Massive subarachnoid hemorrhage after percutaneous balloon compression of the Gasserian ganglion

Background: Percutaneous balloon compression of the Gasserian ganglion is a well-established surgical technique for the treatment of trigeminal neuralgia and is associated with a low incidence of serious complications. Vascular injury leading to subarachnoid hemorrhage is an extremely rare but potentially fatal event. Case Description: A 50-year-old man with right-sided idiopathic trigeminal neuralgia refractory to medical therapy underwent percutaneous balloon compression of the Gasserian ganglion. Due to insufficient balloon configuration and early pain recurrence, a repeat procedure was performed. During the second intervention, excessive needle advancement during puncture of the foramen ovale resulted in vascular injury and the development of Fisher grade III subarachnoid hemorrhage. Postoperatively, the patient developed severe cerebral vasospasm without a focal neurological deficit. Management included intensive care monitoring, oral nimodipine therapy, serial transcranial Doppler ultrasonography with Lindegaard index assessment, and chemical angioplasty. Despite persistently elevated blood flow velocities, further endovascular intervention was deferred because of clinical stability. The patient was discharged in satisfactory condition and remained free of facial pain and neurological deficits during a 6-month follow-up. Conclusion: Although percutaneous balloon compression of the Gasserian ganglion is generally safe, technical errors during foramen ovale puncture may result in catastrophic vascular complications. Careful intraoperative technique and vigilant postoperative monitoring for delayed cerebral vasospasm are essential, and conservative management may be justified in clinically stable patients.