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Advanced Neurology Venous stenting, intracranial hypertension

After stent placement, post-stenting venograms are and was attributed to brachial plexus stretch when
performed to check for appropriate sinus drainage, followed positioning the patient instead of venous injury .
[28]
by a CT to ensure the absence of intracranial hemorrhage . CVSS has shown potential as a treatment option for
[4]
Three months after stent placement, an angiogram should patients with medically refractory IIH with an intrinsic
be repeated to check for complications . cause of stenosis, such as brain encephaloceles . In a
[4]
[35]
6. Emerging developments in CVSS study by Drocton et al. (n = 3), following venous sinus
stent placement, one of the patients showed improvement
As venous stenting has been introduced to patients as in vision and had resolution of papilledema, while another
an acceptable form of treatment, the procedure has patient had complete resolution of headache, blurred
progressed through the advent of breakthroughs in vision, and pulse-synchronous tinnitus . Although
[35]
treatment techniques. A newer technique, known to CVSS is a promising technique for relieving symptoms of
some as the “Cobra” technique, circumvents some of the medically refractory IIH in patients with intrinsic stenosis,
difficulties encountered when placing stents in already- more vigorous research is required .
[35]
narrow vessels . Navigating a catheter and stent around
[29]
the narrowing is a difficult and taxing procedure, which 7. Complications of CVSS
can lead to complications if performed incorrectly. The While cerebral venous stenosis stenting has data supporting
Cobra technique, which is also referred to as “balloon- its efficacy as a minimally invasive procedure, there are
assisted tracking,” uses a “gateway” 3.5 mm balloon shuttled noteworthy complications that may arise from the process.
through the catheter to reach the stenotic region . The Complications following CVSS include restenosis, subdural
[30]
balloon is slightly inflated to a pressure slightly lower hematoma, subarachnoid hemorrhage, intracerebral
than its nominal pressure. The catheter and balloon are hemorrhage, intraventricular hemorrhage, in-stent
then jointly navigated to the venous sinus to allow stent thrombosis, retroperitoneal hemorrhage, and femoral
delivery . In some cases, the balloon may be deflated and pseudoaneurysm. Several studies have shown that the rate
[29]
reinflated to prevent tearing of vasculature through the of minor and major complications is around 1–6% .
[3]
razor effect (caused by the catheter) or vascular looping.
These anomalies lead to challenges in catheterization or The most common complication from CVSS is
the need for alternate vascular access sites [31-34] . A study by headache ipsilateral to the stent. This headache may be
Schwarz et al. has seen success in 30 cases, and Dalfino et al. oppressive in nature and may last for months [35-37] . In a
also reported success using the same Cobra technique. study, 46% of patients experienced headaches described
as mild, moderate, or severe in nature . The cause of the
[36]
Some complications may arise from the Cobra
technique. Venous sinus rupture may occur due to a headaches was hypothesized to be a consequence of the
stretching of dura mater .
[8]
significant level of force needed to inflate the balloon.
This risk of injury must be evaluated before beginning Furthermore, CVSS may affect the function of the vein
the procedure. In addition, some studies have reported of Labbé (VOL). The mechanism is poorly understood but
adverse events such as venous sinus and cortical vein is hypothesized to be secondary to coverage by stents placed
injury appearing as venous sinus stenting becomes more across the transverse and sigmoid sinuses. The VOL, or
common, although a rare occurrence . Since the Cobra inferior anastomotic vein, contributes to a channel forming
[29]
technique is relatively new, no significant long-term studies between the superior sagittal and transverse sinuses and the
[38]
on post-operative complications were found. superficial middle cerebral vein . In several studies, CVSS
has been shown to decrease VOL draining in certain patients.
Another breakthrough is the single-arm access
venous sinus stenting (SAVeS) technique. This technique In a retrospective analysis, the data of 56 patients undergoing
addresses the complications that arise when stenting from CVSS were examined, and 32 of these cases presented with
the femoral vein. The femoral vein is the most common VOL coverage that resulted in diminished vascular caliber,
[39]
venous access site in stenting procedures but it can be sluggish venous filling, and vessel occlusion . Further
challenging to access in obese patients or in those with consequences of VOL include cerebral edema, venous
[8]
other medical indications . SAVeS innovates using large cerebral ischemia, and cerebral hemorrhage .
[28]
upper-extremity veins such as the brachial and basilic The inherent congestive nature of sinus stenosis implies
veins for venous access instead. that the passage of a catheter to access the sinus can result
[46]
In a study, a patient complained of numbness in the in complications, like hemorrhage .
upper extremity after being treated using the SAVeS In addition, serious complications include thrombus
technique. It resolved two to 3 weeks after it was reported formation, subdural hemorrhages, and sinus wall injuries,

Volume 2 Issue 2 (2023) 5 https://doi.org/10.36922/an.284