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Double Block(A case of Bilateral Carotid Artery Stenosis)

Author : Ramon Christian Villasis

This is a case of a 56 year old male admitted due to a 3weeks history of left-sided body weakness and slurred of speech accompanied by few hours history of sudden onset dyspnea and desaturation. Patient is a known hypertensive and dyslipidemic and does not have a regular follow-up. He was a previous smoker (20 pack years). Upon consult at our emergency room, he was seen awake, follows commands but noted to be tachycardic (HR 111), tachypneic (RR 21)and febrile (38.6C). Blood pressure and oxygenation were both normal. Neurologic physical examination showed slurred speech, left homonymous hemianopsia and left central facial palsy. Motor function showed MMT of 0/5 on the left upper and lower extremities. The right lower extremity also showed transient weakness, 3-4/5 but improved eventually to 5/5.

Initial work-ups showed leucocytosis (WBC 30) with neutrophilic predominance. Chest x-ray showed bilateral pneumonia. Plain cranial MRI w/MRA was done and showed acute infarcts in head and body of the right caudate nucleus, right lenticulocapular region and right corona radiata (see Fig 1). There was absent flow signals on the included upper cervical to proximal supraclinoid segments of the right ICA and mild to moderate stenosis in proximal cavernous

segment of the left ICA (see Fig 2 & Fig 3). Similar findings were seen in the carotid duplex scan which showed totally occluded right ICA and 50-69% stenosis with type V plaque morphology in the left ICA.


Fig 1: Acute infarcts in head and body of the right caudate nucleus, right lenticulocapular region and right corona radiata


(LEFT IMAGE)The MRA shows absent flow signals from the included upper cervical to proximal supraclinoid segments (C6) of the RIGHT internal carotid artery are absent (Yellow)

(RIGHT IMAGE) Signals from the terminal segment of the RIGHT internal carotid artery and entire RIGHT middle cerebral artery is also slightly less intense and narrower compared to the LEFT side (yellow)

Fig 3: The proximal cavernous segment of the LEFT internal carotid artery is variably narrowed with normal course and caliber.

He was managed as a case of acute cerebrovascular disease- infarct (right MCA distribution), bilateral carotid stenosis, CAP-MR vs Aspiration Pneumonia,rule out COVID-19 infection, HASCVD, hypertension and dsylipidemia. Stroke protocol was initiated and antibiotics were given. He was initially observed in

the acute stroke unit (COVID isolation area) while waiting to the COVID RT-PCR result. During the first hospital day, he was noted to have a decrease in sensorium and episodes of hypotension. Follow-up cranial CT scan was also done and it showed large acute to subacute infarct with hemorrhagic conversion in the right frontal lobe, corona radiata and lenticulocapsular region. Medical decompression was done. Sepsis protocol was also initiated. On the third

hospital day, he was then referred to the TCVS and neurosurgery for opinion regarding the management of carotid stenosis (possible endarterectomy) and malignant intracerebral infarcts. MRI with MRA of the cervical vessels was then requested and results showed severe short segment stenosis of the proximal cervical segment of the right ICA immediately after the bifurcation and mild to moderate left ICA stenosis (see Fig 4 & Fig 5). The said result was not consistent with the initial cranial MRI with MRA and carotid duplex scan showing totally occluded right ICA. The team then planned to do digital subtraction

angiography (DSA) .


Fig 4: Contrast enhanced angiography exhibits a short segment of severe luminal narrowing of the RIGHT internal carotid artery immediately after the bifurcation into (internal/external carotid) with a length of about 0.6 cm

Fig 5:The previously noted variable narrowing of the proximal cavernous segment of the left internal carotid is still seen, but displays adequate contrast passage.

The patient’s condition eventually stabilized. COVID swab turned out negative and infection eventually improved. The patient was transferred to a regular room on the 14th hospital day. Multidisciplinary team conference was done on the 19th hospital day. The high risk of recurrent stroke in a patient with bilateral carotid stenosis has been the team’s concern. They decided to proceed with the digital subtraction angiography for the following reasons: First, there was a disparity in the cranial imaging results and they needed to confirm the actual degree of stenosis on the bilateral carotid arteries. Second, the team considered the patient to be high risk for carotid endarterectomy (CEA) due to the presence of bilateral carotid stenosis and considering the patient’s

present medical condition (recovering from sepsis, episodes of arrhythmia while in the ICU). They all agreed to do carotid artery stenting (CAS) in case revascularization is warranted. DSA will serve as a guide in doing the CAS.

On the 25th hospital day, the patient underwent DSA. The result showed complete total occlusion of the right ICA from the origin with no robust upstream (intracranial) reconstitution and a short segment stenosis of at least 70% near the origin of left ICA (see Fig 6). As per the 2017 ESC Guidelines on Carotid Diseases, no carotid intervention was done on the totally occluded right ICA.1 The right ICA was managed with best medical therapy (BMT). The team

then proceeded with the left ICA revascularization for stenosis using augmented CAS approach with proximal balloon flow arrest and distal filter embolic protection systems (see Fig 7). Post CAS showed near normal restoration with caliber change of the L ICA and no ICA dissection nor vasospasm (see Fig 8).

Repeat intracranial angiogram showed no evidence of thromboembolic complications. Prior to CAS, initially loading of Aspirin 150mg /tab was given and once tolerated Clopidogrel 75mg/tab was started the day after. After 3days Aspirin was decreased to 80mg OD. The team planned to continue standard dual antiplatelet (ASA plus Clopidogrel) for 30 days (up to 3 months if necessary) then stepdown to single antiplatelet (ASA) thereafter indefinitely.



Right ICA: Complete total occlusion from origin; no robust upstream (intracranial) reconstitution (Green arrow)

Left ICA: compatible with findings of short segment stenosis of at least 70% near origin of the left ICA (Orange arrow)

Fig 7:

(Green Arrow): 8FR Cello Balloon Guide Catheter into L CCA (1st tier of carotid embolic protection system using proximal carotid flow arrest) (Yellow arrow): Filter Wire EZ 3.5 x 5.5mm deployed at distal C2 ICA segment (Red arrow): Monorail ascent and deployment of WallStent 7 mm x 40 mm across the predilated stenotic segment of the L ICA


Fig 8: L ICA pre and post CAS

The patient tolerated the procedure well with no occurrence of any complications. Antibiotic was completed. The patient improved with regular physical therapy & was discharged well on the 39th hospital day.


Bilateral carotid occlusive disease is rare but presents a hemodynamically critical state as patients often rely on the posterior communicating artery or retrograde filling from the ophthalmic artery to maintain adequate perfusion.2,3 Patients with this disease are susceptible to both focal symptoms and global

hypoperfusion.2 In one series of 21 patients presenting with bilateral occlusions, 38% presented with a transient ischemic attack (TIA) , 14% presented with amaurosis fugax, and 24% presented with strokes.4 As in our case, the patient presented with a transient 3-4/5 right lower extremity weakness. Whether to

consider the said symptom as a manifestation of TIA or just part of a generalized body weakness was our first dilemma. As per the 2017 ESC Guidelines on Carotid diseases, the threshold for doing carotid intervention is at least 50% ICA stenosis in a symptomatic patient while at least 70% ICA stenosis in an asymptomatic patient.1

Symptomatic patients initially undergo non-invasive imaging with MRA or CTA. Though these studies are highly sensitive, they can often misclassify high-grade stenosis as an occlusion (pseudo-occlusion). 2,5 Based on the 2017 ESC Guidelines on Carotid diseases, the management of total carotid occlusion and high-grade stenosis are different. Total carotid occlusion is managed by best medical therapy while high-grade stenosis is managed by revascularization

(Endarterectomy or stenting).1 Hence, a catheter-based study is essential in characterizing the true degree of stenosis and to further clarify the nature of collateral anastomosis.1,2 Such would be very essential in choosing the most appropriate therapy. Similarly, there was a disparity in the result of the non-

invasive studies that were done in the case presented. Hence, digital subtraction angiography was done to finally assess the true degree of carotid stenosis.

In patients with bilateral carotid occlusion, medical therapy alone is associated with high rates of mortality and recurrent stroke.2 Surgical approach may represent viable options for patients with bilateral carotid occlusions.6,7 In a case series of 21 patients with bilateral carotid stenosis (with 8 underwent medical therapy and 13 underwent surgical therapy), outcomes in the surgical group included 38% mortality and 15% recurrent events, as compared to 75%

mortality and 75% recurrent events in the medical therapy group.8 Such study showed that surgical revascularization (via carotid endarterectomy or bypass) was associated with lower rates of death, suggesting that revascularization may lead to improved outcomes over medical management. However, while surgery appears to be superior to medical therapy alone, the hemodynamic instability of this population may make general anesthesia and the associated risks

of open microsurgery intolerable for a subset of these patients.2,9 Alternatively, carotid stenting has previously been reported for the management of acute, subacute and chronic unilateral symptomatic carotid occlusive disease with a good safety profile and high rates of revascularization.2,10,11,12 Going back to our case, the totally occluded right ICA was managed with best medical therapy (BMT). On the other hand, the 70% left ICA stenosis, regardless of the symptom

status, was treated with carotid stenting. The team emphasized that the presence of contralateral stroke puts the patient at a higher risk of developing late stroke if he will be treated with BMT alone (annua risk of 3.4% vs 1.2%, OR 3.0).1 Additionally, the team considered the patient to be high risk for carotid endarterectomy (CEA) due to the presence of bilateral carotid stenosis and considering the patient’s medical condition during that time (recovering from sepsis, episodes of arrhythmia while in the ICU).


In the case presented, we were able to show that carotid angioplasty and stenting may represent a safe and doable treatment option for patients with bilateral internal carotid artery disease.


2017 ESC Guidelines on the Diagnosis and Treatment of Peripheral Arterial Diseases, in collaboration with the European Society for Vascular Surgery (ESVS)European Heart Journal (2018) 39, 763-821

2) Jadhav A.P., et al. Management of Bilateral Carotid Occlusive Disease. Intervent Neurol 2015;4:96-103

3) Vernieri F, Pasqualetti P, Diomedi M, et al: Cerebral hemodynamics in patients with carotid artery occlusion and contralateral moderate or severe internal carotid artery stenosis. J Neurosurg 2001;94:559-564.

4) Powers WJ: Management of patients with atherosclerotic carotid occlusion. Curr Treat Options Neurol 2011;13:608-615.

5) Marquering HA, Nederkoorn PJ, Beenen LF, et al: Carotid pseudo-occlusion on CTA in patients with acute ischemic stroke: a concerning observation. Clin Neurol Neurosurg 2013;115:1591-1594.

6) Failure of extracranial-intracranial arterial bypass to reduce the risk of ischemic stroke. Results of an international randomized trial. The EC/IC Bypass Study Group. N Engl J Med 1985;313:1191-1200.

7) Grubb RL Jr, Powers WJ, Clarke WR, Videen TO, Adams HP Jr, Derdeyn CP: Surgical results of the Carotid Occlusion Surgery Study. J Neurosurg 2013;118:25-33.

8) AbuRahma AF, Copeland SE: Bilateral internal carotid artery occlusion: natural history and surgical alternatives. Cardiovasc Surg 1998;6:579-583

9) Reynolds MR, Grubb RL Jr, Clarke WR, et al: Investigating the mechanisms of perioperative ischemic stroke in the Carotid Occlusion Surgery Study. J Neurosurg 2013;119:988-995.

10) Dabitz R, Triebe S, Leppmeier U, Ochs G, Vorwerk D: Percutaneous recanalization of acute internal carotid artery occlusions in patients with severe stroke. Cardiovasc Intervent Radiol 2007;30:34-41.

11) Dalyai RT, Chalouhi N, Singhal S, et al: Stent-assisted endovascular recanalization of extracranial internal carotid artery occlusion in acute ischemic stroke. World Neurosurg 2013;79:143-148.

12) Hauck EF, Natarajan SK, Ohta H, et al: Emergent endovascular recanalization for cervical internal carotid artery occlusion in patients

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