Abstracts

Rationale: To describe the representative safety profile for stereotactic laser ablation (SLA, Visualase, Inc.), used in ablation of epileptogenic foci (EF). Methods: A review of existing peer-reviewed literature either published or presented at national and international conferences was undertaken, to determine the complication profile of this technology. Complication occurrence, nature, severity, and relatedness to the SLA procedure itself (insertion, ablation, or other) were recorded. Complications were stratified for total numbers of: (1) device insertion-related complications; (2) unanticipated complications related to malfunction of device or ablation mechanism; (3) anticipated complications per standard of care risks for similar procedures/lesions using other established technologies; (4) unanticipated complications per standard of care risks; (5) possibly device-related non-neurological complications; and (6) complications unrelated to device. Results: 107 EF patients were described in 8 peer-reviewed works. No unanticipated complications related to device or ablation malfunction were noted. No unanticipated complications per standard of care risks (i.e. previously unrecognized neurological complications of similar procedures/lesions) were noted when SLA was used. Overall, adverse events were reported as follows: 3 cases of misplaced fiber position (<3%), 5 cases of intracranial hemorrhage (5%, of which one (<1%) required evacuation with no residual deficit in any patient reported), 10 visual field defects (VFD, typically superior quandrantanopsia or smaller, related to ablations in the medial temporal lobe), 3 cases (<3%) of neurological deficit, with 2 being transient (lasting 1-3 weeks with leg weakness or memory dysfunction) and 1 with persistent hand weakness; other complications included minor events or human error such as inadvertent mechanical disruption of the skull bolt upon moving the anesthetized patient. No pseudoaneurysms or other unexpected vascular findings were noted, and the ablation volume correlated well with planned ablation targeting. Most patients were discharged to home on the first post-operative day from the hospital ward with very few spending time in the intensive care unit. Conclusions: SLA appears to be generally a safe procedure by analysis of peer-reviewed literature. Complication rates as reported appear comparable or lower than similar procedures utilizing intracranial stereotactic insertion techniques and considerably lower than open craniotomy surgical resections for epilepsy. Patient recovery and release from hospital was rapid due to low morbidity associated with minimally invasive SLA. Ongoing analysis of the over 700 completed SLA cases performed for EF and tumors in over 40 centers using the Visualase system may provide additional safety data helpful to clinicians and their patients in weighing therapeutic options.