Frameless stereotactic ventricular shunt placement for idiopathic intracranial hypertension

Introduction: Cerebrospinal fluid (CSF) shunting effectively reverses symptoms of idiopathic intracranial hypertension (IIH). Lumboperitoneal (LP) shunts have traditionally been used in patients with IIH due to a frequently undersized ventricular system. However, the advent of image-guided stereotaxis has enabled effective ventricular catheter placement in patients with IIH. We describe the first large series of frameless stereotactic ventriculoperitoneal (VP) shunting for patients with slit ventricles and IIH. Methods: We describe the frameless stereotactic VP shunting technique for IIH in 32 procedures. Outcomes following shunt placement, time to shunt failure, and etiology of shunt failure are reported. Results: A total of 21 patients underwent 32 ventricular shunting procedures (20 VP, 10 ventriculoatrial, 2 ventriculopleural). One hundred percent of shunts were successfully placed into slit ventricles, all requiring only one pass of the catheter under stereotactic guidance to achieve the desired location and CSF flow. There were no procedure-related complications and each ventricular catheter showed rapid egress of CSF. All (100%) patients experienced significant improvement of headache immediately after shunting. Ten percent of ventricular shunts failed at 3 months after insertion, 20% failed by 6 months, 50% failed by 12 months, and 60% failed by 24 months. Shunt revision was due to distal obstruction in 67%, overdrainage in 20%, and distal catheter migration or CSF leak in 6.5%. There were no shunt revisions due to proximal catheter obstruction or shunt infection. Conclusions: In our experience treating patients with IIH, frameless stereotactic ventricular CSF shunts were extremely effective at treating IIH-associated intractable headache, and continued to provide relief in nearly half of patients 2 years after shunting without many of the shunt-related complications that are seen with LP shunts. Placing ventricular shunts using image-guided stereotaxis in patients with IIH despite the absence of ventriculomegaly is an effective, safe treatment option.