Frameless stereotactic aspiration of a deep right insular abscess using the Navigus system

Background: Brain abscesses are uncommon but potentially fatal intracranial infections, with deep-seated locations posing diagnostic and therapeutic challenges. Management has shifted toward minimally invasive techniques, with stereotactic aspiration representing the treatment of choice for deep lesions. Frameless navigation systems offer advantages over conventional stereotaxy, including flexibility, reduced setup time, and lower costs. The Navigus system has been used for intracranial procedures, but not for abscess aspiration. Case Description: A 65-year-old man presented with acute focal neurological deficits : left-sided weakness; Glasgow Coma Scale 15/15; no clinical signs of raised intracranial pressure; no seizures. Imaging revealed a right temporo-insular ring-enhancing lesion with edema and restricted diffusion, consistent with a pyogenic abscess. After empiric antibiotic therapy, frameless Navigus-guided aspiration was performed, yielding 15 mL of purulent material. Postoperative imaging confirmed evacuation. Streptococcus intermedius was identified, enabling targeted therapy with intravenous ceftriaxone for 50 days, followed by oral amoxicillin for 6 weeks. Clinical improvement was progressive, and 1-month magnetic resonance imaging showed complete resolution, with mRS 0 at that time. Conclusion: Frameless Navigus-guided aspiration enabled safe, accurate, minimally invasive drainage of a deep insular abscess, supporting its use in selected cases.