Venous Stenting for the Treatment of Idiopathic Intracranial Hypertension - Medical Clinical Policy Bulletins (2024)

Number:1039

Table Of Contents

Policy
Applicable CPT / HCPCS / ICD-10 Codes
Background
References

Policy

Scope of Policy

This Clinical Policy Bulletin addresses venous stenting for the treatment of idiopathic intracranial hypertension.

Medical Necessity

Aetna considers venous stent placement in the transverse sinus medically necessary for the treatment of medically refractory idiopathic intracranial hypertension (IIH) (also known as pseudotumor cerebri) when the following criteria are met:

1. Ophthalmologic evaluation documents vision loss (vision fields or acuity) and papilledema; and
2. Complete neurologic examination shows no focal neurologic deficit (except vision loss and cranial nerve VI palsy); and
3. Neuroimaging (MRI with and without contrast or CT if unable to have MRI) excludes intracranial mass lesions, infection, hydrocephalus, underlying structural defects (e.g., Chiari malformation) and venous sinus thrombosis; and
4. A procedure note documents intracranial pressure (ICP) elevationgreater than or equal to25 cm water cerebrospinal fluid (CSF) during lumbar puncture (LP) performed in lateral decubitus position within the past 3 months; and
5. CSF analysis is normal (no pleocytosis, elevated protein, hypoglycorrhachia, abnormal cytology, or other indication of infection or malignancy); and
6. Normal complete blood count (CBC), electrolytes, prothrombin time/partial thromboplastin time (PT/PTT) are documented (and exclude anemia, hypercoagulable state); and
7. Blood pressure is under 150 mmHg systolic, excluding hypertensive encephalopathy; and
8. The following conditions have been excluded: obstructive sleep apnea, systemic lupus erythematosus, vasculitis, lead poisoning, neurosarcoidosis; and
9. Magnetic resonance venography (MRV) documents bilateral focal transverse sinus stenosis or unilateral focal transverse sinus stenosis and contralateral hypoplasia; and
10. Failure of maximal medical management and CSF shunting is documented; and
11. There must be a documented pressure gradientgreater than 8 mmHg across the stenosis (this step is not required for prior-authorization if all the above criteria are met; but should be documented during venography prior to stent placement).

Background

Idiopathic intracranial hypertension (IIH), also known as pseudotumor cerebri, is a clinical syndrome characterized by increased intra-cranial pressure (ICP) with normal cerebrospinal fluid (CSF) composition without a known cause. Symptoms associated with increased ICP include headache, papilledema, double vision, transient visual obscurations, and vision loss. While IIH typically affects young, obese women, it is relatively rare in children; and its demographic features may differ from those of adults. Before diagnosing IIH, secondary causes of increased ICP should be excluded. While neurosurgical management of IIH remains controversial, shunting and endovascular stenting techniques are part of the neurosurgical armamentarium for the treatment of patients with medically refractory IIH symptoms. Venous sinus stenting (VSS) is a relatively new therapeutic option for the treatment of IIH. Its use results from the observation that many patients with IIH have apparent stenoses of the transverse venous sinus or other cerebral veins; although whether this is a primary or secondary phenomenon is uncertain (Bruce et al, 2010; Wall and Lee, 2023).

Kabanovski et al (2022) stated that dural VSS (DVSS) is a relatively new intervention for the treatment of IIH refractory to medical therapy and lifestyle modifications. In a systematic review, these investigators outlined various hypotheses of IIH pathogenesis and described the role of venous sinus stenosis and the technical details of DVSS. They also presented a summary and critique of the available evidence describing the outcomes of DVSS in IIH and examined the evidence-based guidelines for this procedure. The authors concluded that, although many studies have shown generally favorable outcomes of DVSS in patients with IIH, most have serious limitations, the most common one being paucity of pre- and post-procedure ophthalmological data. Therefore, there is inadequate available evidence to conclude whether DVSS is an effective procedure for the treatment of IIH. These researchers also presented the most commonly used indications for DVSS as described in the literature and emphasized the importance of neuro-ophthalmological assessment before and after the procedure to monitor response and potential complications.

Barrero Ruiz et al (2022) examined the scientific literature on pediatric cases of IIH and its treatment with VVS. These investigators presented the case of a 6-year-old girl with a life-threatening presentation of IIH, who was treated with transverse sinus stenting and a lumbo-peritoneal shunt. They summarized the characteristic of pediatric stenting cases reported and reviewed the literature focusing on the main aspects of VVS. The authors concluded that VSS could be a therapeutic tool for the acute presentation of IIH with severe symptoms and venous sinus stenosis plus an elevated trans-stenotic pressure gradient. However, in some cases, additional surgical treatment may be necessary.

Mugge et al (2022) noted that fulminant IIH can cause rapid vision loss. Transverse sinus stenosis is a finding often associated with IIH, and transverse sinus stenting has been used to rapidly reduce ICP and improve visual symptoms. These researchers described a case of immediate alteration in reversed superior ophthalmic vein (SOV) flow in a fulminant IIH patient who underwent VSS. All charts, imaging, and notes spanning from the initial presentation to the post-intervention follow-up were reviewed and summarized for inclusion. Subject was a 24-year-old woman who presented with several weeks of severe headaches and progressive vision loss. She was found to have severe papilledema and the opening pressure on lumbar puncture (LP) was 70 mm Hg. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed findings consistent with elevated ICP, and CT venography revealed stenosis of the right transverse sinus. She underwent an uncomplicated diagnostic cerebral angiogram, right venous sinus manometry, and right transverse to sigmoid sinus stenting procedure. Before deployment of the stent, a trans-stenotic pressure gradient of 12 mm Hg was observed within the right transverse-sigmoid junction, and flow through the bilateral SOVs was retrograde. Following stent placement, the pressure gradient normalized, and SOV flow was bi-directional. She subjectively reported improved vision, and there was improving papilledema. Repeat LP yielded an opening pressure of 21.6 mm Hg. The authors concluded that this case showed reversed SOV flow should be considered an indicator of severe venous sinus stenosis, and restoration to normal or near normal state following stenting for IIH is likely indicative of procedural success.

Wang et al (2022) identified the main factors that might affect the clinical outcome of patients with IIH treated with VSS. These researchers carried out an analysis of a prospectively collected database of patients with IIH and venous sinus stenosis who underwent stenting. The trans-stenotic pressure gradient was measured before and after intervention. Furthermore, patients' baseline characteristics, procedure details and clinical outcomes at 6-month follow-up (including changes in headache, visual impairment, papilledema, etc.) were recorded. The effects of post-intervention pressure gradient on symptom-free at 6 months were examined using logistic regression analysis, generalized additive model and receiver operator characteristic (ROC) curve. Of 101 patients included in this study, the median pressure gradient across stenosis decreased from 19 mmHg before intervention to 2 mmHg after intervention. At 6 months, symptom-free was observed in 58 cases (57.4 %). Multi-variable logistic analysis and generalized additive model showed that post-intervention pressure gradient (increased by 1 mmHg) was independently and linearly correlated with symptom-free (odds ratio [OR] = 0.79, 95 % confidence interval [CI]: 0.67 to 0.94). Moreover, the post-intervention pressure gradient revealed moderate discrimination with an area under ROC curve of 0.68 (95 % CI: 0.57 to 0.78). Similar associations were observed for the disappearance of headache and papilledema, but not for the visual recovery. The authors concluded that the post-intervention pressure gradient may be a valid and reliable predictor of 6-month clinical outcome in patients with IIH and venous sinus stenosis treated by stenting.

Nia et al (2022) noted that DVSS is an effective intervention for patients with IIH refractory to medical treatment. These investigators examined the effectiveness in a large multi-center sample. A total of 541 patients over the age of 18 years who underwent VSS within 3 years of IIH diagnosis were queried using Current Procedural Terminology and International Classification of Diseases, 10th Revision codes from the TriNetX Analytics Network. Patient demographics, baseline symptoms, procedures, and clinical outcomes were evaluated within 1 year post-operatively. Outcomes examined were headache, tinnitus, blindness/low vision, optic nerve sheath fenestration (ONSF), CSF shunt, and use of medications (acetazolamide, methazolamide, furosemide, topiramate, tricyclic antidepressants, and valproate) for IIH. Pre-stent and post-stent data were compared using Fisher exact test, and the ORs were computed using the Baptista-Pike method. The mean age at VSS was 36.7 ± 10.6 years; 92 % were female, 65 % of patients were Caucasian, 25 % were Black/African American, 1 % were Asian, and 9 % were of other/unknown race. Within the 1-year follow-up, acetazolamide and topiramate use were significantly reduced post-VSS (p < 0.0001; OR = 0.45; CI: 0.35 to 0.57 and p = 0.03∗; OR, 0.71; CI: 0.52 to 0.95, respectively). Furthermore, headaches, visual disturbance, dizziness/giddiness, and tinnitus significantly improved post-VSS (p < 0.005). Finally, the number of CSF shunt procedures and ONSF procedures showed no significant change post-VSS (p > 0.05). The authors concluded that VSS was a safe and effective procedure resulting in significant improvement of headaches, visual impairment, dizziness, and tinnitus; and acetazolamide/topiramate usage were lower after VSS in patients with IIH. The paucity of pre-VSS and post-VSS CSF shunt and ONSF procedure data did not provide enough evidence to establish significance.

In a prospective, cohort study, Yang et al (2023) examined the impact of the pressure gradient on papilledema after stenting in patients with IIH and venous sinus stenosis. These researchers examined 121 patients with IIH and venous sinus stenosis who underwent stenting. The papilledema Frisen grade at the 1-month follow-up was used as a grouping factor (favorable outcome: 0 to 1; unfavorable outcome: 2 to 5). These investigators used multi-variable logistic regression modeling to determine independent predictors of favorable outcome. The performance of the prediction model was examined using a ROC analysis. Subjects included 96 patients had papilledema grades 0 to 1, and 25 patients had papilledema grades 2 to 5. Patients in the 1st group had significantly lower gradient pressures pre-operatively (15.2 mmHg versus 21.4 mmHg, p = 0.001) and post-operatively (2 mmHg versus 3.3 mmHg, p = 0.002) relative to those in the 2nd group. Multi-variate analysis indicated that pre-operative pressure gradient (OR = 1.119; 95 % CI: 1.034 to 1.211]) and post-operative pressure gradient (OR = 1.498; 95 % CI: 1.147 to 1.957) were independent predictors of favorable outcome. In the ROC analysis, the cut-off pressure gradient for the highest sensitivity (0.44) and specificity (0.874) was 22.75 mmHg, with a Youden's index of 0.314. Survival analysis showed that patients with a pre-operative pressure gradient of less than 22.75 mmHg had more rapid improvement of papilledema than did those with a pressure gradient greater than 22.75 mmHg (mean +/- SD: 2.639 +/- 0.382 [95 % CI: 1.890 to 3.388] versus mean +/- SD: 3.882 +/- 0.884 [95 % CI: 2.149 to 5.616]; p = 0.004). The authors concluded that a significant reduction in the pressure gradient appeared to be strongly correlated with the success of VSS in patients with IIH. A higher pre-operative pressure gradient may reduce stenting effectiveness in patients with IIH.

Gorjian et al (2023) stated that VSS for medically refractory IIH is emerging as a safe and effective alternative to shunting. However, stent navigation past the jugular bulb with commonly used carotid stenting systems via femoral access in cases with tortuous venous anatomy can present a challenge, leading to procedural failure. These researchers presented a technical refinement using a cervical access and peripheral vascular stent with a more stable 0.035-in delivery platform as an alternative to the traditional approach to simplify the procedure and overcome the technical difficulties in cases with tortuous venous anatomy. The authors’ institutional database for patients who had IIH and undergone VSS using the peripheral vascular stent between 2013 and 2023 was retrospectively reviewed. Data on 36 patients (33 women, 3 men, mean age of 32 years) was collected. VSS was technically successful in all patients (100 %) without major complications or thrombosis. There was 1 case of minor neck cellulitis treated with oral antibiotics; 3 patients underwent repeat stenting, and 2 patients had ventriculo-peritoneal (VP) shunt placement after stenting due to persistent or recurrent symptoms. All patients (100 %) had improvement or resolution of papilledema; however, 6 patients had evidence of optic atrophy and persistent vision loss. Headache was resolved or improved in 91 % of patients. In the presence of tortuous venous anatomy, VSS using cervical access and a peripheral vascular stent with a more stable 0.035-in. delivery platform can be considered as a safe and effective alternative approach with shorter procedure time. This approach is particularly advantageous in situations where the procedure is prolonged or high dose of contrast has been administered due to the technical challenges associated with the traditional use of carotid systems via femoral access for stent delivery.

Khunte et al (2023) cerebral VSS has emerged as a new surgical procedure for the treatment of severe IIH, and its popularity has been anecdotally on the rise. These investigators examined recent temporal trends of VSS and other surgical IIH treatments in the U.S. Adult IIH patients were identified from the 2016 to 2020 National Inpatient Sample databases, and surgical procedures and hospital characteristics were recorded. Temporal trends of procedure numbers for VSS, CSF shunts, and (ONSF were assessed and compared. A total of 46,065 (95 % CI: 44,710 to 47,420) IIH patients were identified, of whom 7,535 patients (95 % CI: 6,982 to 8,088) received surgical IIH treatments. VSS procedures increased 80 % (150 [95 % CI: 55 to 245) to 270 (95 % CI: 162 to 378) per year (p < 0.001). Concurrently, the number of CSF shunts decreased by 19 % (1,365 [95 % CI: 1,126 to 1,604] to 1,105 (95 % CI: 900 to 1,310] per year, p < 0.001), and ONSF procedures decreased by 54 % (65 [95 % CI: 20 to 110] to 30 [95 % CI: 6 to 54] per year, p < 0.001). The authors concluded that practice patterns for surgical IIH treatment in the U.S. are rapidly evolving, and VSS is becoming increasingly common.

Furthermore, an UpToDate review on “Idiopathic intracranial hypertension (pseudotumor cerebri): Prognosis and treatment” (Wall and Lee, 2023) states that “Choice of procedure -- The two main surgical procedures in IIH are optic nerve sheath fenestration (ONSF) and cerebrospinal fluid (CSF) shunting procedures. Cerebral venous sinus stenting is an alternative intervention for IIH”.

References