Idiopathic intracranial hypertension surgery
Systematic reviews
Prospective studies on the surgical options for Idiopathic intracranial hypertension (IIH) are scant and no evidence-based guidelines for the surgical management of medically refractory IIH have been established. A search in Cochrane Library, MEDLINE and EMBASE from 1 January 1985 to 19 April 2019 for controlled or observational studies on the surgical treatment of IIH (defined in accordance with the modified Dandy or the modified Friedman criteria) in adults yielded 109 admissible studies. Venous sinus stenting (VSS) improved papilledema, visual fields and headaches in 87.1%, 72.7%, and 72.1% of the patients respectively, with a 2.3% severe complication rate and 11.3% failure rate. Cerebrospinal fluid diversion techniques diminished papilledema, visual field deterioration, and headaches in 78.9%, 66.8%, and 69.8% of the cases and are associated with a 9.4 severe complication rate and a 43.4% failure rate. Optic nerve sheath fenestration ameliorated papilledema, visual field defects and headaches in 90.5, 65.2%, and 49.3% of patients. The severe complication rate was 2.2% and the failure rate was 9.4%. This is currently the largest systematic review for the available operative modalities for IIH. VSS provided the best results in headache resolution and visual outcomes, with low failure rates and a very favorable complication profile. In light of this, Venous sinus stenting ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH 1).
Indications
Idiopathic intracranial hypertension patients may require surgical management when maximal medical treatment has failed.
Controversy still exists about which is the preferred initial surgical treatment for IIH. Emerging procedures include venous sinus stenting in cases with venous sinus stenosis, and bariatric surgery for weight loss. Cranial (suboccipital or subtemporal) decompression was a more popular surgical procedure in the past, but can still have a role in selected cases with impaired cerebrospinal flow dynamics (e.g. Chiari malformation) or after multiple failed conventional surgical procedures 2).
Venous sinus stenting ought to be regarded as the first-line surgical modality for the treatment of medically refractory IIH 3).
The election will likely be based on local expertise until well designed, multicentered clinical trials clarify which intervention best suits a particular patient 4).
The visual outcomes of these procedures are favorable, though they tend to be associated with a high rate of complication and failure. Recent trials suggest that venous sinus stenting offers both comparable rates of efficacy – with improved papilledema in 97% of patients, resolved headache in 83%, and improved visual acuity in 78% – and improved safety and reliability relative to older surgical techniques.
Patients whose sight is threatened by medically refractory IIH must often consider invasive procedures to control their disease. Venous sinus stenting may offer equal efficacy and lower failure and complication rates than traditional surgical approaches such as optic nerve sheath fenestration and cerebrospinal fluid diversion.
Several surgical treatment modalities, including lumboperitoneal shunt or ventriculoperitoneal shunt surgery, subtemporal decompression, endovascular venous sinus stenting, optic nerve decompression (OND), were used in the management of idiopathic intracranial hypertension (IIH). Each surgical technique has different advantages and disadvantages. Endoscopic OND is rarely used in the management of IIH. There are only forteen reported cases 5).
Techniques
Cerebrospinal fluid diversion procedures
The most commonly performed surgical treatments for IIH are cerebrospinal fluid diversion procedures (e.g. ventriculo- and lumboperitoneal shunts).
Lumboperitoneal shunt
see Lumboperitoneal shunt for idiopathic intracranial hypertension
Ventriculoperitoneal shunt
see Ventriculoperitoneal shunt for pseudotumor cerebri
Transverse sinus stenting
see Transverse sinus stenting for idiopathic intracranial hypertension.
Optic nerve sheath fenestration
see Optic nerve sheath fenestration.
Subtemporal decompression
see Subtemporal decompression.