Therapeutic advances in interventional neurology

Abstract

Rapid advances in the field of interventional neurology and the development of minimally invasive techniques have resulted in a great expansion of potential therapeutic applications. We discuss therapeutic interventional neurology as applied in clinical practice in one of the two possible ways: 1) embolization leading to occlusion of blood vessels; and 2) revascularization leading to reopening of blood vessels. These procedures can be applied to a broad range of cerebrovascular diseases. In the first section of this review, we will explore the evolution of these interventions to occlude aneurysms, arteriovenous malformations, neurovascular tumors, and injuries. In the second section, revascularization in acute ischemic stroke, stenosis, and dural venous thrombosis will be discussed.

FIG. 1.

A: Case illustration of a symptomatic 8.5 × 8 mm ruptured intracranial carotid aneurysm. B: GDCs being deployed. C: Final result with minimal residual flow in the aneurysm but excellent patency of the parent vessel.

FIG. 2.

A case illustration of an AVM. A: AVM before intervention. B: AVM after staged embolization. C: AVM after surgery. A staged embolization was performed. A large amount of shunting is seen with decreased transit times and early venous filling in panel A. Predominant flow toward the anterior cerebral artery in panel A was converted into a smaller AVM after staged embolizations in panel B. Also, note that there is robust filling of the middle cerebral artery and no diversion in the venous sinuses in B. The postsurgical results are excellent with almost no flow into the nidus of the AVM (C).

FIG. 3.

Mechanical devices for treatment of acute ischemic stroke could be broadly categorized into mechanical disruption and retrieval devices. The figure outlines a few of the available devices categorized in two broad classes. Note that the snare device could be used for either and is probably the most popular device for acute ischemic stroke intervention.

FIG. 4.

Examples of distal protection devices for the prevention of embolic debris causing distal vasculature strokes. The figure also depicts the cartoons depicting the mechanism for each type of filter.

FIG. 5.

A case illustration of vertebral origin stenting through a radial route using a distal protection device. A: Vertebral artery origin stenosis. B: Deployed distal protection device (EpiFilter wire) and stent is seen in unsubtracted digital angiography. C: Flow of contrast post-angioplasty and stent. The distal protection device is eventually recaptured using a 4 French multipurpose catheter.

FIG. 6.

Case illustration depicting carotid angioplasty and stenting using a distal protection device. A: Near-occlusive high grade stenosis of the right internal carotid artery at its origin. B: Angioplasty balloon across the lesion with a distal protection device in place for the angioplasty. C: Stent across the lesion. D: Deployment of the stent. E: Frame of an angiogram run after stenting and angioplasty and final results with a residual stenosis of less than 15%. F: Demonstration of debris collected by the EpiFilter device.

FIG. 7.

Case illustration of vertebral artery origin stenting in a patient who had an atretic contralateral vertebral artery and has continued to have transient posterior circulation ischemic events despite best medical therapy. A: Extent of stenosis. B: Stent across the area of stenosis. C: Results after angioplasty and stenting.

FIG. 8.

This is an example of a drug (paclitaxel) eluting stent in the middle cerebral artery of a patient with recurrent ischemic symptoms despite best medical therapy. The patient was symptom free at 3 months of follow-up with a normal neurologic exam. A high-grade stenosis seen in the trunk (M1) of the middle cerebral artery (A) (highlighted by a black circle) was successfully angioplastied and stented to get the results seen (B). Inset b: Unsubtracted angiogram and the struts of the stent within the confines of orbital ridges as highlighted by the white circle.

FIG. 9.

This is a case illustration of a snare device able to disrupt and ultimately retrieve part of a presumably very large clot in this elderly woman with a large middle cerebral artery (MCA) stroke. The angiographic results are shown before (A) and after (B). B: Superior division of MCA is open. Inset b: Actual clot is shown hanging from tip of the snare device.

FIG. 10.

Case illustration of 28-year-old man with subarachnoid hemorrhage; Hunt and Hess grade 3 and Fisher grade 3 at day 7. A: Cerebral vasospasm of the right middle cerebral artery and anterior cerebral artery after clinical deterioration. B: Improvement after emergent angioplasty, which led to clinical improvement.