Roles of i-ED coils in endovascular treatment of cerebral aneurysms, arteriovenous shunts and cerebrospinal fluid-venous fistulas

Introduction

Endovascular coiling was first introduced for the treatment of intracranial aneurysms, with gradual expansion of the coil usage. A variety of coils have been developed and used in neuro-intervention procedures in the past decades. Coils vary in terms of materials (bioactive versus bare platinum), shapes [helical, three-dimensional (3D), complex, tetra], sizing, stiffness and detachment devices (1). The choice of coil selection depends on the aneurysm or arteriovenous shunt characteristics such as the morphology, location and size.

i-ED coils (with the “i” standing for improved generation of ED coils) have been released into the Japanese market in 2019. The i-ED coil series (Kaneka medics, Kanagawa, Japan) consists of four series: Complex, Complex SilkySoft, Complex Infini and Infini. While some properties of this coil system have been described in the literature, a comprehensive review of the potential applications of individual coil series remains lacking. In this illustrative retrospective case series, we present 7 cases in which i-ED coils were utilized in endovascular treatment, providing detailed insights into their specific applications, highlighting their advantages and illustrating potential complications. We present this article in accordance with the AME Case Series reporting checklist (available at https://jni.amegroups.com/article/view/10.21037/jni-25-32/rc).

Case presentation

A retrospective analysis of cases utilizing i-ED coils in endovascular treatment of neurovascular diseases in our institution from February 2021 to July 2023 was performed. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Singhealth ethics board (ID-number 2022/2298). Informed consent was waived as all patients have been treated according to the current standard of care in National Neuroscience Institute and none of the information collected would affect the current standard of treatment and decisions on patients’ care. Cases best demonstrating the specific roles of i-ED coils were included in this case series (cases 1–6), along with a rare, complicated case (case 7). The technical and clinical details of these illustrative cases were summarized in Table 1.

Case 1—primary coil embolization of a ruptured left anterior choroidal artery (AChA) aneurysm

A 51-year-old male with background hypertension presented with acute subarachnoid hemorrhage from a ruptured left AChA aneurysm. Angiogram demonstrated an elongated, bilobed aneurysm arising from the left supraclinoid internal carotid artery (ICA), measuring 11.1 mm × 5.3 mm with a neck width of 2.6 mm. The origin of the left AChA was incorporated into the base of the aneurysm. Coil embolization of the aneurysm was performed under general anesthesia. Initial framing of the aneurysm was performed with a Target 360 soft coil, filled with a few Target and Axium Prime coils, followed by filling and finishing using 7 i-ED Complex Silky Soft coils. Conscious effort was made to preserve the patency of the AChA origin. Post-procedure angiogram demonstrated mRRC II occlusion with patent AChA. Stable aneurysm occlusion status was shown on magnetic resonance angiogram (MRA) at 4-year mark, with no evidence of aneurysm recurrence (Figure 1).

Figure 1 Primary coiling of a ruptured saccular aneurysm. (A) Angiogram demonstrating an elongated, bilobed aneurysm arising from the left supraclinoid ICA, incorporating the left AChA (arrow) at the base of the aneurysm. I-ED Complex SilkySoft coils were used for filling and finishing of the aneurysm. (B) Post-coiling angiogram and (C) unsubtracted image of the coil mass demonstrating mRRC II occlusion, with patent AChA (arrow). (D) Follow-up MRA at 4 years post procedure demonstrating stable aneurysm occlusion status with no evidence of aneurysm recurrence (arrow). AChA, anterior choroidal artery; ICA, internal carotid artery; MRA, magnetic resonance angiogram; mRRC, modified Raymond-Roy classification.

Complex SilkySoft coils are designed for “filling” and “finishing” of aneurysms. The coils are extremely soft with superior coil resistance to microcatheter kickback, which is important, especially in the late phase of aneurysm coiling (2), as this may increase aneurysm packing density and lower the rate of future aneurysm recurrence (3).

Case 2—coil embolization of distal flow-related aneurysm via a flow-directed microcatheter

A 70-year-old female with poorly controlled hypertension presented with acute left-sided weakness. Computed tomography (CT) scan demonstrated a large intraparenchymal hematoma in the right frontal lobe and diffuse subarachnoid haemorrhage. Angiogram demonstrated the presence of a falco-tentorial dural arteriovenous fistula (DAVF) with a flow-related aneurysm along the proximal segment of the artery of the Davidoff and Schechter (ADS) (Figure 2).

Figure 2 Coiling of a flow-related aneurysm via a single marker flow-directed microcatheter. (A,B) Angiogram demonstrating a flow-related aneurysm centered at the proximal segment of the ADS on the right (arrows). (C) Unsubtracted image of the coil mass. Coil embolization with parent artery sacrifice was performed using i-ED Complex ExtraSoft and SilkySoft coils via a Marathon microcatheter. (D) Post-embolization angiogram demonstrating a well-occluded flow-related aneurysm. ADS, artery of Davidoff and Schechter.

This small, distally located (along the ADS) flow-related aneurysm was accessible with flow-directed microcatheter. Selected series of i-ED coils (SilkySoft and ExtraSoft coils with 0.010'' primary coil diameter) are compatible with flow-directed microcatheter, which allows coil embolization of an aneurysm in this case.

Case 3—coil embolization of ruptured right terminal ICA aneurysm

A 58-year-old female with background hyperlipidemia and hypothyroidism presented with acute subarachnoid hemorrhage from a ruptured wide-neck right carotid terminus aneurysm. The aneurysm is irregular with multiple peripheral lobules, measuring 8.7 mm × 6.5 mm × 5.6 mm with a neck width of 4.9 mm. Stent-assisted coiling of the aneurysm was performed under general anesthesia, achieving mRRC II occlusion (4).

A total of 8 i-ED coils (Complex ExtraSoft, Silky Soft, Complex Infini) were used for aneurysm filling, following the initial framing using 2 Target 360 Soft coils (Figure 3).

Figure 3 Stent-assisted coiling of a ruptured saccular aneurysm. (A,B) Angiogram demonstrating a ruptured wide necked right carotid terminus aneurysm with multiple irregular lobules (arrows). (C) Stent-assisted coiling of the aneurysm was performed. A Neuroform Atlas stent was deployed across the aneurysm, with the coiling microcatheter jailed in place. Difficulty was encountered during attempt coiling of the peripheral lobules of the aneurysm (C, arrow); these peripheral lobules were subsequently successfully coiled using i-ED Complex SilkySoft and Complex Infini coils (D, arrow), owing to their low shape memory and low resistance to straightening phenomenon. (E) Post-coiling angiogram demonstrating mRRC II aneurysm occlusion. Follow-up MRA performed 1 year later (F), demonstrating a largely occluded aneurysm with only a tiny flow signal at the base of the aneurysm. MRA, magnetic resonance angiogram; mRRC, modified Raymond-Roy classification.

The Complex Infini series has low shape memory and comes with a pre-defined range of secondary coil diameter, allowing flexible filling of the aneurysm, and in this case, the peripheral irregular lobules of the aneurysm.

Case 4—coil embolization of bilateral indirect carotid-cavernous fistula (CCF)

A 53-year-old female presented with acute left cranial nerve (CN) VI palsy with left eye chemosis and headache. CT demonstrated abnormal opacification of bilateral cavernous sinuses and superior ophthalmic veins (SOVs). Angiogram confirmed the presence of bilateral indirect carotico-cavernous sinus fistula, supplied by bilateral ICA and external carotid artery (ECA) dural arterial feeders. Transvenous embolization of indirect CCF was performed via the right inferior petrosal sinus. Coiling of the dilated left SOV, left cavernous sinus, inter-cavernous sinus and right cavernous sinus was performed (Figure 4).

Figure 4 Transvenous coil embolization of bilateral indirect CCF. Right (A) and left (C) ECA angiogram demonstrating bilateral indirect CCF. (B) Transvenous coiling of bilateral indirect CCF was performed using a total of 22 i-ED coils and 2 Target coils, with a total coil length of 691 cm. (D,F) Post-embolization angiograms from bilateral ECAs and ICAs (not shown) demonstrating complete occlusion of bilateral indirect CCF. Follow-up MRA performed 1 year later (E) showing no recurrence of the CCF. CCF, carotid-cavernous fistula; ECA, external carotid artery; ICA, internal carotid artery; MRA, magnetic resonance angiogram.

Each of the i-ED Infini coil comes with a pre-defined range of coil diameter and various extended coil lengths (up to 50 cm), allowing the coil to fill different compartments of the cavernous sinuses in a flexible and cost-effective manner.

Case 5—coil embolization of giant right ICA aneurysm with parent artery sacrifice

A 60-year-old female presented with right CN VI palsy with binocular horizontal diplopia, worse on right gaze. A giant right cavernous ICA saccular aneurysm was confirmed on angiogram, measuring 32 mm × 24 mm × 25 mm. Coil embolization of the aneurysm was performed with parent artery sacrifice after passing balloon test occlusion, achieving complete aneurysm occlusion. During coiling, the proximal microcatheter marker was obscured by the coil mass, preventing safe identification of the coil detachment zone under fluoroscopy. The additional sound and light indicators of the electro detach generator (EDG) system allow accurate identification of the detachment zone. The patient recovered well post-coiling with no new neurological deficit, and gradual resolution of diplopia (Figure 5).

Figure 5 Coil embolization of a giant saccular aneurysm with parent artery sacrifice. (A) 3D rotational angiogram demonstrating a giant right cavernous ICA aneurysm. (B) Initial angiographic run of the right ICA demonstrates contrast filling and stasis of the aneurysm, with reduced antegrade flow to the ipsilateral anterior circulation. Coil embolization of the aneurysm was performed with parent artery sacrifice after passing balloon test occlusion, achieving complete aneurysm occlusion. (C) Post-coiling unsubtracted image of the coil mass. (D) Post-embolization angiogram from the left ICA showing good cross flow to the right intracranial anterior circulation. (E) MRA 2 years post-embolization showing no evidence of aneurysm recurrence or new infarcts, with good intracranial cross flow. 3D, three-dimensional; ICA, internal carotid artery; MRA, magnetic resonance angiogram.

Case 6—cerebrospinal fluid (CSF)-venous fistula; coil embolization of a segmental vein through an Eclipse balloon microcatheter to form a distal “plug”, redirecting Onyx for embolization of the epidural venous plexus

A 64-year-old female presented with severe orthostatic headaches preventing her from standing upright for more than 30 minutes, required regular caffeine ergotamine tablets and paracetamol tablets for pain relief. Magnetic resonance imaging (MRI) of the brain demonstrated signs of intracranial hypotension, with no evidence of spinal epidural collection on MRI of the spine. Right lateral decubitus myelography demonstrated contrast filling of the right T8/9 segmental vein, indicative of a right T8/9 CSF venous fistula. Following placement of a guiding catheter into the proximal segmental vein, venography demonstrated multiple small veins filling the epidural venous plexus, preventing superselective catheterization of the fistulous zone. An Eclipse balloon microcatheter (6 mm × 12 mm) was first advanced distally into the segmental vein for coiling of the segmental vein with i-ED ExtraSoft coils. During coiling, the coil detachment zone was accurately identified based on the sound and light indicators of the EDG system, as there was no proximal coiling marker on Eclipse balloon microcatheter. Onyx was then injected under balloon inflation to trap Onyx and to redirect the liquid embolic into the desired target (epidural venous plexus). The patient demonstrated immediate symptom resolution of her orthostatic headaches on the day of treatment. Clinical follow-up 12 weeks post procedure showed no recurrence of symptoms, modified Rankin scale (MRS) 0 (Figure 6).

Figure 6 Coil and Onyx embolization of a CSF-venous fistula via a single marker balloon microcatheter. (A) CT myelogram demonstrating contrast filling of the right paravertebral segmental vein at T8/9 level (arrow), confirming the diagnosis of CSF-venous fistula. (B-D) Transvenous embolization of CSF-venous fistula was performed. Initial venogram (B,C) demonstrates the right T8/9 segmental vein (asterisk) leading to the epidural venous plexus (arrowheads) via multiple small veins (short arrows). An Eclipse balloon microcatheter (6 mm × 12 mm) was first advanced distally into the segmental vein for coiling followed by Onyx injection to form a distal “plug” (C,D) (long arrows). Onyx was then re-directed to the epidural venous plexus (arrowheads) for embolization under balloon inflation. CSF, cerebrospinal fluid; CT, computed tomography.

Case 7—technical complication of i-ED Infini coil—a “stretched” coil

A 77-year-old male with background of Alzheimer’s disease, hypertension and hyperlipidemia on long term medications, presented with an acute subarachnoid haemorrhage secondary to a ruptured anterior communicating artery (ACOM) aneurysm. Angiogram demonstrated an irregularly lobulated aneurysm with a daughter sac at its anterosuperior aspect, measuring 7.5 mm × 6.1 mm × 6.0 mm with neck width of 3.3 mm. Primary coil embolization of the aneurysm was performed using a 7 mm × 30 cm Target 360 soft coil for framing and an i-ED infini coil 4–8 mm × 30 cm for filling. Repeat coil manipulations were required to fill the aneurysm sac with the i-ED coil. Towards the end of the coiling (the last ~5 cm), the coil was noted to be unresponsive and “stretched”. The stretched coil was partially removed using goose-snare and stent retriever, with the remaining strand of stretched coil extending from the right A1 anterior cerebral artery to the right distal cervical ICA. The patient was subsequently loaded with dual antiplatelets to prevent thrombo-embolic complications. The patient recovered well with no new neurological deficits. Follow-up MRA at the 3-year mark showed a stable, tiny residual flow at the aneurysm neck, with no evidence of aneurysm recurrence (Figure 7).

Figure 7 Coiling of a ruptured saccular aneurysm complicated with “stretched coil”. (A) Angiogram demonstrating an irregularly lobulated ruptured ACOM aneurysm. (B) Unsubstracted image demonstrating the partially deployed i-ED Infini coil within a microcatheter. (C) After several repeat manipulations, the coil was “stretched”, with residual segment extending from the ACOM aneurysm neck to the right distal cervical ICA (lateral view, arrows). (D) Post-embolization angiogram demonstrating a well-occluded ACOM aneurysm. No immediate thrombo-embolic complications. ACOM, anterior communicating artery; ICA, internal carotid artery.

Overestimation of coil size and length could lead to complicated aneurysm coiling. This case was complicated with a “stretched” coil, likely due to repeated coil manipulations from attempted filling of an oversize coil, in terms of coil primary diameter (0.014-inch) and length (30 cm) into the aneurysm.

Discussion

The i-ED coil series is designed for clinical versatility, featuring a graded increase in coil stiffness, primary diameter, and length, in alignment with increasing secondary coil diameter. This graduated design enables strategic coil selection tailored to the specific requirements of individual cases—particularly the morphology and size of the target aneurysms or vascular spaces, as well as the phases of coiling (Table 2).

The Complex series is designed for framing and filling. It has secondary coil diameters ranging from 3 to 16 mm with various graded “stiffness” (ranging from ExtraSoft to Standard), length (from 4 to 50 cm) and coil primary diameter (0.010 to 0.014-inch). The Complex SilkySoft series with coil secondary diameter ranging from 1 to 3 mm is designed for finishing as it is extremely soft with a small coil primary diameter (0.010-inch). We used these series mainly for filling and finishing of aneurysms (Figure 1).

Microcatheter kickback in the late phase of coil embolization is a well-documented occurrence due to the straightening phenomenon of the coil (2). One of the unique properties of the i-ED coil series, in particular the SilkySoft series, is the coil resistance to straightening phenomenon, which has been shown to be superior to Target and Axium Prime coils in an in vitro study (3) and in recent case series using i-ED coils (5). This can be attributed to the construct of the coil as it has a wavy stretch resistant wire within with enlarged gaps between pitches. By minimizing microcatheter kickback, there is improved stability of the coiling microcatheter, thus increasing aneurysm packing density and reducing future aneurysm recurrence (6,7).

One of the major advantages of the smaller coils in these coil series with 0.010-inch primary coil diameter is its ability to be deployed through small, flow-directed microcatheters such as the Marathon, Apollo and Headway Duo microcatheters (Figure 2) (8-10), which allows coiling of small and distal aneurysms (for example flow-related or mycotic aneurysms) and in treatment of arteriovenous malformation (AVM) or fistulas when using a “pressure-cooker technique”. Flow-directed microcatheters are usually longer and more flexible with smaller internal diameter, allowing navigation to distal and tortuous vessels with narrower diameter. An example of such flow-directed microcatheters would be the Marathon microcatheter (Medtronic, Minneapolis, Minnesota, USA), which has an internal diameter of 0.013 inch and length of 165 cm. The i-ED coil series with 0.010-inch primary diameter has the narrowest distal end of the pusher wire compared to its counterparts, such as the Target, Axium Prime, or Hypersoft coils, allowing it to pass through the distal opening of the flow-directed microcatheters (8). Mismatch between the microcatheter length and the length of the coil pusher wire is overcome by the i-ED coil series, as it has an extended length of the pusher wire (187 cm), which allows coiling through flow-directed microcatheters without the need to temporarily disconnect the rotating hemostatic valve (RHV), which is essential to maintain continuous flushing to avoid clot formation. Flow-directed microcatheters and balloon microcatheters have only a single marker, lacking the more proximal detachment marker to guide safe placement of coils. This problem is overcome by the design of the EDG system that accurately identifies the detachment point by using flashing lights and beeping sounds, when the proximal microcatheter marker is absent (in flow-directed or balloon microcatheters) or not visible (when the proximal marker on the coiling microcatheter is embedded within the coil mass).

The Infini and Complex Infini series are designed mainly for filling owing to their low shape memory with a pre-defined range of secondary coil diameter. These properties allow the coils to effectively seek spaces in multi-lobulated aneurysms to increase packing density (11-12) and fill vascular spaces of various sizes (such as the multi-compartment cavernous sinuses). The Infini and Complex Infini series also come with extended coil length (up to 50 cm), which allows reduction of coil usage in large vascular spaces and hence improves cost-effectiveness (13).

Coil stretching is an infrequently encountered complication and has been previously reported with other coils (14). The rate of occurrence was up to 2% with GDC coils, as reported by Standard et al. (15) and Cognard et al. (16). It could potentially lead to thrombo-embolic event(s) (17), parent vessel occlusion or aneurysmal rupture (18). In our case, coil “stretching” is likely attributed to excessive manipulation of this oversize coil with extended coil length. Appropriate coil selection based on individual coil properties and sizing is the key step in achieving optimal aneurysm occlusion and minimizing complications.

Strengths and limitations

This retrospective, single-center study illustrates several case examples best demonstrating the specific applications and advantages of i-ED coils. The study is limited by data heterogeneity, largely due to inter-operator variability and the combined use of coils from different manufacturers within individual cases. In our practice, i-ED coils have predominantly been employed for filling and finishing; thus, their role in aneurysm framing remains to be defined. Assessing the efficacy and outcomes of exclusive i-ED coil use, as well as making direct comparisons between different coil systems, remains challenging. The ongoing prospective, multicenter, non-randomized Kaneka Endovascular Embolization and Protection (KEEP) study, designed to assess the performance of i-ED coils in treating intracranial aneurysms, is anticipated to yield further insight into their efficacy and clinical outcomes.

Conclusions

Our study illustrates the unique properties and roles of i-ED coils in endovascular treatment of aneurysms, arteriovenous shunts and CSF-venous fistulas. Highlighted features include compatibility of small i-ED coils with flow directed microcatheters, reliable indicator of coil detachment zone with the EDG system in the absence of dual microcatheter markers or when the marker is obscured, low shape memory coils allowing flexible coiling, and cost-effectiveness with extended coil length. Future large-scale studies focusing on the long-term outcomes and safety of i-ED coils would be valuable to validate their long-term performance and risk profile.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the AME Case Series reporting checklist. Available at https://jni.amegroups.com/article/view/10.21037/jni-25-32/rc

Peer Review File: Available at https://jni.amegroups.com/article/view/10.21037/jni-25-32/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jni.amegroups.com/article/view/10.21037/jni-25-32/coif). J.P.T. reports honorarium received from ColorViz lecture–GE (07/2024), Stryker round table–Stryker (11/2024), Rapid AI lecture–Rapid AI (06/2025). S.K.S. was a speaker on Kaneka product at ATIN conference 2024. T.P.K. received travel support from Kaneka as an invited speaker for WFITN in August 2022. The other authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. The study was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. The study was approved by the Singhealth ethics board (ID-number 2022/2298). Informed consent was waived as all patients have been treated according to the current standard of care in National Neuroscience Institute and none of the information collected would affect the current standard of treatment and decisions on patients’ care.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Xiao N, Lewandowski RJ. Embolic Agents: Coils. Semin Intervent Radiol 2022;39:113-8. [Crossref] [PubMed]
2. Miyachi S, Izumi T, Matsubara N, et al. The mechanism of catheter kickback in the final stage of coil embolization for aneurysms: the straightening phenomenon. Interv Neuroradiol 2010;16:353-60. [Crossref] [PubMed]
3. Ishida M, Izumi T, Araki Y, et al. Evaluation of the Straightening Phenomenon of Various Types of Coils. Neurol Med Chir (Tokyo) 2021;61:356-60. [Crossref] [PubMed]
4. Mascitelli JR, Moyle H, Oermann EK, et al. An update to the Raymond-Roy Occlusion Classification of intracranial aneurysms treated with coil embolization. J Neurointerv Surg 2015;7:496-502. [Crossref] [PubMed]
5. Bazil MJ, Fifi JT, Yaeger KA, et al. Low-memory shape coils for intracranial aneurysm coiling: Initial and single-center experience with the i-ED coil. Surg Neurol Int 2023;14:142. [Crossref] [PubMed]
6. Sluzewski M, van Rooij WJ, Slob MJ, et al. Relation between aneurysm volume, packing, and compaction in 145 cerebral aneurysms treated with coils. Radiology 2004;231:653-8. [Crossref] [PubMed]
7. Yagi K, Satoh K, Satomi J, et al. Evaluation of aneurysm stability after endovascular embolization with Guglielmi detachable coils: correlation between long-term stability and volume embolization ratio. Neurol Med Chir (Tokyo) 2005;45:561-5; discussion 565-6. [Crossref] [PubMed]
8. Bhogal P, AlMatter M, Hellstern V, et al. High-Grade Dural Arteriovenous Fistulas : Use of Kaneka ED Coils with the Marathon Microcatheter for Transvenous Coil Embolization. Clin Neuroradiol 2019;29:653-60. [Crossref] [PubMed]
9. Beckett JS, Duckwiler GR, Tateshima S, et al. Coil embolization through the Marathon microcatheter: Advantages and pitfalls. Interv Neuroradiol 2017;23:28-33. [Crossref] [PubMed]
10. Horie N, Hayashi K, Morikawa M, et al. A Novel Method for Super-selective Coil Embolization Using an Extremely Soft Bare Coil through a Liquid Embolic Delivery Microcatheter. Neurol Med Chir (Tokyo) 2015;55:605-9. [Crossref] [PubMed]
11. Harada K, Morioka J. Initial experience with an extremely soft bare platinum coil, ED coil-10 Extra Soft, for endovascular treatment of cerebral aneurysms. J Neurointerv Surg 2013;5:577-81. [Crossref] [PubMed]
12. Sadato A, Hayakawa M, Adachi K, et al. Relationship between the Volume Rate of Ed Coil (Ed Ratio) and Packing Density in Endosaccular Embolization of Cerebral Aneurysms. Asian J Neurosurg 2018;13:619-25.
13. Sadato A, Hayakawa M, Adachi K, et al. Use of a new soft and long coil reduces the number of coils to embolize a small aneurysm. Interv Neuroradiol 2015;21:161-6. [Crossref] [PubMed]
14. Lee CY. Use of wire as a snare for endovascular retrieval of displaced or stretched coils: rescue from a technical complication. Neuroradiology 2011;53:31-5. [Crossref] [PubMed]
15. Standard SC, Chavis TD, Wakhloo AK, et al. Retrieval of a Guglielmi detachable coil after unraveling and fracture: case report and experimental results. Neurosurgery 1994;35:994-8; discussion 999. [Crossref] [PubMed]
16. Cognard C, Weill A, Castaings L, et al. Intracranial berry aneurysms: angiographic and clinical results after endovascular treatment. Radiology 1998;206:499-510. [Crossref] [PubMed]
17. Ihn YK, Shin SH, Baik SK, et al. Complications of endovascular treatment for intracranial aneurysms: Management and prevention. Interv Neuroradiol 2018;24:237-45. [Crossref] [PubMed]
18. Fox B, Humphries WE, Doss VT, et al. Rupture of giant vertebrobasilar aneurysm following flow diversion: mechanical stretch as a potential mechanism for early aneurysm rupture. J Neurointerv Surg 2015;7:e37. [Crossref] [PubMed]