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

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.

The impact of 1.5-T intraoperative magnetic resonance imaging in pediatric tumor surgery: Safety, utility, and challenges.

Objective: In this study, we present our experience with 1.5-T high-field intraoperative magnetic resonance imaging (ioMRI) for different neuro-oncological procedures in a pediatric population, and we discuss the safety, utility, and challenges of this intraoperative imaging technology. Methods: A pediatric consecutive-case series of neuro-oncological surgeries performed between February 2020 and May 2022 was analyzed from a prospective ioMRI registry. Patients were divided into four groups according to the surgical procedure: intracranial tumors (group 1), intraspinal tumors (group 2), stereotactic biopsy for unresectable tumors (group 3), and catheter placement for cystic tumors (group 4). The goal of surgery, the volume of residual tumor, preoperative and discharge neurological status, and postoperative complications related to ioMRI were evaluated. Results: A total of 146 procedures with ioMRI were performed during this period. Of these, 62 were oncology surgeries: 45 in group 1, two in group 2, 10 in group 3, and five in group 4. The mean age of our patients was 8.91 years, with the youngest being 12 months. ioMRI identified residual tumors and prompted further resection in 14% of the cases. The mean time for intraoperative image processing was 54 ± 6 min. There were no intra- or postoperative security incidents related to the use of ioMRI. The reoperation rate in the early postoperative period was 0%. Conclusion: ioMRI in pediatric neuro-oncology surgery is a safe and reliable tool. Its routine use maximized the extent of tumor resection and did not result in increased neurological deficits or complications in our series. The main limitations included the need for strict safety protocols in a highly complex surgical environment as well as the inherent limitations on certain patient positions with available MR-compatible headrests.

Prolonged Perioperative Low-Dose Ketamine Does Not Improve Short and Long-term Outcomes After Pediatric Idiopathic Scoliosis Surgery.

STUDY DESIGN: A randomized, double-blind, placebo-controlled study, with a six-month follow-up period. OBJECTIVES: The aim of this study was to test the hypothesis that a 72-hour dose of subanesthetic ketamine in this surgical procedure reduces postoperative morphine use and to assess whether there are fewer adverse effects, if postoperative recovery is faster, if there is less peri-incisional hyperalgesia, or if there is lower incidence of persistent postsurgical pain. SUMMARY OF BACKGROUND DATA: Tissue injury and high opioid requirements following posterior spinal fusion surgery produce central sensitization, which can in turn be associated with hyperalgesia and chronic pain. Clinical trials involving this type of procedure using subanesthetic ketamine doses have assessed pain and morphine requirements with contradictory results. The effects of prolonged subanesthetic ketamine doses on postoperative recovery, mechanical hyperalgesia, and the incidence of chronic pain are unknown. METHODS: A total of 48 pediatric patients between 10 and 18 years diagnosed with idiopathic scoliosis were randomized to receive perioperative low-dose ketamine or placebo for 72 hours. They received general anesthesia, intraoperative remifentanil, and morphine postoperatively (patient-controlled analgesia). We measured morphine consumption, pain at rest and during movement (coughing), undesirable effects, and sedation during morphine treatment. The onset of oral intake, ambulation, and hospital stay were recorded. The extent of the peri-incisional hyperalgesia was measured at 72 hours and pain controls were conducted postsurgery. RESULTS: Primary endpoint results (total cumulative morphine consumption while admitted) were obtained in 44 patients. Results were 2.72 (SD 1.13) in the placebo group and 3.13 (SD 1.13) in the study group (P = 0.2903), with no significant differences. Moreover, differences were not found between the experimental group and the placebo group in the secondary endpoints analyzed. CONCLUSION: Our findings do not support the routine combining of prolonged subanesthetic ketamine doses with opioids in posterior fusion surgery in children with idiopathic scoliosis. LEVEL OF EVIDENCE: 2.

Oral to nasal tube exchange under fibroscopic view: a new technique for nasal intubation in a predicted difficult airway.

For a predicted difficult airway, oral intubation techniques are well established in pediatric anesthesia, but nasotracheal intubation remains a problem. There are many reports concerning this, but the risk of bleeding, added to the lack of cooperation make this procedure difficult and hazardous. We describe a modification of the nasal intubation technique in two stages. First an oral intubation and then exchanging the oral for a nasal tube, in the case of a 13-year-old boy affected by an advanced stage of cherubism. Oral intubation using a laryngeal mask technique has already been reported, but problems appear during the exchange procedure and even more when direct laryngoscopy is impossible. Fiberscopic control of the exchange, and the introduction of a Cook Exchange Catheter into the trachea through the oral tube before withdrawal, permits oxygenation of the patient and acts as a guide for oral tube reintroduction if required.

Study of the adjustment of the Ambu laryngeal mask under magnetic resonance imaging.

BACKGROUND: Our aim in this study was to analyze the adjustment of the laryngeal mask, Ambu AuraOnce, in pediatric patients during magnetic resonance imaging (MRI) and to look for a correlation between clinical parameters such as the sealing pressure and the ease of introduction with radiological parameters. METHODS: One-hundred and twenty-one pediatric patients from 4 months to 17 years who required a cranial MRI for other reasons were enrolled in the study. General anesthesia was induced with sevofluorane and no relaxant was used. Insertion attempts, sealing pressure, desaturation episodes and maintenance of anesthesia were recorded. Spontaneous ventilation was maintained throughout all procedures and no episodes of desaturation below 95% were seen. Patients without cough or pharyngeal pain were discharged after 1 h. Data were classified into three groups according to the size of the used laryngeal mask (group 1 for laryngeal mask number 1(1/2); group 2 for laryngeal mask number 2, and group 3 for laryngeal mask number 2(1/2)). Sagittal MRI cuts were reviewed to calculate neck flexion, laryngeal mask position and its relationship with the trachea. RESULTS: First-attempt introduction rate of the laryngeal mask was 96%, and it was 100% after a second attempt. Sealing pressure was 22.1+/-4.15 mmHg for group 1, 22.23+/-3.94 for group 2, and 23.83+/-3.28 for group 3. The angles between the laryngeal mask and the four first cervical vertebrae were calculated (group 1, 33.65+/-8.05; group 2, 28.09+/-6.65; group 3, 25.79+/-4.26). Distances between trachea and proximal and distal cuffs were measured to evaluate proper fitting of the laryngeal mask. Anomalous placement seen on MRI, using distances from proximal and distal cuff to trachea, occurred in 23.5% in group 1, 10.9% in group 2, and 13.8% in group 3. We found no correlation between this anomalous position of the laryngeal mask and sealing pressure or ease of introduction. CONCLUSIONS: The Ambu AuraOnce can be regarded as a safe product for airway maintenance in pediatric patients. No relationship was found between radiological measurements and sealing pressures.