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.

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.

Feasibility of a silicone vascular phantom replicating real arterial contrast filling dynamics on cerebral angiography: An in-vitro pilot study.

Some cerebral arterial silicone phantoms have been used in preclinical evaluations. However, typical silicone-based phantoms are limited in their capacity to reproduce real contrast filling dynamics of the human cerebral artery. This study aimed to develop a cerebral arterial silicone phantom to analyze the feasibility of real contrast filling dynamics. The fluid circulation phantom system consisted of a cerebral arterial silicone phantom without or with additional devices, a pump, an injection system, a pressure-monitoring system, a constant-temperature bath, and a venous drainage container. Vascular resistance was reproduced with a plastic cistern only or a plastic cistern filled with a sponge pad. Three phantom groups were constructed as follows: a) the cerebral arterial silicone phantom used as the control group (type A), b) phantom with the incorporated plastic cistern (type B), and c) phantom with the incorporated plastic cistern filled with a sponge pad (type C). The contrast concentration-time curve patterns of the three groups obtained from digital subtraction angiography (DSA) were compared. Consequently, the DSA pattern of the type C phantom was the most similar to that obtained from the control group as the reference data, which showed the broadest full-width-at-half-maximum and the area under the curve values and the highest maximum contrast concentration. In conclusion, we could emulate the arterial contrast filling dynamics of clinical cerebral angiography by applying a small cistern filled with a sponge pad at the drainage side of the phantom.

A modified method of elastase-induced saccular aneurysm creation in rabbits: Schematic representation of the method.

BACKGROUND: The purpose of our study was to investigate the safety and effectiveness of a modified technique using a short guiding catheter for instillation of elastase in comparison with the previously described method of creating elastase-induced aneurysm in rabbits. METHODS: Following right common carotid artery (RCCA) access using an arterial sheath and inflating the Fogarty balloon in the subclavian artery, a short guiding catheter was used for the instillation of the elastase in the experimental group (n = 5) while it was performed with a microcatheter in the control group (n = 5). The procedure duration was recorded from the RCCA puncture to the sheath removal. The histological changes were characterized using H&E and Masson's trichrome (MT) staining. RESULTS: The procedure time was 23 ± 2 min in the experimental group and 29 ± 2 min in the control group. All the rabbits (100%) in the experimental group survived without neurologic deficits, but two rabbits (40%) survived in the control group. All aneurysms were created in the saccular shape (100%) with a neck size of 2.3 ± 0.29 mm, a width of 2.75 ± 0.36 mm, and height of 6.37 ± 0.46 mm, and a dome to neck ratio of 1.21 ± 0.23. The aneurysm walls were partly thickened due to the degradation of the media tunica and adventitia proliferation with loss of the internal elastic lamina. CONCLUSION: By using a short guiding catheter, we could instill the elastase in a more effective and safe manner in the creation of the elastase-induced aneurysm model in rabbits.

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.

Safety and Effectiveness of the Novel Catheter 3.0 System for Diagnostic Cerebral Angiography: A Pilot Study.

PURPOSE: The purpose of this study was to evaluate the safety and effectiveness of a new angiographic system (Catheter 3.0 system) using a 5 French (Fr), large-bore angiography catheter, a 0.032-inch stiff guidewire, and a continuous flushing system in diagnostic cerebral angiography. MATERIALS AND METHODS: This retrospective study included 30 consecutive patients who underwent transfemoral cerebral angiography using the Catheter 3.0 system from October 2019 to March 2020. As the control group, we included 30 consecutive patients examined before the Catheter 3.0 system was introduced. Procedural outcomes, including technical success, procedure time, dose metrics, procedure-related complications, and image quality were reviewed and analyzed. RESULTS: All transfemoral cerebral angiographies were performed for a diagnosis of unruptured intracranial aneurysms. The Catheter 3.0 system showed a significantly shorter fluoroscopy time (6.2 vs. 9.7 minutes, P=0.008) and lower fluoroscopy dose (387.2 vs. 614.4, P=0.002) compared with the conventional 4-Fr catheter system. The Catheter 3.0 system also showed better results in terms of procedural time (21.0 vs. 22.5 minutes, P=0.072) and technical success rate (98.1% vs. 94.0%, P=0.078), although a statistical significance was not reached. The complication rate and qualitative assessment of the digital subtraction angiography (DSA) image quality were similar between the two groups. CONCLUSION: The Catheter 3.0 system using a 5 Fr catheter with a large inner diameter was convenient, effective, and safe compared with the conventional system in diagnostic cerebrovascular angiography.