Intraprocedural Plaque Protrusion during Carotid Artery Stenting with a CASPER Stent: A Case Report.

Objective: Plaque protrusion (PP) during carotid artery stenting (CAS) is considered to be associated with periprocedural ischemic stroke. A new double-layer micromesh stent, the CASPER stent (CS), was approved for use in Japan in 2020. The expectation is that this micromesh stent system will reduce the risk of PP, but we report a case of PP during CAS despite the use of a CS. Case Presentation: An 87-year-old man presented with left hemiparesis. MRI showed right brain infarction and angiography showed right internal carotid artery stenosis with thrombus. Follow-up angiography after medical treatment showed that thrombus disappeared. We therefore performed CAS for right internal carotid artery stenosis with unstable plaque. CAS was performed under local anesthesia with Mo.Ma Ultra and FilterWire EZ protection using a CS placed to sufficiently cover the stenotic region. Conservative post-dilatation was then performed. Intravascular ultrasonography (IVUS) after post-dilatation showed the presence of PP. A second CS was then added using the stent-in-stent technique. No postoperative neurological abnormalities were found and the patient was discharged without postoperative complications. No stroke or restenosis has been observed as of 16 months after CAS. Conclusion: PP can occur even when CAS is performed using the CS for carotid artery stenosis with unstable plaque. The importance of checking for PP using IVUS is suggested.

Symptomatic Intracranial Hemorrhage after Mechanical Thrombectomy - the Difference between Iso-Osmolar and Low-Osmolar Contrast Media.

Objective: Symptomatic intracranial hemorrhage (SICH) after mechanical thrombectomy (MT) is generally considered a critical complication. Hemorrhagic transformation after ischemic stroke has also been associated with contrast media administration. The objective of our study was to evaluate correlations between contrast media type and incidence of SICH after MT. Methods: Ninety-three consecutive patients (41 men; mean age, 80.2 years; range, 44-98 years) underwent MT reperfusion (expanded thrombolysis in cerebral infarction score, 2a-3) for acute large-vessel occlusion ischemic stroke within 8 h after symptom onset between April 2020 and July 2023 were retrospectively reviewed. Correlations between contrast media type (iso-osmolar or low-osmolar medium) and incidence of SICH were assessed. Results: Contrast media were iso-osmolar in 60 cases or low-osmolar in 33 cases. The overall incidence of SICH was 5.5%. The frequency of SICH was significantly lower in the iso-osmolar group (1.7%) than in the low-osmolar group (12.1%; P = 0.033). Conclusion: Iso-osmolar contrast media was associated with a lower incidence of SICH compared with low-osmolar contrast media in patients after MT.

Carotid Artery Stenting for Near Occlusion with Full Collapse.

OBJECTIVE: Carotid near occlusions show a lower risk of stroke than other types of severe stenosis. However, emerging evidence suggests that near occlusion with full collapse differs from that without full collapse. The results of treatment with carotid artery stenting for near occlusion with full collapse are presented. METHODS: Between March 2007 and December 2020, 18 of 477 carotid artery stenting procedures were performed in patients with near occlusion with full collapse (3.8%). A total of 17 men and one woman with a mean age of 76.1 years were included. Eleven patients (61%) were symptomatic. The technical success rate, incidence of symptomatic stroke within 30 days, new ipsilateral ischemic lesions on diffusion tensor imaging within 48 hours after carotid artery stenting, and follow-up results (ipsilateral stroke rate and restenosis rate) were retrospectively assessed. RESULTS: The technical success rate was 100%. All carotid artery stenting procedures were performed using embolic protection devices. No symptomatic stroke occurred within 30 days. New ipsilateral ischemic lesions on magnetic resonance imaging were observed in 16.7% (3/18) of patients. Asymptomatic minor cerebral hemorrhage occurred in 2 patients (11.1%) with cerebral hyperperfusion syndrome. The median follow-up period was 77 months. Asymptomatic restenosis of 50% occurred in one patient (5.5%), and asymptomatic occlusion occurred in one patient (5.5%). During follow-up, no patients experienced ipsilateral stroke. Three patients (16.7%) died from nonneurological causes. CONCLUSIONS: Carotid artery stenting for near occlusion with full collapse seems to be a feasible and safe procedure that can be performed by an experienced neuro-interventional team.

A Case of Intraprocedural Plaque Protrusion during Carotid Artery Stenting Using the Stent-in-Stent Technique for Carotid Artery Stenosis with Unstable Plaque.

Objective: Carotid artery stenting (CAS) using the stent-in-stent technique was reported to prevent intraprocedural plaque protrusion (PP) in patients with carotid artery stenosis with unstable plaque. We report a case of intraoperative PP after CAS despite the use of stent-in-stent technique. Case Presentation: A 63-year-old man presented with rapid progression of right carotid artery stenosis with unstable plaque during follow-up and was admitted to undergo CAS. Under local anesthesia with Mo.Ma Ultra and FilterWire EZ protection, CAS was performed using the stent-in-stent technique. The first 8 mm × 29 mm Carotid Wallstent (CWS) was placed. The second CWS (6 mm × 22 mm) was placed in a stent-in-stent manner to match the stenotic lesion, and conservative postdilation was performed. Then the third CWS (6 mm × 22 mm) was added due to the presence of PP on intravascular ultrasonography (IVUS). No postoperative neurological abnormalities were found, and no new high-signal areas were observed on diffusion-weighted MRI the day after surgery. The patient was discharged without postoperative complications. No stroke and restenosis were observed at 3 months after CAS. Conclusion: PP can occur even with stent-in-stent technique, suggesting the importance of diagnosis by IVUS.

Treatment of Coral Reef Aorta by Endovascular VIABAHN VBX Balloon-Expandable Stent-Graft Placement.

Coral reef aorta (CRA) has been described as a rare disease characterized by the presence of dense calcifications of the aorta. In this study, we report on two patients with CRA caused by intermittent claudication (IC) who underwent endovascular VIABAHN VBX balloon-expandable stent-graft (VVBX) placement. Both patients underwent successful endovascular VVBX placement via transfemoral artery approach, and hemostasis was achieved via vascular closure device. Their symptoms were observed to disappear completely after treatment, and they were discharged without serious adverse events. No symptoms were noted at 1.5-year and 1-year follow-up.

Initial Experience of Coil Embolization for Unruptured Intracranial Aneurysm Combined with Neuroform Atlas and Undersized Flexible Coils.

Objective: Intraprocedural rupture (IPR) is a rare complication that can occur during endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs). However, it leads to high morbidity and mortality rates. Others have showed that coil flexibility is a risk factor for IPR. Neuroform Atlas (NA) stents can be deployed with 0.0165-inch microcatheters to enable stent assisted coiling (SAC) with a high likelihood. Undersized flexible coils can be inserted initially during SAC. This study aimed to determine whether SAC using NA and highly flexible coils for UIAs can be conducted without IPR. Methods: We retrospectively analyzed nine consecutive patients (mean age, 73.2 years; female, n = 6) who underwent SAC for UIAs combined with NA stents and undersized flexible coils between January 2017 and December 2019. Two aneurysms were located at the internal carotid artery (ICA), and one each was located at the ICA-posterior communicating, anterior communicating, middle cerebral, vertebral, vertebra-posterior inferior cerebral and basilar arteries. The mean size of the aneurysms was 4.6 (range, 3.1-8.6) mm. SAC proceeded using the jailing technique. All coils were selected from among the most flexible coils available. We retrospectively assessed technical success rates, aneurysm occlusion at final digital subtraction angiography (DSA), volume embolization ratios (VERs), rates of IPR and symptomatic stroke within 30 days, angiographic findings of aneurysm occlusion at 3 months post-procedure and late adverse events (frequency of aneurysmal rupture, ipsilateral ischemic stroke, and retreated targeted aneurysms). Results: The technical success rate was 100%. Complete occlusion (CO) was immediate in 8 (89%) patients and a neck remnant persisted in 1 (11%). No IPR or symptomatic stroke developed within 30 days. During a mean follow-up period of 11.8 months, CO persisted in 8 (89%) patients. No late adverse events occurred. Conclusion: The early clinical and angiographic findings of SAC for UIAs combined with an NA stent and undersized flexible coils were favorable for this series.

A Rat Model of Frozen Shoulder Demonstrating the Effect of Transcatheter Arterial Embolization on Angiography, Histopathology, and Physical Activity.

PURPOSE: To assess the angiographic findings and the effects of transcatheter arterial embolization on physical activity and histopathology using a frozen shoulder rat model. MATERIALS AND METHODS: First, the angiographic and histopathologic findings of rats in which the shoulder was immobilized with molding plaster for 6 weeks (n = 4) were compared to control rats with normal non-immobilized shoulders (n = 4). Next, a total of 16 frozen shoulder rats were divided into 2 groups. In the transcatheter arterial embolization group (n = 8), imipenem/cilastatin was injected into the left thoracoacromial artery. The changes of physical activity before and after procedures were evaluated and compared with a saline-injected control group (n = 8). Histopathologic findings were also compared between the 2 groups. RESULTS: Angiography revealed abnormal shoulder staining in all of the rats with a frozen shoulder. On histopathology, the numbers of microvessels and mononuclear inflammatory cells in the synovial membrane of the joint capsule were significantly higher compared with the control rats (both P = .03). In the transcatheter arterial embolization group, the running distance and speed were improved (P = .03 and P = .01, respectively), whereas there were no significant differences in the control group. The number of microvessels and mononuclear inflammatory cells in the transcatheter arterial embolization group were significantly lower than the control group (P = .002 and P = .001, respectively). CONCLUSIONS: The rat frozen shoulder model revealed the development of neovascularization. Transcatheter arterial embolization decreased the number of blood vessels and inflammatory changes in the frozen shoulder and increased the moving distance and speed of the rats.

Delayed Intracranial Parenchymal Changes After Aneurysmal Coil Embolization Procedures for Unruptured Intracranial Aneurysms.

BACKGROUND: With the recent advances in endovascular treatment devices, it has become standard in wide-neck or large intracranial aneurysms to perform coil embolization with adjunctive techniques. However, device-related perioperative complications have been reported because of the use of more complex systems. OBJECTIVE: To investigate patients who developed multiple parenchymal lesions after undergoing coil embolization for treating an unruptured intracranial aneurysm. METHODS: This study investigated 305 consecutive patients who underwent coil embolization of unruptured intracranial aneurysms between 2015 and 2017. Delayed inflammatory changes referred to the delayed observation of multiple cerebral white matter lesions on follow-up magnetic resonance imaging at an area corresponding to the perfused area of the treatment target vessel. The timing and pattern of onset, device used, the combined use of adjunctive techniques, and the clinical course after steroid treatment were retrospectively investigated. RESULTS: The 7 patients (2.3%) who showed delayed inflammatory changes were all women with a mean age of 59 yr. A mean duration from treatment to onset was 28 d. Symptoms were convulsions in 3 patients, hemiplegia in 2 patients, and homonymous hemianopia in 1 patient. All 7 patients were treated with adjunctive technique including stents, double catheter method, and balloon assist. Response to steroid treatment was satisfactory both clinically and on imaging in all 7 patients. Skin patch test was positive for nickel allergy in 2 patients. CONCLUSION: Clinicians must be fully aware of symptomatic delayed inflammatory changes may occur after endovascular aneurysmal treatment with the use of various devices.

Carotid Artery Stenting Using a Closed-Cell Stent-in-Stent Technique for Unstable Plaque.

Purpose: To examine whether carotid artery stenting (CAS) of stenoses with unstable plaque using a closed-cell stent-in-stent technique prevents plaque protrusion. Materials and Methods: Between December 2014 and August 2018, 35 consecutive patients (mean age 75.8 years; 29 men) with carotid artery stenosis (20 symptomatic) and unstable plaque diagnosed by magnetic resonance imaging were prospectively analyzed. Mean diameter stenosis was 83.5%. All CAS procedures were performed with stent-in-stent placement of Carotid Wallstents using an embolic protection device and conservative postdilation. The technical success rate, incidence of plaque protrusion, ischemic stroke rate within 30 days, and new ipsilateral ischemic lesions on diffusion-weighted imaging (DWI) within 48 hours after CAS were prospectively assessed. Follow-up outcomes included the incidences of ipsilateral stroke and restenosis. Results: The technical success rate was 100%. No plaque protrusion or stroke occurred in any patient. New ischemic lesions were observed on DWI in 10 (29%) patients. During the mean 11.6-month follow-up, no ipsilateral strokes occurred. Two (6%) patients developed asymptomatic restenosis recorded as 53% lumen narrowing and occlusion, respectively. Conclusion: CAS using a closed-cell stent-in-stent technique for unstable plaque may be useful for preventing plaque protrusion and ischemic complications.

Carotid Artery Stenting: Investigation of Plaque Protrusion Incidence and Prognosis.

OBJECTIVES: This study sought to clarify the incidence and prognosis of PP in carotid artery stenting (CAS). BACKGROUND: Projections thought to be plaque may be observed inside the stent on angiography or intravascular ultrasound (IVUS) during CAS. Known as plaque protrusion (PP), the incidence and prognosis of this complication are unclear. METHODS: A total of 354 consecutive carotid atherosclerotic stenoses in 328 patients (285 men, 43 women; age range 51 to 97 years [mean age 73.6 years]; 158 symptomatic cases; stenosis rate, 50% to 99% [mean 81.0%]) who underwent CAS under IVUS between October 2007 and March 2016 were retrospectively analyzed. PP was defined as plaque seen inside the stent lumen on both digital subtraction angiography and IVUS. The incidence and prognosis (rate of stroke within 30 post-operative days) of PP and the rate of ischemic lesions on the treated side on diffusion-weighted imaging performed within 48 post-operative hours within the PP group were investigated. RESULTS: PP was observed in 9 cases (2.6%). Ischemic stroke occurred in 6 of 9 PP cases (66.7%; 1 major, 5 minor). Ischemic lesions were observed on diffusion-weighted imaging in 8 of 9 cases (88.9%). PP was strongly associated with perioperative ischemic stroke. A significant increase in PP susceptibility was observed with open-cell stent use and unstable plaque. CONCLUSIONS: The incidence of PP in CAS was 2.6%, with a high risk of ischemic complications if PP was observed. The present findings indicate the necessity of appropriate device selection to avoid PP.

Structures Showing Negative Correlations of Signal Intensity with Postnatal Age on T1-weighted Imaging of the Brain of Newborns and Infants.

PURPOSE: Although the neonatal and infantile brain typically shows sequential T1 shortening according to gestational age as a result of myelination, several structures do not follow this rule. We evaluated the relationship between the signal intensity of various structures in the neonatal and infantile brain on T1-weighted imaging (T1WI) and either postnatal or gestational age. MATERIALS AND METHODS: We examined magnetic resonance images from 120 newborns and infants without any abnormalities in the central nervous system. Written informed consent was obtained from all parents and the institutional review board approved the study. Gestational age at examination ranged from 35 weeks, 3 days to 46 weeks, 6 days, and postnatal age ranged from 7 days to 127 days. Signal intensity on T1WI was evaluated on a scale from Grade 1 (indistinguishable from surrounding structures) to Grade 4 (higher than cortex and close to fat). We evaluated relationships between the T1 signal grades of various structures in the neonatal brain and postnatal or gestational age using Spearman's correlation analysis. RESULTS: Significant positive correlations were identified between T1 signal grade and gestational age in the pyramidal tract (P < 0.001). Conversely, significant negative correlations were evident between T1 signal grade and postnatal age (P < 0.001), in structures including the stria medullaris thalami, fornix cerebellar vermis, dentate nucleus and anterior pituitary gland. CONCLUSION: Significant negative correlations exist between signal intensity on T1WI and postnatal age in some structures of the neonatal and infantile brain. Some mechanisms other than myelination might play roles in the course of signal appearance.

A novel approach to the treatment of a direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV.

We report a case of a direct carotid-cavernous fistula (CCF) in a patient with Ehlers-Danlos syndrome type IV who presented with progressive chemosis and diplopia. To prevent potential lethal arterial wall injury due to the fragility of the arterial vessel wall, the ipsilateral carotid artery and internal jugular vein were surgically exposed for direct insertion of endovascular sheaths, and transvenous embolization was performed using triple microcatheters with detachable coils. The clinical course was uneventful, and chemosis and diplopia subsequently resolved. By the 6 month follow-up, MRI revealed no recurrence of the CCF. These techniques offer a unique access alternative for endovascular treatment, thereby reducing the risks associated with arterial dissection that often accompanies transfemoral access in this particular condition.

Dural Thickening of the Internal Auditory Canal in Patients With Spontaneous Intracranial Hypotension Syndrome.

OBJECTIVE: This study aimed to assess the utility of dural thickening of the internal auditory canal (IAC) in patients with spontaneous intracranial hypotension (SIH) syndrome and determined the sensitivity and specificity of this image finding. METHODS: Magnetic resonance images were evaluated for 22 cases of definite SIH and 16 cases of unlikely SIH. On contrast-enhanced magnetic resonance imaging, pachymeningeal enhancement and dural thickening of the IAC were assessed. RESULTS: Pachymeningeal enhancement was observed in 21 of 22 patients in the definite SIH group and 1 of 16 patients in the unlikely SIH group (sensitivity, 95.5%; specificity, 93.8%). Dural thickening of the IAC was observed in 15 of 22 patients in the definite SIH group and 0 of 16 patients in the unlikely SIH group (sensitivity, 68.2%; specificity, 100%). CONCLUSIONS: Dural thickening of the IAC showed 100% specificity for SIH syndrome and can increase the accuracy of diagnosis of SIH syndrome.

Optimization of scan timing for aortic computed tomographic angiography using the test bolus injection technique.

BACKGROUND: With fast computed tomography (CT), it is possible for the scanning to outpace the contrast medium bolus during aortic CT angiography (CTA). PURPOSE: To evaluate the effectiveness of a new method for reducing the risk of outpacing in which the scan start timing (ST) and speed can be estimated from the peak enhancement time measured at the femoral artery using a single test-bolus injection (femoral artery test injection method [FTI method]). MATERIAL AND METHODS: In 30 cases of aortic CTA, we measured the time to peak enhancement at the femoral artery (TPF) and the ascending aorta (TPA) with test-bolus injection performed twice in each examination. From the resultant linear relationship between TPF and transit time (TT = TPF - TPA), we developed a method for determining the ST and TT from TPF. One hundred patients were assigned to two groups: FTI and bolus tracking (BT), each with 50 patients. CT values were measured in main vessels (ascending aorta, descending aorta, femoral artery). The CT values of the vessels and the rate of cases with more than 300 HU (good cases) were compared between the two groups. RESULTS: The enhancement in the FTI method was significantly higher than that of the BT method (average CT values: FTI, 388.3 ± 52.4; BT, 281.2 ± 59.1; P < 0.001). The rates of good cases for FTI and BT were 86.0% and 46.0%, respectively. CONCLUSION: The FTI method was very effective in reducing the risk of outpacing of the contrast medium transit in aortic CTA without the need for an additional contrast medium dose.

Influence of Diabetes Mellitus and Cigarette Smoking on Variability of the Clopidogrel-Induced Antiplatelet Effect and Efficacy of Active Management of the Target P2Y12 Reaction Unit Range in Patients Undergoing Neurointerventional Procedures.

BACKGROUND: Optimal antiplatelet inhibition is essential in patients undergoing neurointerventional procedures; however, variability in response to clopidogrel can contribute to thromboembolic and hemorrhagic complications. The present study evaluated the influence of diabetes mellitus and cigarette smoking on clopidogrel reactivity. METHODS: Between 2011 and 2013, 71 consecutive patients underwent aneurysmal coil embolization (CE) or carotid artery stenting (CAS) and received clopidogrel (75 mg daily) and aspirin (100 mg daily) before the treatment. The patients were divided into 2 groups: CE (n = 31) and CAS (n = 40). The patients underwent prospective assessment of preoperative platelet function using VerifyNow assay and received adjunctive cilostazol (200 mg daily, triple antiplatelet therapy) in case of clopidogrel hyporesponse. Patients with clopidogrel hyper-response underwent clopidogrel dose reduction (clopidogrel, 12.5-50 mg daily). RESULTS: Clopidogrel resistance was noted in 15 patients (37.5%) in the CAS group and in 4 patients (12.9%) in the CE group (P = .031). Clopidogrel hyper-response was noted in 2 patients (5%) in the CAS group and in 11 patients (54.8%) in the CE group (P < .001). There was a significant difference in the baseline clinical characteristics between the 2 groups. In the multivariate logistic regression analysis, diabetes and age were independent predictors of clopidogrel hyporesponse, whereas current smoker was an independent predictor of clopidogrel hyper-response. CONCLUSIONS: Significant differences in baseline clinical characteristics were present when comparing patients undergoing endovascular treatment of unruptured cerebral aneurysms and carotid artery stenosis. Diabetes mellitus and current smoker status were independent factors related to reactivity to clopidogrel.

Stent Placement for Severe Stenosis of the Left Common Carotid Artery with Internal-to-External Carotid Steal.

We report the case of a 64-year-old male with internal carotid artery (ICA)-to-external carotid artery (ECA) steal due to severe stenosis of the common carotid artery (CCA). Left CCA occlusion was initially diagnosed on 3-dimensional time-of-flight magnetic resonance angiography, but digital subtraction angiography revealed severe stenosis of the left CCA and retrograde flow through the left ICA feeding the left ECA. Diverted blood flow from ECA to ICA in cases with occlusion or severe stenosis of the CCA represents a well-known alternative collateral flow pattern called ECA-to-ICA steal. However, collateral flow from ICA to ECA is rarely observed and may be termed ICA-to-ECA steal. We treated CCA stenosis in our patient by carotid artery stenting (CAS) because his CCA stenosis had been gradually progressing since the initial ischaemic attack. Antegrade ICA flow subsequently recovered. To the best of our knowledge, this is the first report of ICA-to-ECA steal normalised by the treatment of CCA stenosis using CAS.

A novel approach to the treatment of a direct carotid-cavernous fistula in a patient with Ehlers-Danlos syndrome type IV.

We report a case of a direct carotid-cavernous fistula (CCF) in a patient with Ehlers-Danlos syndrome type IV who presented with progressive chemosis and diplopia. To prevent potential lethal arterial wall injury due to the fragility of the arterial vessel wall, the ipsilateral carotid artery and internal jugular vein were surgically exposed for direct insertion of endovascular sheaths, and transvenous embolization was performed using triple microcatheters with detachable coils. The clinical course was uneventful, and chemosis and diplopia subsequently resolved. By the 6 month follow-up, MRI revealed no recurrence of the CCF. These techniques offer a unique access alternative for endovascular treatment, thereby reducing the risks associated with arterial dissection that often accompanies transfemoral access in this particular condition.

Hybrid revascularization for critical limb ischemia triggered by multiple organ dysfunction due to acute pneumonia; urgent catheter intervention followed by low-density-lipoprotein apheresis and elective peripheral bypass surgery.

A 66-year-old man was referred for treatment of critical limb ischemia arising with multiple organ dysfunction due to acute pneumonia. Angiographic examinations demonstrated total obstruction of the bilateral external iliac arteries and the bilateral superficial femoral arteries with collateral circulation to the distal vessels. Urgent percutaneous transluminal angioplasty dissolved the obstruction of the left external iliac artery, and subsequent low-density-lipoprotein apheresis ameliorated his progressive ischemia in the lower extremities. Femoro-femoral and bilateral femoro-popliteal bypasses were performed 31 days after the endovascular intervention, which achieved successful limb salvage with the relief of ischemic symptoms related to arteriosclerotic obliterans.

Long-term treatment outcomes after intravascular ultrasound evaluation and stent placement for atherosclerotic subclavian artery obstructive lesions.

The objective of this study was to determine long-term outcomes after stent placement for subclavian artery (SA) obstructive lesions assisted by intraoperative intravascular ultrasound (IVUS). The study included 25 lesions in 24 patients who underwent stent placement assisted by intraoperative IVUS for subclavian artery stenosis or obstruction at our hospital between January 2003 and August 2010. Outcome was evaluated based on the results within 30 postoperative days (technical success rate, improvement in upper extremity ischemia, steal syndrome, left-right blood pressure difference, and perioperative complications) and the results after 30 postoperative days (incidence of vertebrobasilar artery territory infarction and restenosis). Stent placement and vessel dilatation were successful in all patients, without perioperative complications. Upper extremity ischemia, steal syndrome, and left-right blood pressure difference disappeared in all cases. During follow-up observation (6-96 months; median 51 months), no restenosis occurred at the stent placement site in any patient. In one case, four years after initial treatment, stenosis was noted proximal to the stent placement site. Satisfactory long-term as well as short-term outcomes were achieved after stent placement for SA obstructive lesions assisted by intraoperative IVUS evaluation.