Endovascular Treatment of Large Vessel Occlusion Strokes Due to Intracranial Atherosclerotic Disease

Abstract

Mechanical thrombectomy (MT) has become the gold-standard for patients with acute large vessel occlusion strokes (LVOS). MT is highly effective in the treatment of embolic occlusions; however, underlying intracranial atherosclerotic disease (ICAD) represents a therapeutic challenge, often requiring pharmacological and/or mechanical rescue treatment. Glycoprotein IIb/IIIa inhibitors have been suggested as the best initial approach, if reperfusion can be achieved after thrombectomy, with angioplasty and/or stenting being reserved for the more refractory cases. In this review, we focus on the therapeutic considerations surrounding the endovascular treatment of ICAD-related acute LVOS.

Keywords: Angioplasty; Cerebral infarction; Endovascular procedures; Intracranial arteriosclerosis; Intracranial embolism and thrombosis; Stents.

Figure 1.

Etiologies of all cerebral infarctions and acute intracranial large vessel occlusion strokes (LVOS). The causes of cerebral infarction vary widely, while the causes of acute intracranial LVOS are relatively simple. Embolism from the heart, blood and extracranial atherosclerosis origins are the major causes of acute intracranial LVOS, followed by intracranial atherosclerotic disease (ICAD).

Figure 2.

Schematic illustrations for subtle terminological differences between intracranial stenosis and intracranial atherosclerotic disease (ICAD). (A) Intracranial stenosis is an angiographical term. Although it can differentiate pathophysiology, its reading on digital subtraction imaging is a gold-standard for diagnosis. (B) From the aspects of pathophysiology, intracranial stenosis may consist of atherosclerosis itself and also in situ thrombi. Despite this aspect, pathological diagnosis is never practical. In this context, intracranial stenosis on angiography is generally referred as ICAD or intracranial atherosclerotic stenosis.

Figure 3.

Considerations for rescue therapy in patients with intracranial atherosclerotic disease (ICAD)-related acute large vessel occlusion stroke (LVOS). Baseline and procedural conditions on the green area, which may include perforator infarct pattern, small ischemic penumbra, excellent collaterals, intravenous tissue plasminogen activator (IV tPA) infused, and good anterograde flow without reocclusion tendency after thrombectomy, favor glycoprotein (GP) infusion only. Conditions on the red area, which may include borderzone or territorial infarct pattern, large ischemic penumbra, poor collaterals, recurrent stroke due to the culprit ICAD lesion, no IV tPA infused, loading of antiplatelet or statin agents, reocclusion tendency after thrombectomy, and iatrogenic dissection due to thrombectomy, favor mechanical angioplasty. In case of thrombectomy failure, intracranial stenting has been reported to improve outcomes as rescue treatment. Intracranial stenting may necessitate GP inhibitor and balloon angioplasty as well. MT, mechanical thrombectomy.

Figure 4.

A self-expanding stent (SES) placement for small vessel diameter around culprit stenosis. A 77-year-old African-American female with hypertension, hyperlipidemia, and diabetes mellitus had acute steno-occlusive intracranial atherosclerotic disease (ICAD) and presented with an unwitnessed fall the night prior. In the following morning, she presented to an outside hospital with aphasia and right hemiparesis. After telemedicine consultation, she was loaded with clopidogrel 600 mg+aspirin 325 mg and transferred for potential endovascular intervention. Upon arrival, National Institutes of Health Stroke Scale was 14, and non-contrast computed tomography (CT) showed chronic scattered borderzone infarcts in the left hemisphere. (A) CT perfusion showed a delay on Tmax >4 seconds in the left middle cerebral artery superior division territory. She was brought to angiography suite for endovascular reperfusion treatment. VerifyNow, a point-of-care testing, showed acceptable platelet inhibition (PRU 210). (B) Initial digital subtraction angiography showed diffuse ICAD with severe stenosis of a left insular M3 branch resulting in critical hypoperfusion. (C) The atherosclerotic lesion was long (>10 mm) and located is a small vessel (1.5 mm) along a curved course, so a SES was chosen for intracranial stenting. (D) Balloon angioplasty was performed (Sprinter Legend Rx angioplasty balloon, 1.5×12 mm) over an exchange-length microguidewire. The balloon catheter was exchanged for a 0.021 microcatheter. (E) An Enterprise-2 stent (4×23 mm) was advanced over the microcatheter. (F) The stent was unsheathed and deployed. (G) The vessel was successfully recanalized. (H) Final angiography showed complete recanalization and reperfusion. She made a complete functional recovery.

Figure 5.

A self-expanding stent (SES) placement for landing zone tortuosity and mismatch: directly after intracranial balloon angioplasty (without exchange of the balloon catheter) for acute occlusion in the M1 segment of the left middle cerebral artery (MCA) due to underlying intracranial atherosclerotic disease in 54-year-old African-American male with history of diabetes mellitus and prior stroke in left MCA presented to the emergency room with aphasia and mild right hemiparesis (National Institutes of Health Stroke Scale 6). (A) Computed tomography angiography (not shown) and conventional angiography showed complete occlusion of the left MCA-M1 (black arrow) with evidence of multifocal intracranial stenosis. (B) Mechanical thrombectomy was performed with a Trevo XP (4×30 mm) stent-retriever. There was severe “pinching” of the device suggesting underlying intracranial atherosclerotic disease (white arrows) versus “hard-clot.” (C) A focal severe stenosis (white arrows) was disclosed after one device pass. There was a mismatch across the diameters of stent landing zones due to the presence of post-stenotic dilation and a trifurcation, thus a SES was selected for intracranial stenting. Intravenous tirofiban bolus was administered in anticipation to the stent implantation. (D) Balloon was performed using a Mini Trek 2×12 mm over-the-wire coronary balloon catheter. Subsequently, the balloon catheter was advanced 2 to 3 mm and the microwire was removed. (E) A Neuroform Atlas 4.5×22 mm SES was then advanced through the coronary balloon catheter and placed across the target lesion. The stent was then carefully unsheathed by withdrawing the balloon catheter (black arrows, distal and proximal ends of the stent; white arrows distal and proximal ends of the balloon catheter during stent deployment). (F, G) There was complete resolution of the stenosis (white arrows) with good wall apposition (black arrows). (H) Final angiography shows complete recanalization and reperfusion. The patient recovered to his baseline.

Figure 6.

Placement of a balloon-mounted stent (BMS) for large vessel diameter and short length of the culprit stenosis. An acute middle cerebral artery (MCA) occlusion occurred in a 79-year-old female with history of previous stroke due to stenosis in M1 segment of left MCA (baseline modified Rankin Scale 1) currently treated with aspirin monotherapy presenting to an outside hospital with fluctuating severe aphasia and right hemiparesis. After telemedicine consultation, she was loaded with ticagrelor 180 mg prior to transfer. Upon arrival, National Institutes of Health Stroke Scale was 13 and time from last known normal was greater than 12 hours. Multimodal computed tomography (CT) showed left MCA-M1 occlusion with Alberta Stroke Program Early CT Score 9 and a large perfusion mismatch. The patient was brought to angiography suite for endovascular reperfusion treatment. (A) Initial angiogram showed complete left M1 occlusion. (B) Standard thrombectomy was performed with a Trevo XP (4×30 mm) stent-retriever. (C) After one device pass, a focal severe stenosis was found. The atherosclerotic lesion was short, and both diameters of stent landing zones were similar and over 2 mm, so a BMS was chosen for intracranial stenting. (D) The mounted balloon is inflated for deployment. (E) The Integrity stent (2.25×9 mm) is deployed with good wall apposition. (F) Final angiography shows complete recanalization and reperfusion. The patient recovered to her baseline.

Figure 7.

Indications of self-expanding stents vs. balloon-mounted stents for underlying intracranial atherosclerotic disease in acute large vessel occlusion stroke.