Laser Ablation of Intracranial Lesions (Visualase)

Laser Ablation of Intracranial Lesions (Visualase)

General: This procedure involves stereotactic insertion of a laser probe to an intracranial target area followed by thermablation of the lesion. Most procedures are for patients with medically refractory seizures. The procedure involves several anesthesia locations and patient transports. Targeting is done by CT after a head frame placement. Laser probe is inserted in the OR and the thermablation happens in the MRI scanner.
Preop: Three different anesthesia locations need to be set up (CT, OR, MRI). The patient will be transported anesthetized between these locations. Appropriate equipment (transport monitor, Jackson Reese system, infusion pump, emergency equipment) need to be available before indution of anesthesia. Patients will receive general anesthesia. Premedicate with up to 2 mg of midazolam.
Monitors: Routine monitors in CT scanner, OR and during transports. Sensors and monitors need to be changed to MRI compatible monitors for the MRI portion of the case.
Anesthesia: Goals are to prevent unintended patient movement after induction of anesthesia due to the stereotactic nature of the procedure. Induction of anesthesia with propofol in the CT scanner. Fentanyl up to 5 μg /kg in divided doses throughout induction, prior to intubation. Special attention need to be paid when securing the endotracheal tube, as reintubation after head frame application is not feasible. Tape eyes, insert esophageal temperature probe (must be removed before MRI). Maintain anesthesia with oxygen, sevoflurane, propofol infusion (50-100 μg/kg/min) and additional fentanyl boluses as needed. Propofol infusion during transports and sevoflurane in MRI. Maintain muscle relaxation throughout the procedure. Remember the increased metabolism for muscle relaxants in patients taking tegretol or dilantin. Maintain euvolemia. Reverse NM relaxation after the last MRI scan. Laser applicator and head frame will be removed and the insicion closed in the MRI.
Potential complications: Potential for air embolus during burr hole and laser probe placement in the OR as patient will be in a semi sitting position. Small possibility for intracranial hemorrhage during laser probe placement. Multiple anesthesia locations and patient transports will have associated risks. Moving the patient with the head frame and the laser probe on needs special attention. Most patients will be on antiepileptic medications and may have increased anesthetic and NM relaxant requirements. Typical MRI related concerns (monitors, no temperature probes, no wire enforced ET tubes etc). Please refer to the UCSF Department of Radiology website for general details of MRI safety. http://radiology.ucsf.edu/patient-care/patient-safety/mri-safety
Recovery: Wake up and extubation in the MRI control room. Use a hemodynamic monitor and supplemental oxygen during patient transport to PACU or NICU. 

Last revised 080115 

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This information is meant to serve as an educational resource. Clinicians should use their own professional judgment in the care of any individual patient as the guidance contained in this document may not be appropriate for all patients or all situations.