike and polyspike wave activity over T4TP10 [arrow]). B: Preoperative no REM sleep (NREMS) VEEG with significant activation of epileptiform abnormalities in the posterior region of the right cerebral hemisphere (arrow) and contralateral diffusion (asterisks). C: Postoperative awake VEEG with asymmetrical basal activity. Spikes/spikes and wave over O2T6 (arrows), posterior alpha rhythm reactive to ocular opening (OA) and closing (OC; asterisk), subcontinuous slowing over the right cerebral hemisphere. D: NREMS VEEG showing spikes/spikes and wave (arrows) plus beta activity (18 Hz/30–40 mV) over O2T6 (β) plus contralateral diffusion at O1T5 (asterisks). Figure is available in color online only.

FIG. 4.
FIG. 4.

Images from the case with treatment failure (patient 4). A: Planned transverse trajectory through the uncinate fasciculus viewed in an in-line T1-weighted MR image using the Voxim software for the first MRIgLITT. B: Postoperative in-line FLAIR image showing the ablation of this connection. C: Preoperative in-line coronal TI-weighted enhanced MR image showing the planned longitudinal trajectory for the uncinate ablation in the second MRIgLITT. D: Postoperative in-line coronal FLAIR image showing the complete ablation of the uncinate fasciculus. E: Coronal T1-weighted enhanced MR image showing anatomical hemispherectomy after the failed second MRIgLITT. F: Axial T1-weighted enhanced MR image showing the anatomical hemispherectomy. G: Awake VEEG with right frontal epileptiform abnormalities (arrow) and contralateral diffusion (asterisks) after the anatomic hemispherectomy. H: NREMS VEEG after anatomical hemispherectomy showing right frontal epileptiform abnormalities (arrow) and contralateral diffusion (asterisk). Figure is available in color online only.

No complications were reported in any patient. Neuropathological findings for patient 4 are shown in Fig. 5.

FIG. 5.
FIG. 5.

Photomicrographs showing histopathological findings in patient 4. A and B: Cavity in the cerebral cortex and white matter in the area of laser ablation. H&E. C and D: Reactive astrogliosis at the periphery of the laser ablation tract (C) with aggregates of foamy macrophages (D). Glial fibrillary acidic protein (C), CD68 (D). E and F: Marked depletion of the axons in the vicinity of the cavity (E) compared with white matter without laser ablation (F). Neurofilament. G and H: Rarefaction in the subcortical white matter with spongiosis at the periphery of the cavity (G) with numerous aggregates of lipofuscin with calcified neurons (H) is identified. H&E. Figure is available in color online only.

Discussion

The most frequent cause of surgical failure in disconnective surgeries is incomplete disconnection, and reoperation is the treatment of choice.1416 Usually, persisting connections are deep-seated and small and are particularly suited to being disrupted by MRIgLITT.

Previous experience disrupting white matter pathways has been described, using partial or complete callosotomy, with a decrease in drop attacks and improvement of epilepsy outcome,2833 and palliative hemispherotomy, with minimal morbidity and good results as well.34 We have observed different persisting connections in our patients depending on the surgical technique chosen for the hemispherotomy. When the perisylvian technique5,7 was used, there was more risk of leaving small connections at the posterior insula, and when the vertical technique6 was used, connections could persist at the uncinate fasciculus. Because of the risk of hypothalamic damage, we are always very cautious in the frontoorbital disconnection, and it can lead to a connection at this level. For the TPO procedure, we performed the temporal disconnection through the middle temporal gyrus in some cases, and it led to a persisting connection along the superior temporal gyrus.

The number of persisting connections and their diameters are the most important data points for considering LITT for completing a disconnective surgery. In our series, we used a maximum of two laser fibers per patient to cover one or two persisting connections. The reason for this limit is merely financial, based on the cost of the laser fibers and the budget per patient provided by our public health system. 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 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. In fact, during the first treatment of this patient, we performed a perpendicular (transverse) trajectory to avoid a long trajectory. This strategy did not prevent us from accomplishing the ablation. No fibers needed to be relocated.

The amount of energy delivered in our patients was relatively large compared to the energy needed in HHs, for example.27 The energy delivered in HHs was 11,615 ± 6887 J, while in these surgeries it was 16,075 ± 6746 J. This difference could be explained because the connections were widely surrounded by freely circulating CSF that cooled the targeted area during the treatment. Additionally, as our targets were bordered by disconnected brain tissue, we considered it safe to use high-energy ablations. In fact, our patients did not experience any complications. As in HHs, it is desirable to lower the amount of energy.27 More selective ablations could contribute to this purpose and shorten the surgical time.

The maximum ablation diameter obtained in our series was 25 mm. Larger, persisting connections should be excluded or approached with more than one laser fiber. Laser ablation was effective in 5 of our 6 patients after more than 1 year of follow-up. The method was only unsuccessful in 1 patient, who required reintervention by MRIgLITT and later open surgery to complete the anatomical hemispherectomy, also without success. Neuropathological examination of the excised tissue revealed changes attributable to the white matter disruption by MRIgLITT. This patient has epilepsy secondary to a perinatal infarction, and we believe that there could be a contralateral parasagittal epileptic focus.

This technique was minimally invasive. There is no need to reopen the cranium to address major anatomical distortions, previous scars, or adhesions between the brain and meninges. Blood loss was negligible; therefore, none of our patients required blood transfusions, which is especially important in younger patients. None of the patients developed hydrocephalus, which is a risk factor for open reoperations in disconnective surgery.43 Two of the 6 patients who had previously undergone a hemispherotomy reoperation through a craniotomy developed hydrocephalus (33%), compared with only 4 (12%) of 34 patients after the first hemispherotomy surgery in our series. Furthermore, the hospital stay was much shorter.

Considering these theoretical advantages of MRIgLITT over open reoperation, this technique has become our institution’s first choice for completing disconnective surgeries. Because this is a complex and expensive technique, specialized centers should be defined to increase safety and efficacy.

Conclusions

In our limited experience, MRIgLITT has been deemed safe and effective in its ability to complete hemispherotomies and TPO disconnections, resulting in 5 of 6 patients with Engel class IA after this procedure. However, studies with a larger sample size and longer follow-up periods need to be conducted to better assess the safety and efficacy of MRIgLITT in completing disconnective surgeries.

Acknowledgments

We thank Lucia Bentabol for her technical support. We thank Manel Gomez Ponce, Fernando Borreguero, Sonia Acero, Miriam Álamo, and Rosa Aguilar for their professional and personal involvement. We thank Carles Fàbrega and Gemma Fernández for figure and video editing. We are indebted to the "Biobanc de l’Hospital Infantil Sant Joan de Déu per a la Investigació," part of the Spanish Biobank Network of ISCIII, for the sample and data procurement.

Disclosures

Dr. Candela-Cantó reports having a teaching and education contract with Medtronic.

Author Contributions

Conception and design: Candela-Cantó. Acquisition of data: Candela-Cantó, Muchart, Valera, Jou. Analysis and interpretation of data: Candela-Cantó, Muchart, Valera, Jou. Drafting the article: Candela-Cantó. Critically revising the article: all authors. Reviewed submitted version of manuscript: all authors. Approved the final version of the manuscript on behalf of all authors: Candela-Cantó. Study supervision: Aparicio, Hinojosa, Rumià.

Supplemental Information

References

  • 1

    Cross JH. Epilepsy surgery in childhood. Epilepsia. 2002;43(suppl 3):65-70.

  • 2

    Duchowny M, Jayakar P, Resnick T, et al. Epilepsy surgery in the first three years of life. Epilepsia. 1998;39(7):737-743.

  • 3

    Guerrini R. Epilepsy in children. Lancet. 2006;367(9509):499524.

  • 4

    Rasmussen T. Hemispherectomy for seizures revisited. Can J Neurol Sci. 1983;10(2):7178.

  • 5

    Mascott C, Choi T, Rasmussen T, Villemure JG. The evolution of functional hemispherectomy at the MNI. Epilepsia. 1992;33(3):99.

  • 6

    Delalande O, Pinard JM, Basdevant C, Gauthe M, Plouin P, Dulac O. Hemispherotomy: a new procedure for central disconnection. Epilepsia. 1992;33(3):99100.

    • Search Google Scholar
    • Export Citation
  • 7

    Schramm J, Behrens E, Entzian W. Hemispherical deafferentation: an alternative to functional hemispherectomy. Neurosurgery. 1995;36(3):509516.

  • 8

    Villemure JG, Mascott CR. Peri-insular hemispherotomy: surgical principles and anatomy. Neurosurgery. 1995;37(5):975981.

  • 9

    Daniel RT, Meagher-Villemure K, Farmer JP, Andermann F, Villemure JG. Posterior quadrantic epilepsy surgery: technical variants, surgical anatomy, and case series. Epilepsia. 2007;48(8):14291437.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    De Ribaupierre S, Delalande O. Hemispherotomy and other disconnective techniques. Neurosurg Focus. 2008;25(3):E14.

  • 11

    Dorfer C, Czech T, Mühlebner-Fahrngruber A, et al. Disconnective surgery in posterior quadrantic epilepsy: experience in a consecutive series of 10 patients. Neurosurg Focus. 2013;34(6):E10.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12

    Rizzi M, Revay M, d’Orio P, et al. Tailored multilobar disconnective epilepsy surgery in the posterior quadrant. J Neurosurg. 2019;132(5):13451357.

  • 13

    Mohamed AR, Freeman JL, Maixner W, Bailey CA, Wrennall JA, Harvey AS. Temporoparietooccipital disconnection in children with intractable epilepsy. J Neurosurg Pediatr. 2011;7(6):660670.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 14

    Bartoli A, El Hassani Y, Jenny B, et al. What to do in failed hemispherotomy? Our clinical series and review of the literature. Neurosurg Rev. 2018;41(1):125132.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15

    Vadera S, Moosa AN, Jehi L, et al. Reoperative hemispherectomy for intractable epilepsy: a report of 36 patients. Neurosurgery. 2012;71(2):388393.

  • 16

    Chen S, Guan Y, Liu C, et al. Treatment for patients with recurrent intractable epilepsy after primary hemispherectomy. Epilepsy Res. 2018;139:137142.

  • 17

    Curry DJ, Gowda A, McNichols RJ, Wilfong AA. MR-guided stereotactic laser ablation of epileptogenic foci in children. Epilepsy Behav. 2012;24(4):408414.

  • 18

    Tovar-Spinoza Z, Carter D, Ferrone D, Eksioglu Y, Huckins S. The use of MRI-guided laser-induced thermal ablation for epilepsy. Childs Nerv Syst. 2013;29(11):20892094.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19

    González-Martínez J, Vadera S, Mullin J, et al. Robot-assisted stereotactic laser ablation in medically intractable epilepsy: operative technique. Neurosurgery. 2014;10 Suppl 2:167-173.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20

    Lewis EC, Weil AG, Duchowny M, Bhatia S, Ragheb J, Miller I. MR-guided laser interstitial thermal therapy for pediatric drug-resistant lesional epilepsy. Epilepsia. 2015;56(10):15901598.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 21

    Curry DJ, Raskin J, Ali I, Wilfong AA. MR-guided laser ablation for the treatment of hypothalamic hamartomas. Epilepsy Res. 2018;142:131134.

  • 22

    Hawasli AH, Bandt SK, Hogan RE, Werner N, Leuthardt EC. Laser ablation as treatment strategy for medically refractory dominant insular epilepsy: therapeutic and functional considerations. Stereotact Funct Neurosurg. 2014;92(6):397404.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 23

    Willie JT, Laxpati NG, Drane DL, et al. Real-time magnetic resonance-guided stereotactic laser amygdalohippocampotomy for mesial temporal lobe epilepsy. Neurosurgery. 2014;74(6):569585.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24

    Kang JY, Wu C, Tracy J, et al. Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy. Epilepsia. 2016;57(2):325334.

  • 25

    North RY, Raskin JS, Curry DJ. MRI-guided laser interstitial thermal therapy for epilepsy. Neurosurg Clin N Am. 2017;28(4):545557.

  • 26

    Prince E, Hakimian S, Ko AL, Ojemann JG, Kim MS, Miller JW. Laser interstitial thermal therapy for epilepsy. Curr Neurol Neurosci Rep. 2017;17(9):63.

  • 27

    Candela-Cantó S, Muchart J, Ramírez-Camacho A, et al. Robot-assisted, real-time, MRI-guided laser interstitial thermal therapy for pediatric patients with hypothalamic hamartoma: surgical technique, pitfalls, and initial results. J Neurosurg Pediatr. 2022;29(6):681692.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28

    Ho AL, Miller KJ, Cartmell S, Inoyama K, Fisher RS, Halpern CH. Stereotactic laser ablation of the splenium for intractable epilepsy. Epilepsy Behav Case Rep. 2016;5:2326.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 29

    Ball T, Sharma M, White AC, Neimat JS. Anterior corpus callosotomy using laser interstitial thermal therapy for refractory epilepsy. Stereotact Funct Neurosurg. 2018;96(6):406411.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 30

    Karsy M, Patel DM, Halvorson K, Mortimer V, Bollo RJ. Anterior two-thirds corpus callosotomy via stereotactic laser ablation. Neurosurg Focus. 2018;44(VideoSuppl2):V2.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 31

    Palma AE, Wicks RT, Popli G, Couture DE. Corpus callosotomy via laser interstitial thermal therapy: a case series. J Neurosurg Pediatr. 2018;23(3):303307.

  • 32

    Huang Y, Yecies D, Bruckert L, et al. Stereotactic laser ablation for completion corpus callosotomy. J Neurosurg Pediatr. 2019;24(4):433441.

  • 33

    Roland JL, Akbari SHA, Salehi A, Smyth MD. Corpus callosotomy performed with laser interstitial thermal therapy. J Neurosurg. 2021;134(1):314322.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 34

    Chua MMJ, Bushlin I, Stredny CM, Madsen JR, Patel AA, Stone S. Magnetic resonance imaging–guided laser-induced thermal therapy for functional hemispherotomy in a child with refractory epilepsy and multiple medical comorbidities. J Neurosurg Pediatr. 2020;27(1):3035.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 35

    Fisher RS, Cross JH, French JA, et al. Operational classification of seizure types by the International League Against Epilepsy: position paper of the ILAE Commission for Classification and Terminology. Epilepsia. 2017;58(4):522530.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 36

    Engel J Jr, Cascino GD, Van Ness PC, Rasmussen TB, Ojemann LM. Outcome with respect to epileptic seizures. In: Engel J Jr, ed. Surgical Treatment of the Epilepsies. 2nd ed. Raven Press;1993:609-621.

    • Search Google Scholar
    • Export Citation
  • 37

    Candela S, Vanegas MI, Darling A, et al. Frameless robot-assisted pallidal deep brain stimulation surgery in pediatric patients with movement disorders: precision and short-term clinical results. J Neurosurg Pediatr. 2018;22(4):416425.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 38

    Candela-Cantó S, Aparicio J, López JM, et al. Frameless robot-assisted stereoelectroencephalography for refractory epilepsy in pediatric patients: accuracy, usefulness, and technical issues. Acta Neurochir (Wien). 2018;160(12):24892500.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 39

    Candela-Cantó S, Alamar M, Aláez C, et al. Highly realistic simulation for robot-assisted hypothalamic hamartoma real-time MRI-guided laser interstitial thermal therapy (LITT). Childs Nerv Syst. 2020;36(6):11311142.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 40

    Ascher PW, Justich E, Schröttner O. Interstitial thermotherapy of central brain tumors with the Nd:YAG laser under real-time monitoring by MRI. J Clin Laser Med Surg. 1991;9(1):7983.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 41

    Quesson B, de Zwart JA, Moonen CT. Magnetic resonance temperature imaging for guidance of thermotherapy. J Magn Reson Imaging. 2000;12(4):525533.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 42

    Helgager J, Lidov HG, Mahadevan NR, Kieran MW, Ligon KL, Alexandrescu S. A novel GIT2-BRAF fusion in pilocytic astrocytoma. Diagn Pathol. 2017;12(1):82.

  • 43

    Lew SM, Matthews AE, Hartman AL, Haranhalli N. Posthemispherectomy hydrocephalus: results of a comprehensive, multiinstitutional review. Epilepsia. 2013;54(2):383389.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • Collapse
  • Expand

Figure from Candela-Cantó et al. (pp 61–70).

  • View in gallery
    FIG. 1.

    Implantation of the laser fiber assisted by the Neuromate robotic arm. A: Preoperative MRI for coregistration and laser ablation are performed in the MRI facility located next door to the operating room. Spatial patient coregistration is performed through ultrasounds. The fiducial star-shaped array, with which the preoperative MRI is performed, is replaced by an ultrasound emitter, and an ultrasound receiver is attached to the robotic arm. In this way, the robot is able to locate the patient in the operating room space and achieve very precise coregistration. B: The drill bit is guided by the robotic arm through the 3.2-mm instrument holder. C: Fixation of the anchoring screw with a 1.7-mm stylet held by the robotic arm. D: Patient positioning in the MRI machine, using the soft coils to allow connection of the cooling catheter and laser fiber (or fibers) with the Visualase system without bending them. Figure is available in color online only.

  • View in gallery
    FIG. 2.

    Examples of planned trajectories (left column) and ablations (right column) using Voxim software: A: In-line coronal T1-weighted enhanced MR image showing a trajectory longitudinal to the posterior insular connection in patient 2. B: Postoperative in-line coronal FLAIR image showing complete ablation of the connection. C: Preoperative in-line sagittal T1-weighted enhanced trajectory including posterior insular and uncinate fasciculus connections in patient 3. D: Postoperative sagittal in-line FLAIR image in patient 3 corresponding to the insular trajectory, in which uncinate fasciculus ablation can also be seen. E: Preoperative in-line sagittal T1-weighted enhanced trajectory along the superior temporal gyrus in patient 5. F: Postoperative sagittal in-line FLAIR imaging in patient 5 showing the laser ablation of the superior temporal gyrus. G: Preoperative in-line coronal T1-weighted enhanced MR image showing a trajectory to complete a frontoorbital disconnection in patient 6. H: Postoperative in-line coronal FLAIR image showing the frontoorbital disconnection. Figure is available in color online only.

  • View in gallery
    FIG. 3.

    Pre- and postoperative VEEGs 6 months after the second MRIgLITT in patient 3 (bipolar; high-pass filter 0.4 Hz, low-pass filter 70 Hz, gain 150 μV/cm). A: Preoperative awake VEEG showing asymmetrical basal activity and subcontinuous slowing over the right cerebral hemisphere due to interference of the anomalies (spike and polyspike wave activity over T4TP10 [arrow]). B: Preoperative no REM sleep (NREMS) VEEG with significant activation of epileptiform abnormalities in the posterior region of the right cerebral hemisphere (arrow) and contralateral diffusion (asterisks). C: Postoperative awake VEEG with asymmetrical basal activity. Spikes/spikes and wave over O2T6 (arrows), posterior alpha rhythm reactive to ocular opening (OA) and closing (OC; asterisk), subcontinuous slowing over the right cerebral hemisphere. D: NREMS VEEG showing spikes/spikes and wave (arrows) plus beta activity (18 Hz/30–40 mV) over O2T6 (β) plus contralateral diffusion at O1T5 (asterisks). Figure is available in color online only.

  • View in gallery
    FIG. 4.

    Images from the case with treatment failure (patient 4). A: Planned transverse trajectory through the uncinate fasciculus viewed in an in-line T1-weighted MR image using the Voxim software for the first MRIgLITT. B: Postoperative in-line FLAIR image showing the ablation of this connection. C: Preoperative in-line coronal TI-weighted enhanced MR image showing the planned longitudinal trajectory for the uncinate ablation in the second MRIgLITT. D: Postoperative in-line coronal FLAIR image showing the complete ablation of the uncinate fasciculus. E: Coronal T1-weighted enhanced MR image showing anatomical hemispherectomy after the failed second MRIgLITT. F: Axial T1-weighted enhanced MR image showing the anatomical hemispherectomy. G: Awake VEEG with right frontal epileptiform abnormalities (arrow) and contralateral diffusion (asterisks) after the anatomic hemispherectomy. H: NREMS VEEG after anatomical hemispherectomy showing right frontal epileptiform abnormalities (arrow) and contralateral diffusion (asterisk). Figure is available in color online only.

  • View in gallery
    FIG. 5.

    Photomicrographs showing histopathological findings in patient 4. A and B: Cavity in the cerebral cortex and white matter in the area of laser ablation. H&E. C and D: Reactive astrogliosis at the periphery of the laser ablation tract (C) with aggregates of foamy macrophages (D). Glial fibrillary acidic protein (C), CD68 (D). E and F: Marked depletion of the axons in the vicinity of the cavity (E) compared with white matter without laser ablation (F). Neurofilament. G and H: Rarefaction in the subcortical white matter with spongiosis at the periphery of the cavity (G) with numerous aggregates of lipofuscin with calcified neurons (H) is identified. H&E. Figure is available in color online only.

  • 1

    Cross JH. Epilepsy surgery in childhood. Epilepsia. 2002;43(suppl 3):65-70.

  • 2

    Duchowny M, Jayakar P, Resnick T, et al. Epilepsy surgery in the first three years of life. Epilepsia. 1998;39(7):737-743.

  • 3

    Guerrini R. Epilepsy in children. Lancet. 2006;367(9509):499524.

  • 4

    Rasmussen T. Hemispherectomy for seizures revisited. Can J Neurol Sci. 1983;10(2):7178.

  • 5

    Mascott C, Choi T, Rasmussen T, Villemure JG. The evolution of functional hemispherectomy at the MNI. Epilepsia. 1992;33(3):99.

  • 6

    Delalande O, Pinard JM, Basdevant C, Gauthe M, Plouin P, Dulac O. Hemispherotomy: a new procedure for central disconnection. Epilepsia. 1992;33(3):99100.

    • Search Google Scholar
    • Export Citation
  • 7

    Schramm J, Behrens E, Entzian W. Hemispherical deafferentation: an alternative to functional hemispherectomy. Neurosurgery. 1995;36(3):509516.

  • 8

    Villemure JG, Mascott CR. Peri-insular hemispherotomy: surgical principles and anatomy. Neurosurgery. 1995;37(5):975981.

  • 9

    Daniel RT, Meagher-Villemure K, Farmer JP, Andermann F, Villemure JG. Posterior quadrantic epilepsy surgery: technical variants, surgical anatomy, and case series. Epilepsia. 2007;48(8):14291437.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 10

    De Ribaupierre S, Delalande O. Hemispherotomy and other disconnective techniques. Neurosurg Focus. 2008;25(3):E14.

  • 11

    Dorfer C, Czech T, Mühlebner-Fahrngruber A, et al. Disconnective surgery in posterior quadrantic epilepsy: experience in a consecutive series of 10 patients. Neurosurg Focus. 2013;34(6):E10.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 12

    Rizzi M, Revay M, d’Orio P, et al. Tailored multilobar disconnective epilepsy surgery in the posterior quadrant. J Neurosurg. 2019;132(5):13451357.

  • 13

    Mohamed AR, Freeman JL, Maixner W, Bailey CA, Wrennall JA, Harvey AS. Temporoparietooccipital disconnection in children with intractable epilepsy. J Neurosurg Pediatr. 2011;7(6):660670.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 14

    Bartoli A, El Hassani Y, Jenny B, et al. What to do in failed hemispherotomy? Our clinical series and review of the literature. Neurosurg Rev. 2018;41(1):125132.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 15

    Vadera S, Moosa AN, Jehi L, et al. Reoperative hemispherectomy for intractable epilepsy: a report of 36 patients. Neurosurgery. 2012;71(2):388393.

  • 16

    Chen S, Guan Y, Liu C, et al. Treatment for patients with recurrent intractable epilepsy after primary hemispherectomy. Epilepsy Res. 2018;139:137142.

  • 17

    Curry DJ, Gowda A, McNichols RJ, Wilfong AA. MR-guided stereotactic laser ablation of epileptogenic foci in children. Epilepsy Behav. 2012;24(4):408414.

  • 18

    Tovar-Spinoza Z, Carter D, Ferrone D, Eksioglu Y, Huckins S. The use of MRI-guided laser-induced thermal ablation for epilepsy. Childs Nerv Syst. 2013;29(11):20892094.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 19

    González-Martínez J, Vadera S, Mullin J, et al. Robot-assisted stereotactic laser ablation in medically intractable epilepsy: operative technique. Neurosurgery. 2014;10 Suppl 2:167-173.

    • PubMed
    • Search Google Scholar
    • Export Citation
  • 20

    Lewis EC, Weil AG, Duchowny M, Bhatia S, Ragheb J, Miller I. MR-guided laser interstitial thermal therapy for pediatric drug-resistant lesional epilepsy. Epilepsia. 2015;56(10):15901598.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 21

    Curry DJ, Raskin J, Ali I, Wilfong AA. MR-guided laser ablation for the treatment of hypothalamic hamartomas. Epilepsy Res. 2018;142:131134.

  • 22

    Hawasli AH, Bandt SK, Hogan RE, Werner N, Leuthardt EC. Laser ablation as treatment strategy for medically refractory dominant insular epilepsy: therapeutic and functional considerations. Stereotact Funct Neurosurg. 2014;92(6):397404.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 23

    Willie JT, Laxpati NG, Drane DL, et al. Real-time magnetic resonance-guided stereotactic laser amygdalohippocampotomy for mesial temporal lobe epilepsy. Neurosurgery. 2014;74(6):569585.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 24

    Kang JY, Wu C, Tracy J, et al. Laser interstitial thermal therapy for medically intractable mesial temporal lobe epilepsy. Epilepsia. 2016;57(2):325334.

  • 25

    North RY, Raskin JS, Curry DJ. MRI-guided laser interstitial thermal therapy for epilepsy. Neurosurg Clin N Am. 2017;28(4):545557.

  • 26

    Prince E, Hakimian S, Ko AL, Ojemann JG, Kim MS, Miller JW. Laser interstitial thermal therapy for epilepsy. Curr Neurol Neurosci Rep. 2017;17(9):63.

  • 27

    Candela-Cantó S, Muchart J, Ramírez-Camacho A, et al. Robot-assisted, real-time, MRI-guided laser interstitial thermal therapy for pediatric patients with hypothalamic hamartoma: surgical technique, pitfalls, and initial results. J Neurosurg Pediatr. 2022;29(6):681692.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 28

    Ho AL, Miller KJ, Cartmell S, Inoyama K, Fisher RS, Halpern CH. Stereotactic laser ablation of the splenium for intractable epilepsy. Epilepsy Behav Case Rep. 2016;5:2326.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 29

    Ball T, Sharma M, White AC, Neimat JS. Anterior corpus callosotomy using laser interstitial thermal therapy for refractory epilepsy. Stereotact Funct Neurosurg. 2018;96(6):406411.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 30

    Karsy M, Patel DM, Halvorson K, Mortimer V, Bollo RJ. Anterior two-thirds corpus callosotomy via stereotactic laser ablation. Neurosurg Focus. 2018;44(VideoSuppl2):V2.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 31

    Palma AE, Wicks RT, Popli G, Couture DE. Corpus callosotomy via laser interstitial thermal therapy: a case series. J Neurosurg Pediatr. 2018;23(3):303307.

  • 32

    Huang Y, Yecies D, Bruckert L, et al. Stereotactic laser ablation for completion corpus callosotomy. J Neurosurg Pediatr. 2019;24(4):433441.

  • 33

    Roland JL, Akbari SHA, Salehi A, Smyth MD. Corpus callosotomy performed with laser interstitial thermal therapy. J Neurosurg. 2021;134(1):314322.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 34

    Chua MMJ, Bushlin I, Stredny CM, Madsen JR, Patel AA, Stone S. Magnetic resonance imaging–guided laser-induced thermal therapy for functional hemispherotomy in a child with refractory epilepsy and multiple medical comorbidities. J Neurosurg Pediatr. 2020;27(1):3035.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 35

    Fisher RS, Cross JH, French JA, et al. Operational classification of seizure types by the International League Against Epilepsy: position paper of the ILAE Commission for Classification and Terminology. Epilepsia. 2017;58(4):522530.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 36

    Engel J Jr, Cascino GD, Van Ness PC, Rasmussen TB, Ojemann LM. Outcome with respect to epileptic seizures. In: Engel J Jr, ed. Surgical Treatment of the Epilepsies. 2nd ed. Raven Press;1993:609-621.

    • Search Google Scholar
    • Export Citation
  • 37

    Candela S, Vanegas MI, Darling A, et al. Frameless robot-assisted pallidal deep brain stimulation surgery in pediatric patients with movement disorders: precision and short-term clinical results. J Neurosurg Pediatr. 2018;22(4):416425.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 38

    Candela-Cantó S, Aparicio J, López JM, et al. Frameless robot-assisted stereoelectroencephalography for refractory epilepsy in pediatric patients: accuracy, usefulness, and technical issues. Acta Neurochir (Wien). 2018;160(12):24892500.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 39

    Candela-Cantó S, Alamar M, Aláez C, et al. Highly realistic simulation for robot-assisted hypothalamic hamartoma real-time MRI-guided laser interstitial thermal therapy (LITT). Childs Nerv Syst. 2020;36(6):11311142.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 40

    Ascher PW, Justich E, Schröttner O. Interstitial thermotherapy of central brain tumors with the Nd:YAG laser under real-time monitoring by MRI. J Clin Laser Med Surg. 1991;9(1):7983.

    • Crossref
    • Search Google Scholar
    • Export Citation
  • 41

    Quesson B, de Zwart JA, Moonen CT. Magnetic resonance temperature imaging for guidance of thermotherapy. J Magn Reson Imaging. 2000;12(4):525533.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation
  • 42

    Helgager J, Lidov HG, Mahadevan NR, Kieran MW, Ligon KL, Alexandrescu S. A novel GIT2-BRAF fusion in pilocytic astrocytoma. Diagn Pathol. 2017;12(1):82.

  • 43

    Lew SM, Matthews AE, Hartman AL, Haranhalli N. Posthemispherectomy hydrocephalus: results of a comprehensive, multiinstitutional review. Epilepsia. 2013;54(2):383389.

    • Crossref
    • PubMed
    • Search Google Scholar
    • Export Citation

Metrics

All Time Past Year Past 30 Days
Abstract Views 1558 1558 0
Full Text Views 1052 1052 633
PDF Downloads 644 644 396
EPUB Downloads 0 0 0