Treatment Strategies for Acute Ischemic Stroke Caused by Carotid Artery Occlusion

Neuroendocrine tumours (NETs) are uncommon tumours which have a diverse biology. The aims of this thesis were to identify potential new biomarkers and further develop understanding of tumour biology in NETs. The following were assessed i) somatostatin receptor (SSTR) and dopamine-2 receptor (D2R) expression in NETs, ii)HER expression and their associated prognosis, iii) Angiopoietin expression in NETs and their prognostic significance, iv) proteomic analysis of serum and NET cell lines to identify novel markers and finally v) the role of 68Ga-DOTATATE PET in imaging of NETs.
\nImmunohistochemical studies were performed to determine whether SSTR and D2R are co-expressed in NETs. D2R was co-expressed with SSTR-2 and -5 in 93% of low grade tumours, with lower co-expression in higher grade tumours.
\nHER family of receptors are involved in oncogenesis; the expressions of these receptors were assessed. Immunohistochemical analysis of these receptors was performed in 82 cases. EGFR was expressed in 86%, HER-2 0%, HER-3 8.5% and HER-4 91.5%. The expression of EGFR was not associated with poor prognosis.
\nAngiopoietins (Ang) are involved in tumourogenesis. Serum Ang-1 and Ang-2 were measured in patients and healthy controls. Ang-2 was significantly higher in patients compared to controls. Patients with Ang-2 levels >4756pg/ml had a shorter time to progression.
\nProteomic analysis using gel electrophoresis and LC/MS/MS of plasma from NET patients and established NET cell lines was performed to identify biomarkers. Proteomic cell line analysis identified 17 proteins in all cell lines including Mac-2 binding protein. We validated Mac-2 binding protein and it appears to be a potential marker for NETs.
\nFinally, we performed a study to ascertain whether 68Ga-DOTATATE PET identifies more lesions in NET patients in whom 111In-DTPA-Octreotide showed faint/negative lesion uptake. 111In-DTPA-Octreotide scintigraphy identified 27 lesions compared to 168 lesions identified with Ga-68-DOTATATE PET. 68Ga-DOTATATE PET is a sensitive imaging modality for identifying NETs.

IntroductionAcute ischemic stroke (AIS) due to internal carotid artery (ICA) occlusion has a poor prognosis if treated by intravenous thrombolysis. Intra-arterial (IA) treatment is a promising alternative. However, its effectiveness...

Between March 1996 and December 1997, 15 consecutive patients with carotid artery occlusion diagnosed with duplex sonography were treated with intravenous recombinant tissue plasminogen activator (rt-PA), following a protocol similar to that of the National Institute of Neurological Disorders and Stroke (NINDS) study. On the basis of ultrasound findings, six of the 15 patients had internal carotid artery dissection (ICD), and the remaining nine had atherothrombotic internal carotid artery (ICA) occlusion. No relevant haemorrhagic complications were observed after rt-PA treatment of ICA occlusion. Excellent late functional outcome was observed in three of the 15 patients with ICA occlusion, moderate and poor outcome in four patients. Four patients died, and mortality was related to stroke severity upon admission. A good outcome seemed to be more likely in the small group of patients with ICD, than in the patients suffering atherothrombotic ICA occlusion. As the results of rt-PA treatment in this case series are by no means devastating, our data do not corroborate the hypothesis that patients with acute ischemic stroke following ICA occlusion should a priori be excluded from intravenous thrombolysis. The possible benefit of rt-PA treatment in stroke following acute or chronic ICA occlusion should be assessed in a larger prospective trial, for which this case series might serve as a pilot study.

Prompt endovascular thrombectomy is crucial for patients with acute ischemic stroke due to internal carotid artery (ICA) occlusion. However, distinguishing acute from chronic carotid disease can be challenging. This study investigates the utility of initial CT angiography (CTA) findings in differentiating acute and chronic ICA disease among acute cerebral infarction patients with ICA occlusion. We conducted a retrospective analysis of CTA data from acute stroke patients with apparent ICA occlusion at a single stroke center. Patients were categorized into acute and chronic groups based on clinical information, mechanical thrombectomy outcomes, and infarct patterns. We compared CTA findings between the groups, focusing on occlusion site and carotid atherosclerosis burden. Between January 2016 and June 2021, 42 patients were included in the study (28 acute; 14 chronic). The acute group had a significantly higher proportion of tapering patterned proximal occlusion compared to the chronic group. Patients with chronic ICA disease were more likely to have stump patterned proximal occlusion and advanced atherosclerotic burden in the contralateral proximal ICA. The carotid occlusion imaging score, comprising occlusion pattern and atherosclerosis burden, demonstrated good performance in discriminating chronic carotid disease from acute carotid occlusion (area under the receiver operating curve = 0.94, 95% confidence interval = 0.87–1.00, p < 0.001). The occlusion shape of the ipsilateral ICA and the atherosclerotic burden of the contralateral ICA can aid in differentiating chronic carotid disease from acute ICA occlusion among acute stroke patients with ICA occlusion.

Purpose. In chronic internal carotid artery (ICA) occlusion, cere bral hemodynamics are likely to be stable due to collateral flow. The authors evaluated cerebral hemodynamics in ICA occlusion using the sonographic method of cerebral blood flow volume (CBVF) measurement to find differences that might identify patients with large hemispheric stroke in ICA occlusion.Methodand Results. The ultrasound method of CBVF measurement was used, which represents the sum of flow volumes of both internal carotid and both vertebal arteries. CBVF was measured in 29 patients with ICA occlusion including patients with (1) chronic ICA occlusion without acute minor stroke, (2) chronic ICA occlusion with acute minor stroke, (3) acute minor stroke due to acute ICA occlusion, and (4) ICA occlusion and large hemispheric stroke. In ICA occlusion, overall CBVF is lower compared to healthy volunteers, due to a significant reduction of CBVF in groups 3 and 4. Comparing groups, there were no differences in CBVF between groups 1, 2, and 3. CBVF in group 4 is reduced compared to all other groups. By receiver‐operating characteristic analysis, a CBVF cutoff value for large hemi spheric stroke was computed with a sensitivity of 100% and a specificity of 95.8%.Conclusion. Stroke due to acute ICA occlusion is associated with decreased CBVF compared to chronic ICA occlusion. Moreover, ICA occlusion and large hemispheric stroke are associated with decreased CBVF compared to all other groups, indicating instability of cerebral hemodynamics. CBVF measurement thus may be a useful tool in predicting large middle cerebral artery stroke early in ICA occlusion.

In chronic internal carotid artery (ICA) occlusion, cerebral hemodynamics are likely to be stable due to collateral flow. The authors evaluated cerebral hemodynamics in ICA occlusion using the sonographic method of cerebral blood flow volume (CBVF) measurement to find differences that might identify patients with large hemispheric stroke in ICA occlusion. The ultrasound method of CBVF measurement was used, which represents the sum of flow volumes of both internal carotid and both vertebal arteries. CBVF was measured in 29 patients with ICA occlusion including patients with (1) chronic ICA occlusion without acute minor stroke, (2) chronic ICA occlusion with acute minor stroke, (3) acute minor stroke due to acute ICA occlusion, and (4) ICA occlusion and large hemispheric stroke. In ICA occlusion, overall CBVF is lower compared to healthy volunteers, due to a significant reduction of CBVF in groups 3 and 4. Comparing groups, there were no differences in CBVF between groups 1, 2, and 3. CBVF in group 4 is reduced compared to all other groups. By receiver-operating characteristic analysis, a CBVF cutoff value for large hemispheric stroke was computed with a sensitivity of 100% and a specificity of 95.8%. Stroke due to acute ICA occlusion is associated with decreased CBVF compared to chronic ICA occlusion. Moreover, ICA occlusion and large hemispheric stroke are associated with decreased CBVF compared to all other groups, indicating instability of cerebral hemodynamics. CBVF measurement thus may be a useful tool in predicting large middle cerebral artery stroke early in ICA occlusion.

Introduction: Internal carotid artery (ICA) occlusion may cause an acute stroke or may remain asymptomatic for years. Differences in the perfusion characteristics between patients with acute symptomatic ICA occlusions and those with chronic ICA occlusions have not been defined. The aim of this study is to identify the characteristics of the relatively “benign” perfusion pattern associated with chronic asymptomatic ICA occlusions and to determine if this pattern can be differentiated from the pattern observed in acutely symptomatic cases. Methods: We included 31 chronic ICA patients who had no history of a cerebral ischemic event for at least 1 year at the time of imaging and 20 patients with acute ischemic stroke caused by ICA occlusions from DEFUSE 2. All patients underwent MRI with perfusion. Perfusion parameters, including Tmax lesion volumes, hypoperfusion index (Tmax10/Tmax6), and CBV index (rCBV in Tmax6) were calculated by RAPID software. The status of the CBV, CBF, and MTT in the ischemic hemisphere was also rated by visual inspection on a 3-point scale (unchanged, reduced or increased). Differences were assessed by Mann-Whitney and Fisher’s exact tests. Results: The average age was 65.0±9.9 years in chronic vs. 64.7±14.2 years in acute ICA occlusion group ( p =0.90). Most of the chronic ICA patients had no territory with Tmax&gt;10s (29/31) or Tmax&gt;8s (24/31) in the ischemic hemisphere. The average Tmax lesion volumes were lower in the chronic ICA group (Tmax&gt;6 of 14 ml and Tmax&gt;4 of 81 ml) than in the acute ICA occlusion group (Tmax&gt;6 of 131 ml and Tmax&gt;4 of 220 ml, p &lt;0.0001 for both, Figure). CBV was unchanged in all chronic occlusion cases. In the acute occlusion group, there were 12 out of 20 cases (60%) with decreased CBV ( p &lt;0.0001). CBF was decreased in 1 (3%) patient with a chronic occlusion and 17 cases (85%) with acute occlusions ( p &lt;0.0001). MTT prolonged in 7 cases (22%) with chronic occlusions vs. all cases (100%) with acute occlusions ( p &lt;0.0001). Conclusions: Several features on perfusion MRI distinguish chronic ICA occlusions from acute occlusions. Patients with chronic ICA occlusions tend to have none or a minimal volume of tissue with Tmax&gt;8s or &gt;10s delay, smaller volumes of tissue with Tmax&gt;4s and &gt;6s delay, and normal appearing CBV and CBF maps.

Background and PurposeStrokes secondary to acute internal carotid artery (ICA) occlusion are associated with extremely poor prognosis. Best treatment approach to acute stroke in this setting is unknown. We sought...

Surgical treatment of internal carotid artery occlusion

Chronic total occlusion and spontaneous recanalization of the internal carotid artery: Natural history and management strategy.

Association between Carotid Artery Occlusion and Ultrasonographic Plaque Type

HighlightsWe have analyzed the parameters of cerebral hemodynamics and left ventricular functional capacity in patients with occlusion and stenosis of the contralateral internal carotid artery during vascular surgery. Considering the importance of the left ventricular functional capacity and treatment options to ensure the stability of cerebral circulation in patients with occlusion and hemodynamically significant stenosis of the contralateral carotid artery, its detailed study at all stages of vascular surgery remains necessary. AbstractAim. To study cerebral hemodynamics and left ventricular functional capacity in patients with occlusion and stenosis of the contralateral internal carotid artery (ICA) to optimize treatment at the preoperative phase.Methods. The study compared the hemodynamic parameters of the blood flow of the ICA, vertebral arteries and left ventricular functional capacity in patients with ICA occlusion and contralateral ICA stenosis, which formed the 1 group (12 patients), and patients with unilateral hemodynamically significant stenosis, which formed the 2 group (52 patients). The blood flow in the extracranial portions of the major arteries of the head and heart was assessed using ultrasound, and the arterial vascular system and brain structure was assessed using MRI and MRA.Results. Before surgery, statistically significant differences in velocity parameters in the vertebral arteries on the occlusion side were found; on the contralateral occlusion side, velocity parameters in ICA were significantly different from the corresponding indicators in the group with unilateral stenosis; after surgery, statistically significant differences were found in the common carotid and vertebral arteries on the occlusion side; on the contralateral occlusion side, differences in velocity parameters in the common carotid, internal, and vertebral arteries were revealed in comparison with the group with unilateral stenosis. Of the indicators of the left ventricular functional capacity, only left ventricular ejection fraction differed significantly when comparing the group of patients with occlusion and stenosis of ICA and the group of patients with unilateral stenosis. Moreover, when evaluating pre- and postoperative outcomes in the group of patients with occlusion, significant differences were obtained only regarding the vertebral artery on the side of occlusion – the peak systolic blood flow velocity and the volumetric blood flow velocity significantly decreased. There were no significant differences between the common carotid, internal carotid arteries on the contralateral occlusion side, and middle cerebral arteries.Conclusion. Carrying out a comprehensive ultrasound examination of the main arteries of the head in combination with magnetic resonance imaging of the brain is a reliable and adequate way to assess cerebral hemodynamics, changes in the vascular bed and structure of the brain. Given the extreme importance of the left ventricular functional capacity to ensure the stability of cerebral circulation in patients with occlusion of the internal carotid artery and contralateral hemodynamically significant stenosis, its detailed study before carotid endarterectomy is necessary to adjust therapeutic measures.

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 …

Concerning endovascular treatment for acute ischemic stroke with intracranial vessel occlusion, shortening the door-to-puncture time (DTP) improves the patient's outcome. To determine endovascular treatment, magnetic resonance angiography or computed tomography angiography is performed for occluded vessel detection. Another detection method of internal carotid artery (ICA) occlusion or middle cerebral artery first segment (M1) occlusion is ultrasound (US). Bilateral flow pattern analysis of common carotid arteries by US leads to the diagnosis of ICA or M1 occlusion within a few minutes. Moreover, it can be conducted in the emergency department. The addition of the US for the initial evaluation of vessel occlusion can shorten the DTP. In this study, we evaluated the effectiveness of carotid artery US imaging in detecting large vessel occlusion (LVO) and shortening the DTP. This is a retrospective case-control study. Our analysis was based on the data from 150 patients with LVO or medium vessel occlusion who underwent endovascular revascularization treatment at our hospital between January 2015 and December 2022. Among them, 104 patients who had an anterior circulation vessel occlusion were included. They were divided into the US evaluation group and the non-US evaluation group, and their characteristics, treatment time course, and outcomes were compared. This study included 104 patients with a median age of 81 years (interquartile range: 73-89 years), 57.7% were females, and the pre-stroke modified Rankin Scale (mRS) median was 0.5 (interquartile range: 0-3). Our cohort included advanced aged patients; therefore, this study included 56.7% of patients over 80 years old and 35.6% of pre-stroke mRS over 3. The US (US group) and non-US (non-US group) evaluation groups included 54 and 50 patients, respectively. As magnetic resonance imaging evaluation in the non-US group was performed over the 4.5 hours delayed arrival of patients from the last known well (LKW) to consider the evaluation of tPA administration, selection bias occurred. The US group included high National Institutes of Health Stroke Scale (NIHSS) patients (P = 0.0152) and more ICA occlusions (P = 0.0146). Onset (LKW) to door time was shorter in the US group (median, 75 min (35-146.5 minutes)) than the non-US group (median, 179 minutes (47.3-432.8 minutes); P = 0.0426), and the DTP was shorter for the US group (median, 75.5 minutes (63.8-87.3 minutes)) than for the non-US group (median, 85 minutes (67-129 minutes); P = 0.0102). Statistical difference was not seen in puncture to reperfusion time among the US group (median, 71.5 minutes (51-114 minutes)) and non-US group (median, 67 minutes (42.3-98.5 minutes); P = 0.5581). The onset (LKW) to reperfusion was shorter for the US group (median, 251 minutes (201-327.3 minutes)) than for the non-US group (median, 319 minutes (200-633.5 minutes); P = 0.0348). No statistical differences were seen for thrombolysis in cerebral infarction grade 2b-3 after treatment, improvement of NIHSS, and mRS at 90 days. US is a useful imaging method to identify an anterior circulation LVO. It can distinguish patients with severe internal carotid or middle cerebral artery occlusion from medium vessel occlusion or other peripheral vessel occlusions. US helps to shorten the DTP time of LVO.

"True" posterior communicating artery (PCoA) aneurysms are extremely rare. A case of a 63-year-old patient with a ruptured "true" aneurysm of the right PCoA associated with the occlusion of the right internal carotid artery is presented. For nine years before he suffered from subarachnoid hemorrhage, the patient had developed symptoms of transient ischemic attack (TIA) due to the occlusion of the right internal carotid artery. The left vertebral angiogram demonstrated a "true" right PCoA aneurysm and collateral flow from the right posterior communicating artery to the right internal carotid artery. The right internal carotid system was also fed by collateral circulation from the left carotid artery through the anterior communicating artery. Transcranial colour-coded real-time sonography (TCCS) demonstrated increased velocity and turbulent blood flow in both communicating arteries. The patient was operated on and the aneurysm was clipped successfully. This case report suggests that the blood flow disturbances resulting from the collateral circulation through the PCoA could be a conductive factor in the formation and development of the aneurysm. This is the first described case of a "true" aneurysm of the PCoA coexistent with the occlusion of the internal carotid artery.