Perioperative and Anesthetic Considerations for Neurosurgical Laser Interstitial Thermal Therapy Ablations

Airway Management with Leksell Frame in situ with or without Frontal Bar: A Mannequin Study

BACKGROUND

The use of stereotactic headframes for neurosurgical procedures requiring targeted localization continues to grow with new advancements in technology and treatment modalities. A configuration of the Leksell stereotactic G frame with a straight front bar, useful in epilepsy and laser cases, almost completely obscures oral access and presents a significant airway challenge for the anesthetist. Although previous papers have suggested that the entire headframe should be removed during an airway emergency, we describe a novel method to remove only the front bar.

METHODS

We performed an observational mannequin study. Anesthesia personnel from a single center were asked to intubate a mannequin with the Leksell frame fully in situ and again with the front bar removed. In addition, the time to remove the entire frame versus only the front bar was investigated.

RESULTS

Eighteen anesthesia personnel participated in the study as well as four neurosurgeons. The average time to intubate the mannequin in the frame was 23.5 (11.4) seconds and with the front bar removed, 10.9 (2.5) seconds (p < 0.001). The average time taken to remove just the front bar by the neurosurgeons was 35.4 (7.3) seconds compared to an average of 83.3 (18.6) seconds to remove the headframe entirely (p < 0.001).

CONCLUSION

Our study demonstrates that intubating with the Leksell front bar in situ is possible with videolaryngoscopy under an ideal situation. More importantly, the removal of just the front bar is a simpler more streamlined approach requiring statistically less time to secure an airway.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

Techniques to Ensure Accurate Targeting for Delivery of Awake Laser Interstitial Thermotherapy

BACKGROUND

Magnetic resonance imaging (MRI) guided laser interstitial thermal therapy (LITT) is an emerging neurosurgical treatment modality that is typically performed under general anesthesia. We describe a novel workflow developed at the University of Florida to deliver LITT in conscious patients without the use of general anesthesia.

OBJECTIVE

To describe a novel workflow for LITT implementation in the awake patient with equivalent treatment results when compared to procedures performed under general anesthesia.

METHODS

For trajectories near a post of the Cosman-Roberts-Wells (CRW) frame (Integra LifeSciences, Plainsboro, New Jersey), we used preoperative MRI imaging to 3-dimensional-print a patient-specific mask with a trajectory guide to indicate the planned entry point during headframe placement. Otherwise, routine headframe placement and stereotactic registration were performed. Stereotactic biopsy and placement of the cranial bolt were performed in a standard neurosurgical operating room. The patient was transferred to a diagnostic MRI suite and positioned in the MRI scanner using beanbags and a custom molded thermoplastic mask. LITT was delivered with the patient conscious in the MRI scanner according to the manufacturer's recommendations. We collected patient demographics, treatment time, length of stay, and calculated preoperative tumor volume and postoperative ablation volumes.

RESULTS

Ten sequential patients were treated with LITT from January 2016 until March 2017. The average preoperative tumor volume was 6.9 cm3. The average tissue volume ablated was 18.3 cm3. The mean operative time was 31 min (standard deviation [SD] 10 min) and mean time with laser delivery in MRI was 79 min (SD 27 min). The mean length of stay was 1.4 d (SD 0.9). There were no major complications.

CONCLUSION

Using trajectory preplanning, customized face masks, and noninvasive head immobilization, LITT can be delivered to patients safely and accurately without general anesthesia.

Single and staged laser interstitial thermal therapy ablation for cortical tubers causing refractory epilepsy in pediatric patients

OBJECTIVE Magnetic resonance-guided laser interstitial thermal therapy (MRgLITT) is a novel, minimally invasive treatment for the surgical treatment of epilepsy. In this paper, the authors report on clinical outcomes for a series of pediatric patients with tuberous sclerosis complex (TSC) and medication-refractory epileptogenic cortical tubers. METHODS A retrospective chart review was performed at SUNY Upstate Golisano Children's Hospital in Syracuse, New York. The authors included all cases involving pediatric patients (< 18 years) who underwent MRgLITT for ablation of epileptogenic cortical tubers between February 2013 and November 2015. RESULTS Seven patients with cortical tubers were treated (4 female and 3 male). The patients' average age was 6.6 years (range 2-17 years). Two patients had a single procedure, and 5 patients had staged procedures. The mean time between procedures in the staged cases was 6 months. All of the patients had a meaningful reduction in seizure frequency as reported by Engel and ILAE seizure outcome classifications, and most (71.4%) of the patients experienced a reduction in AED burden. Three of the 4 patients who presented with neuropsychiatric symptoms had some improvement in these domains after laser ablation. No perioperative complications were noted. The mean duration of follow-up was 19.3 months (range 4-49 months). CONCLUSIONS Laser ablation represents a minimally invasive alternative to resective epilepsy surgery and is an effective treatment for refractory epilepsy due to cortical tubers.

Neuroanesthesiology Update

This review provides a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, traumatic brain injury, neuromonitoring, neurotoxicity, and perioperative disorders of cognitive function.