Abstract 084: Intracranial Onyx Resolute Stenting In Idiopathic Intracranial Hypertension Patient With Pre‐existing Nickel Allergy: Case Report

Abstract

Introduction Idiopathic intracranial hypertension (IIH) is a pathology involving an increase in intracranial pressure leading to symptoms including papilledema, tinnitus, and elevated cerebrospinal fluid opening pressure. Recent research has identified venous sinus stenosis as a cause of IIH, a common treatment of which is venous stenting and angioplasty. An adverse event of this procedure is in‐stent stenosis (ISS), due to either neointimal hyperplasia or hypersensitivity to an element in the stent. There has been speculation regarding whether nickel in intracranial stents is a cause of concern, due to its potential to cause a Type IV hypersensitivity reaction and ISS, which is an indicator of future stroke. The purpose of this case report is to determine if the cobalt‐based alloy Onyx Resolute intracranial stents can safely treat IIH in patients with allergic contact dermatitis to nickel. Methods We present a 38‐year old woman who presented with migraines and IIH with papilledema and severe pulsatile tinnitus. Headaches had been present for 5‐10 years. Ophthalmology consult revealed bilateral papilledema, upon which an MRI and MRV revealed venous stenosis. There was a 17mmHg pressure gradient measured in the patient. Patient could not tolerate acetazolamide, with kidney stones and loss of sheen in hair. Cerebral angiogram indicated right transverse‐sigmoid junction stenosis and atretic left venous sinus. The patient had an Onyx Resolute stent placed in the right transverse sigmoid junction. The Onyx Resolute stent is a Zotarolimus‐eluting stent made up of a cobalt‐based shell and a platinum‐Iridium core and is not recommended for patients with a hypersensitivity to nickel, cobalt, or chromium, but has a lower nickel content than a self‐expanding stent. Results Patient underwent cerebral angiogram, revealing right transverse‐sigmoid junction stenosis with a 17mmHg pressure gradient. Stenting and angioplasty were performed; this reduced the venous sinus pressure in the R transverse sinus (pre‐stenotic segment) from 43 mm Hg to 24 mm Hg with resolution of the R transverse‐sigmoid junction pressure gradient. Patient was treated with prasugrel (Effient) for one month. At the one‐month follow‐up, the patient reported an improvement of symptoms, with near‐resolution of her prior headaches in terms of severity and frequency following her procedure. Visual acuity is at baseline, pending formal follow‐up assessment for papilledema. Follow‐up CT Head Venogram with and without contrast showed a patent R transverse to sigmoid venous stent. The patient was continued on aspirin 81mg daily and prasugrel 5mg daily and is to continue follow‐up with yearly ophthalmologic exams. Conclusion Although there is speculation regarding the use of metal intracranial stents in patients allergic to nickel, our patient has shown that it is safe to use the Onyx Resolute intracranial stent despite a pre‐existing nickel hypersensitivity.