Chronic occlusions: etiology, prevalence, natural history
- Caroline Arquizan (Montpellier, France)
The prevalence remains mostly unknown due to a lack of published studies, but it is postulated that around 10% of all ischemic strokes and any portion of ICA might be involved with the biggest causes being atherosclerotic (65%), cardioembolic and dissection, respectively.
- ICA occlusions are the most variable cerebrovascular syndrome showing a large number of different clinical symptoms. Immediate prognosis is very severe with as much as 67% mRS 3 or higher reported.
- Recurrent stroke is reported at about 7% per year and mortality is between 6 to 9% per year.
- Cognitive impairment is also often seen and is best studied using the Montreal Cognitive assessment.
- Evolution relies mostly on the collaterals, mechanism and etiology of the ICA occlusion.
No prospective follow-up study assessed the predictive value of the hemodynamic aspects for recurrent ischemic stroke.
Treatment might be medical, surgical or endovascular and medical decisions should rely on different factors such as a lack of cerebrovascular reserve. The use of IV tPA in ICA occlusions remains mostly unknown as very few patients were included in published series, even if it seems effective in the ICARO study.
While the endovascular approach did not demonstrate any superiority in published series, it seems very promising. A good profile, as defined by TIA presentation and low hypoperfusion seems suitable for anticoagulant use. On the other hand, a bad profile will show evidence for chronic stroke abnormalities in white matter associated with cognitive impairment. The COSS study showed no clinical benefit of ECA-ICA bypass in selected patients with hemodynamic impairment.
In conclusion, treatment strategies remain a challenge with a lot of variables that should be taken into account.
Revascularization of chronic carotid occlusion
- Vincent Costalat (Montpellier, France)
The second lecture, by Prof. Costalat, used a case which demonstrated a recurrent stroke at day 3 after an ICA occlusion without intracranial occlusion. Permanent ICA occlusions showed chronic lesions in the affected hemisphere and ICA hemodynamic decompensation was reported at 1 month.
A second example demonstrated new ischemic lesions after 1 month in another case with an ICA occlusion. Reopening of the vessel was feasible and showed a highly developed capillary bed and diffuse collaterals coming from clival branches arising on the contralateral ICA.
Reopening was accomplished retrogradely with coronary stents through an iatrogenic dissection. Carotid rupture was not seen because the carotid was embedded in the carotid sheath.
The question was then asked about whether we should change the paradigm and reopen a vessel in the first days after symptom onset because recanalization is around 90% during these days as compared with 60% for revascularization in the late and chronic phase.
Prof. Jovin underlined the lack of current advanced tools to improve patient selection and avoid technical pitfalls.
We clearly lack a randomized controlled trial on patients suffering from ICA occlusion without intracranial occlusion.
Treatment of coronary chronic total occlusion: rational and techniques
- Benjamin Faurie (Grenoble, France)
A very interesting talk about CTOs began with the rationale for treating them which is currently more driven by feasibility instead of clinical status.
The cases shown highlighted the futility of recanalization in instances of extensive myocardial infarction in the subsequent territory of coronary occlusion. More CTOs mean more instable coronary disease, so selection should finally be made and based on stress US, MRI and scintigraphy.
Dr Faurie then gave us tips on procedural planning such as choosing the access site or the anesthesiology protocol. A hybrid algorithm can be helpful in procedural planning using only 4 questions focused on coronary anatomy which will dictate the type of revascularization.
This hybrid approach seems more effective in difficult CTO cases and technical success is currently at 90%. Training is really important and the faster the better when dealing with these sometimes-difficult procedures.
Specific devices have been developed, like the Crossboss and Stingray reentry catheters, which improve reentry in the true lumen after subintimal dissection.
Dr Faurie concluded that the medical decision to reopen a CTO should be based on clinical parameters. On the other hand, the mode of revascularization should be based on anatomy and performed in high volume centers.
Case 4: Montpellier
- Vincent Costalat (Montpellier, France)
The first live case of the day was presented by Prof. Costalat of a 79-year-old male with a NIHSS of 8 and a left ICA occlusion without intracranial occlusion. The patient received IV tPA and was transferred in a comprehensive stroke center. Access was first done through the femoral approach but proved to be impossible on both sides due to extensive calcifications. Humeral access was then accomplished on the right side with a Chaperon 6 Fr guiding catheter. Tirofiban was injected 30 minutes before stent placement (X-act stent). Unfortunately, the patient did not recover.
The discussion centered on whether distal embolus was present from the beginning which would explain part of the clinical status.
Acute stenting of dissection in a subpetrosal loop
- Raoul Pop (Strasbourg, France)
A patient was seen presenting with NIHSS of 4 and an acute occlusion in M3 and M4 branches complicating a dissected subpetrosal loop in the left carotid artery. No collaterals came from the ACom. An anterograde aspiration was done through a 6 Fr intermediate and the dissected loop discovered. A Casper stent was used in the loop after 300 mg of clopidogrel and 250 mg of aspirin was administered. As a thrombus appeared on the proximal portion of the stent, a bolus of tirofiban was given. Secondly, aspiration was done through an ACE catheter mounted over a 0.021 Wedge microcatheter. The stent was patent on the control angiogram as well as on follow-up at day 6.
The patient totally recovered.
Massive carotid cardio embolic occlusion
- Gregory Gascou (Montpellier, France)
An interesting silicon case was presented showing a massive thrombus in the cervical ICA complicated by 2 intracranial thrombus in M1 and M2. A 9 Fr balloon guiding catheter (Merci, Stryker neurovascular) was inserted in the common carotid artery. A first aspiration was made through a 6 Fr intermediate (Catalyst) ending in a total occlusion of the 9 Fr guiding catheter under balloon inflation. Unsuccessful aspiration through the 9 Fr led to distal catheterization up to the M2-M3 segment and stent deployment. At the end of the retrieval, a proximal thrombus migration was observed due to an early balloon deflation. A second pass was made with a complete ICA reopening and persistent M2 occlusion.
- Amrou Sarraj (Houston, United States)
Dr Sarraj presented the rationale behind the SELECT trial that prospectively recruited patients with large vessel occlusions treated either by medical or endovascular treatment.
The SELECT trial compared CT and perfusion CT imaging among patients treated before and after 6 hours of symptoms onset.
So far, 361 patients have been included and a comparison made on imaging modalities did not find any differences in terms of functional prognosis. Mortality was slightly higher in the CT selected patients.
In the TREVO registry, patients treated in the late time window showed the same clinical outcome when selected with either CT or CTP/MR + perfusion.
Nevertheless, CTP seems to be a more efficient method to screen patients with discordant profiles between CT and CTP and at high-risk for complications.
What remains unknown is the potential clinical benefit in patients with a large infarct core on either CT or CTP.
In the SELECT trial, patients with a large infarct core benefited from thrombectomy but patients were not randomized. An ischemic core was found to be one of the biggest prognostic factors influencing the clinical outcome.
The SELECT 2 trial will be a randomized controlled trial focusing on evaluating the efficacy of thrombectomy as compared with medical treatment in patients with a large infarct core during the first 24 hours. Patients included should present an M1 or T carotid occlusion with an ASPECTS score of 3 to 5.
Call for case
- Eitan Abergel (Haifa, Israël)
An interesting case of the retrograde approach on a proximal left vertebral occlusion with total basilar occlusion via the right vertebral artery. Stent retriever was not done through the right side due to an V4 fenestration. After retrograde catheterization with a microwire, the ostium of the left vertebral was finally catheterized anterogradely via a second guiding catheter in the subclavian artery. Angioplasty was done on the ostium and a thrombectomy was performed on the basilar trunk. While considering a potential stenting, a CT on table showed intraparenchymal bleeding with massive infarct that ended in brain death at 24 hours.
Case 5: Bicêtre
- Laurent Spelle (Paris, France)
Prof. Spelle from Kremlin Bicêtre presented a case of an acute right M1 occlusion with a limited infarct core on diffusion imaging. An 8 Fr Arrow long sheath was placed in the right internal carotid and a 8 Fr Flowgate balloon guiding catheter with a 6 Fr Catalyst were inserted. A 4×20 mm Trevo stent was deployed and retrieved following the ARTS technique. Final control showed a TICI 2b revascularization with a distal M4 embolus in the parietal territory. However, a dissection was also patent in the cervical ICA, most likely due to balloon catheter movement during retrieval. A dose of 500 mg of aspirin was then given IV and a carotid stent was placed. At 6 hours, as CT ruled out any hemorrhagic complication, ticagrelor 180 mg was given. Follow-up showed mRS 0 and NIHSS 0 at 3 months.
- Xavier Barreau (Bordeaux, France)
This presentation focused on an analysis of the ETIS registry of patients treated with the Sofia intermediate catheter and aspiration first line following the ADAPT technique. A total of 296 patients were included with a successful reperfusion (TICI 3 and 2b) in 86% of the cases. Clinical outcome at 3 months was similar to previous RCTs. Rescue therapy was done in 30% of the cases. More TICI 3 reperfusion was seen in patients treated with a 6 Fr Sofia than with a 5 Fr.
Mechanical thrombectomy in pediatric stroke
- Francisco Mont’Alverne (Fortaleza, Brazil)
This interesting case involved an 8-year-old boy presenting with a headache 735 minutes from symptoms onset. Imaging showed a right ICA occlusion, NIHSS 10 with hemiparesia and dysarthria. The ASPECT score was 6 and early signs of hypodense cortical lesions were seen. The ensuing discussion highlighted the lack of perfusion or dynamic imaging, crucial in the decision making. MRA showed an occlusion in the right T carotid. After one pass with a Trevo stent and an ACE intermediate catheter, a total revascularization was seen, and a dissection of the T carotid was patent. The procedure was stopped, and the patient recovered with an NIHSS of 2 the following day.
Case 6: Bern
- Jan Gralla (Bern, Switzerland)
The third live case of the day focused on a 77-year-old female presenting with symptoms beginning 24 hours earlier who was fluctuating between NIHSS 4 and 12 with conscience impairment. CTP showed a hypoperfusion in the right ACA territory. A stenosis and distal occlusion were seen on CTA in the A2 segment. After discussion, no IV tPA was given. Distal catheterization was done with a SL 10 microcatheter and a Catch mini was placed distally to the occlusion site. Unfortunately, the position of the stent was too proximal, so the microcatheter was then removed and an aspiration catheter was inserted over the stent pusher.
After aspiration and stent retrieval, transient revascularization was seen, but then the vessel reoccluded.
Intracranial stenosis (ICAS) was thought to be responsible for the reocclusion.
A second pass was attempted, and a complete reopening was achieved, and the procedure was stopped after injection of 5000 UI of heparin.
Various options were discussed, specifically whether to give Reopro or not in order to stent the suspected ICAS lesion.
Raul Nogueira underlined that, in such case, an Atlas stent might be used.
Clinical evolution showed a worsening and vasculitis was suspected, although a brain biopsy was negative.
The patient was placed under corticosteroids with the suspicion of rheumatoid vasculitis, but finally deteriorated.
Case 7: Bern
- Jan Gralla (Bern, Switzerland)
This case was of an 84-year-old female with an NIHSS of 14 and an unwitnessed onset of stroke.
A tandem occlusion with a right ICA and M1 occlusion was depicted at CTA. A 9 Fr balloon guiding catheter (Merci) was then inserted into the right common carotid artery and an intermediate catheter navigated distally to the occlusion site over a 0.021 microcatheter.
The discussion opened on the differences between the retrograde and anterograde approaches – something which remains unsolved in the recent literature.
Dr. Ribo described a technique which involved the anchoring of the stentriever distal to the intracranial occlusion and an intermediate crossing over the pusher of the extracranial occlusion.
A first pass of the stentriever in the M1 segment achieved a TICI 2b revascularization with multiple distal stagnations.
Doubt remained concerning the origin of this angiographic appearance: Multiple emboli? Good collaterals with flow competition?
The intermediate catheter was retrieved after embolic protection device deployment under proximal balloon inflation and with a prolongation wire. At this point, 500 mg of aspirin was injected and an X-act stent was placed with secondary PTA dilatation.
The final control showed a reopening without residual stenosis of the ICA and multiple distal stagnation pattern.
The patient died in the follow-up due to massive MCA infarct.
Chronic occlusion stroke: thrombectomy or not?
- Tran Chi Cuong (Cantho city, Vietnam)
Dr. Cuong presented an interesting case of a chronic occlusion of left ICA in a patient with a medical history of ipsilateral stroke one month before admission. A bilateral ICA stenosis was found on imaging. The left ICA was reopened after clopidogrel and aspirin were loaded 24 hours earlier.
The right ICA was done 20 days afterwards with a successful result.
Another case was shown of a 51-year-old patient presenting with an M1 near occlusion on CTA that worsened on MRA without clinical worsening. Treatment was conservative with dual antiplatelet aggregation and the patient recovered.
In conclusion, reopening should be focused on chronic occluded patients with poor collaterals. Medical treatment seems safe in patients with good collaterals.
Failed thrombectomy management and stenting
- Raul Gomes Nogueira (Atlanta, United States)
Intracranial stenosis includes a lot of different diagnoses apart from intracranial atherosclerotic disease (ICAD).
However, suspicion for ICAD is higher when specific clinical and radiological criteria are present, which were subsequently detailed.
ICAS is associated with more reocclusion following thrombectomy with a stentriever and is best managed with either stent or PTA dilatation, which is very often associated with Gp2b3a inhibitors.
Nevertheless, a stentriever is still useful in getting rid of an occlusive thrombus on the plaque.
A Mori classification was designed in order to choose the right stent in cases of ICAS.
Balloon mounted stents could be used, but only in vessels larger than 2 mm and self-expandable stents in vessels larger than 1.5 mm. Balloon mounted stents should be used in short lesions without vessel diameter mismatch and without tortuosity.
Oversizing self-expandable stents is a way to increase radial force.
An illustrative case of a C2 segment ICA stenosis showed the usefulness of a 5 Fr intermediate placed proximally when dealing with arterial lesions that need balloon mounted stent.
The second illustrative case underlined the efficiency of a Sprinter PTA balloon in cases of a long stenosis in a vessel of less than 2 mm prior to an Enterprise stent deployment.
Dr Nogueira insisted on avoiding heparin IV in such ICAS cases.
He reported a tremendous decrease of complications when he switched from heparin to a loading dose of antiplatelet drugs.
He also reminded us that a strict blood pressure control should be reached in order to lower hemorrhagic complications.