Endovascular treatment of a large aneurysm arising from a basilar trunk fenestration using the waffle-cone technique

A Case Report of Stent-Assisted Coiling with One-and-a-Half-Lap Approach for Basilar Artery Fenestration Aneurysm

Objective

Fenestrated basilar artery aneurysms (fBA-ANs) typically arise at the proximal bifurcation of the fenestration limb. It is reported that endovascular treatment with conventional coil embolization or balloon-assisted embolization techniques is often challenging and associated with a high complication rate, especially for wide-neck fBA-ANs. We present a case of fBA-AN successfully treated with stent-assisted coil (SAC) embolization using a novel one-and-a-half-lap approach with an open-cell stent, ensuring reliable neck coverage while preserving parent artery patency.

Case Presentation

A 33-year-old man with a history of an unruptured fBA-AN, previously treated with coil embolization via the double-catheter technique 6 years ago, presented with coil compaction and aneurysm recurrence. DSA revealed an fBA-AN measuring 8.7 mm in diameter, requiring retreatment. Under general anesthesia, SAC was performed using a one-and-a-half-lap approach. A Neuroform Atlas stent (Stryker Neurovascular, Fremont, CA, USA) was deployed via a 2.4 Fr microcatheter, positioned in a clockwise direction from the left loop fenestration to the right loop across the aneurysm neck, followed by coil embolization. Postoperatively, the patient remained free of ischemic complications, and follow-up imaging showed no recurrence of the fBA-AN.

Conclusion

This case demonstrates the efficacy of SAC with a one-and-a-half-lap approach using an open-cell stent for the treatment of complex fBA-ANs. This technique provides a viable treatment option for wide-neck fBA-ANs, ensuring durable aneurysm occlusion while maintaining parent artery patency.

Endovascular Treatment of Large Proximal Basilar Artery Fenestrated Aneurysms: Overlapping Stent with Coil Embolization-A Case Report

This detailed case report presents and discusses the endovascular treatment of a large proximal basilar artery fenestrated aneurysm (PBAFA). Aneurysms occur rarely at the vertebrobasilar junction, with a moderate proportion of cases presenting fenestrations. Considering the high risk associated with posterior circulation aneurysms, including estimated rupture risk, periprocedural complications, or treatment difficulties in surgical procedures, endovascular treatment options are becoming increasingly favored, particularly considering the advancements in stent and flow diverter techniques. Our report focuses on a case of a 58-year-old male with a large unruptured PBAFA, treated using overlapping stent with coil embolization (OSCE) and triple catheter technique. This method was selected considering the size of the aneurysm, its complex vascular structure, and the risk of recurrence and complications. Our findings emphasize that a comprehensive understanding of vascular anatomy, hemodynamics, and the characteristics of endovascular treatment devices is essential for the treatment success. In addition, they demonstrate that the OSCE using low-profile visible intraluminal support devices combined with the triple catheter technique are an effective treatment option for large PBAFAs.

Kissing Aneurysms at Fenestrated Proximal Basilar Artery: Double-barrel Stent-assisted Coiling Using Dual Closed-cell Stents

Kissing aneurysms associated with a proximal basilar artery fenestration are an exceedingly rare and unique therapeutic challenge due to anatomical complexity. This report describes double-barrel stent-assisted technique with dual closed-cell stents for the successful endovascular coiling of kissing aneurysms from a proximal basilar artery fenestration.

Intra-aneurysmal hemodynamics: evaluation of pCONus and pCANvas bifurcation aneurysm devices using DSA optical flow imaging

BACKGROUND

Implantation of self-expanding stents from the parent artery into the sac of a bifurcation aneurysm is regularly used to facilitate endovascular coil occlusion with the so-called waffle cone technique (WCT). Self-expanding aneurysm bridging stents like Solitaire AB, can be used; however, bifurcation devices like pCONus and pCANvas are especially designed for WCT. These devices provide additional support for coil implantation owing to intraluminal nylon fibers (pCONus) or membranes (pCANvas) covering the intracranial aneurysm neck.

OBJECTIVE

Assessment of the intra-aneurysmal hemodynamic impact of these three devices: a regular intracranial stent (Solitaire AB) and two bifurcation devices (pCONus and pCANvas).

MATERIAL AND METHODS

An in vitro experiment was set up using a silicone model of a basilar tip aneurysm filled with blood mimicking fluid under a pulsatile circulation. Solitaire AB, pCONus, and pCANvas were successively implanted in the model for hemodynamic evaluation. High frame rate DSA series were acquired under various conditions. Intra-aneurysmal flow changes, including mean aneurysm flow amplitude ratio (R), were subsequently assessed by the optical flow method, measuring the detector velocity field before and after device implantations.

RESULTS

pCONus and Solitaire minimally reduced the intra-aneurysmal flow (R=0.96, p=0.17 and R=0.91, p=0.01, respectively), whereas pCANvas strongly diminished the intra-aneurysmal flow (R=0.41, p=5×10-12).

CONCLUSIONS

Waffle cone deployment of stents and technique-specific devices had no undesirable effect on the intra-aneurysmal flow. In particular, no increased flow was redirected into the aneurysm sac. The intraluminal membrane of the pCANvas strongly reduced the intra-aneurysmal flow, potentially preventing recanalization problems.

Treatment of fenestrated vertebrobasilar junction-related aneurysms with endovascular techniques

Fenestrated vertebrobasilar junction-related aneurysms (fVBJ-AN) are uncommon and endovascular management strategies have become the first options for the treatment of these lesions. This clinical study aimed to report our experience in the endovascular management of these lesions and to review the literature. We retrospectively reviewed 10 consecutive patients harboring 12 fVBJ-AN between January 2007 and December 2014. The demographic, angiographic and clinical data were reviewed. Additionally, a literature review was performed. Endovascular management strategies were successfully applied in all 10 patients. Post-procedural angiograms indicated total occlusion in eight (66.7%) aneurysms, a residual neck in one (8.3%) aneurysm, and three residual aneurysms (25%). No procedure-related complications were observed. Follow-up angiograms were obtained in eight patients and revealed nine occluded aneurysms and one improved aneurysm; two patients were lost to angiographic follow-up. Clinical follow-ups were obtained in all patients (until July 2015), and the modified Rankin Scale scores at 69.5months (range 17-101months) of follow-up were 0 in eight patients and 1 in two patients. Endovascular management strategies provided a high occlusion rate and an acceptable complication rate and are thus efficacious in the treatment of fVBJ-AN. Further studies are necessary to validate the utility of these treatments due to the low incidence of fVBJ-AN.

Flow diverter placement for management of dissecting ruptured aneurysm in a non-fused basilar artery

Intracranial vertebral artery dissection can be associated with subarachnoid hemorrhage (SAH) and pseudoaneurysm formation. Dissecting aneurysms have a high risk of rebleeding in the acute phase. To our knowledge, the management of an acute vertebrobasilar junction dissecting aneurysm associated with a basilar non-fusion has not been previously reported. We report here a case of SAH due to rupture of a dissecting aneurysm involving the vertebrobasilar junction and extending to involve the right limb and proximal junction of a non-fused basilar artery, managed by insertion of a flow-diverting stent with excellent clinical outcome and long-term patency of the flow diverter.

[Endovascular treatment of large and giant intracranial aneurysms using stent assistance]

OBJECTIVE

The study objective was to evaluate the efficacy of occlusions of large and giant intracranial aneurysms with microcoils using stent assistance (SA).

MATERIAL AND METHODS

The study is based on analysis of treatment outcomes in 37 patients with large (15-25mm) and giant (more than 25mm) intracranial aneurysms, aged 18 to 72 years, who were hospitalized at the Burdenko Neurosurgical Institute in the period between 2004 and 2014. Selection of patients for endovascular treatment using SA was based on the anatomical parameters of the aneurysm and carrier vessel. The main determining factor was the index of the aneurysm body to neck size ratio. Occlusion of aneurysms was performed with microcoils of different configurations, including those with a biologically active coating. Self-expanding stents with both an open-cell and closed-cell design were used for SA. The results of intervention for large and giant aneurysms were evaluated using control angiography immediately after occlusion of the aneurysm. The condition of patients with unruptured aneurysms as well as with ruptured aneurysms in the "cold" period was evaluated using the modified Rankin scale. The condition of patients in the acute period of SAH was evaluated on the Hunt and Hess scale.

RESULTS

The technical success (successful implantation of stents and coils with total or subtotal aneurysm occlusion) was 94.5%. The postoperative disability was 2.7%; mortality was 2.7%. 28 patients were followed up for the period of 5 to 84 months (the mean was 20 months.). In the long-term period, the total and subtotal occlusion rate, including the results of re-operations, amounted to 90%. Delayed disability was 10.7%, and mortality was 3.5%.

CONCLUSION

Stent assistance enables achieving total or subtotal occlusion of large and giant aneurysms in 90% of cases. In certain clinical situations, it is an alternative to other existing methods.

Dual flow diversion stents for aneurysm treatment in a partial unfused basilar artery

Unfused basilar arteries, frequently but erroneously referred to as 'fenestrations', are not uncommonly associated with aneurysms. The difficulty in treating these aneurysms lie in the fact that they are often wide necked and frequently incorporate both channels of the unfused segment, with varying calibres of the channels, necessitating technically challenging treatment strategies. It is important to preserve both channels because of the potential presence of perforating arteries originating from these segments. There are numerous case reports of such aneurysms being treated by coils alone, coiling with balloon assistance and stent-assisted coiling in configurations such as 'X', 'double barrel' or waffle cone. We present an exemplary case, in which an aneurysm on a partial unfused basilar segment was treated with parallel flow diverters with an excellent result on follow-up imaging.

Embolization of Ruptured Aneurysm Arising From Basilar Artery Fenestration Using Hydrocoils

Aneurysms arising from the basilar artery fenestration are considered among the rare cerebrovascular diseases. Here, we report on a 44-year-old gentleman who presented with the sudden onset of severe headache complicated by several episodes of vomiting and an altered level of consciousness. A subarachnoid hemorrhage in the interpeduncle and ambient cisterns was detected by computed tomography of the head. During left vertebral arteriography, a basilar fenestration with a ruptured aneurysm just above the proximal end of vertebrobasilar junction was identified. The aneurysm was successfully occluded by means of endovascular treatment using Hydrosoft coils. In the 15-month follow-up angiography, 100% occlusion without recurrence and recanalization was observed. Bilateral anterior inferior cerebellar arteries and both channels of the basilar artery fenestration were entirely filled in follow-up angiograms.

Vertebro-basilar junction aneurysms: a single centre experience and meta-analysis of endovascular treatments

Vascular lesions of the vertebrobasilar junction (VBJ) are challenging in neurosurgical practice, and their gold-standard therapy is still under debate. We describe the operative strategies currently in use for the management of these complex vascular lesions and discuss their rationale in a literature meta-analysis and single centre blinded retrospective study. The single centre study included a review of initial presentation, angiographic features and clinical outcome (with modified Rankin Scale [mRS] scores) over a long-term follow-up. In our series, small aneurysms were effectively treated by endosaccular coil embolization, whereas a strategy including flow-diverter devices combined with endosaccular coil embolization was the option of choice in large and giant aneurysms, leading to satisfactory outcomes in most cases. Our Medline review showed that endovascular treatment was chosen in most VBJ cases, whereas the microsurgical option was assigned to only a few cases. Among the endovascular treatments, the most common techniques used for the treatment of VBJ aneurysms were: coiling, stent-assisted coiling and flow diversion. Our study highlights that aneurysm morphology, location and patient-specific angio-architecture are key factors to be considered in the management of VBJ aneurysms. Most case series, including our own, show that parent artery reconstruction using a flow-diverter device is a feasible and successful technique in some cases of giant and complex aneurysms (especially those involving the lower third of the basilar artery) while a "sit back, wait and see" approach may represent the safest and most reasonable option.

Cerebral arterial fenestrations

Arterial fenestrations are an anatomic variant with indeterminate significance. Given the controversy surrounding fenestrations we sought their prevalence within our practice along with their association with other cerebrovascular anomalies. We retrospectively reviewed 10,927 patients undergoing digital subtraction angiography between 1992 and 2011. Dictated reports were searched for the terms "fenestration" or "fenestrated" with images reviewed for relevance, yielding 228 unique cases. A Medline database search from February 1964 to January 2013 generated 304 citations, 127 cases of which were selected for analysis. Cerebral arterial fenestrations were identified in 228 patients (2.1%). At least one aneurysm was noted in 60.5% of patients, with an aneurysm arising from the fenestration in 19.6% of patients. Aneurysmal subarachnoid hemorrhage or non-aneurysmal subarachnoid hemorrhage were present in 60.1% and 15.8%, respectively. For the subset of patients with an aneurysm arising directly from a fenestration relative to those patients with an aneurysm not immediately associated with a fenestration, the prevalence of aneurysmal subarachnoid hemorrhage was 66.7% vs. 58.6% (p = 0.58). Fenestrations were more often within the posterior circulation (73.2%) than the anterior circulation (24.6%), though there was no difference in the prevalence of aneurysms within these groups (61.1% vs. 60.7%, p = 1.0). Cerebral arterial fenestrations are an anatomic variant more often manifesting at the anterior communicating arterial complex and basilar artery and with no definite pathological relationship with aneurysms.

Coil occlusion of wide-neck bifurcation aneurysms assisted by a novel intra- to extra-aneurysmatic neck-bridging device (pCONus): initial experience

BACKGROUND AND PURPOSE

The pCONus is a new stentlike self-expanding nitinol implant with 4 distal petals, which is fully retrievable and electrolytically detachable. The distal end is implanted inside the aneurysm at the neck. The shaft is anchored in the parent vessel. In selected wide-neck bifurcation aneurysms, the pCONus was used to assist coiling. The device was evaluated for its safety and efficacy.

MATERIAL AND METHODS

Twenty-eight patients with 28 wide-neck aneurysms (9 recently ruptured) were treated with pCONus-assisted coiling at the discretion of the operator. Other treatment options were considered but were discarded due to anticipated difficulties. Technical issues, immediate posttreatment angiographic findings, clinical outcome, and follow-up imaging were assessed.

RESULTS

There were 11 MCA, 7 anterior communicating artery, 1 posterior cerebral artery, 1 A2, and 8 basilar artery aneurysms. Insertion and deployment of the pCONus and subsequent coiling were possible in all cases. There were no clinically evident complications associated with the use of the device. Initial anatomic outcome showed 8 complete occlusions, 9 neck remnants, and 11 incomplete occlusions. Neurologic status remained unchanged at follow-up. Angiographic controls were obtained in 22 patients (mean, 7.5 months). Of these, 13 had complete occlusion, 9 showed improvement, and 7 were unchanged. Four died from SAH sequelae or other diseases, and 2 have not yet undergone follow-up. No intimal hyperplasia was observed.

CONCLUSIONS

The pCONus facilitates coil occlusion of unruptured and ruptured wide-neck bifurcation aneurysms. The device can be deployed safely. Coil retention is sufficient to protect the efferent vessels. So far, no intimal hyperplasia in the shaft has been observed.

Waffle Y technique: pCONus for tandem bifurcation aneurysms of the middle cerebral artery

Broad based bifurcation aneurysms are challenging. Various endovascular techniques aim at stabilizing the coil package in the aneurysm. Among these, the waffle cone technique provides a viable alternative to Y stenting in selected cases, incorporating a less complex delivery, and the reduced inherent risk of a single stenting procedure compared with the use of two stents in Y configuration. Unlike conventional stents, the distal end of the new pCONus device opens like a blossoming flower inside of the aneurysm to facilitate the waffle cone technique. In a case with tandem unruptured broad based middle cerebral artery bifurcation aneurysms, the complex anatomical challenge was resolved by a unique combination of both techniques: two pCONus deployed in Y configuration, offering stable neck coverage for coiling both aneurysms. The angiographic results with complete occlusion of both aneurysms and the uneventful clinical course at 90 days with continued daily administration of dual antiplatelet therapy are encouraging.

Treatment of ruptured saccular aneurysms of the fenestrated vertebrobasilar junction with balloon remodeling technique. A short case series and review of the literature

Fenestration of the intracranial arteries is a relatively common occurrence. This anatomic variation may predispose to aneurysm formation at certain sites. Treatment of such aneurysms is difficult as it may occlude one of the limbs of fenestration with resultant deficit. Thus, preservation of both the limbs with adequate exclusion of the aneurysm from the circulation should be the aim of any treatment. We describe a series of four cases of ruptured aneurysms arising from a fenestrated vertebrobasilar junction treated with endovascular balloon remodeling technique.

Stent/balloon combination assist technique for wide-necked basilar terminal aneurysms

We describe an enhanced endovascular procedure for the coiling of broad-necked basilar terminal aneurysms with a combined balloon/stent assist technique. A balloon-assisted catheter is inserted in the origin of one posterior cerebral artery (PCA) and an assisted stent is deployed from the opposite PCA to the basilar artery. A microcatheter for coiling is inserted through the stent strut (trans-cell approach), and the aneurysm is coiled under stent support and assisted balloon inflation to keep the patency of both PCAs. This technique is more beneficial for reducing the risk of stent deformity than Y-stenting, and it provides a simpler procedure than other advanced stent techniques. Additionally, it enables an easy approach when retreatment is necessary for aneurysm recurrence. This technique may be one of the useful procedures for embolizing broad-necked basilar terminal aneurysms safely and effectively.

Reverse waffle cone technique in management of stent dislodgement into intracranial aneurysms

Stent-assisted coil embolization (SACE) is a common method to manage intracranial wide-neck aneurysm. Using this technique, a stent must be successfully deployed into the parent artery to cross the aneurysm neck. We describe the reverse waffle cone technique in management of intra-procedural stent dislodgement during SACE of internal carotid artery (ICA) wide-neck aneurysms. Two patients with unruptured wide-neck ICA aneurysms underwent SACE. Intra-procedural forward stent migration occurred during catheterization with proximal stent dislodgement and migration into the aneurysm sac. Navigation of a second stent to bridge the aneurysm neck failed in one patient because the second stent was impeded by the dislodged stent. Using the reverse waffle cone technique, a microcatheter was navigated into the aneurysm sacs. Coils were safely detached into each aneurysm sac without any device assistance. The two wide-neck aneurysms were successfully treated with preservation of flow to the internal carotid arteries. The complication of intra-procedural distal stent migration and dislodgement, with proximal stent prolapse into an aneurysm sac, may not result in a failure to coil the aneurysm. The reverse waffle cone technique provides an effective treatment in the management of this complication.

Enterprise stent for waffle-cone stent-assisted coil embolization of large wide-necked arterial bifurcation aneurysms

Background:

Large wide-necked arterial bifurcation aneurysms present a unique challenge for endovascular coil embolization treatment. One technique described in the literature deploys a Neuroform stent into the neck of the aneurysm in the shape of a waffle-cone, thereby acting as a scaffold for the coil mass. This case series presents four patients with large wide-necked bifurcation aneurysms treated with the closed-cell Enterprise stent using the waffle-cone technique.

Case Description:

Four patients (59 ± 18 years of age) with large wide-necked arterial bifurcation aneurysms (three basilar apex and one MCA bifurcation) were treated with the waffle-cone technique using the Enterprise stent as a supporting device for stent-assisted coil embolization. Three of the patients presented with aneurysmal subarachnoid hemorrhage (Hunt-Hess 2-3; Fisher Grade 3-4). There was no procedural morbidity or mortality associated with treatment itself. One aneurysm was completely obliterated, and three had small residual necks. One patient developed an area of PCA infarct and visual field cut one month after the procedure and required recoiling of the residual neck. The flared ends of the Enterprise stent remodeled the aneurysm neck by conforming to the shape of the neck without any technical difficulty, resulting in a stable scaffold holding the coils into the aneurysm.

Conclusion:

The closed cell construction, flexibility, and flared ends of the Enterprise stent allow it to conform to the waffle-cone configuration and provide a stable scaffold for coil embolization of large wide-necked arterial bifurcation aneurysms. We have had excellent initial results using the Enterprise stent with the waffle-cone technique. However, this technique is higher risk than standard treatment methods and therefore should be reserved for large wide-necked bifurcation aneurysms where Y stenting is needed, but not possible, and surgical clip ligation is not an option.