Early Response to Endovascular Thrombectomy after Stroke: Early, Late, and Very Late Time Windows.

BACKGROUND AND PURPOSE: Endovascular thrombectomy (EVT) has benefits in selected patients 6-24 h after stroke onset. However, the response to EVT >24 h after stroke onset is still unclear. We compared the early response to EVT in patients with different time windows. METHODS: Patients who underwent EVT in an emergency setting were enrolled and categorized according to when EVT was performed: within 6 (early), 6-24 (late), and >24 h (very late) after stroke onset. Early neurological improvement (ENI) and deterioration (END) were defined as improvement and worsening, respectively, of National Institutes of Health Stroke Scale (NIHSS) score by ≥4 points after EVT. The three groups' clinical characteristics and response to EVT were compared. We also investigated factors associated with ENI and END. RESULTS: During study period, 274 patients underwent EVT (109 early, 104 late, and 61 very late). Patients who underwent EVT very late were younger (p = 0.007), had smaller ischemic cores, and had lower initial NIHSS scores (8 ± 5) than those who underwent EVT early (14 ± 6) and late (13 ± 7; p < 0.001). Stroke mechanisms also differed according to the time window (p < 0.001): cardioembolism was more common after early EVT, whereas large-artery atherosclerosis was more prevalent among patients who underwent EVT very late. ENI was significantly more common after early (60.6%) and late EVT (51.0%) than after very late EVT (29.5%; p = 0.001); however, rates of END did not differ (11.0%, 13.5%, and 4.9%, respectively). ENI was independently associated with male, higher NIHSS score, and early and late EVT. END was associated with failure of recanalization. CONCLUSIONS: ENI was more observed and associated with early and late EVT. Highly selected patients receiving very late EVT may not benefit from ENI but may still have a chance to prevent END. The occurrence of END was associated not with time window but with failure of recanalization.

In-stent restenosis and stented-territory infarction after carotid and vertebrobasilar artery stenting.

BACKGROUND: Prognosis after vertebrobasilar stenting (VBS) may differ from that after carotid artery stenting (CAS). Here, we directly compared the incidence and predictors of in-stent restenosis and stented-territory infarction after VBS and compared them with those of CAS. METHODS: We enrolled patients who underwent VBS or CAS. Clinical variables and procedure-related factors were obtained. During the 3 years of follow-up, in-stent restenosis and infarction were investigated in each group. In-stent restenosis was defined as reduction in the lumen diameter > 50% compared with that after stenting. Factors associated with the occurrence of in-stent restenosis and stented-territory infarction in VBS and CAS were compared. RESULTS: Among 417 stent insertions (93 VBS and 324 CAS), there was no statistical difference in in-stent restenosis between VBS and CAS (12.9% vs. 6.8%, P = 0.092). However, stented-territory infarction was more frequently observed in VBS than in CAS (22.6% vs. 10.8%; P = 0.006), especially a month after stent insertion. HbA1c level, clopidogrel resistance, and multiple stents in VBS and young age in CAS increased the risk of in-stent restenosis. Diabetes (3.82 [1.24-11.7]) and multiple stents (22.4 [2.4-206.4]) were associated with stented-territory infarction in VBS. However, in-stent restenosis (odds ratio: 15.1, 95% confidence interval: 3.17-72.2) was associated with stented-territory infarction in CAS. CONCLUSIONS: Stented-territory infarction occurred more frequently in VBS, especially after the periprocedural period. In-stent restenosis was associated with stented-territory infarction after CAS, but not in VBS. The mechanism of stented-territory infarction after VBS may be different from that after CAS.

Risk of recurrent ischemic stroke in patients with patent foramen ovale: The role of D-dimer.

BACKGROUND: Paradoxical embolism under elevated thromboembolic conditions is known to be the primary mechanism of patent foramen ovale (PFO)-related stroke. We hypothesized that higher levels of D-dimer, a marker of thromboembolism, could increase the risk of stroke recurrence in patients with PFO. METHODS: We conducted a retrospective analysis of data from 1226 consecutive patients with acute ischemic cryptogenic stroke (CS) who underwent transesophageal echocardiography (TEE). D-dimer was assessed during admission. We used a multivariate Cox proportional hazards model to evaluate the association of long-term outcomes between the presence of PFO and levels of D-dimer. RESULTS: Of the 1226 patients, the study included 461 who underwent TEE. Among them, 242 (52.5%) had PFOs. Among PFO patients, those with a D-dimer level >1.0 mg/L had a significantly higher risk of stroke recurrence compared to those with <0.5mg/L (adjusted hazard ratio (aHR) 4.04, 95% confidence interval [CI] 1.63-10.02). A pattern of increased risk of event with increasing D-dimer levels was observed (Ptrend=0.008). However, there was no significant difference in the risk of stroke recurrence at any D-dimer level compared to D-dimer level <0.5 mg/L among patients without PFO. In these patients, there was little evidence of increased risk with increasing D-dimer levels (Ptrend=0.570). CONCLUSIONS: This study demonstrated that the elevated D-dimer level increased the recurrence of stroke in CS patients with PFO, particularly showing a dose-dependent relationship between D-dimer levels and recurrence. However, no such effect was observed in patients without PFO. These findings provide valuable insights into the potential benefits of anticoagulation for strokes related to PFO.

Clinical-Diffusion Mismatch Is Associated with Early Neurological Improvement after Late-Window Endovascular Treatment.

BACKGROUND: Clinical-diffusion mismatch (CDM) and perfusion-diffusion mismatch (PDM) are used to select patients for endovascular thrombectomy (EVT) in the late-window period. As CDM well reflects true penumbra, we hypothesized that patients with CDM and PDM would respond better to EVT than those with PDM only at the late-window period. METHODS: Acute ischemic stroke patients who received EVT 6-24 h after stroke onset were included. PDM (perfusion-/diffusion-weighted image (DWI) lesion volume >1.8) was used to select candidates for EVT in this time-period in our center. CDM was defined according to the DAWN trial criteria. Response to EVT was compared between patients with and without CDM. Early neurological improvement (ENI) was defined as improvement >4 points on National Institutes of Health Stroke Scale (NIHSS) score 1 day after EVT. Multivariable analysis was performed to investigate independent factors associated with ENI. The correlation between DWI lesion volume and NIHSS score was investigated in those with and without CDM. RESULTS: Among 94 patients enrolled, all patients had PDM and 44 (46.3%) had CDM. Forty-eight patients (51.1%) showed ENI. The prevalence of hypertension, initial NIHSS score, improvement in NIHSS score after EVT, and prevalence of ENI were greater in patients with CDM than those without. ENI was independently associated with onset-to-door time (odds ratio [95% confidence interval]: 0.998 [0.997-1.000]; p = 0.042), complete recanalization (23.912 [2.238-255.489]; p = 0.009), initial NIHSS score (1.180 [1.012-1.377]; p = 0.034), and the presence of CDM (5.160 [1.448-18.386]; p = 0.011). The correlation between DWI lesion volume and initial NIHSS score was strong in patients without CDM (r = 0.731) but only moderate in patients with CDM (r = 0.355). CONCLUSION: Patients with both CDM and PDM had a better response to late-window EVT than those with PDM only.

High serum total cholesterol associated with good outcome in endovascular thrombectomy for acute large artery occlusion.

BACKGROUND: The effect of cholesterol on the functional outcome after endovascular thrombectomy (EVT) is still controversial. This study aimed to investigate whether the lipid profile is associated with the EVT prognosis. METHODS: We retrospectively analyzed patients with emergent large vessel occlusion who underwent EVT. The blood lipid levels were measured in the fasting state, 1 day after admission. We divided patients into terciles of serum total cholesterol (TC) levels and compared the clinical characteristics among the groups. The factors associated with a good outcome at 3 months (modified Rankin scale 0-2) were investigated, considering the stroke mechanism and recanalization status. RESULTS: Among 274 patients, good outcomes were observed in 108 (39.4%) patients. Low initial severity (odds ratio (OR), 0.91, 95% confidence interval (CI), 0.858-0.954; p < 0.001) and high TC level (1.35, 1.034-1.758; p = 0.041) were associated with good outcomes. In patients with cardioembolism, young age (0.95, 0.915-0.991; p = 0.021), low initial severity (0.92, 0.857-0.988; p = 0.024), and high TC level (1.60, 1.019-2.499; p = 0.036) were associated with good outcomes. The lipid profile was not associated with a functional outcome in those with large artery atherosclerosis. In patients with complete recanalization, young age (0.97, 0.941-0.994; p = 0.016), low initial severity (0.91, 0.864-0.961; p = 0.001), absence of diabetes (0.45, 0.218-0.947; p = 0.035) or any hemorrhage (0.33, 0.142-0.760; p = 0.009), and high TC level (1.40, 1.031-1.879; p = 0.031) were associated with good outcomes. CONCLUSIONS: A high TC level was associated with favorable outcomes after EVT, especially in patients with cardioembolism and complete recanalization.

Tailored antiplatelet agent medication in clopidogrel hyporesponsive patients before stent-assisted coiling: single-center experience.

PURPOSE: In patients requiring stent procedures, resistance or hyperresponsiveness to antiplatelet medications is often observed. This study aims to evaluate the efficacy and safety of tailoring medications in these patients. METHODS: This retrospective study included 223 patients who underwent endovascular treatment for intracranial aneurysm between October 2018 and October 2019. Patients were categorized as hyporesponsive, hyperresponsive, and normoresponsive groups according to the initial PRU response. For the hypo- or hyperresponders, we tailored medication by modifying the dose or changing the drug. PRUs before and after tailoring were compared in each group. PRU reponses in patients who underwent Cytochrome P450 2C19 (CYP2C19) genotyping were also determined. RESULTS: Of the 73 clopidogrel-resistant patients, the mean PRU values after tailoring showed a greater decrease in the group that switched to prasugrel (n = 56), from 223 to 131, than in the clopidogrel reloading group (n = 17), from 238 to 209. In 31 hyperresponders, PRU increased from 49 to 94 after the dose adjustment. CYP2C19 genotyping showed that PRU tended to increase as the number of mutated alleles increased. There were five (2.3%) ischemic events (three transient ischemic attacks and two minor strokes) in a mean follow-up of 8 months, but no hemorrhage. CONCLUSIONS: The stent-assisted coiling was successfully performed with acceptable range of ischemic events and without hemorrhage in all patients, including those who applied tailored medication. Low-dose prasugrel was effective for obtaining appropriate PRU values for initial medication as well as for clopidogrel-resistant patients. The genetic test did not provide reliable results in determining clopidogrel resistance.

Facilitated Retrograde Access via the Facial Vein for Transvenous Embolization of the Cavernous Sinus Dural Arteriovenous Fistula with Isolated Ophthalmic Venous Drainage.

Management of cavernous sinus dural arteriovenous fistula (CSDAVF) continues to present significant challenges, particularly when the inferior petrosal sinus is thrombosed, collapsed, or angiographically invisible. In this study, we introduce facilitated retrograde access via the facial vein, which is employed in the transvenous embolization of CSDAVF with isolated superior ophthalmic venous drainage. We also present illustrative cases and technical points.

Impact of Patient Head Posture on Lens Radiation Exposure During Cerebral Angiography.

BACKGROUND AND PURPOSE: Cerebral angiography remains crucial for detailed characterization and preoperative assessments for intracranial aneurysm. Despite its diagnostic importance, cerebral angiography poses challenges due to its invasiveness, the risk of neurological complications, and radiation exposure. To investigate the impact of head posture on lens radiation exposure during cerebral angiography, this study focused on the correlation between radiation doses to the eye lens, head flexion angles, and head size. MATERIALS AND METHODS: A retrospective analysis was performed on 20 patients who underwent cerebral angiography for unruptured intracranial aneurysms between October and November 2022. Radiation doses to the lens, which were measured in a prior prospective study using photoluminescent glass dosimeters, were analyzed alongside head flexion angles, anteroposterior (AP) head diameters, and kerma-area product (KAP) to evaluate their correlation with lens radiation exposure. The lateral radiation source is located on the left side of the patients. RESULTS: The cohort consisted of 20 patients (60% female, mean age: 62.3 ± 9.9 years). The radiation dose to the left eye (the eye closer to the x-ray source) was 2.8 times higher than that to the right eye (9.18 ± 3.31 mGy vs. 3.3 ± 0.60 mGy, P < 0.001). A strong positive correlation was observed between the left eye lens dose and head flexion angle (R = 0.815, P < 0.001). While the AP head diameter significantly correlated with the flexion angle, it showed no significant correlation with lens dose. The KAP was inversely correlated with both the left lens dose (R = -0.597, P = 0.005) and the flexion angle (R = -0.689, P < 0.001). CONCLUSIONS: Our findings underscore the significant impact of head posture on lens radiation exposure during cerebral angiography. Adjusting head positioning may provide a practical approach to reduce radiation exposure to the lens. Furthermore, it is worth noting that the left lens received more radiation than the right, likely due to the X-ray source being on the left side of the patient. ABBREVIATIONS: AP = anteroposterior; KAP = kerma-area product, PLD = photoluminescent glass dosimeter.

In Vitro Head-to-Head Comparison of Flow Reduction between Fibered and Non-Fibered Pushable Coils.

PURPOSE: To compare the embolization effects of a non-fibered pushable coil with a conventional fibered pushable coil in an in vitro bench-top experiment. MATERIALS AND METHODS: A simplified vascular phantom with 4 channels (1 for the non-fibered coil, 1 for the fibered coil, and 2 for continuous circuit flow) was used. A single coil of the longest length was inserted to evaluate the effect of single-coil embolization, and 3 consecutive coils were inserted to assess the effect of multiple-coil embolization. Post-embolization angiography was performed to obtain flow variables (time to peak [TTP], relative peak intensity [rPI], and angiographic flow reduction score [AFRS]) from time density curves. The packing densities of the two coil types were calculated, and the AFRS of each channel was determined by dividing the TTP by the rPI. RESULTS: When inserting a single coil, the conventional fibered coil demonstrated better flow reduction, as indicated by a higher AFRS (25.6 vs. 17.4, P=0.034). However, the non-fibered coil exhibited a significantly higher packing density (12.9 vs. 2.4, P=0.001). Similar trends were observed with multiple coils. CONCLUSION: The conventional fibered pushable coil showed better flow reduction efficiency, while the non-fibered pushable coil had a higher packing density, likely due to the flexibility of the coil loops. A better understanding of the distinct characteristics of different pushable coils can enhance the outcomes of various vascular embolization.

Effect of Intravenous Thrombolysis Prior to Mechanical Thrombectomy According to the Location of M1 Occlusion.

BACKGROUND AND PURPOSE: The additive effects of intravenous thrombolysis (IVT) before mechanical thrombectomy (MT) remain unclear. We aimed to investigate the efficacy and safety of IVT prior to MT depending on the location of M1 occlusion. METHODS: We reviewed the cases of patients who underwent MT for emergent large-vessel occlusion of the M1 segment. Baseline characteristics as well as clinical and periprocedural variables were compared according to the location of M1 occlusion (i.e., proximal and distal M1 occlusion). The main outcome was the achievement of functional independence (modified Rankin Scale score, 0-2) at 3 months after stroke. The main outcomes were compared between the proximal and distal groups based on the use of IVT before MT. RESULTS: Among 271 patients (proximal occlusion, 44.6%; distal occlusion, 55.4%), 33.9% (41/121) with proximal occlusion and 24.7% (37/150) with distal occlusion underwent IVT prior to MT. Largeartery atherosclerosis was more common in patients with proximal M1 occlusion; cardioembolism was more common in those with distal M1 occlusion. In patients with proximal M1 occlusion, there was no association between IVT before MT and functional independence. In contrast, there was a significant association between the use of IVT prior to MT (odds ratio=5.30, 95% confidence interval=1.56-18.05, P=0.007) and functional independence in patients with distal M1 occlusion. CONCLUSION: IVT before MT was associated with improved functional outcomes in patients with M1 occlusion, especially in those with distal M1 occlusion but not in those with proximal M1 occlusion.

Distal normal vessel diameter might be associated with silent brain infarcts after stenting for symptomatic carotid stenosis.

BACKGROUND: Carotid artery stenting (CAS) has been the standard treatment for carotid stenosis because it is less invasive; however, the risk of periprocedural thromboembolism is high. We investigated the predictors for silent brain infarcts (SBIs), focusing on embolic protection in CAS. METHODS: This study was single-center retrospective study, and we obtained baseline demographics and clinical, laboratory, and periprocedural variables of patients who underwent CAS. Also, methods used for embolic protection (no EPD, distal EPD, or proximal balloon guiding catheter) during CAS were obtained. Distal normal vessel diameter was defined as the diameter of cervical internal carotid artery where the artery wall becomes parallel. Diffusion-weighted imaging was performed before and after procedure to detect SBIs. The primary outcome was stented territory SBIs, and the secondary outcomes were any territories SBIs and stented territory SBIs in cases with EPD. RESULTS: A total of 196 CAS procedures with mean age 69.1 ± 9.9 years were included. After CAS, stented territory SBIs occurred in 53 (27.0 %) cases and any territories SBIs in 60 (30.6 %) cases. Univariable analyses revealed that distal normal vessel diameter (odds ratio = 1.71, 95 % confidence interval = 1.20-2.43, P = 0.003) was associated with the occurrence of stented territory SBIs after CAS. After adjusting for potential variables, larger distal normal vessel diameter (1.61 [1.10-2.36], P = 0.014) increased the occurrence of SBIs after CAS. Consistent results were obtained when the outcome was any territories SBIs or stented territory SBIs in cases with EPD. CONCLUSIONS: Distal normal vessel diameter was a predictor for the occurrence of SBI after CAS. The passable pore size of EPDs may vary depending on vessel diameter, and may impact the occurrence of SBIs.

Ruptured Medullary Hemangioblastoma Mimicking a Craniocervical Junction Dural Arteriovenous Fistula with a Pseudoaneurysm.

Hemangioblastomas (HBMs) are rare vascular tumors commonly located in the posterior fossa of adults. A mid-50s patient presented with sudden unconsciousness. Computed tomography scans revealed acute hemorrhages around the posterior fossa, predominantly in the subarachnoid space. Digital subtraction angiography (DSA) revealed an 8-mm round lesion filled with contrast agent, fed by the C1 segmental artery of the left vertebral artery (VA), showing early venous drainage to the spinal cord and brainstem. Emergent embolization was attempted under suspicion of a ruptured dural arteriovenous fistula, resulting in parent artery occlusion due to feeder selection failure. Follow-up DSA after a month depicted a persistent aneurysm via collaterals from both VAs. Consequently, the decision was made to proceed with surgical intervention, leading to the resection of the lesion, confirming its diagnosis as a HBM through histological examination. This case underscores the potential for misdiagnosis when HBMs with an intratumoral shunt mimic vascular shunt lesions.

Flow Diverter Treatment Using a Flow Re-Direction Endoluminal Device for Unruptured Intracranial Vertebral Artery Dissecting Aneurysm: Single-Center Case Series and Technical Considerations.

PURPOSE: This study aimed to evaluate the effectiveness, safety, and technical considerations of flow diverter (FD) treatment using a Flow Re-direction Endoluminal Device (FRED) for unruptured intracranial vertebral artery dissecting aneurysms (VADAs). MATERIALS AND METHODS: We conducted a retrospective study of 23 patients with unruptured intracranial VADAs who underwent FD treatment using a FRED between June 2017 and August 2021. Symptoms, imaging findings, treatment strategies, and angiographic and clinical outcomes were evaluated. Dissections were categorized according to the dominance of the VA in which they occurred: dominant VA, co-dominant VA, and non-dominant VA. RESULTS: All patients successfully underwent FD treatment with either a FRED (n=11) or FRED Jr. (n=12). Complete occlusion rates were 78.3% at 6-month follow-up magnetic resonance angiography and 91.3% at 12-month. There were no instances of complications, recurrence, or retreatment during a median follow-up of 20 months. Dissections occurred in the dominant VA in 3 cases (13.0%), the co-dominant VA in 13 cases (56.5%), and the non-dominant VA in 7 cases (30.4%). Intimal flap and true lumen stenosis were observed in 39.1% and 30.4% of cases, respectively. Four cases required a bilateral VA approach due to technical difficulties, all in the non-dominant VA. CONCLUSION: Flow diversion treatment using a FRED for unruptured intracranial VADAs proved feasible and safe, yielding satisfactory occlusion rates. Technical challenges were more likely in lesions involving non-dominant VAs in the acute or subacute stage, mainly due to associated intraluminal lesions compromising the arterial lumen.

Addendum: Outpatient Day-Care Management of Unruptured Intracranial Aneurysm: A Retrospective Cohort Study.

This corrects the article on p. 828 in vol. 23, PMID: 35762182.

Trends of Expanding Indications of Woven EndoBridge Devices for the Treatment of Intracranial Aneurysms: A Systematic Review and Meta-analysis.

PURPOSE: Woven EndoBridge (WEB) was introduced for the endovascular therapy of wide-neck intracranial aneurysms. The safety and efficacy have been evaluated through several meta-analyses. However, these reviews did not cover the expanding indications in detail. Therefore, we aimed to show the changing trends for intracranial aneurysm treatment using the WEB device. METHODS: A systematic review and meta-analysis was conducted with PubMed, Embase, and Cochrane databases. We searched for studies that reported baseline characteristics of aneurysms and the WEB devices, which had treated more than 20 aneurysms consecutively. The pooled proportions of aneurysm indications and used WEB device types were obtained. To evaluate the changing indications for the treated aneurysm size, including the neck diameter, a trend line and linear regression model was measured. RESULTS: A total of 27 cohorts were included encompassing 1831 aneurysms treated with the WEB. A total of 86% were used in the four major locations as on-label indications (middle cerebral artery bifurcation; 34%, anterior communicating artery; 26%, basilar tip; 18%, internal carotid artery terminus; 7%). Among off-label indications, the most common location was the posterior communicating artery (8%), followed by the anterior cerebral artery including the pericallosal artery (6%). The median aneurysm size and neck diameter was 7 mm and 4.6 mm, respectively. The WEB device has been used for the treatment of smaller aneurysms than the initial indication. Also, the proportion for ruptured aneurysm treatment was increased up to 15%. CONCLUSION: The mechanical and technical development of the WEB resulted in expanding the indications for the treatment of intracranial aneurysms. The off-label indications accounted for 14% in total and an increasing number of small aneurysms are treated with WEB devices. Moreover, the proportion for ruptured aneurysm treatment was currently increased up to 14% more than in the beginning.

Delayed low cerebellar perfusion status is associated with poor outcomes in top-of-basilar occlusion treated with thrombectomy.

Background and purpose: Top-of-basilar artery occlusion (TOB) is one of the most devastating strokes despite successful mechanical thrombectomy (MT). We aimed to investigate the impact of initial low cerebellum perfusion delay on the outcomes of TOB treated with MT. Methods: We included patients who underwent MT for TOB. Clinical and peri-procedural variables were obtained. Perfusion delay in the low cerebellum was defined as (1) time-to-maximum (Tmax) >10 s lesions or (2) relative time-to-peak (rTTP) map >9.5 s with a diameter of ≥6 mm in the low cerebellum. The good functional outcome was defined as the achievement of a modified Rankin Scale score of 0-3 at 3 months after stroke. Results: Among the 42 included patients, 24 (57.1%) patients showed perfusion delay in the low cerebellum. The admission National Institutes of Health Stroke Scale (NIHSS) score was significantly higher in those with perfusion delay [17 (12-24) vs. 8 (6-15), P = 0.002]. Accordingly, the proportion of good functional outcomes was lower in those with perfusion delay than in those without [5 (20.8%) vs. 13 (72.2%), P = 0.003]. From the multivariable analysis, the admission NIHSS score [odds ratio (OR) = 0.86, 95% confidence intervals (CIs) = 0.75-0.98, P = 0.021] and low cerebellum perfusion delay (OR = 0.18, 95% Cis = 0.04-0.86, P = 0.031) were independently associated with the 3-month functional outcomes. Conclusion: We found that initial perfusion delay proximal to TOB in the low cerebellum might be a predictor for poor functional outcomes in TOB treated with MT.

Impact of a selective lens dose reduction protocol in 3D rotational angiography on radiation exposure to the eye lens during cerebral angiography: a randomized controlled trial.

BACKGROUND: We aimed to investigate the radiation dose to the eye lens (lens dose) during cerebral angiography and to evaluate the effectiveness of the lens dose reduction protocol for 3-dimensional rotational angiography (3D-RA) in reducing overall lens dose exposure. METHODS: We conducted a randomized, controlled clinical trial at a tertiary hospital with patients undergoing cerebral angiography. The lens dose reduction protocol in 3D-RA involved raising the table to position the patient's eye lens away from the rotation axis. The lens dose was estimated by measuring the entrance surface air kerma using a photoluminescent glass dosimeter. The lens doses of 3D-RA, overall examination, and image quality were analyzed and compared between the two groups. RESULTS: A total of 20 participants (mean age, 58±9.4 years; including 12 men [60%]) were enrolled and randomly assigned to either the conventional group or the dose reduction group. The median lens dose in 3D-RA was significantly lower in the dose reduction group compared with the conventional group (1.1 mGy vs 4.5 mGy, p<0.001). The total dose was significantly lower in the dose reduction group (median of 7.5 mGy vs 10.2 mGy, p=0.003). In the conventional group, 3D-RA accounted for 46% of the total lens dose, while in the dose reduction group, its proportion decreased to 16%. No significant differences were observed in the image quality between the groups. CONCLUSION: The lens dose reduction protocol resulted in a significant reduction in the lens dose of the 3D-RA as well as entire cerebral angiography, while maintaining the image quality.

Reduction of Radiation Dose to Eye Lens in Cerebral 3D Rotational Angiography Using Head Off-Centering by Table Height Adjustment: A Prospective Study.

OBJECTIVE: Three-dimensional rotational angiography (3D-RA) is increasingly used for the evaluation of intracranial aneurysms (IAs); however, radiation exposure to the lens is a concern. We investigated the effect of head off-centering by adjusting table height on the lens dose during 3D-RA and its feasibility in patient examination. MATERIALS AND METHODS: The effect of head off-centering during 3D-RA on the lens radiation dose at various table heights was investigated using a RANDO head phantom (Alderson Research Labs). We prospectively enrolled 20 patients (58.0 ± 9.4 years) with IAs who were scheduled to undergo bilateral 3D-RA. In all patients' 3D-RA, the lens dose-reduction protocol involving elevation of the examination table was applied to one internal carotid artery, and the conventional protocol was applied to the other. The lens dose was measured using photoluminescent glass dosimeters (GD-352M, AGC Techno Glass Co., LTD), and radiation dose metrics were compared between the two protocols. Image quality was quantitatively analyzed using source images for image noise, signal-to-noise ratio, and contrast-to-noise ratio. Additionally, three reviewers qualitatively assessed the image quality using a five-point Likert scale. RESULTS: The phantom study showed that the lens dose was reduced by an average of 38% per 1 cm increase in table height. In the patient study, the dose-reduction protocol (elevating the table height by an average of 2.3 cm) led to an 83% reduction in the median dose from 4.65 mGy to 0.79 mGy (P < 0.001). There were no significant differences between dose-reduction and conventional protocols in the kerma area product (7.34 vs. 7.40 Gy·cm², P = 0.892), air kerma (75.7 vs. 75.1 mGy, P = 0.872), and image quality. CONCLUSION: The lens radiation dose was significantly affected by table height adjustment during 3D-RA. Intentional head off-centering by elevation of the table is a simple and effective way to reduce the lens dose in clinical practice.

Association between lipid profile changes and risk of in-stent restenosis in ischemic stroke patients with intracranial stenosis: A retrospective cohort study.

OBJECTIVE: The risk of ischemic stroke with intracranial stenosis is associated with various serum lipid levels. However, the effects of changes in the lipid profile on the risk of in-stent restenosis have not been verified. Therefore, we investigated the association between the occurrence of in-stent restenosis at 12-month follow-up and changes in various lipid profiles. METHODS: In this retrospective cohort study, we included ischemic stroke patients who had undergone intracranial stenting for symptomatic intracranial stenosis between February 2010 and May 2020. We collected data about serum low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), total cholesterol (TC), and triglyceride (TG) levels, and calculated the TC/HDL-C and LDL-C/HDL-C ratios at baseline and after 12 months. We conducted multivariable logistic regression analyses to verify the association between various lipid profile changes and in-stent restenosis at 12 months. RESULTS: Among the 100 patients included in the study (mean age, 60.8 ± 10.0 years; male: 80 [80.0%]), in-stent restenosis was found in 13 (13.0%) patients. The risk of in-stent restenosis of more than 50% was significantly decreased when TC/HDL-C ratio (odds ratio [OR] 0.22, [95% confidence interval (CI) 0.05-0.87]) and LDL-C/HDL-C ratio (OR 0.23, [95% CI 0.06-0.93]) decreased or when HDL-C levels (OR 0.10, [95% CI 0.02-0.63]) were increased at 12 months compared with baseline measurements. CONCLUSIONS: Improvement of HDL-C levels, TC/HDL-C ratio, and LDL-C/HDL-C ratio were associated with decreased risk of in-stent restenosis at 12-month follow-up. Management and careful monitoring of various lipid profiles including HDL-C levels, TC/HDL-C ratio, and LDL-C/HDL-C ratio may be important to prevent in-stent restenosis in patients with intracranial stenting.

Physiologic Flow Diversion Coiling Technique for Wide-Necked Aneurysms with an Asymmetric Bidirectional Flow at the Aneurysm Neck.

PURPOSE: Wide-necked aneurysms in the circle of Willis (CoW) are prone to recur due to reciprocal bidirectional flow. We present a novel concept of coil embolization to prevent recurrence that uses physiologic flow diversion at the CoW. MATERIALS AND METHODS: We enrolled 14 patients (15 aneurysms) who underwent aneurysm coiling for wide-necked aneurysms with asymmetric bidirectional inflow into the aneurysm. Four patients had recurrent aneurysms after coiling. The concept of physiologic flow diversion included obliterating antegrade flow into the aneurysm sac as well as opposite CoW flow by performing compact coil packing with intentional protrusion out of the aneurysm neck to the communicating part. RESULTS: Fifteen aneurysms, including 4 recurrent aneurysms, in an anterior communicating artery (n=7), posterior communicating artery (n=5), and tip of the basilar artery (n=3) were treated with coil embolization (n=10) and stent-assisted coiling (n=5). All aneurysms had a wide neck, and the mean largest diameter was 9.0 mm. The mean packing density was 45.1%. Twelve aneurysms were completely occluded, and 3 aneurysms had tiny residual neck remnants. There was neither a neurological event nor recurrence during the mean 12.5 months of follow-up. CONCLUSION: Wide-necked aneurysms at the CoW tend to recur. As a strategy to prevent a recurrence, physiologic flow diversion can be an option in treating wide-necked aneurysms in the CoW.