Chronic Carotid Artery Occlusion Research Articles

MEDIA-Net: Multi-scale Feature Extraction and DepthwIse Attention Network for Accurate Carotid Artery Segmentation

Accurate segmentation of the carotid artery in digital subtraction angiography (DSA) imaging is crucial for the diagnosis, prognosis and therapy planning of chronic carotid artery occlusion (CCAO). However, general segmentation methods often produce misclassifications and fuzzy boundaries, making it challenging to obtain precise segmentation results. This paper suggests a solution to these problems by proposing a Multi-scale Feature Extraction and DepthwIse Attention Network (MEDIA-Net) consisting of the Multi-scale Feature Extraction (MFE) module and the DepthwIse Attention (DA) module. The MFE module extracts and blends features at different scales to capture dependencies between multi-scale components. In contrast, the DA module further utilizes depthwise convolution, gated attention and spatial attention to enhance the network's classification and boundary delineation accuracy. Experimental results show that MEDIA-Net outperforms general methods regarding mIoU and Dice score, producing fewer misclassifications and s harper boundaries. The proposed method offers a promising solution for carotid artery segmentation in DSA imaging. It highlights the importance of densely combining multi-scale feature extraction and depthwise attention in general medical image segmentation.

Sixteen years progress in recanalization of chronic carotid artery occlusion: A comprehensive review.

Although chronic carotid artery occlusion seems to be associated with significant risk of ischemic stroke, revascularization techniques are neither well established nor widespread. In contrast, extracranial-intracranial bypass is common despite the lack of evidence regarding neurological improvement or prevention of ischemic events. The aim of current review is to evaluate the effectiveness of various methods of recanalization of chronic carotid artery occlusion. Comprehensive literature search through PubMed, Scopus, Cochrane and Web of Science databases performed. Various parameters were assessed among patients underwent surgical, endovascular and hybrid recanalization for chronic carotid artery occlusion. 40 publications from 2005 to 2021 with total of more than 1300 cases of revascularization of chronic carotid artery occlusion have been reviewed. Further parameters were assessed among patients underwent surgical, endovascular and hybrid recanalization for chronic carotid artery occlusion: mean age, male to female ratio, mean duration of occlusion before treatment, rate of successful recanalization, frequency of restenosis and reocclusion, prevalence of ischemic stroke postoperatively, neurological or other symptoms improvement and complications. Based on proposed through reviewed literature indications for revascularization and predictive factors of various recanalizing procedures, an algorithm for clinical decision making have been formulated. Although treatment of chronic carotid artery occlusion remains challenging, current literature suggests revascularization as single option for verified neurological improvement and prevention of ischemic events. Surgical and endovascular procedures should be taken into account when treating patients with symptomatic chronic carotid artery occlusion.

Symptomatic and Asymptomatic Chronic Carotid Artery Occlusion on High-Resolution MR Vessel Wall Imaging.

Chronic carotid artery occlusion remains a poorly understood risk factor for subsequent stroke, and potential revascularization is dependent on understanding the anatomy and nature of the occlusion. Luminal imaging cannot assess the nature of an occlusion, so the internal structure of the occlusion must be inferred. The present study examines the signal characteristics of symptomatic and asymptomatic carotid occlusion that may point to management differentiation. We prospectively recruited patients who were diagnosed with chronic carotid artery occlusion defined as longer than 4 weeks and confirmed by DSA. All patients underwent high-resolution MR vessel wall imaging examinations after enrollment. Baseline characteristics, vessel wall imaging features, and DSA features were collected and evaluated. The vessel wall imaging features included segment involvement, signal intensity, contrast enhancement, and vessel wall thickness. The symptomatic and asymptomatic chronic carotid artery occlusions were compared. A total of 44 patients with 48 lesions were included in this study from February 2020 to December 2020. Of the 48 lesions, 35 (72.9%) were symptomatic and 13 (27.1%) were asymptomatic. There was no difference in baseline and DSA features. On vessel wall imaging, C1 and C2 were the most commonly involved segments (91.7% and 68.8%, respectively). Compared with symptomatic lesions, asymptomatic lesions were more often isointense (69.2%) in the distal segment (P = .03). Both groups had diffuse wall thickening (80% and 100%). Signal characteristics between those with symptomatic and asymptomatic carotid artery occlusions differ in a statistically significant fashion, indicating a different structure of the occlusion.

Combined Endovascular and Surgical Treatment of Chronic Carotid Artery Occlusion: Hybrid Operation.

Objectives The optimal treatment choice of chronic carotid artery occlusion (CAO) remains inconclusive. This study was aimed at exploring the safety and effectiveness of hybrid surgery in the treatment of CAO and at determining predictors for successful recanalization. Methods In this study, we enrolled 37 patients with CAO who underwent hybrid surgical treatment during the period 2016–2018. We extracted and analyzed patients' demographic data, disease characteristics, surgical success rates, perioperative complications, and prognosis. Results A total of 37 patients with symptomatic CAO underwent hybrid surgical treatment. Thirty cases (81.1%) were successfully recanalized, while seven were not. Blood reflux after carotid endarterectomy occurred in 18 patients (60%) of the success group and 1 (14.3%) of the failure group (OR, 9.0; 95% CI, 0.95-54.5; P = 0.042). The rate of distal ICA reconstruction below the clinoid segment was 20 (66.7%) in the success group and 1 (14.3%) in the failure group (OR, 12.0; 95% CI, 1.3-113.7; P = 0.029). In patients with successful recanalization, no ischemic events occurred after surgery and during follow-up, but restenosis of >50% was found in one case. In the failure group, two patients experienced recurrent ischemic events during follow-up. Perfusion imaging in successful recanalization cases is significantly improved, preoperative I/C ratio was 1.44 (IQR 1.27-1.55), and postoperative 1.12 (IQR 1.05-1.23). National Institutes of Health Stroke Scale (NIHSS) score of successful recanalization cases was 5.35 (2.26) before surgery and 2.03 (1.40) at 6 months (P < 0.01). Conclusion Hybrid surgery might be a safe and effective way to treat CAO. Distal internal carotid artery reconstruction to below the clinoid segment and blood reflux after carotid endarterectomy are predictors of successful recanalization.

Evaluation of chronic carotid artery occlusion by non-contrast 3D-MERGE MR vessel wall imaging: comparison with 3D-TOF-MRA, contrast-enhanced MRA, and DSA.

To analyze the accuracy of a non-contrast MR vessel wall imaging technique, three-dimensional motion-sensitized driven equilibrium prepared rapid gradient echo (3D-MERGE) for diagnosing chronic carotid artery occlusion (CCAO) characteristics compared with 3D time-of-flight (TOF) MRA, and contrast-enhanced MRA (CE-MRA), using digital subtraction angiography (DSA) as a reference standard. Subjects diagnosed with possible CCAO by ultrasound were retrospectively analyzed. Patients underwent 3.0-T MR imaging with 3D-MERGE, 3D-TOF-MRA, and CE-MRA followed by DSA within 1 week. Diagnostic accuracy of occlusion, occlusion site, and proximal stump condition were assessed independently on 3 MRI sequences and DSA. Agreement of the above indicators was evaluated in reference to DSA. One hundred twenty-four patients with 129 suspected CCAO (5 with bilateral occlusions) met the inclusion criteria for our study. 3D-MERGE demonstrated a sensitivity, specificity, and accuracy of 97.0%, 86.7%, and 94.6%, respectively, with excellent agreement (Cohen's κ = 0.85; 95% CI, 0.71, 0.94) for diagnosing CCAO in reference to DSA. 3D-MERGE was superior in diagnosing CCAO compared with 3D-TOF-MRA (Cohen's κ = 0.61; 95% CI, 0.42, 0.77) and similar to CE-MRA (Cohen's κ = 0.93; 95% CI, 0.86, 1.00). 3D-MERGE also had excellent agreement compared with DSA for assessing occlusion sites (Cohen's κ = 0.85; 95% CI, 0.71, 0.97) and stump condition (Cohen's κ = 0.83; 95% CI, 0.71, 0.94). Moreover, 3D-MERGE provided additional information regarding the occluded segment, such as distal lumen collapse and vessel wall lesion components. 3D-MERGE can reliably assess chronic carotid occlusive characteristics and has the ability to identify other vessel wall features of the occluded segment. This non-contrast MR vessel wall imaging technique is promising for assessment of CCAO. • Excellent agreement was found between 3D-MERGE and DSA for assessing chronic carotid artery occlusion, occlusion site, and proximal stump condition. • 3D-MERGE was shown to be a more accurate and efficient tool than 3D-TOF-MRA to detect the characteristics of the occluded segment. • 3D-MERGE provides not only luminal images for characterizing the proximal characteristics of occlusion but also vessel wall images for assessing the distal lumen and morphology of occlusion segment, which might help clinicians to optimize the treatment strategy for patients with chronic carotid artery occlusion.

Long-term Outcomes After Endovascular Recanalization in Patients with Chronic Carotid Artery Occlusion

Successful carotid artery stenting may correct ipsilateral hemisphere hypoperfusion and improve neurocognitive function in patients with chronic internal carotid artery occlusion (ICAO). Its effect on long-term outcomes, however, has never been studied. From May 2004 to April 2015, endovascular recanalization for chronic ICAO was attempted in 118 consecutive patients (119 lesions; 98 men; 67 ± 10 years old) with either recurrent neurologic events or objectively impaired ipsilateral hemisphere perfusion. Technical success in recanalization was achieved in 70 lesions (59%, 70/119). 3-months cumulative any stroke or death rate was 5% (6/119; 4 in recanalized group, 2 in failure group), including 2 periprocedural ischemic stroke, 2 intracranial hemorrhage, and 2 subarachnoid hemorrhage. In recanalized patients without periprocedural complication, 1-year reocclusion rate was 15% (10/65). Up to 7 years after procedure, cumulative events of transient ischemic attack (TIA), or any stroke, or death were 17 in recanalized group, compared with 23 in failure group (hazard ratio 0.51, 95% confidence interval 0.27 to 0.97; p = 0.04). The difference became more significant after excluding patients with periprocedure events (hazard ratio 0.41, 95% confidence interval 0.20 to 0.84, p = 0.015). In conclusions, the technical success and periprocedural complication rates of endovascular recanalization for chronic ICAO were acceptable. The cumulative event rates of any stroke or death up to 7 years were more favorable in patients after successful recanalization, compared to those in patients after failed procedure.

Correction: Individual and temporal variability of the retina after chronic bilateral common carotid artery occlusion (BCCAO).

[This corrects the article DOI: 10.1371/journal.pone.0193961.].

Efficacy of endovascular treatment for high-risk patients with chronic carotid artery occlusion

Objective To investigate the safety and short-term effect of endovascular treatment for high-risk patients of chronic carotid artery occlusion. Methods We retrospectively analyzed the data of 12 patients with high-risk chronic carotid artery occlusion who were admitted to First Affiliated Hospital of Xinjiang Medical University from October 2014 to February 2016 and underwent endovascular treatment. National Institute of Health stroke scale(NIHSS)was used to evaluate patients'neuronal functions.Follow-up studies were conducted 1 week, 30 days and 6 months post operations to observe the adverse events. The follow-up time ranged from 4 to 17 months(mean, 13.6 months). Results 11 patients(11/12) achieved recanalization successfully.The degrees of preoperative and postoperative carotid stenosis in 12 patients was 100% and (22.5±8.9)%, respectively (P<0.05). At 1 week post operation, the adverse event of persistent hypotension occurred in 1 case. Among the 11 patients with successful endovascular treatment, the 6-month postoperative score (3.36±1.56) based on the NIHSS was significantly improved from preoperative level (2.59±1.37) (P<0.05). Conclusion Endovascular treatment suggests to be a safe and effective method for high-risk patients of chronic carotid artery occlusion in terms of short- and medium-term effects. Key words: Carotid arteries; Arterial occlusive diseases; Endovascular treatment; Treatment outcome

Predicting procedure successful rate and 1-year patency after endovascular recanalization for chronic carotid artery occlusion by CT angiography

BackgroundProper patient selection criteria for treatment of carotid chronic total occlusion (CTO) are unclear. This study was designed to predict procedure successful rate and 1-year patency after carotid artery stenting (CAS) for carotid CTO using pre-procedural CTA. MethodsPatients with CTO detected on CTA who underwent recanalization within 3months were divided into those with occlusions at (or distal to) the clinoid segment of the internal carotid artery (group A) and those with occlusions proximal to the clinoid segment (group B) and outcomes were compared between groups. ResultsTechnical success rates, major complications, and re-occlusions within 1-year were 52%, 22%, 91% in group A (N=23), and 89%, 0%, 0% in group B (N=19), respectively. Diabetes was more frequent in group A (43%) compared with group B (11%). ConclusionCTA may play a role in predicting successful rate and 1-year patency for endovascular recanalization in carotid CTO.

Carotid endarterectomy alone or combined with fogarty catheter embolectomy for chronic symptomatic occlusion of the internal carotid artery

Objective To investigate the therapeutic effect of carotidendarterectomy(CEA) alone or combined with Fogarty catheter embolectomy in the treatment of chronic symptomatic internal carotid artery occlusion. Methods From April 2008 to December 2013, 12 patients with transient ischemic attack (TIA) or minor stroke underwent digital subtraction angiograph to confirmation t of ICA occlusion. All patients underwent operative exploration with CEA or CEA plus Fogarty thrombectomy. Patients who failed revascularization underwent external CEA and ICA ligation. All clinical and radiological data were retrospectively reviewed. Results CEA in 7 patients and CEA plus Fogarty thrombectomy in 3 patients were performed successfully to restore blood flow of internal carotid artery. External CEA and internal carotid artery ligation were performed in 2 patients. Postoperative CT angiography or DSA imaging demonstrated patency of the internal carotid artery in 10 patients. The ischemic symptoms were relieved in most of the patients. Postoperatively, 3 patients suffered from hyperperfusion syndrome, but there were no perioperative stroke or death.The duration of follow-up was 15-66 months. No patient developed a new stroke. No re-occlusion but one mild re-stenosis(40%) was detected. 2 patients suffered from TIA occasionally.One of the two patients failed in recanalization relieved from the symptom, the another still suffered from TIA. Conclusions Carotid endarterectomy alone or combined with Fogarty catheter embolectomy to treat chronic symptomatic internal carotid artery occlusion is feasible and safe, but preoperative evaluation and selection of patient should be carefully. Key words: Carotid artery, internal; Arterial occlusive diseases; Endarterectomy, carotid; Embolectomy; Fogarty catheter

Neurocognitive Improvement After Carotid Artery Stenting in Patients With Chronic Internal Carotid Artery Occlusion

Symptomatic internal carotid artery (ICA) occlusion with hemodynamic impairment remains a dismal disease when untreated. In this prospective, single-center, controlled study, we investigated the feasibility, safety, and long-term outcome of stenting by endovascular recanalization for patients with chronic ICA occlusion. Forty patients with symptomatic chronically occluded ICA were assigned to receive endovascular recanalization (group A, n = 18) or conservative management (group B, n = 22). The primary end point was 100% complete recanalization of the primary occlusion at 60 minutes, and secondary end points were improvement in neurologic function and cognitive function. Patients in the 2 groups were comparable in demographic and baseline characteristics. Successful recanalization was achieved in 88.9% (16 of 18) of patients with the restoration of Thrombolysis in Myocardial Ischemia/Thrombolysis in Cerebral Ischemia 2 or 3 flow. There was no procedural or new cerebral ischemic event. Improvement in brain perfusion was observed in 12 (12 of 18, 75%) patients on single-photon emission computed tomography. Improvement in neurologic function defined as a reduction of ≥4 points on the National Institutes of Health Stroke Scale (NIHSS) at 6 months was observed in group A (baseline, 6.83 ± 3.01 vs 6 months, 2.61 ± 1.20; P < .01) and group B (baseline, 6.05 ± 2.75 vs 6 months, 4.77 ± 1.69; P < .05). A significant difference in NIHSS scores was noted between group A and B at 1, 3, and 6 months (P < .05 or .001). Improvement in cognitive function defined as an increase of ≥8 on the Montreal Cognitive Assessment (MoCA) was observed in group A at 3 and 6 months (baseline, 14.67 ± 3.56 vs 3 months, 24.17 ± 3.55 and 6 months, 24.72 ± 2.85; P < .01). Significant improvement in MoCA was also observed in group B (P < .01). Furthermore, a significant difference in MoCA scores was noted between group A and B at 1, 3, and 6 months (P < .05 or .001). Endovascular recanalization is feasible and safe for patients with symptomatic chronic carotid artery occlusion. Successful carotid artery stenting can improve neurological function and global cognitive function than nonrevascularization.

Establishment and assessment of modified cerebral palsy model in rats

Objective To construct a novel type of cerebral palsy model in rats with intraperitoneal injection of lipopolysaccharide(LPS) and sequential oxygen deficit from pregnancy 16th day to the end of pregnancy and chronic bilateral common carotid artery occlusion on the 28th day.Assessing by weight, behaviour, modified neurological severity score, and pathological changes and to explain the superiority of our model. Methods Twelve SD pregnant rats were randomly selected as the experimental group, 3 SD pregnant rats were selected as the control group.From 16 days of pregnant, the pregnant rats were injected with LPS by intraperitoneal injection.and received oxygen deficit in the experimental group, and the pregnant rats were received saline solution in the control group until delivery.On the postnatal 7th day, bilateral common carotid arteries were ligated in the experimental group.The weight, eye-opening time, grip test, rotarod test and pathological section of the brain of newborn rats in the both groups were detected. Results In the experimental group and the control group, the weight were (5.6±0.9)g and (6.2±0.8) g, the left eyes open day were (16.9±2.0) d and (13.0±2.0) d, the right eyes were (23.1±2.6) d and (13.7±1.7) d, respectively, there were significant differences between the both groups (all P<0.05). In the experimental group and the control group, the score in grip test were (2.7±0.8) scores and (1.5±0.4) scores and MNSS were (4.9±2.5) scores and (1.2±1.0) scores, there were significant differences (all P<0.01). Neurons arrange in disorder, the white matter is thinner and inflammatory cells infiltrated in the experimental group pups.However in control group, brain tissue patho-logy slices showed neurons in neat rows, the gray and write matters boundaries were clear, and the corpus callosum was mature. Conclusions In late pregnancy intraperitoneal injection LPS and hypoxia with postnatal bilateral common carotid artery ligation can build a stable lasting rat cerebral palsy model. Key words: Brain damage; Infection; Cerebral palsy; Hypoxia-ischemia; Behavior

Response to Letter Regarding Article “Neurocognitive Improvement After Carotid Artery Stenting in Patients With Chronic Internal Carotid Artery Occlusion and Cerebral Ischemia”

Response: We appreciate the interest of Dr Sposato and his colleagues1 in our recent publication regarding neurocognitive function improvement after endovascular recanalization in patients with chronic carotid artery occlusion and ipsilateral hemisphere ischemia.2 The authors call attention to some methodological points in our study and are concerned about the interpretation of the result. First of all, they considered that group analysis may not reflect actual changes of individual patients. We therefore did event rate analysis according to their suggestion and still found a trend of a higher proportion of improvement in the successful group on 3 cognitive tests (Alzheimer Disease Assessment Scale–Cognitive Subtest: 8 of 12 [66.7%] versus …

Direct Endovascular Recanalization of Chronic Carotid Occlusion: Should We Do It? Case Report

Patients with chronic carotid artery occlusion face a significant risk of stroke. It is believed that treatment is indicated if medical therapy fails or even as prophylaxis in high-risk patients. Direct surgical repair with carotid endarterectomy has a considerable failure rate and significant associated risks. Indirect repair with an extracranial-to-intracranial bypass has become the mainstay of surgical treatment. In this case study, the authors assess the feasibility of direct endovascular recanalization in the setting of chronic carotid occlusion, and discuss technical nuances and indications in comparison with the world literature and alternative options. Two patients presented with symptomatic, chronic, complete occlusion of the proximal carotid artery. The duration of documented occlusion exceeded 3 years in one patient and 6 months in the other. Endovascular recanalization was attempted using extracranial and intracranial stenting with proximal protection (flow arrest/reversal). Both patients had an excellent radiographic result, improving from Thrombolysis in Cerebral Infarction (TICI) grade 0 (no perfusion) to grade 3 (complete perfusion). The first patient's clinical symptoms resolved. The second patient remained unchanged with a mild facial droop. These preliminary results show potential for the endovascular management of this complicated disease. Long-term results and more data will determine the ultimate place of endovascular recanalization for symptomatic chronic carotid occlusion among other therapies.

Carotid Stenting for Chronic Total Occlusion of the Internal Carotid Artery

In 1954, Eastcott et al1 opened the era of the surgical treatment of carotid atherosclerosis. In the ensuing 54 years, much has been learned about the benefits of carotid endarterectomy (CEA) for the treatment of symptomatic and asymptomatic carotid artery stenosis. Recently, carotid artery stenting has gained acceptance as a reasonable alternative to CEA for patients who are deemed at high risk for complications from surgery.2 Despite all of the advancements in the techniques of carotid artery revascularization, little progress has been made in the treatment of chronic total occlusion. Article see p 119 Through extensive personal experience, the early leaders of vascular surgery defined the parameters for carotid surgery. In 1965, De Bakey3 first highlighted the challenges associated with the treatment of internal carotid artery occlusion when he pointed out that “because of intracranial extension of the thrombotic process and its organization, the incidence of restoration of circulation for complete occlusion at (the internal carotid artery) declined sharply after 24 hours.” In 1970, Thompson et al4 published a landmark series of 592 patients undergoing CEA that included 118 totally occluded internal carotid arteries. In this subgroup, flow was restored in only 41%, with …

Arterial Chemoreceptors and Sympathetic Nerve Activity

Chronic elevation in sympathetic nerve activity (SNA) is associated with the development and maintenance of certain types of hypertension1 and contributes to the progression of chronic heart failure (CHF).2 The mechanisms involved in sympathetic dysfunction in these disorders appear to be complex and multifactorial. A unified hypothesis is likely to encompass alterations in multiple autonomic reflex pathways, central integratory sites, and chemical mediators that control sympathetic outflow. For example, tonic restraint of sympathetic outflow by arterial and cardiopulmonary baroreflexes is depressed in CHF2 and depressed or reset in hypertension.3 Moreover, maladaptive changes also occur in the central nervous system at integrative sites for autonomic control in both disease processes.4,5 It is also clear that sympathoexcitatory cardiac,6 somatic,7 and central/peripheral chemoreceptor reflexes8 are enhanced in CHF and hypertension. Arterial chemoreceptors serve an important regulatory role in the control of alveolar ventilation, but they also exert a powerful influence on cardiovascular function.9 Activation of arterial chemoreceptors by hypoxemia increases sympathetic outflow to systemic vascular beds to compensate for the direct vasodilating effects of hypoxia on these vessels and to redistribute blood flow to essential organs. In this review, we highlight relevant information that implicates the arterial chemoreflex as a contributory mechanism for the sympathetic hyperactivity in CHF and hypertension and illustrate proposed mechanisms for this altered function. Arterial chemoreceptors located in the aortic and carotid bodies (CBs) respond to hypoxemia and hypercapnia. Because central chemoreceptors also respond to hypercapnia, hypoxia is typically used as a specific stimulus to arterial chemoreceptors. In some mammals, such as rats and rabbits, reflex responses to hypoxemia arise solely from the CB, whereas in other species, the aortic chemoreceptor contribution can be significant. However, it is not possible to experimentally separate the relative contribution of the aortic and …

Carotid angioplasty with stenting for chronic internal carotid artery occlusion: technical note

Carotid angioplasty with stenting (CAS) is becoming accepted as an effective and reliable treatment option for severe carotid artery stenosis. However, it is rarely applied for carotid occlusion, especially in its chronic stage. We report our experience of CAS for chronic internal carotid artery occlusion representing compromised cerebral blood flow using various protection methods. A 77-year-old woman, who was already diagnosed with severe left internal carotid artery stenosis, suddenly had right hemiparesis and aphasia. At that time, she was treated conservatively because her neurological status was quite good, in spite of left carotid artery occlusion. Her symptoms improved in the short term, except slight aphasia, but deteriorated again 18 days from the onset, and magnetic resonance imaging (MRI) showed new ischemic lesions. CAS was then performed for the occluded carotid artery on the 23rd day from the first onset. Using the proximal protection technique, the occluded lesion was crossed carefully with a microguidewire. Stents were also placed successfully with the distal protection technique. The occluded carotid artery was completely recanalized without any unfavorable events or neurological deterioration. In this patient, CAS was successfully to treat chronic carotid artery occlusion. These procedures and techniques are reviewed and discussed.