Transcirculation endovascular treatment of complex cerebral aneurysms: technical considerations and preliminary results

Transcirculation retrograde placement of a Pipeline embolization device for treatment of a vertebrobasilar junction aneurysm

Transcirculation catheterization, also known as the retrograde approach, involves the navigation of a catheter or other endovascular device from one arterial circulation to the other (right to left, or anterior to posterior).1-4 We present a case of a complex vertebrobasilar junction aneurysm previously treated by bilateral vertebral artery deconstruction, precluding antegrade access (video 1). Following the creation of a protective occipital artery to posterior inferior cerebellar artery (PICA) bypass, the patient was treated with transcirculation placement of a Pipeline embolization device (PED).5-9 The right internal carotid artery was accessed with a guide catheter using a transradial approach. The microwire-microcatheter combination was then tracked through the right posterior communicating artery, down the basilar trunk, and to the left PICA. The PED was successfully deployed from the left vertebral artery to the mid-basilar artery. At 3-month follow-up, the aneurysm was completely obliterated. The nuances of transcirculation technique, especially for flow diversion, are discussed. (Used with permission from Barrow Neurological Institute, Phoenix, Arizona, USA.)neurintsurg;jnis-2023-021363v1/V1F1V1Video 1Transcirculation retrograde placement of a Pipeline embolization device for treatment of a vertebrobasilar junction aneurysm previously treated by bilateral vertebral artery deconstruction, precluding antegrade access.

The Rationale Behind Transcirculation Neuroendovascular Interventions: Literature Review Through a Case-Series Approach

BACKGROUND

With the development of advanced endovascular techniques and materials, neurointerventionalists can perform challenging and complex cases that were previously difficult to perform. Transcirculation approaches could be a useful tool used in complicated cases, providing access to the target vessel, through the contralateral or opposite circulation, when anterograde access is difficult or nonachievable.

OBJECTIVE

To retrospectively review cerebrovascular interventions performed through a transcirculation approach performed by staff at our Institution.

METHODS

English-language studies, published until August 2022, reporting transcirculation interventions in the cerebrovascular circulation were retrospectively collected. Type of intervention, number of cases, rationale, and complications were analyzed. Furthermore, similar cases performed by staff currently at our institution were also reviewed and described.

RESULTS

Including our cases, a total of 273 transcirculation treatment approaches have been reported. Intracranial aneurysm embolization, stroke thrombectomies, intra-arterial ophthalmic chemotherapy, arteriovenous malformationss, arteriovenous fistulas embolizations, and intracranial angioplasty and stenting are common indications. Reason for using a retrograde approach were stent/balloon-assisted coiling of wide neck aneurysm in 116 cases, difficult angulation of branch in 91 cases, occlusion of parent vessel in 55 cases, and bailout/other in 11 cases.

CONCLUSION

Transcirculation approaches can be considered for cases where conventional anterograde treatment options are not feasible or as a bailout strategy in failed or complicated treatment attempts. They represent a strategy to consider when facing challenging cases, and if performed by experienced and dedicated neurointerventionalists, they can represent a safe alternative.

Stent-assisted Coil Embolization Using a Transcirculation Technique for Superior Cerebellar Artery Aneurysm: A Report of Two Cases

Stent-assisted coil embolization (SACE) is useful for treating wide-necked aneurysms. Most superior cerebellar artery (SCA) aneurysms have a wide neck, but there are few reports of SCA aneurysms treated with SACE.

One reason is that the anatomical characteristic of SCA aneurysm is not suitable for standard SACE. It is often challenging to deliver a stent to SCA via the basilar artery in an anterograde manner. In contrast, it is not difficult to deliver a stent to SCA from the anterior circulation via the posterior communicating artery. This method, in which a catheter is navigated from the anterior to the posterior circulation, is called a transcirculation technique.

We report two cases of SCA aneurysm successfully treated with SACE using transcirculation technique. This approach is helpful for wide-necked SCA aneurysms.

Early spontaneous occlusion of a vertebral artery dissecting aneurysm caused by subarachnoid hemorrhage: A case report

We report a case of vertebral artery dissecting aneurysm (VADA) that developed with subarachnoid hemorrhage and was found to be occluded based on subsequent digital subtraction angiography. Few reports have been published on ruptured VADA in which ipsilateral vertebral arteries are occluded. The proper management of this type of aneurysm is controversial. A 44-year-old woman developed a sudden onset headache. Computed tomography and three-dimensional computed tomography were immediately performed and showed subarachnoid hemorrhage and VADA distal to the right posterior inferior cerebellar artery bifurcation. We decided to treat the VADA immediately and performed digital subtraction angiography but found the VADA had spontaneously occluded. We performed coil embolization, including the aneurysm and the parent artery, with reference to the findings of three-dimensional computed tomography. On Day 16, recurrence was considered due to the finding of dilation of the distal end where the coil was embolized. An additional embolization was performed via the posterior communicating artery. No cases of endovascular treatment have been reported in VADA cases in which the rupture site is spontaneously occluded. In such cases, the treatment may be incomplete, so strict follow-up is required.

Horizontal stenting via retrograde route for recurrent ruptured posterior communicating artery aneurysm after clipping: A case report and literature review

Treatment of recurrent ruptured aneurysms incorporating a branch vessel arising from the dome is challenging. Here, we attempted horizontal stent-assisted coil embolization via a retrograde route from the contralateral internal carotid artery to treat a small ruptured posterior communicating artery aneurysm incorporating a fetal variant posterior cerebral artery after clipping.

Balloon-Assistance for the Transcirculation Access of a Remodeling Balloon for Coiling of Wide-Necked Aneurysms: Report of Two Cases

Balloons are valuable tools in the armamentarium of a neurointerventionist. In this report, we describe 2 cases in which a balloon aided in the navigation of a second remodeling balloon through difficult vascular anatomy. The first case was a patient with a ruptured proximal posterior inferior cerebellar artery aneurysm and the second case was a patient with a ruptured anterior communicating artery aneurysm. In both cases, the coiling microcatheter and the remodeling balloon catheters were advanced through different vessels. The remodeling balloon reached the target location using a transcirculation approach, and the navigation of the remodeling balloon was aided by utilizing a second balloon. Challenging vascular anatomy is often encountered when performing neuroendovascular procedures. The strategy of using balloon assistance for the transcirculation access of a remodeling balloon can be used successfully in difficult situations to manage complex aneurysms.

The evolution of intracranial aneurysm treatment techniques and future directions

Treatment techniques and management guidelines for intracranial aneurysms (IAs) have been continually developing and this rapid development has altered treatment decision-making for clinicians. IAs are treated in one of two ways: surgical treatments such as microsurgical clipping with or without bypass techniques, and endovascular methods such as coiling, balloon- or stent-assisted coiling, or intravascular flow diversion and intrasaccular flow disruption. In certain cases, a single approach may be inadequate in completely resolving the IA and successful treatment requires a combination of microsurgical and endovascular techniques, such as in complex aneurysms. The treatment option should be considered based on factors such as age; past medical history; comorbidities; patient preference; aneurysm characteristics such as location, morphology, and size; and finally the operator’s experience. The purpose of this review is to provide practicing neurosurgeons with a summary of the techniques available, and to aid decision-making by highlighting ideal or less ideal cases for a given technique. Next, we illustrate the evolution of techniques to overcome the shortfalls of preceding techniques. At the outset, we emphasize that this decision-making process is dynamic and will be directed by current best scientific evidence, and future technological advances.

Transcirculation approach for stent-assisted coiling of intracranial aneurysms: a multicenter study

BACKGROUND

The transcirculation approach (TCA) for stent-assisted coiling (SAC) of intracranial aneurysms may be useful for certain wide-neck bifurcation aneurysms as well as those with acute-angle efferent branches.

OBJECTIVE

To describe a multicenter experience using the TCA for SAC.

METHODS

A multicenter, retrospective study (2016-2020) of aneurysm treatment using SAC via the TCA. Angiographic outcome was scored using the Raymond Scale (adequate occlusion 1 and 2), and clinical outcome was scored using a modified Rankin Scale (good outcome 0-2) RESULTS: Twenty-nine patients with 29 aneurysms were included (62.1% female; average age 61; 89.7% unruptured; 13.8% previously treated; average dome size 6.4 mm; average neck 4.4 mm). Aneurysm locations included internal carotid artery-fetal posterior cerebral artery (n=4), internal carotid artery terminus (n=4), anterior communicating artery (n=8), vertebral artery-posterior inferior cerebellar artery (n=2), and basilar tip (n=11). The TCA used communicating arteries (93.1%; average 1.6 mm), intermediate catheters (51.7%), jailing technique (62.1%), and staged procedures (10.3%). The most common stent was the Neuroform Atlas (Stryker; 69%). Immediate adequate occlusion was obtained in 75.9%, and five patients with inadequate occlusion progressed to adequate occlusion at follow-up. One (3.4%) procedural complication occurred: a watershed stroke in the setting of baseline four-vessel extracranial disease. Two patients had a poor outcome unrelated to the TCA. The majority of patients (86.4%) had a good clinical outcome. One case of in-stent stenosis due to non-compliance with medication was seen, which resolved with medication resumption.

CONCLUSIONS

The TCA for SAC can be performed for a variety of aneurysms with a low complication rate and good clinical outcomes.

Treatment of complex intracranial pathologies with transcirculation endovascular approaches

OBJECT

The breadth and complexity of neurovascular pathologies treated with endovascular neurosurgery has expanded dramatically in recent years. Many aneurysms remain difficult to treat safely. Transcirculation (contralateral and/or retrograde) approaches through the circle of Willis are useful alternatives for treating challenging lesions endovascularly. Here, we present a series of patients treated with unconventional transcirculation techniques.

METHODS

A total of six patients were treated: four patients with five aneurysms, one patient with an MCA stroke, and one patient with a meningioma requiring preoperative embolization were initially thought not to be amenable to endovascular treatment. The decision was made to treat these patients with transcirculation approaches. All patients were treated by one interventionist. One aneurysm was located in the cavernous internal carotid artery (ICA), one in the vertebral artery, two in the paraclinoid ICA, and one in a cerebellar AVM feeder vessel were treated.

RESULTS

Five of six patients (83%) made a full neurologic recovery. Three aneurysms were treated to complete occlusion, one aneurysm was left with small residual neck filling, and one aneurysm was not able to be treated. One patient underwent mechanical thrombectomy of a middle cerebral artery (MCA) embolus and MCA filling was restored after treatment. One patient underwent complete embolization of the deep vascular supply of a meningioma.

CONCLUSIONS

Although many neurovascular pathologies remain unsuitable for endovascular treatment, transcirculation approaches can allow for safe, successful treatment of challenging lesions in select patients.

The LUNA aneurysm embolization system for intracranial aneurysm treatment: short-term, mid-term and long-term clinical and angiographic results

BACKGROUND AND PURPOSE

Intrasaccular aneurysm flow disruption represents an emerging endovascular approach to treat intracranial aneurysms. The purpose of this study was to determine the clinical and angiographic outcomes of using the LUNA aneurysm embolization system (AES) for treatment of intracranial aneurysms.

MATERIALS AND METHODS

The LUNA AES Post-Market Clinical Follow-Up study is a prospective, multicenter, single-arm study that was designed to evaluate device safety and efficacy. Bifurcation and sidewall aneurysms were included. Aneurysm occlusion was assessed using the Raymond-Roy classification scale. Disability was assessed using the Modified Rankin Scale (mRS). Morbidity was defined as mRS >2 if baseline mRS ≤2, increase in mRS of 1 or more if baseline mRS >2, or mRS >2 if aneurysm was ruptured at baseline. Clinical and angiographic follow-up was conducted at 6, 12 and 36 months.

RESULTS

Sixty-three subjects with 64 aneurysms were enrolled. Most aneurysms were unruptured (60/63 (95.2%)); 49 were bifurcation or terminal (49/64 (76.6%)). Mean aneurysm size was 5.6±1.8 mm (range, 3.6-14.9 mm), and mean neck size was 3.8±1.0 mm (range, 1.9-8.7 mm). Though immediate postoperative adequate occlusion was low (11/63, 18%), adequate occlusion was achieved in 78.0% (46/59) and 79.2% (42/53) of the aneurysms at 12 months and 36 months, respectively. Four patients were retreated by the 12-month follow-up (4/63 (6.3%)) and three patients were retreated by the 36-month follow-up (3/63 (4.8%)). There were two major strokes (2/63 (3.2%)), one minor stroke (1/63 (1.6%)) and three incidents of intracranial hemorrhage in two subjects (2/63 (3.2%)) prior to the 12-month follow-up. There was one instance of mortality (1/63, 1.6%). Morbidity was 0% (0/63) and 1.8% (1/63) at the 12-month and 36-month follow-ups, respectively.

CONCLUSIONS

LUNA AES is safe and effective for the treatment of bifurcation and sidewall aneurysms.

CLINICAL TRIAL REGISTRATION

ISRCTN72343080; Results.

Utility of bulging technique for endovascular treatment of small and wide-necked aneurysms with a Low-profile Visualized Intraluminal Support (LVIS Jr.) device: A case report and review of the literature

Small and broad-necked aneurysms are generally very difficult to treat using endovascular therapy. The arrival of the low-profile stent (e.g., Low-profile Visualized Intraluminal Support; LVIS) has enabled reconstructive treatment for these aneurysms. In addition, the bulging technique using LVIS is an effective and attractive technique for performing stent-assisted coiling to preserve parent arteries and achieve neck coverage. We report here a patient with a small and wide-necked ruptured basilar artery (BA) top aneurysm, in whom successful treatment was achieved by stent-assisted coiling with LVIS Jr. using the bulging technique. A 74-year-old woman with moderate hypertension consulted for treatment of subarachnoid hemorrhage with a ruptured BA top aneurysm measuring 2.7 mm in height with a 4.3 mm neck. We initially tried emergency balloon-assisted coiling, but coiling proved difficult. We therefore performed stent-assisted coiling with LVIS Jr. using the bulging technique. The postoperative course was uneventful, with no aggravation of neurological symptoms, and the patient was discharged 14 days postoperatively. This treatment strategy with LVIS Jr. using the bulging technique may be very useful for patients with a ruptured aneurysm with a small and broad neck that would otherwise require treatment with intravascular devices or open surgery.

Combined direct and indirect traumatic carotid-cavernous fistula (CCF): Case report and review of the literature

BACKGROUND

Within the current Barrow classification system, there are no categorical descriptions or reports in the literature of cavernous carotid fistulas (CCFs) with both a direct component (type A) and separate indirect contribution (type B, C, or D). We report the first definitive case of a combined simultaneous traumatic direct and indirect CCF, and review the literature on the similar existing entity of traumatic indirect CCFs presenting delayed and subsequent to the treatment of traumatic, direct CCFs.

METHODS

We report a case of simultaneous direct type A CCF with a traumatic indirect CCF component and a review of the relevant literature.

RESULTS

An 18year-old female presented after a motor vehicle collision. A diagnostic cerebral angiogram confirmed the diagnosis of CCF, with contribution both directly from the ICA and indirectly via branches of the ECA. The direct component of the CCF was first treated in 3 stages via both transarterial and transvenous coil embolization, followed by a final 4th stage of parent vessel sacrifice in order to treat the residual direct component, with transarterial embolization to treat residual indirect CCF activity.

CONCLUSIONS

To our knowledge, this is the first report of a traumatic CCF with simultaneous direct (type A) and indirect via the ECA (type C) contributions.

Transcirculation Pipeline embolization device deployment: a rescue technique

The Pipeline embolization device (PED) has become a very important tool in the treatment of nonruptured cerebral aneurysms. However, a patient’s difficult anatomy or vascular stenosis may affect the device delivery. The purpose of this article was to describe an alternate technique for PED deployment when ipsilateral anatomy is not amenable for catheter navigation.

A 44-year-old woman with a symptomatic 6-mm right superior hypophyseal artery aneurysm and a known history of right internal carotid artery dissection presented for PED treatment of her aneurysm. An angiogram showed persistence of the arterial dissection with luminal stenosis after 6 months of dual antiplatelet treatment. The contralateral internal carotid artery was catheterized and the PED was deployed via a transcirculation approach, using the anterior communicating artery. Transcirculation deployment of a PED is a viable option when ipsilateral anatomy is difficult or contraindicated for this treatment.

Jailed double-microcatheter technique following horizontal stenting for coil embolization of intracranial wide-necked bifurcation aneurysms: A technical report of two cases

The horizontal stenting technique facilitates endovascular treatment of wide-necked bifurcation intracranial aneurysms. Previous literature shows, however, that subsequent coil embolization at initial treatment results in incomplete obliteration in many cases. The authors present two consecutive cases of wide-necked large bifurcation aneurysms to describe an additional coil embolization technique following horizontal stenting. The patients were a 53-year-old female with an unruptured internal carotid artery terminus aneurysm and a 57-year-old female with a recurrent basilar artery tip aneurysm. Both patients underwent endovascular treatment with horizontal stenting followed by coil embolization with jailed double-microcatheters. Immediate complete obliteration was achieved with no complications, and no recanalization was observed at the one-year follow-up in both cases. Coil embolization with jailed double-microcatheter technique following horizontal stenting is a safe and effective strategy for wide-necked bifurcation aneurysms.

Keyhole Supraorbital Craniotomy for Aneurysm Clipping in the Setting of Bypass for Moyamoya Disease

BACKGROUND

In 3%-15% of patients with moyamoya disease, aneurysms occur throughout the circle of Willis. In moyamoya patients treated with a superficial temporal artery-to-middle cerebral artery (STA-MCA) bypass, treatment of a new or an enlarging aneurysm can be complicated by the presence of the bypass and by limitations on the use of standard frontotemporal craniotomies to gain access to the aneurysm. Furthermore, endovascular access can be limited by the presence of fragile moyamoya vessels and precluded by atresia of large vessels.

CASE DESCRIPTION

A 45-year-old female patient with a history of moyamoya disease and previous left STA-MCA bypass presented with an enlarging left superior cerebellar artery aneurysm. We used a keyhole supraorbital craniotomy as a minimally invasive route to treat this aneurysm of the circle of Willis, with minimal interruption to the existing bypass or collateral circulation.

CONCLUSIONS

In patients with moyamoya disease who have existing STA-MCA bypass and de novo or expanding aneurysms, treatment is fraught with challenges. We advocate the use of a minimally invasive keyhole supraorbital craniotomy with an eyebrow incision for aneurysms associated with moyamoya disease occurring on the proximal anterior cerebral and middle cerebral arteries, the anterior communicating artery, the basilar apex, the posterior communicating artery, the proximal superior cerebellar artery, and the posterior cerebral artery.

Stent-assisted coiling and balloon-assisted coiling in the management of intracranial aneurysms: A systematic review & meta-analysis

BACKGROUND

Stent-assisted coiling and balloon-assisted coiling are well-established minimally invasive techniques for treatment of intracranial aneurysms. The aim of this study was to use meta-analysis methods to compare clinical outcomes of aneurysms treated with stent-assisted coiling versus balloon-assisted coiling.

METHODS

We searched for two-arm prospective studies and retrospective studies that compared the clinical outcomes in patients that received stent-assisted or balloon-assisted aneurysm treatment. Database search was performed through May 2015. Odds ratios (OR) with 95% confidence intervals (CI) were used to compare the clinical outcomes in patients that underwent either stent-assisted or balloon-assisted coiling for intracranial aneurysms management.

RESULTS

Complete occlusion rates at the end of the coiling procedure were similar between patients that received stent-assisted and balloon-assisted aneurysm treatment (OR=0.763, 95% CI=0.47 to 1.23, P=0.270). However, complete occlusion rates were higher with stent-assisted coiling at 6months or later after the procedure (OR=1.82, 95% CI=1.21 to 2.74). The overall complication rates and retreatment rates in patients with recurrence were similar between stent-assisted and balloon-assisted aneurysm treatments.

CONCLUSION

Stent-assisted coiling achieved better complete occlusion rates of aneurysms at 6months or later after the procedure compared to balloon-assisted coiling, without being associated with a higher risk of intraprocedural complications and retreatment.

Successful Cross-circulation Stent-Retriever Embolectomy Through Posterior Communicating Artery for Acute MCA Occlusion by Using Trevo XP ProVue

Acute ischemic stroke due to embolic occlusion of the middle cerebral artery (MCA) in patients with chronic ipsilateral internal carotid artery (ICA) occlusion is quite rare. Several previous reports demonstrated that intra-arterial (IA) thrombolytic therapy or aspiration thrombectomy using the cross-circulation technique via an alternative collateral pathway is feasible in acute stroke patients with an unfavorable direct route to the occluded sites. However, stent-retriever embolectomy via the cross-circulation approach has not been reported in the literature. The present paper reports the first case of successful stent-retriever embolectomy for acute MCA occlusion via the patent posterior communicating artery (PComA) by using Trevo XP ProVue stent-retriever in a patient with acute MCA stroke and chronic occlusion at the origin site of the ipsilateral ICA.

Coiling of a recurrent broad-necked posterior communicating aneurysm incorporating a fetal cerebral artery: A technical case report

We describe a case of a right broad-necked posterior communicating artery (PcomA) aneurysm with a fetal posterior cerebral artery (PCA) incorporated in the aneurysm neck. We performed waffle cone stent-assisted coiling and achieved almost complete occlusion of the aneurysm. At 18-month follow-up angiography, the aneurysm was recanalized and further coiling was needed. The same waffle cone method of coiling might be expected to produce the same unsatisfactory results on follow-up, so we decided to use retrograde stent navigation and placement through the anterior communicating artery (AcomA) from the contralateral internal carotid artery (ICA) to the ipsilateral ICA and fetal PCA. The stent delivery microcatheter from the contralateral ICA could not be introduced in the AcomA. So 2 mg nimodipine was infused through the stent delivery microcatheter to the AcomA and the stent delivery microcatheter was passed through the AcomA easily and could be navigated to the ipsilateral A1, ICA, and to the fetal PCA. With this additional stent, the aneurysm was completely separated from the fetal PCA and ICA. Further coiling could be performed safely through the microcatheter in the ipsilateral ICA. The patient had stable aneurysm occlusion at the six-month follow up.

Navigation of Stents across Communicating Arteries for Aneurysm Embolization

Introduction:

Endovascular coiling of aneurysms crossing the Circle of Willis has been described in small case series. The technical challenges in manipulating a stent across the Circle of Willis lie in negotiating difficult angles and small arteries. We present our experience with treating aneurysms by stent assistance in which the Circle of Willis was crossed to facilitate optimal stent deployment.

Materials and methods:

We retrospectively reviewed the cases in our institution from January 2009 to June 2012 in which the Circle of Willis was traversed to facilitate optimal stent deployment. We measured the diameter of the communicating arteries traversed, caliber of the target arteries in which the stent was deployed and the most acute angle negotiated (“critical angle”). We compare our results with other published series in the literature.

Results:

Eight patients fulfilled the criteria: 5 males (45-66 years). There were three anterior and five posterior circulation aneurysms. Four of the aneurysms were ruptured. The PCOM was traversed in five cases, the ACOM in three cases. The mean diameter of the communicating artery was 1.17mm. The mean diameter of target arteries was 1.27mm. The “critical angle” was 72-147 degrees. In all patients, there was satisfactory obliteration of the aneurysm. There were two cases of minor SAH post procedure.

Conclusion:

Utilizing the Circle of Willis for optimal stent placement in aneurysm remodeling is technically feasible but challenging. This technique can be performed successfully in patients with acute SAH. The procedural risk must be balanced against potential complications such as SAH.

Transcirculation balloon-assisted stent-supported coil embolization of a basilar tip aneurysm

We present the case of a balloon-assisted, stent-supported coil embolization of a basilar tip aneurysm. Initially, a balloon extending from the basilar artery into the right PCA was placed. However, even with a more proximal purchase, coils were found to impinge on the left PCA. Subsequently, a transcirculation approach was performed, where the left posterior communicating artery was utilized as a conduit for balloon support and the coils were embolized from the ipsilateral vertebral artery. However, after this transcirculation approach was completed, there was a coil tail extruding from the aneurysm. The balloon was then removed over an exchange wire and a horizontal stent advanced, spanning the entire neck of the aneurysm, eliminating the extruded coil. The video can be found here: http://youtu.be/bMbtZoPnYvo .

Stent-assisted coiling versus coiling in treatment of intracranial aneurysm: a systematic review and meta-analysis

Background and Purpose

Stent-assisted coiling was initially invented for wide-neck aneurysms, but is now used for smaller berry aneurysms. The aim of this study was to compare the safety and efficiency of stent-assisted coiling with conventional coiling in treatment of intracranial aneurysms.

Methods

A meta-analysis of studies that compared stent-assisted coiling with coiling only was conducted by searching English literatures via Pubmed, Medline and Cochrane Library databases without restricting the publication year. The primary outcomes in this study were immediate occlusion, progressive thrombosis rate, all-complication rate and angiographic recurrence. The secondary outcomes examined were packing density, mortality, permanent complication and thromboembolic complication rate.

Results

Ten retrospective cohort studies were included. There is currently only one unfinished randomized study. Although the stent-assisted coiling group tended to show a lower initial occlusion rate than that of the coiling-only group (57.6% versus 68.7%; OR, 0.66; 95% CI, 0.30–1.44; P = 0.30), it achieved a significantly higher progressive thrombosis rate during follow up compared to that of the coiling only group (37.5% versus 19.4%; OR, 2.75; 95% CI, 1.95–3.86; P<0.00001) and a significantly lower recurrence rate (16.2% versus 34.4%; OR, 0.35; 95% CI, 0.25–0.49; P<0.00001). With respect to safety concerns, the all-complication rate (17.6% versus 15.9%; OR, 1.12; 95% CI, 0.77–1.62; P = 0.56), mortality rate (9.1% versus 2.6%; OR, 2.31; 95% CI, 0.68–7.82; P = 0.18), permanent complication rate (5.6% versus 3.9%; OR, 1.52; 95% CI, 0.96–2.41; P = 0.08) and thromboembolic complication rate (4.2% versus 4.9%; OR, 0.99; 95% CI, 0.41–2.38; P = 0.97) did not show significant difference between the two groups.

Conclusions

Stent-assisted coiling has a lower recurrence rate than conventional coiling. Analysis of complication events did not show any significant difference between the two methods. Despite the findings reported herein, further validation by well-designed prospective studies is needed.

Vertebral artery-to-vertebral artery bypass with interposed radial artery or occipital artery grafts: surgical technique and report of three cases

BACKGROUND

The treatment of unclippable vertebral artery (VA) aneurysms incorporating the posterior inferior cerebellar artery with parent artery preservation is among one of the most formidable challenges for cerebrovascular microsurgery and endovascular surgery. We propose that intracranial VA reconstruction using an extracranial VA-to-intracranial VA (VA-VA) bypass with a radial artery graft or an occipital artery graft may be an additional technique in the armamentarium to treat these formidable lesions. The rationale, surgical technique, and complications are discussed.

METHODS

Three illustrative cases are described, in which the lesions were a VA dissecting aneurysm with ischemic lesions, bilateral asymptomatic unruptured VA aneurysms, and a VA giant aneurysm with subarachnoid hemorrhage.

RESULTS

The partial extreme lateral infrajugular transcondylar approach was used. Computed tomographic angiography was useful for preoperative evaluation of the depth of the distal aneurysmal neck. A VA-VA bypass was performed in two patients. Because there was another ipsilateral aneurysm at the V2 segment in one patient, an external carotid artery-VA bypass was performed. Although two patients were discharged with good clinical results, one patient with subarachnoid hemorrhage died because of brainstem infarction.

CONCLUSIONS

The VA-VA bypass using a radial artery graft or an occipital artery graft is an option that can be considered in the strategy for treating VA aneurysms to preserve the normal anatomic vascular configuration in the posterior circulation.

Extracranial carotid-vertebral bypass for endovascular access to complex posterior circulation aneurysms: a novel management approach

BACKGROUND

Endovascular embolization is a desirable treatment option for complex posterior circulation aneurysms, particularly recurrent aneurysms or those in difficult-to-access surgical locations. However, endovascular access is occasionally prohibited by proximal vertebral artery (VA) occlusion or vessel tortuosity. One strategy in such instances involves creation of an extracranial bypass conduit to the distal VA.

OBJECTIVE

To describe a novel strategy to allow for endovascular treatment of aneurysms at high risk for direct surgery.

METHODS

Three cases of carotid-VA bypass performed to provide endovascular access to posterior circulation aneurysms were identified. The clinical indications, radiographic characteristics, operative technique, and outcomes were reviewed.

RESULTS

Indications for bypass were previously clipped recurrent basilar tip aneurysm, previously coiled midbasilar aneurysm with compaction requiring stent placement, and distal intracranial VA aneurysm with iatrogenic vertebral dissection/occlusion after initial coil attempt. In all cases, routine endovascular access for primary or stent-assisted coiling was prohibited by VA tortuosity. Bypass with the use of interposition saphenous vein grafts was successfully performed to the C1-C2 region of the V2 segment without complications. The bypass was followed by successful endovascular treatment in all cases 2 to 6 weeks after surgery. In 1 patient, 2 recurrent treatments through the graft were subsequently performed for coil compaction.

CONCLUSION

Extracranial carotid-VA bypass can be a valuable tool in the management of complex posterior circulation aneurysms. It is a safe and efficacious technique providing a conduit for repeated access to the posterior circulation in patients with otherwise prohibitive vertebral anatomy.

Treatment strategies for complex intracranial aneurysms: review of a 12-year experience at the university of cincinnati

Complex intracranial aneurysms (CIAs) include those classified as giant, those located in brain regions of technically difficult access, or that involve arterial trunks/branches, and/or have complicated wall structure. We reviewed retrospectively our management of such lesions in a 12-year period. From 1997 to 2009, 192 patients were admitted with CIAs (133 females, 59 males; average age 55 years); 128 presented with subarachnoid hemorrhage (SAH) and 64 with unruptured, symptomatic CIAs. The SAH group had 73 anterior- and 55 posterior-circulation aneurysms. Most frequent location was middle cerebral artery. Treatment strategies included clipping (65.6%), coiling/stenting (28.1%), bypass (3.1%), no treatment (3.1%). Coiling/stenting was exclusively used for posterior-circulation aneurysms. Outcomes were good (modified Rankin Scale [mRS] 0 to 2) in 54 patients (42.2%), fair (mRS = 3 to 4) in 38 (29.7%), and poor (mRS = 5 to 6) in 36 (28.1%). Among unruptured CIAs, there were 47 anterior- and 17 posterior-circulation aneurysms. Most frequent location was ophthalmic. Thirty (46.9%) were clipped, 19 (29.7%) coiled, 6 (9.4%) by-passed, 2 (3.1%) wrapped, and 7 (10.9%) had no treatment. Outcomes were good in 57 patients (89%) and fair in 7 (11%). Good outcomes were obtained in unruptured CIAs using a multidisciplinary approach. Ruptured CIAs carry a significantly worse prognosis than overall SAH patients.

Y-configuration stent placement (crossing and kissing) for endovascular treatment of wide-neck cerebral aneurysms located at 4 different bifurcation sites

BACKGROUND AND PURPOSE

The Y-stent technique, including crossing-Y and kissing-Y, is a promising therapeutic option for some complex bifurcation aneurysms. Here, its efficacy and safety are evaluated on the basis of 11 bifurcation aneurysms.

MATERIALS AND METHODS

A retrospective review was conducted for all patients who underwent endovascular treatment of aneurysms in our department between January 2009 and June 2011 to identify and analyze cases with bifurcation aneurysms reconstructed by using Y-stents.

RESULTS

Eleven patients (4 ruptured and 7 unruptured aneurysms) were identified (4 men, 7 women) with a mean age of 60.4 years. Nine aneurysms (2 AcomAs, 3 MCA-Bifs, 1 PcomA, 3 BA apexes) were treated by using the crossing-Y technique, and 2 (both BA apexes) were treated with the kissing-Y technique, achieving complete occlusion in 6 aneurysms, residual neck in 4, and partial occlusion in 1. Perioperatively, a single thromboembolic event occurred in 1 case without neurologic deficit, which required a salvaging second stent implantation. Means of 9.9 months of angiographic and 13.7 months of clinical follow-up were available. As a result, 9 (81.8) aneurysms were completely occluded, 1 with a residual neck remained stable, and 1 residual aneurysm sac was recanalized, which was retreated and achieved a complete occlusion. All patients were independent with an mRS score of 0-1 at discharge and follow-up.

CONCLUSIONS

In selected patients, the reconstruction of bifurcation aneurysms by using the Y-stent can be successfully achieved with satisfactory midterm results.

Stent-assisted coiling of intracranial bifurcation aneurysms leads to immediate and delayed intracranial vascular angle remodeling

BACKGROUND AND PURPOSE

Wide-neck bifurcating aneurysms are increasingly treated with intracranial stent-assisted coiling by using shape-memory alloy microstents. We sought to investigate the short- and long-term effects of intracranial stent implantation on the geometry and angular conformation of the stent-coiled vascular bifurcation.

MATERIALS AND METHODS

Thirty patients underwent stent-mediated coiling for 31 bifurcation aneurysms by using 31 self-expanding Neuroform (n = 14) and Enterprise (n = 17) stents (17 women; mean age, 56 years). The angle (δ) between the stented mother and daughter vessels at the bifurcation was measured by using multiplanar imaging of reconstructed rotational conventional angiography volumes and was compared by using matched-pair statistics. Neuroform and Enterprise longitudinal stent stiffness was measured in vitro at an increasing bending angle θ (θ = 180°-δ).

RESULTS

Stent deployment increased the bifurcation angle δ from 101.5° to 119.8° postprocedurally and to 137.3° (P < .0001) at latest follow-up, resulting in effective straightening; the angular remodeling was greater in distal-versus-proximal arteries (anterior cerebral > MCA > BA > ICA), inversely proportional to mother-vessel diameter and proportional to pretreatment bending angle θ. At follow-up, angle δ continued to significantly expand, with remodeling being greater in the early period (1-6 versus >7 months) and more pronounced with the longitudinally stiffer closed-cell Enterprise compared with the open-cell Neuroform stent.

CONCLUSIONS

Stent placement across bifurcation aneurysms leads to a significant biphasic angular remodeling related to stent type and vessel caliber, altering morphology to mimic sidewall lesions, a phenomenon needing consideration during procedural planning. Future work is needed to uncover the hemodynamic implications of this structural change and any possible effect on aneurysm-recurrence rates.

Coiling of a residual internal carotid artery aneurysm via an extracranial-intracranial bypass graft following parent vessel occlusion

We report the case of a ruptured internal carotid artery (ICA) aneurysm that demonstrated significant persistent filling despite management with a common carotid to middle cerebral artery saphenous vein extracranial-intracranial bypass and subsequent permanent ICA balloon occlusion. The residual aneurysm was successfully embolised with detachable coils using a novel endovascular approach via the bypass graft.