MR-Guided Stereotactic Laser Amygdalohippocampotomy for Epilepsy
This video is an illustrative treatment cycle of magnetic resonance thermometry-guided stereotactic laser thermal amygdalohippocampotomy for epilepsy.
Patient 4 was stereotactically implanted via a twist drill hole from an occipital approach along the long axis of the amygdalohippocampal complex with a saline-irrigated cooling cannula containing the optical fiber with 10 mm-long diffusion tip. Laser energy was delivered by the Visualase® workstation while MR thermal imaging data was acquired and fed back for real time presentation and safety monitoring. Data is presented within 4 seconds of acquisition in two formats: color thermal map and total irreversible damage estimate. The color thermal map allows visualization of laser thermal energy deposition during two treatment cycles. The first treatment was performed anteriorly, then the optical fiber was withdrawn by 1 cm, and a second treatment cycle was performed. User-defined safety monitoring points placed at off-target structures were set to automatically trigger therapy discontinuation should off-target temperatures reach undesirable temperatures.
Contemporaneously, the workstation provides an integral of locations maintaining ablative temperatures over time. Axial planes are presented here, but other user-defined planes may be monitored simultaneously. Videographic image is sped up 40x. Total laser treatment time was 6.7 minutes in this case.
The final three static axial images demonstrate laser fiber location, final ablation zone estimate, and immediate postprocedure ring-enhancing ablation zone.