Distal Internal Carotid Artery Research Articles

Surgical Repair of Complex Distal Internal Common Carotid Artery Aneurysm

<h3>Introduction</h3> Carotid artery aneurysms are a rare occurrence with potentially severe complications including neurological symptoms from embolization and rarely rupture. They comprise between 0.4%-4% of all peripheral aneurysms and are between 0.1%-3.7% of carotid procedures at major centers. The following is a discussion of one such procedure for a complex right common carotid with distal extension into the internal carotid artery. <h3>Methods/Results</h3> Patient was a 64-year-old male with incidental finding of right common and internal carotid artery aneurysm and occlusion of the contralateral side seen on Computer Tomography scan. Based on the patient's age and anatomy the decision was made to proceed with an open repair of the aneurysm. Due to the distal location of the internal catrotid aneurysm adequate exposure was achieved using general nasotracheal anesthesia and ligation of the occipital artery. The oral maxillofacial surgeon was on standby for possible mandible dissection; however, this was unnecessary. The reconstruction was performed using reversed femoral vein. An Argyle shunt was used to bypass the aneurysm to maintain blood flow through the internal carotid artery. An ulcerated region of the aneurysm was resected and the distal and proximal anastomosises were created. The external carotid artery was then ligated and a carotid duplex ultrasound performed intraoperatively revealed satisfactory endpoints and no evidence of significant stenosis. Upon awakening the patient, a brief neurological exam showed no deficits.Figure 1CTA of AneurysmFigure 1Figure 23D Reconstruction of CTFigure 2Figure 3Intraoperative Image Prior to BypassFigure 3Figure 4Intraoperative Image After BypassFigure 4Figure 5Follow Up Ultrasound at 4 WeeksFigure 5 Intraoperative cerebral oximetry and neuromonitoring were used throughout the procedure. Immediately post-operation the patient had transient hypoparesis which had resolved at 4 week follow up. <h3>Conclusion</h3> Carotid artery aneurysms, although rare, have a mortality rate up to 70% and a stroke rate greater than 50%; therefore, surgical intervention is the treatment of choice, with open intervention being the most common. This case demonstrates that even with an occluded contralateral carotid artery and a complex aneurysm with distal extension, carotid bypass can be done safely using stents and adequate neuromonitoring.

Long-term results and comparison of flow re-direction endoluminal device and pipeline embolization device in endovascular treatment of intracranial carotid aneurysms.

This study aims to compare the efficacy, safety, and long-term outcomes of two flow diverters, i.e., pipeline embolization device and flow re-direction endoluminal device, in the treatment of distal carotid aneurysms. A total of 138 patients with 175 aneurysms were included from February 2012 to September 2019. Ninety-nine aneurysms were treated with flow re-direction endoluminal device and 76 with pipeline embolization device. Angiographic follow-ups were at the 6th, 12th, 24th, 36th, and 60th months; the O'Kelly-Marotta grading scale was used to assess aneurysms occlusion. Outcomes of two devices were compared; possible associations regarding patient characteristics, aneurysm properties, treatment details, and adverse events were evaluated. The mean follow-up period was 33 months, with 10 patients lost to follow-up. Occlusion rates at the 6th and 12th months and during the last follow-up were similar for flow re-direction endoluminal device (81%, 84%, and 90%) and pipeline embolization device (82%, 85%, and 93%). Occlusion rates were also similar after stand-alone use without coiling. There was no significant difference regarding adverse event rates with a 10.9% overall complication rate, 3.6% mortality, and 0.7% permanent morbidity. All the mortality and morbidity were related to hemorrhagic complications. Device deployment failure was observed with five flow re-direction endoluminal devices and two pipeline embolization devices, whereas two severe in-stent stenoses occurred with each device. Both flow re-direction endoluminal device and pipeline embolization device are feasible and effective in flow diversion of distal internal carotid artery aneurysms, with similar adverse events rates and aneurysm occlusion success. Aneurysm occlusion rates increase with time, while the presence of an integrated branch significantly decreases treatment success.

Nimodipine reduces delayed cerebral vasospasm after intracranial tumour surgery: A Retrospective Study.

Cerebral vasospasm (CVS) is a frequent and serious neurosurgical complication, without sufficient therapy. This retrospective study was performed to analyze if nimodipine can improve prognosis and reduce ischaemia secondary to delayed CVS after intracranial tumour surgery. A retrospective review was performed over the years 2011 to 2012 for patients with an anterior cranial fossa tumour and underwent intracranial tumour surgery. The surgical field was soaked with nimodipine solution or normal saline. Transcranial Doppler ultrasonography was used to measure velocity in the middle cerebral artery (MCA) and the distal extracranial internal carotid artery (eICA). Follow-up was performed using the Glasgow Outcome Scale (GOS) after discharge. There were 94 patients that met the inclusion criteria. They included 50males and 44 females, with a mean age of 49.6years. In the nimodipine group, CVS occurred in 13 patients; 9 patients had CVS between 4 and 7days, and 4had CVS between 8 and 14days. In the normal saline group, 19 patients had CVS, 3 presented with CVS within 3days, 11 between 4-7days and 5 between 8-14days. A significant difference in the occurrence of CVS was observed between the two groups. Preoperative and postoperative the MCA velocities were compared, revealing a significant change in the normal saline group but not in the nimodipine group. Nimodipine markedly improves prognosis and significantly reduces ischaemia secondary to delayed CVS after intracranial tumour surgery, as well as the risks of mortality and morbidity.

The mechanobiological theory: a unifying hypothesis on the pathogenesis of moyamoya disease based on a systematic review.

Moyamoya angiopathy (MMA) affects the distal internal carotid artery and is designated as moyamoya disease (MMD) when predisposing conditions are absent, or moyamoya syndrome (MMS) when it occurs secondary to other causes. The authors aimed to investigate the reason for this anatomical site predilection of MMA. There is compelling evidence to suggest that MMA is a phenomenon that occurs due to stereotyped mechanobiological processes. Literature regarding MMD and MMS was systematically reviewed to decipher a common pattern relating to the development of MMA. A systematic review was conducted to understand the pathogenesis of MMA in accordance with PRISMA guidelines. PubMed MEDLINE and Scopus were searched using "moyamoya" and "pathogenesis" as common keywords and specific keywords related to six identified key factors. Additionally, a literature search was performed for MMS using "moyamoya" and "pathogenesis" combined with reported associations. A progressive search of the literature was also performed using the keywords "matrix metalloprotease," "tissue inhibitor of matrix metalloprotease," "endothelial cell," "smooth muscle cell," "cytokines," "endothelin," and "transforming growth factor" to infer the missing links in molecular pathogenesis of MMA. Studies conforming to the inclusion criteria were reviewed. The literature search yielded 44 published articles on MMD by using keywords classified under the six key factors, namely arterial tortuosity, vascular angles, wall shear stress, molecular factors, blood rheology/viscosity, and blood vessel wall strength, and 477 published articles on MMS associations. Information obtained from 51 articles that matched the inclusion criteria and additional information derived from the progressive search mentioned above were used to connect the key factors to derive a network pattern of pathogenesis. Based on the available literature, the authors have proposed a unifying theory for the pathogenesis of MMA. The moyamoya phenomenon appears to be the culmination of an interplay of vascular anatomy, hemodynamics, rheology, blood vessel wall strength, and a plethora of intricately linked mechanobiological molecular mediators that ultimately results in the mechanical process of occlusion of the blood vessel, stimulating angiogenesis and collateral blood supply in an attempt to perfuse the compromised brain.

Abstract P174: Nuclear Smooth Muscle α-actin Is Critical For Smooth Muscle Cell Differentiation And To Prevent Cerebrovascular Disease

Missense mutations in ACTA2, encoding α-smooth muscle actin (α-SMA), predispose to thoracic aortic aneurysms. A subset of these ACTA2 mutations also predispose to childhood onset cerebrovascular disease characterized by occlusion of the distal internal carotid arteries and small vessel disease. In our studies to identify how specific ACTA2 mutations predispose to cerebrovascular disease, we confirmed that α-SMA translocates to the nucleus in wildtype (WT) smooth muscle cells (SMCs), is enriched in the nucleus over β-actin with differentiation of SMCs, associates with the INO80 chromatin remodeling complex, and selectively binds to the promoters of SMC contractile genes. Expression of individual mutant α-SMAs in 293 cells determined that missense mutations associated with cerebrovascular disease inhibit this nuclear translocation. To further examine the effects of reduced nuclear α-SMA with ACTA2 mutations, we used two model systems: pluripotent stem cell-derived SMCs from patients with ACTA2-associated cerebrovascular disease (ACTA2 R179C) as well as SMCs explanted from a knockin mouse model (Acta2SMC-R179C/+). Both mouse and human cells harboring the R179C mutation proliferate and migrate more than WT SMCs, are less differentiated than WT SMCs, and have increased expression of pluripotency-associated genes. Although the mutation is heterozygous, these cells show a dominant negative impact on nuclear α-SMA function through dramatically reduced levels of α-SMA in the nucleus, in the INO80 chromatin remodeling complex, and on the promoters of SMC-specific genes. Finally, forced nuclear localization of α-SMA in WT SMCs increases levels of SMC contractile proteins. Taken together, we have identified a novel role for α-SMA in driving differentiation of SMCs, and our data supports that defects in this nuclear role drive cellular phenotypes consistent with the cerebrovascular disease seen in patients with ACTA2 R179 mutations.

Image-based patient-specific flow simulations are consistent with stroke in pediatric cerebrovascular disease.

Moyamoya disease (MMD) is characterized by narrowing of the distal internal carotid artery and the circle of Willis (CoW) and leads to recurring ischemic and hemorrhagic stroke. A retrospective review of data from 50 pediatric MMD patients revealed that among the 24 who had a unilateral stroke and were surgically treated, 11 (45.8%) had a subsequent, contralateral stroke. There is no reliable way to predict these events. After a pilot study in Acta-/- mice that have features of MMD, we hypothesized that local hemodynamics are predictive of contralateral strokes and sought to develop a patient-specific analysis framework to noninvasively assess this stroke risk. A pediatric MMD patient with an occlusion in the right middle cerebral artery and a right-sided stroke, who was surgically treated and then had a contralateral stroke, was selected for analysis. By using an unsteady Navier-Stokes solver within an isogeometric analysis framework, blood flow was simulated in the CoW model reconstructed from the patient's postoperative imaging data, and the results were compared with those from an age- and sex-matched control subject. A wall shear rate (WSR) > 60,000s-1 (about 12 × higher than the coagulation threshold of 5000s-1 and 9 × higher than control) was measured in the terminal left supraclinoid artery; its location coincided with that of the subsequent postsurgical left-sided stroke. A parametric study of disease progression revealed a strong correlation between the degree of vascular morphology altered by MMD and local hemodynamic environment. The results suggest that an occlusion in the CoW could lead to excessive contralateral WSRs, resulting in thromboembolic ischemic events, and that WSR could be a predictor of future stroke.

The Asterion-to-Transverse Process of the Atlas Line as a Surgical Landmark.

Introduction Proposed landmarks to predict the anatomical location and trajectory of the sigmoid sinus have varying degrees of reliability. Even with neuronavigation technology, landmarks are crucial in planning and performing complex approaches to the posterolateral skull base. By combining two major dependable structures-the asterion (A) and transverse process of the atlas (TPC1)-we investigate the A-TPC1 line in relation to the sigmoid sinus and in partitioning surgical approaches to the region. Methods We dissected six cadaveric heads (12 sides) to expose the posterolateral skull base, including the mastoid and suboccipital bone, TPC1 and suboccipital triangle, distal jugular vein and internal carotid artery, and lower cranial nerves in the distal cervical region. We inspected the A-TPC1 line before and after drilling the mastoid and occipital bones and studied the relationship of the sigmoid sinus trajectory and major muscular elements related to the line. We retrospectively reviewed 31 head and neck computed tomography (CT) angiograms (62 total sides), excluding posterior fossa or cervical pathologies. Bone and vessels were reconstructed using three-dimensional segmentation software. We measured the distance between the A-TPC1 line and sigmoid sinus at different levels: posterior digastric point (DP), and maximal distances above and below the digastric notch. Results A-TPC1 length averaged 65 mm and was posterior to the sigmoid sinus in all cadaver specimens, coming closest at the level of the DP. Using the transverse-asterion line as a rostrocaudal division and skull base as a horizontal plane, we divided the major surgical approaches into four quadrants: distal cervical/extreme lateral and jugular foramen (anteroinferior), presigmoid/petrosal (anterosuperior), retrosigmoid/suboccipital (posterosuperior), and far lateral/foramen magnum regions (posteroinferior). Radiographically, the A-TPC1 line was also posterior to the sigmoid sinus in all sides and came closest to the sinus at the level of DP (mean, 7 mm posterior; range, 0-18.7 mm). The maximal distance above the DP had a mean of 10.1 mm (range, 3.6-19.5 mm) and below the DP 5.2 mm (range, 0-20.7 mm). Conclusion The A-TPC1 line is a helpful landmark reliably found posterior to the sigmoid sinus in cadaveric specimens and radiographic CT scans. It can corroborate the accuracy of neuronavigation, assist in minimizing the risk of sigmoid sinus injury, and is a useful tool in planning surgical approaches to the posterolateral skull base, both preoperatively and intraoperatively.

Quantitative magnetic resonance angiography to assess post embolization hemodynamics following pipeline embolization.

Delayed intraparenchymal hemorrhage is a known complication of the Pipeline Embolization device (PED); however, its etiology is unclear and some have suggested it is a flow related phenomenon. Quantitative magnetic resonance angiography (QMRA) serves as a powerful tool to collect and analyze hemodynamic data. We report a detailed characterization of short-term hemodynamics after PED placement. Patients who underwent PED placement for a distal internal carotid artery (ICA) aneurysm between 2017 to 2019 with post embolization QMRA were reviewed. Aneurysm characteristics, flow volume rate (ml/min), mean, systolic, and diastolic flow velocities (cm/s), vessel diameter (mm), pulsatility index, Lindegaard ratio, and wall shear stress (WSS) were collected. A total of 67 patients were included. Post-procedure patients were found to have a significantly lower ICA flow on the side with flow diversion when compared to the side without flow diversion (218 vs. 236.3; P < 0.05). Average ICA flow after flow diversion for aneurysms >2 cm was significantly lower when compared to the untreated side (187.7 vs. 240.4; P < 0.05). There was no difference in MCA or ACA flow or velocity. WSS was significantly lower in the treated ICA (8.2 vs. 9.0; P < 0.05). Lindegaard ratio was not different in the treated vs. contralateral untreated sides. PED placement for distal ICA aneurysms results in lower flow, mean velocity, and WSS when compared to the contralateral untreated ICA. This is not demonstrated distal to the Pipeline device in the ACA or MCA territories. Ultimately these findings suggest hemodynamic changes are not a cause of PED complications.

Crossing the Carotid Siphon: Techniques to Facilitate Distal Access in Tortuous Anatomy: 2-Dimensional Operative Video.

As capabilities for endovascular treatment of intracranial vascular pathologies continue to expand, the need for access to the distal internal carotid artery with rigid support catheter systems continues to increase. One of the dominant factors limiting this access is patient anatomy, specifically vessel tortuosity. Increased tortuosity of the carotid siphon is a frequently encountered anatomic variant and may complicate endovascular procedures in adults and children.1,2 Failed attempts to navigate the carotid siphon with a distal access catheter carry a risk of vessel injury and treatment failure. For this reason, techniques that aid in supporting safe advancement of a distal access catheter across a tortuous carotid siphon are essential.3,4 In this video, we demonstrate 2 ways in which this may be accomplished. The first technique uses a larger diameter microcatheter, such as the AXS Offset catheter (Stryker, Kalamazoo, Michigan), to increase support for the distal access catheter, while the second uses a buddy wire technique to accomplish this increased support. Both of these techniques can help increase the safety of navigating a tortuous carotid siphon and increase the likelihood of successful treatment. The procedures shown were performed with the informed consent of the patients.

Near-Occlusion is a Common Variant of Carotid Stenosis: Study and Systematic Review.

Symptomatic carotid near-occlusion is often described as rare. Recent studies have shown that near-occlusions are overlooked, especially near-occlusion without full collapse (with a small but normal-appearing distal internal carotid artery). To assess the prevalence of near-occlusion among symptomatic ≥50% carotid stenosis, incidence of symptomatic near-occlusion, and review the literature. Prospective controlled single-center cross-sectional study. Consecutive cases with symptomatic ≥50% carotid stenosis were examined with computed tomography angiography (CTA). The CTAs were assessed for near-occlusion by two observers. A systematic literature review was performed with emphasis on how study design affects prevalence estimate. Totally, 186 patients with symptomatic ≥50% carotid stenosis were included, 34% (n = 63, 95% CI 27, 41) had near-occlusion. The incidence of symptomatic near-occlusion was 3.4 (95% CI 2.5, 4.2) per 100,000 person-years. Inter-rater κ was 0.71. The average prevalence of near-occlusion among symptomatic ≥50% carotid stenosis was higher in studies with good design (30%, range 27%-34%) than studies without good design (9%, range 2%-10%). Near-occlusion is common variant of symptomatic ≥50% carotid stenosis, both in the current study and in all previous studies of good design. Studies that suggest that near-occlusion is rare have had methodological issues.

Defining carotid near-occlusion with full collapse: a pooled analysis

PurposeCreate a new definition of near-occlusion with full collapse to predicting recurrent stroke.MethodsPooled analysis of two studies. Patients with symptomatic ≥ 50% carotid stenoses were included. Outcome was preoperative recurrent ipsilateral ischemic stroke or retinal artery occlusion within 28 days of presenting event. We analyzed several artery diameters on computed tomography angiography and stenosis velocity on ultrasound.ResultsA total of 430 patients with symptomatic ≥ 50% carotid stenosis were included, 27% had near-occlusion. By traditional definition, 27% with full collapse and 11% without full collapse reached the outcome (p = 0.047). Distal internal carotid artery (ICA) diameter, ICA ratio, and ICA-to-external carotid artery ratio were associated with the outcome. Best new definition of full collapse was distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42. With this new definition, 36% with full collapse and 4% without full collapse reached the outcome (p < 0.001).ConclusionsDefining near-occlusion with full collapse as distal ICA diameter ≤ 2.0 mm and/or ICA ratio ≤ 0.42 seems to yield better prognostic discrimination than the traditional appearance-based definition. This novel definition can be used in prognostic and treatment studies of near-occlusion with full collapse.

Validation of a Deep Learning Tool in the Detection of Intracranial Hemorrhage and Large Vessel Occlusion.

Purpose: Recently developed machine-learning algorithms have demonstrated strong performance in the detection of intracranial hemorrhage (ICH) and large vessel occlusion (LVO). However, their generalizability is often limited by geographic bias of studies. The aim of this study was to validate a commercially available deep learning-based tool in the detection of both ICH and LVO across multiple hospital sites and vendors throughout the U.S.Materials and Methods: This was a retrospective and multicenter study using anonymized data from two institutions. Eight hundred fourteen non-contrast CT cases and 378 CT angiography cases were analyzed to evaluate ICH and LVO, respectively. The tool's ability to detect and quantify ICH, LVO, and their various subtypes was assessed among multiple CT vendors and hospitals across the United States. Ground truth was based off imaging interpretations from two board-certified neuroradiologists.Results: There were 255 positive and 559 negative ICH cases. Accuracy was 95.6%, sensitivity was 91.4%, and specificity was 97.5% for the ICH tool. ICH was further stratified into the following subtypes: intraparenchymal, intraventricular, epidural/subdural, and subarachnoid with true positive rates of 92.9, 100, 94.3, and 89.9%, respectively. ICH true positive rates by volume [small (<5 mL), medium (5–25 mL), and large (>25 mL)] were 71.8, 100, and 100%, respectively. There were 156 positive and 222 negative LVO cases. The LVO tool demonstrated an accuracy of 98.1%, sensitivity of 98.1%, and specificity of 98.2%. A subset of 55 randomly selected cases were also assessed for LVO detection at various sites, including the distal internal carotid artery, middle cerebral artery M1 segment, proximal middle cerebral artery M2 segment, and distal middle cerebral artery M2 segment with an accuracy of 97.0%, sensitivity of 94.3%, and specificity of 97.4%.Conclusion: Deep learning tools can be effective in the detection of both ICH and LVO across a wide variety of hospital systems. While some limitations were identified, specifically in the detection of small ICH and distal M2 occlusion, this study highlights a deep learning tool that can assist radiologists in the detection of emergent findings in a variety of practice settings.

MOYAMOYA SYNDROME: RARE CASE IN 34 YEAR OLD MALE PATIENT IN INDIAN POPULATION – A CASE REPORT

Moyamoya is a rare idiopathic progressive vaso-occlusive disease involving cerebral vessels like distal internalcarotid arteries on both sides, To compensate for the occlusion there is development of collateral vessels. Unilateral presentation of the condition is known as Moyamoya syndrome. Authors are presenting a case of a 34-year-old male who presented to the emergency department of Marwari Hospital and Research Centre with sudden loss of consciousness. Patient had past history of difculty in holding objects with left hand &amp; difculty in walking for 3 years. The patient had undergone MRI BRAIN, diagnosed as Moyamoya disease and treated with revascularization surgery.

Current trends in pediatric moyamoya: a survey of international practitioners.

Moyamoya angiopathy (MM) is a chronic, progressive steno-occlusive arteriopathy of the distal internal carotid artery and its proximal branches. MM is recognized as a shared end-pathway common to a broad range of inciting pathologies, suggesting that tailored management is important. Pediatric MM differs from MM in adults. Currently, there are many uncertainties and controversies regarding the diagnosis and management of children with MM. Hence, we conducted an international survey to identify the contemporary management trends followed worldwide. A survey relating to lifestyle modifications, medical management, diagnosis, surgical management, and follow-up for pediatric MM was circulated across web-based platforms, through various international pediatric neurological and neurosurgical societies. Data collected included geographic region of practice, experience, responses to questions, and comments. One hundred twenty-seven responses were evaluated (104 neurosurgeons and 23 neurologists, from 32 countries, across 6 continents). We found wide variations in the recommendations for management and lifestyle modification, with significant differences between regions of practice. Eighty percent recommend restrictions on physical activity, particularly for symptomatic and non-operated patients. Eighty-four percent prescribe aspirin. Sixty-five percent perform indirect revascularization. Seventy-eight percent recommend performing a staged surgery for bilateral MM. Only 26% perform acetazolamide challenge SPECT to evaluate brain perfusion. Only 15% of responders were from highly experienced centers. This survey reflects the contemporary trends in management of pediatric MM, while highlighting the heterogeneity in the management approach of these patients. There is a need for multicenter, international studies to evaluate the safety, efficacy, and long-term outcome of various aspects of treatment of these patients.

Delayed Endovascular Thrombectomy for Ischemic Stroke in a Young Woman with No Known Risk Factors: A Case Report

Patient: Female, 26-year-oldFinal Diagnosis: Internal carotid artery dissectionSymptoms: Dysarthria • gaze palsy • hemiplegia • sensory lossMedication: —Clinical Procedure: Endovascular stenting and mechanical thrombectomySpecialty: Neurology • RadiologyObjective:Unusual clinical courseBackground:National guidelines and consensus statements suggest a 24-hour window for endovascular recanalization in patients presenting with acute ischemic stroke due to large-vessel occlusion. However, the safety and efficacy of extending the window for intervention remains to be definitively established.Case Report:A healthy 26-year-old woman presented with headache, left-sided hemiplegia, and rightward gaze palsy 2 days after a minor trauma. Time last known well was approximately 50 hours prior to presentation. Computed tomography angiography revealed dissection of the distal right internal carotid artery and occlusion of the M1 segment of the right middle cerebral artery. Magnetic resonance imaging showed a small area of acute infarct in the right basal ganglia and right insular cortex, but suggested a large ischemic penumbra; this was confirmed with cerebral perfusion analysis. In light of the patient’s young age and potential for penumbral salvage, mechanical thrombectomy of an M1 thrombus and stenting of an internal carotid artery dissection were performed nearly 60 hours after the onset of symptoms. The patient demonstrated marked clinical improvement over the following days and was discharged home in excellent condition one week after presentation. Based on our clinical experience and other emerging data, we propose that extension of the 24-hour window for endovascular intervention may improve functional outcomes among select individuals.Conclusions:A 24-hour window for endovascular thrombectomy is appropriate for many patients presenting with acute ischemic stroke. However, in select individuals, extension of the window to 48 hours or beyond may improve functional outcomes.

16886 Moyamoya-Like Vasculopathies Observed In a Novel Mouse Surgical Model

ABSTRACT IMPACT: Development of our animal model of moyamoya will provide a meaningful assessment of therapeutic efficacy of interventions applicable to the clinical setting. OBJECTIVES/GOALS: Moyamoya is a cerebrovascular condition with progressive stenosis of the internal carotid arteries (ICA) and formation of abnormal vascular collaterals at the base of the brain, all of which result in ischemic and hemorrhagic strokes. We aim to develop a needed animal model of this condition in order to develop new therapeutics. METHODS/STUDY POPULATION: Male and female C57Bl/6J mice (4 months old) underwent surgery for the unilateral placement of a microcoil (0.16 mm ID) onto the proximal ICA or sham control. After 30 and 60 days (N = 6-8/time point), the brain blood vessels were examined for changes in diameter, number of anastomoses, and development of new collaterals using DiI stain. Brain tissue was examined for micro-hemorrhages using Prussian blue stain, and cross-sections of blood vessels were examined for intimal thickening using H&amp;E and smooth muscle actin. Expression of vascular endothelial growth factor (VEGF), which is associated with angiogenesis and moyamoya syndrome, was quantified by qPCR. Blood samples were also analyzed for inflammatory biomarkers using ELISA. RESULTS/ANTICIPATED RESULTS: Within 30 days, the distal ICA and anterior cerebral artery (ACA) had significantly decreased diameters at the Circle of Willis, with an initial decrease in the number of cortical anastomoses. Histology demonstrated smaller lumen diameter and alterations to in the various layers of the blood vessels, indicating intimal thickening and stenosis of the affected blood vessels. There was also a significant increase in the number of intracranial micro-bleeds, suggesting a compromised vascular integrity. This may be due, in part, to a significant upregulation in VEGF gene expression within the striatum, a region of hemorrhagic occurrence in moyamoya patients. DISCUSSION/SIGNIFICANCE OF FINDINGS: We report the development of an animal model with vasculopathies that mimic those observed in patients with moyamoya syndrome. With further characterization, this animal model will have a positive impact as a meaningful assessment of therapeutic efficacy of interventions applicable to the clinical setting.

Abstract P574: Anatomic Distribution of High-Resolution Vessel Wall Imaging Findings in a Cohort of Patients With Moyamoya Disease Evaluated at a Midwest American Institution

Introduction: High-resolution vessel wall imaging (HR-VWI) of the intracranial vasculature may aid in the diagnosis and management of Moyamoya Disease (MMD). The patterns of HR-VWI findings of the cerebral vasculature of MMD patients remains uncertain, however. We sought to describe HR-VWI findings in a single-center cohort of MMD patients. Methods: Consecutive patients who were evaluated at a Midwest American medical center with a HR-VWI exam were included. Fourteen anterior circulation arterial segments in each patient were analyzed: proximal and distal supraclinoid Internal Carotid Artery, proximal M1 segment of the Middle Cerebral Artery, mid-portion of the M1, distal M1, proximal A1 segment of the Anterior Cerebral Artery and distal A1. Imaging variables that were collected from each segment included the presence of wall thickening (concentric vs eccentric), degree and pattern (concentric or eccentric) of contrast enhancement, and presence of positive or negative vessel remodeling. The total number and percentage of vessel segments demonstrating these characteristics were calculated. The number and percentage of patients with at least one segment demonstrating these characteristics were calculated. Results: Thirty-six patients (32 females, 88.9%) with a diagnosis of MMD were included. Overall, 221 of 504 segments (43.8%) demonstrated negative remodeling in 29 (75%) patients. Ninety-eight segments (19.4%) demonstrated wall enhancement (71 concentric, 27 eccentric; 22 high grade, 76 low grade) in 32 (88.9%) patients. Eighty-seven segments (17.3%) demonstrated wall thickening (52 concentric, 35 eccentric) in 32 patients (88.9%). Conclusions: Negative remodeling was the most-commonly observed vessel wall abnormality in all segments analyzed. However, a high percentage of patients had at least one segment demonstrating wall enhancement, wall thickening and negative remodeling. Continued study is necessary to further elucidate the HR-VWI patterns of the cerebral arterial system in MMD patients.

Carotid Endarterectomy Using Lone Star Retractor System

Cervical carotid disease is typical atherosclerosis, which is responsible for ischemic stroke. The effectiveness of carotid endarterectomy (CEA) for advanced carotid stenosis has been established in many large studies, and CEA is the gold standard in surgical treatment. On the other hand, endovascular carotid artery stenting (CAS) has become increasingly popular recently. It is very important to avoid any complications to maintain the effectiveness of CEA. The retractor device is important for the exposure of carotid arteries and for the safe surgical manipulation.We have started to use lone star retractor system (LSRS) to deploy the surgical field.LSRS provides the usability to handle and a shallower surgical field without the disturbance of surgical manipulation. And it can facilitate exposure of the distal internal carotid artery because surgeon can retract freely in whole circumference by towing with moderate strength. LSRS may bring the smoother and easier surgical manipulations in CEA.

A novel rabbit thromboembolic occlusion model

BackgroundTo develop a preclinical thromboembolic occlusion model for studying revascularization strategies.MethodsClot analog with barium sulfate was injected into the distal aorta in 9 New Zealand white rabbits. The situation of...

Imaging Identification and Prognosis of the Distal Internal Carotid Artery With Near and Complete Occlusion After Recanalization.

Background and Purpose: Previous studies have mainly focused on treatment strategies and clinical outcomes for internal carotid artery near occlusion (ICANO) and internal carotid artery complete occlusion (ICACO). However, reports on the morphological changes of distal internal carotid artery (ICA) after recanalization are scarce. This study aimed at illustrating identifying features, assessing prognosis of the distal ICA after recanalization, and exploring best practices for treatment for ICANO and ICACO.Materials and Methods: We retrospectively studied the clinical characteristics of 57 patients with ICANO or ICACO who underwent surgical recanalization. The clinical data, angiographic morphology, technical successful rate, perioperative complications, and the lumen changes of distal ICA before and after successful recanalization were analyzed.Results: Fifty-two patients who achieved successfully recanalization were studied. Based on the postoperative lumen diameter changes in the distal ICA, 19 cases were classified as distal-dilatation and the remaining 33 as distal-narrowness. Patients in the distal-narrowness group mostly had ICACO (21.1 vs. 54.5%) and were men (68.4 vs. 93.9%). In the distal-narrowness group, the lumen of the distal ICA recovered to normal in 32 of the 33 patients during the follow-up period. Of the 32 patients reviewed, the ICA of 28 patients dilated back to normal after 1 week of surgery; the ICA of remaining patients 4 dilated 2 weeks postoperatively.Conclusions: Narrowness of the distal ICA after hybrid recanalization was more prevalent in male patients with ICACO. Homogeneous stenosis of the whole course of the distal ICA is a low-perfusion narrowness which does not require intervention and will spontaneously recover after successful recanalization with an increase in the forward flow.