The Source for Neurovascular News and Education

March 29, 2024

 

Key Points:

  • Two studies explore use of venous stenting for idiopathic intracranial hypertension
  • One shows coverage of the vein of Labbé of no concern, other identifies race and BMI as possible risk factors for revision

  

Two new studies are exploring the use of venous stenting for the treatment of idiopathic intracranial hypertension, an alternative treatment that is increasingly proving to have important benefits over standard options.

One demonstrates that coverage of the vein of Labbé is not of clinical concern, and the other helps identify patients most likely to require revision. Both were recently published online ahead of print in the Journal of NeuroInterventional Surgery.

David A. Kumpe, MD, of the University of Colorado Anschutz Medical Campus (Aurora, CO), was among the first to explore stents for idiopathic intracranial hypertension back in the 1990s. He told NXV that the recent slew of publications on this topic may represent the beginning of a paradigm shift away from the more standard therapies of shunting and optic sheath fenestration, both of which are typically temporary solutions that offer only limited relief and generally require multiple revisions.

In addition to these two new studies, investigators from the Medical University of South Carolina, University of Kansas, and Barrow Neurological Institute have recently reported on it. “I think there is going to be more interest in more different centers than there has been,” he said.

For one of the latest JNIS papers, Kenneth C. Liu, MD, of the University of Virginia Health System (Charlottesville, VA), and colleagues reviewed a prospectively collected database of 56 patients who underwent venous sinus stenting for the treatment of idiopathic intracranial hypertension with evidence of venous stenosis.

The stent covered the vein of Labbé in 52 of the 56 patients (92.9%). In patients with coverage, 32 had evaluable angiograms performed immediately after stent placement and 46 had angiographic follow-up at least 3 months (mean 7.2 months) later.

Angiography revealed that the vein of Labbé filled normally in three-quarters of patients immediately following surgery, 3% of patients had full occlusion of the vein, and the remainder had some slowed filling or reduced vessel caliber. At the time of follow-up, more than 70% of patients still had normally filling veins, and none of the patients had evidence of full occlusion (table 1).

 

Table 1. Filling of the Vein of Labbé Following Stent Coverage

 

Immediately After Stenting

(n = 32)

At Follow-up

(n = 46)

Filled Normally

75.0%

71.7%

Filled Sluggishly

18.8%

2.2%

Diminished Caliber With Normal Transit Time

3.1%

26.1%

Occluded

3.1%

0%

 

Neither stent coverage of the vein of Labbé nor its patency immediately after stenting or at follow-up were associated with stent-adjacent stenosis. Coverage of the vein of Labbé and any identified changes in drainage patterns were not linked with any neurological sequelae.

Dr. Liu told NXV that for patients whose idiopathic intracranial hypertension appears to be caused by venous stenosis, stenting addresses the underlying cause of the problem, while shunting is more of a “band-aid” approach. He compared the condition to an overflowing toilet, where shunting represents scooping away the water to keep the floor dry and stenting represents removing the blockage.

 

Identifying Appropriate Patients

Investigators are still trying to pinpoint which patients will benefit most from stenting and which will likely require revisions. This question was addressed in a report by Dr. Kumpe not long ago. More recently, Amgad El Mekabaty, MD, of The Johns Hopkins Hospital (Baltimore, MD), and colleagues conducted a retrospective review of a prospectively maintained database of all patients with idiopathic intracranial hypertension who were screened for possible venous sinus stenting at a single center between December 2011 and May 2015.

Among the 31 patients who received a stent, 8 (25.8%) required a revision. The investigators explored multiple factors that might predict the need for revision, including gender, age, race, body mass index (BMI), central venous pressure, poststenting pressures, presence of endocrine disorders, steroid immunosuppression, intrinsic etiology, and size of the stents used. Of these, only race and BMI emerged as predictive factors (table 2).

 

Table 2. Predictors of Retreatment

 

No

(n = 23)

Yes

(n = 8)

P Value

Race

.0001

African-American

0%

100%

Caucasian

88%

12%

BMI Class

.031

Normal

26%

0%

Class I

30%

0%

Class II

13%

25%

Class III

30%

75%

 

In an email to NVX, Dr. Mekabaty warned that “due to the low number of African-Americans in our series, [this] risk factor should be viewed with caution.” He did point out, however, that a previous report has linked high BMI and African-American ethnicity with more severe disease.

 

Moving Toward Stenting as Standard of Care

The question of how to move forward remains unclear. A randomized controlled trial is being planned by Dr. Liu’s team that will compare stenting with shunting, but Dr. Kumpe remains unconvinced that is the best approach. He pointed to inappropriate patient selection and the fact that stenting remains an evolving therapy as the main limitations of doing a randomized trial. There is still no consensus on how best to approach stenting, and a clinical trial would likely tie investigators to a single strategy that may not be optimal, even as tools and techniques improve in the meantime, he explained. Instead, Dr. Kumpe recommended a multicenter registry trial as the best method for collecting data on this approach, at least for now.

Already, evidence is mounting that stenting is likely among the best options in many cases. Dr. Liu noted that an Australian meta-analysis provided compelling evidence in favor of stenting, and Dr. El Mekaby noted that “preliminary prospective work by Dinkin et al has already shown promising evidence of the efficacy of stenting in alleviating visual, auditory (tinnitus), and headache symptoms.” But what is really needed to drive a change toward stenting, according to Dr. Kumpe, is for those physicians in a position to diagnose patients with idiopathic intracranial hypertension—neuro-ophthalmologists and ophthalmologists as well as neurologists and general practitioners who treat headache—to be aware that stenting is an option and to refer patients to centers that know about it and are capable of performing it.

Dr. Liu agreed that the procedure needs a higher profile. “I’m always surprised at how unpopular this procedure is or that people just don’t know about it,” he said. “One of the things we are trying to get out there is it has a much higher safety profile than most of the procedures that we perform. Some surgeons are nervous about putting these sorts of stents in the brain, but it’s actually safer than putting a stent in the brain artery.”

Research into the underlying causes of venous stenosis behind idiopathic intracranial hypertension is also needed, said both Drs. Liu and El Mekabaty. “There is a group of people who believe it is caused by a problem with the vein, and another that believes it is a more global issue,” Dr. Liu observed. “These patients tend to be young and obese. And with the extra weight, blood has a harder time returning to heart, and this causes blood to back up into every part of the body, including the brain. This may cause the brain to swell a little bit and squish the veins even more, which causes more blood to back up,” creating a positive feedback loop. Indeed, he noted, weight loss often produces reduced pressure, but it is still not known why this phenomenon occurs in some obese patients and not others.

Next, Dr. El Mekabaty and his team will be exploring the reliability of endovascular manometry measurements during venous stenting as well as evaluating the value of venous pulsatility in determining which patients are most likely to benefit from stenting.

 


 

Sources:

  • Raper DM, Ding D, Chen CJ, et al. Patency of the vein of Labbé after venous stenting of the transverse and sigmoid sinuses. J NeuroInterv Surg. 2017;Epub ahead of print.
  • El Mekabaty A, Obuchowski NA, Predictors for venous sinus stent retreatment in patients with idiopathic intracranial hypertension. J NeuroIntervent Surg. 2016;Epub ahead of print.

 

Disclosures:

Drs. Liu, Hui, and Kumpe report no relevant conflicts of interest.