Chronic total symptomatic carotid artery occlusion treated successfully with stenting and angioplasty

Delayed revascularization in acute ischemic stroke patients

Stroke shares a significant burden of global mortality and disability. A significant decline in the quality of life is attributed to the so-called post-stroke cognitive impairment including mild to severe cognitive alterations, dementia, and functional disability. Currently, only two clinical interventions including pharmacological and mechanical thrombolysis are advised for successful revascularization of the occluded vessel. However, their therapeutic effect is limited to the acute phase of stroke onset only. This often results in the exclusion of a significant number of patients who are unable to reach within the therapeutic window. Advances in neuroimaging technologies have allowed better assessment of salvageable penumbra and occluded vessel status. Improvement in diagnostic tools and the advent of intravascular interventional devices such as stent retrievers have expanded the potential revascularization window. Clinical studies have demonstrated positive outcomes of delayed revascularization beyond the recommended therapeutic window. This review will discuss the current understanding of ischemic stroke, the latest revascularization doctrine, and evidence from clinical studies regarding effective delayed revascularization in ischemic stroke.

Clinical study on endovascular recanalization of non-acute symptomatic middle cerebral artery occlusion

Objective

Endovascular recanalization in patients with non-acute symptomatic middle cerebral artery occlusion remains clinically challenging. Here, we aimed to evaluate the feasibility and safety of endovascular recanalization for non-acute symptomatic middle cerebral artery occlusion and propose a new patient classification.

Methods

Between January 2019 and December 2021, 88 patients with non-acute symptomatic middle cerebral artery occlusion underwent prospective endovascular recanalization at our hospital. All patients were divided into three groups according to occlusion length, occlusion duration, occlusion nature, calcification of the occlusion site, and occlusion angulation. The indicators of each group were analyzed, including general baseline data, imaging data, surgical conditions, and follow-up results.

Results

Of the 88 patients, 73 were successfully recanalized and 15 were abandoned because the instruments either could not reach the distal true lumen of the occlusion or broke through the blood vessels. The overall technical success rate was 83.0% (73/88), and perioperative complications occurred in 15 patients. Preoperatively, all patients were divided into three risk groups: low, medium, and high. From the low- to high-risk groups, the recanalization rate gradually decreased (100.0, 91.7, and 16.7%, respectively, P = 0.020), the perioperative complication rate gradually increased (0, 13.9, and 83.3%, respectively, P < 0.001), the proportion of the modified Rankin scale scores >2 at 90 days increased (0, 11.7, and 50.0%, P < 0.001), and the restenosis/reocclusion rates in the 73 cases of successful recanalization increased (0, 16.1, and 100%, P = 0.012) during follow-up.

Conclusion

Endovascular recanalization may be feasible and safe in well-selected patients with non-acute symptomatic middle cerebral artery occlusion, especially in the low- and medium-risk groups.

Spotlight on clinical strategies of Chronic Internal Carotid Artery Occlusion: Endovascular interventions and external-intracarotid bypasses compared to conservative treatment

Chronic internal carotid artery occlusion (CICAO) has high prevalence and incidence rates, and patients with CICAO can be completely asymptomatic, experience a devastating stroke or die. It is important to note that CICAO causes cerebrovascular accidents. Currently, the external carotid-internal carotid (EC-IC) bypass technique is used to treat CICAO. However, many clinical studies showed that EC-IC bypass was not beneficial for many patients with CICAO. Meanwhile, endovascular intervention treatment options for CICAO are evolving, and an increasing number of patients are undergoing endovascular intervention therapy. Accordingly, a review comparing both techniques is warranted. For this review, we searched PubMed and collected relevant case study reports comparing endovascular interventional therapy and internal and external cervical bypass surgeries to provide strategies for clinical treatment.

A systematic review of endovascular treatment for chronic total occlusion of the internal carotid artery

The management of patients with symptomatic chronic total occlusion (CTO) of the internal carotid artery (ICA) is controversial. The aim of this systematic review was to investigate patient selection, technical success, early and late outcome of endovascular treatment for CTO of the ICA. PubMed/Medline and EMBASE databases were searched until January 2, 2020 for studies on endovascular treatment for CTO of the ICA. A descriptive analysis of demographic, clinical and anatomic data, endovascular technique, perioperative and late outcomes was performed. A total of 1,222 articles were screened, 8 retrospective or prospective cohort studies were reviewed; 276 patients, 18.9% females, mean age: 64.3 years, underwent attempt at endovascular treatment of 278 lesions. Two hundred and thirteen patients (77.2%) had neurological symptoms; the others had evidence of ipsilateral cerebral hypoperfusion. Two hundred and thirty-eight lesions (91.2%) were treated >30 days after diagnosis of occlusion. Technical success was 66.9%. Perioperative mortality was 1.64% (4/243), early stroke rate was 3.3%. Follow-up averaged 23.4 months (range, 0.25–84 months), late mortality was 1.89% (5/265), stroke rate was 3.4% (9/265). Stroke rate was similar after successful stenting (3.57%, 4/112) vs. failed stenting (3.61%, 2/61; P=1.00), stroke/death rates were also similar after successful stenting (5.36%, 6/112) than after failed stenting (3.28%, 2/61; P=0.71). Endovascular treatment of CTO of the ICA in eight cohort studies was safe and feasible with a technical success of 67% and a low rate of early and late neurological complications. Pooled data in this review failed to confirm the benefit of successful stenting on stroke and mortality, but some of the included studies suggest benefit and some also supported improvement in neurocognitive function after successful stenting. Prospective randomized trials to investigate the benefit of endovascular treatment in addition to best medical therapy for symptomatic CTO of the ICA are urgently needed.

Evolution of the stroke paradigm: A review of delayed recanalization

While the time window for reperfusion after ischemic stroke continues to increase, many patients are not candidates for reperfusion under current guidelines that allow for reperfusion within 24 h after last known well time; however, many case studies report favorable outcomes beyond 24 h after symptom onset for both spontaneous and medically induced recanalization. Furthermore, modern imaging allows for identification of penumbra at extended time points, and reperfusion risk factors and complications are becoming better understood. Taken together, continued urgency exists to better understand the pathophysiologic mechanisms and ideal setting of delayed recanalization beyond 24 h after onset of ischemia.

Delayed Recanalization-How Late Is Not Too Late?

Stroke has become the second most prevalent cause of mortality in the world. Currently, the treatment of ischemic stroke is based on thrombolytic and thrombectomy therapy shortly after the ischemic event (≤ 4.5 h for thrombolytic strategies; ≤ 6 h for thrombectomy strategies). However, the majority of patients are unable to receive prompt treatment, particularly in undeveloped countries. Alternative solutions are lacking for those patients that miss the optimal window of opportunity for treatment. Recently, new developments in imaging techniques and intravascular interventional devices enable the expansion of the window of opportunity for treating stroke patients. Clinical studies have reported that delayed recanalization at 24 h, or even more than 1 month, was beneficial for some patients. However, the mechanisms of neuroprotection that underly the delayed recanalization in these ischemic stroke patients remain unclear. In this review, we will summarize the clinical studies of delayed recanalization, and organize them according to the duration of occlusion. Additionally, we will discuss the changing guidelines and possible mechanisms based on animal research, and attempt to draw conclusions and future perspectives.

A Novel Endovascular Technique for Recanalization of Carotid Artery Chronic Total Occlusion: Staged Carotid Angioplasty and Stenting

AIM

Symptomatic carotid artery chronic total occlusion (SCACTO) can lead to neurocognitive function decline and carries a high risk or recurrent stroke. The treatment option is limited, endovascular intervention may be an alternative treatment but still controversial. To our knowledge, the staged carotid angioplasty and stenting (SCAS) did not previously reported. The purpose of this study was to report our experiences in this novel technique.

METHODS

In 2017-2018, we attempted the staged carotid angioplasty and stenting (SCAS) approach in 13 patients who received SCACTO treatment. The SCAS approach involves two stages of intervention. The first stage involves initial recanalization and initial small-sized balloon angioplasty. The second stage, which is performed 4-6 weeks later, involves angioplasty and carotid stent placement.

RESULTS

The success rate of SCAS was 76.9%. At the second stage, the lumen remained patent in all the patients. The mean spontaneous increase in lumen diameter after 4-6 weeks was 51.7%. The median length of the stent was 4.0 cm, and the median number of stents used was 1. One patient had a complication of dissection, with a complication rate of 7.6%.

CONCLUSIONS

SCAS is a novel technique in the endovascular treatment of SCACTO. It is a feasible and safe approach that could reduce the complication rate and number of carotid stents needed.

Cognitive and cerebral hemodynamic effects of endovascular recanalization of chronically occluded cervical internal carotid artery: single-center study and review of the literature

OBJECTIVE

Revascularization of a symptomatic, medically refractory, cervical chronically occluded internal carotid artery (COICA) using endovascular techniques (ETs) has surfaced as a viable alternative to extracranial-intracranial bypass. The authors aimed to assess the safety, success, and neurocognitive outcomes of recanalization of COICA using ETs or hybrid treatment (ET plus carotid endarterectomy) and to identify candidate radiological markers that could predict success.

METHODS

The authors performed a retrospective analysis of their prospectively collected institutional database and used their previously published COICA classification to assess the potential benefits of ETs or hybrid surgery to revascularize symptomatic patients with COICA. Subjects who had undergone CT perfusion (CTP) imaging and Montreal Cognitive Assessment (MoCA) testing, both pre- and postprocedure, were included. The authors then performed a review of the literature on patients with COICA to further evaluate the success and safety of these treatment alternatives.

RESULTS

The single-center study revealed 28 subjects who had undergone revascularization of symptomatic COICA. Five subjects had CTP imaging and MoCA testing pre- and postrevascularization and thus were included in the study. All 5 patients had very large penumbra involving the entire hemisphere supplied by the ipsilateral COICA, which resolved postoperatively. Significant improvement in neurocognitive outcome was demonstrated by MoCA testing after treatment (preprocedure: 19.8 ± 2.4, postprocedure: 27 ± 1.6; p = 0.0038). Moreover, successful revascularization of COICA led to full restoration of cerebral hemodynamics in all cases. Review of the literature identified a total of 333 patients with COICA. Of these, 232 (70%) showed successful recanalization after ETs or hybrid surgery, with low major and minor complication rates (3.9% and 2.7%, respectively).

CONCLUSIONS

ETs and hybrid surgery are safe and effective alternatives to revascularize patients with symptomatic COICA. CTP imaging could be used as a radiological marker to assess cerebral hemodynamics and predict the success of revascularization. Improvement in CTP parameters is associated with significant improvement in neurocognitive functions.

Recanalization of the Chronically Occluded Internal Carotid Artery: Review of the Literature

Introduction

We reviewed the literature on interventions for patients with medically refractory chronically occluded internal carotid artery (COICA) to assess the risks and/or benefits after recanalization via an endovascular technique (ET) or hybrid surgery (HS, i.e., ET plus carotid endarterectomy).

Methods

A systematic search of the electronic databases was performed. Patients with COICA were classified into 4 different categories according to Hasan et al classification.

Results

Eighteen studies satisfied the inclusion criteria. Only 6 studies involved an HS procedure. We identified 389 patients with COICA who underwent ET or HS; 91% were males. The overall perioperative complication rate was 10.1% (95% confidence interval [CI]: 7.4%-13.1%). For types A and B, the successful recanalization rate was 95.4% (95% CI: 86.5%-100%), with a 13.7% (95% CI: 2.3%-27.4%) complication rate. For type C, the success rate for ET was 45.7% (95% CI: 17.8%-70.7%), with a complication rate of 46.0% (95% CI: 20.0%-71.4%) for ET and for the HS technique 87.6% (95% CI: 80.9%-94.4%), with a complication rate of 14.0% (95% CI: 7.0%-21.8%). For type D, the success rate of recanalization was 29.8% (95% CI: 7.8%-52.8%), with a 29.8% (95% CI: 6.1%-56.3%) complication rate. Successful recanalization resulted in a symmetrical perfusion between both cerebral hemispheres, resolution of penumbra, normalization of the mean transit time, and improvement in Montreal Cognitive Assessment (MoCA) score (ΔMoCA = 9.80 points; P = 0.004).

Conclusions

Type A and B occlusions benefit from ET, especially in the presence of a large penumbra. Type C occlusions can benefit from HS. Unfortunately, we did not identify an intervention to help patients with type D occlusions. A phase 2b randomized controlled trial is needed to confirm these findings.

Current understanding of chronic total occlusion of the internal carotid artery

At present, there is limited understanding of chronic total occlusion (CTO) of the internal carotid artery (ICA). Therefore, the present report collected related cases from PubMed and reviewed the literature. Cerebral vessels may form collateral circulation immediately or gradually following CTO of the ICA. The natural history of CTO of the ICA includes a variety of outcomes, all of which are biased toward a non-benign progressive process and are characterized by insufficient cerebral perfusion, embolus detachment and cognitive dysfunction. The majority of cases of CTO of the ICA require treatment. In early studies, the results of external-ICA bypass were unsatisfactory, while recanalization is now considered the only viable option. The current treatment indications mainly depend on the degree of injury to the cerebrovascular reserve and the extent to which the oxygen extraction fraction is increased. The length, height and duration of ICA occlusion are also relevant, though more frequently, the condition depends on multiple factors. Endovascular interventional recanalization, carotid endarterectomy (CEA) and hybrid surgery may be conducted in a select group of patients. As novel materials are developed, the success rate of simple recanalization may gradually increase; however, hybrid surgery may be more representative of the current trend, as advanced CEA can remove carotid atherosclerosis plaques, thus reducing the technological demands of the subsequent interventional recanalization. There are many complications that may result from recanalization following CTO of the ICA, including hyperperfusion and technical errors; therefore, the operation must be conducted carefully. If the recanalization is successful, it typically results in a stable improvement of patient condition in the long term. However, despite these conclusions, more studies are required in the future to further improve current understanding of CTO of the ICA.

Cerebral misery perfusion due to carotid occlusive disease

Purpose

Cerebral misery perfusion (CMP) is a condition where cerebral autoregulatory capacity is exhausted, and cerebral blood supply in insufficient to meet metabolic demand.

We present an educational review of this important condition, which has a range of clinical manifestations.

Method

A non-systematic review of published literature was undertaken on CMP and major cerebral artery occlusive disease, using Pubmed and Sciencedirect.

Findings

Patients with CMP may present with strokes in watershed territories, collapses and transient ischaemic attacks or episodic movements associated with an orthostatic component. While positron emission tomography is the gold standard investigation for misery perfusion, advanced MRI is being increasingly used as an alternative investigation modality. The presence of CMP increases the risk of strokes. In addition to the devastating effect of stroke, there is accumulating evidence of impaired cognition and quality of life with carotid occlusive disease (COD) and misery perfusion. The evidence for revascularisation in the setting of complete carotid occlusion is weak. Medical management constitutes careful blood pressure management while addressing other vascular risk factors.

Discussion

The evidence for the management of patients with COD and CMP is discussed, together with recommendations based on our local experience. In this review, we focus on misery perfusion due to COD.

Conclusion

Patients with CMP and COD may present with a wide-ranging clinical phenotype and therefore to many specialties. Early identification of patients with misery perfusion may allow appropriate management and focus on strategies to maintain or improve cerebral blood flow, while avoiding potentially harmful treatment.

Protected endovascular revascularization of subacute and chronic total occlusion of the internal carotid artery

BACKGROUND AND PURPOSE

The natural course of symptomatic carotid artery occlusion with hemodynamic impairment is poor. Surgical revascularization may improve the outcome; however, its efficacy has not been established yet. The goal of this study was to characterize the technical and clinical outcomes following endovascular recanalization of the ICA under cerebral circulatory protection.

MATERIALS AND METHODS

Endovascular recanalization was attempted in 8 patients with symptomatic ICA occlusions. The duration of the occlusion ranged from 7 days to 7 months (mean, 2.5 months), and the mean length of the occlusion was 95 mm. Cerebral hemodynamics ipsilateral to the side of the occlusion were severely impaired in all patients. The endovascular procedure was performed under total cerebral circulatory protection, beginning with proximal protection with a subsequent switch to distal protection after successful guidewire passage.

RESULTS

The occlusion was recanalized successfully in 7 of 8 patients (88%), resulting in improvement of ipsilateral cerebral hemodynamics without symptomatic stroke. Small asymptomatic ischemic lesions were detected in 6 of 8 patients (75%) on DWI, and 1 patient developed a mild groin hematoma. Ischemic episodes did not recur during the mean follow-up period of 19 months. However, 1 patient experienced asymptomatic reocclusion, which was re-treated successfully without complications, while another patient developed mild retinal hemorrhage at 3 months after the procedure due to the combination of antiplatelet and anticoagulant therapy.

CONCLUSIONS

Endovascular revascularization of an ICA occlusion is feasible and well-tolerated in patients with subacute or chronic total occlusion of the ICA.