MRI-Guided Stereotactic Laser Ablation of Deep-Seated Cerebral Cavernous Malformations

Abstract

Abstract INTRODUCTION Magnetic resonance imaging (MRI)-guided stereotactic laser ablation (SLA) is a minimally invasive alternative to open surgery for symptomatic cerebral cavernous malformations (CCMs). While SLA of neocortical and medial temporal lesions is described, we examined the safety and effectiveness of SLA of deep-seated symptomatic CCMs in patients considered to be poor candidates for open resection. METHODS We analyzed 4 patients who presented with neurological symptoms associated with a CCM in deep brain structures. Each patient underwent CCM SLA with an effort to exclude adjacent brain parenchyma followed by standard clinical and imaging follow-up. RESULTS Three patients presented with chronic medically refractory headache and small lesions (0.1-2.6 cm3) consistent with CCM in thalamus (2) or putamen (1). A fourth patient presented with recurrent bleeding and hemiparesis associated with a large CCM (4.3 cm3) of the subthalamus/midbrain. Symptoms durations were 0.5 to 7 yr. SLA was performed using Visualase (Medtronic, Inc.); perilesional brain was monitored to avoid thermal injury. Out of 4 patients, all demonstrated a decrease in CCM volume and improvement of neurological symptoms at 5 to 23 mo follow-up. Two patients (one thalamus, one putamen), experienced evidence of hemorrhage during ablation (apparent with intraoperative MRI), limiting the extent of ablation in one case. Both patients were stabilized and made full recoveries. The ablation in subthalamus/midbrain was not associated with bleeding but did exacerbate hemiparesis, requiring rehabilitation. Hospital stays ranged from 2 to 5 d. CONCLUSION In a retrospective series, MR thermography guided SLA of symptomatic deep brain CCM was technically feasible. Unlike a prior series of more superficial epileptogenic CCM in which no hemorrhages were observed, SLA of deep CCM may carry higher risk of bleeding and neurological deficits. Larger, longer-term studies are required.