Laser Interstitial Thermal Therapy (LITT)
General Considerations:
LITT stands for laser interstitial thermal therapy. The case involves placement of a fiberoptic catheter in the OR which is confirmed with O-Arm imaging. Once the catheter is confirmed, the patient must be transported to MRI without damaging or dislodging the catheter. In MRI, scans are used to confirm placement and then continuous MRI imaging is used while the catheter is used to ablate the target area. Following ablation, post-procedure imaging is performed and then the patient is removed from the scanner. The surgeon removes the catheter and closes the incision. The patient can then be awakened from anesthesia and recovered.
Patient Considerations:
Disease Specific Considerations
In Pediatric Patients, this will usually be performed for intractable seizures. This is done in the hopes of avoiding more invasive procedures like Temporal Lobectomy
Associated Co-morbidities/Syndromes
The patients frequently have tumors not amenable to surgical excision or seizure disorders. Patients with seizure disorder may be on anti-epileptic medications and have increased clearance of muscle relaxation.
Case Planning:
Specific or Unique Room Set-Up Requirements
Airway
Endotracheal intubation
Drugs/Infusions
The surgeon may request dexamethasone
Once the catheter is in place, patient movement must be avoided and neuromuscular blockade is encouraged.
An infusion of sedation is needed for transport from the OR to the MRI scanner.
Monitors
Standard ASA Monitors with MRI Compatible monitors for MRI scan
Arterial line is not necessary for procedural monitoring
Foley catheter is useful due to the length of the procedure
Blood Availability (if indicated)
Blood loss is usually minimal
PICU Bed Availability (if indicated)
The patient usually requires PICU monitoring for post-op neurochecks.
Other
Plan to transport the patient under GETA from the OR to MRI
It helps to walk the route before the case
Have a monitor with EtCO2 availability and an AMBU and/or Mapleson circuit
Ensure that MRI is set-up to receive an anesthetized patient.
Anesthetic Considerations:
Induction
Induction and intubation may be accomplished using traditional methods
A second PIV is recommended due to due to the length and positioning requirements of the procedure.
Positioning
The patient will be in Mayfield pins for catheter placement.
Once the catheter placement is confirmed, avoid head movement unless directed by the surgeon
In MRI, position with appropriate padding. Ensure all OR monitors (EKG electrodes, pulse oximetry probe, temp probe) are removed
Once in MRI, tape the pilot balloon to the ETT away from the MRI coil.
Maintenance
Maintenance of Anesthesia
Volatile anesthesia may be used in the OR and MRI scanners
An infusion of propofol is needed for transport to MRI and during wound closure
Neuromuscular blockade is recommended to ensure no patient movement occurs once the catheter is placed
Hemodynamic/Physiologic goals
The surgeon requests normocapnea during the procedure.
No special hemodynamic or physiologic goals for the procedure
Surgical Considerations (such as neuromonitoring, muscle relaxation, anticipated blood loss)
Expected blood loss is minimal
Once the catheter is placed, surgical stimulation and post-op pain is minimal.
The O-Arm is used for catheter placement. Anesthesia staff should exit the OR and watch the patient through the window for this portion (less than 60 seconds)
Emergence/Disposition
After the MRI guided ablation, the patient is removed from the scanner and the skin incision is closed. The patient may emerge from anesthesia at that time either in PACU or the MRI holding area.
The patient is then recovered in PACU prior to admission to PICU for observation.
Attending to Attending handover should be called to the PICU attending.
Consider dexmetomedine to facilitate a smooth emergence from anesthesia
Post-Op Pain Management
Post-op pain is minimal.
Case-Specific Complications
None identified
More information may be found here:
https://journals.lww.com/jnsa/Abstract/2018/01000/Perioperative_and_Anesthetic_Considerations_for.3.aspx