Basilar Apex Aneurysms Research Articles

Microsurgery for Upper Basilar Tip Aneurysm With Intraoperative Rupture: 3-Dimensional Operative Video.

In the last years, a shift from the microsurgical treatment to an endovascular therapy in patients with basilar apex aneurysm has been settled, part of this phenomenon is related to the significant tendency of vital perforators to be involved in the aneurysm dissection and clipping, which can implicate unfavorable outcomes. Nevertheless, microsurgical treatment remains the treatment that can provide the superior rates of stable and durable aneurysm occlusion, which is most important to young patients.In this video, we present the case of a 45-yr-old female patient who complained of a sudden and severe headache and presented with progressive lethargy during the following 3 d.At admission, computed tomography did not show abnormal findings. However, cerebrospinal fluid analysis showed erythrocytes and corroborated the clinical suspicion of spontaneous subarachnoid hemorrhage. The patient signed the Institutional Consent Form, which allows the use of his/her images and videos for any type of medical publications in conferences and/or scientific articles.Angiography and magnetic resonance imaging revealed a saccular basilar apex aneurysm. It showed a wide neck as well as a lobulated dome with upward and slightly left projection. The aneurysm did not involve angiographically visible thalamoperforator arteries, which allowed the microsurgical treatment by the fronto-orbitozygomatic approach. However, during the interpeduncular cistern dissection, an intraoperative rupture of the aneurysm occurred. This video exemplifies the steps required to manage an intraoperative rupture of a basilar apex aneurysm.

Flow Diversion of Posterior Circulation Cerebral Aneurysms: A Single-Institution Series of 59 Cases.

Posterior circulation cerebral aneurysms are at higher risk of rupture and are more symptomatic than those in the anterior circulation. Existing treatments carry significant morbidity. Early reports of flow diversion for posterior circulation aneurysms have suggested high complication and low occlusion rates. To report safety and efficacy of flow diversion with the pipeline embolization device (ev3, Medtronic Inc, Dublin, Ireland) for aneurysms located throughout the posterior circulation. A prospective, institutional review board-approved database was analyzed for all patients with posterior circulation aneurysms treated by flow diversion at our institution. Fifty-nine embolization procedures were performed on 55 patients. Average aneurysm size was 9.4 mm. Morphology was saccular (45%), fusiform (29%), or dissecting/pseudo-aneurysms (25%). Sixty-two percent of aneurysms arose along the vertebral artery. There were 7 mid-basilar (13%) and 7 basilar apex (13%) aneurysms. Procedural success was 98%; 1 Pipeline embolization device was placed in 85%; and coiling was performed in 17% of cases. There were 5 major complications (8%), all strokes. Patients with major stroke had modified Rankin Scale score at last follow-up of 1, 3, 4, 6, and 6 (2 mortalities). There were zero intracerebral or subarachnoid hemorrhages. No variable predicted complications on univariate or multivariate analysis. Follow-up digital subtraction angiography was performed for 43 patients (78%). Complete occlusion was 68% at 6 mo and 78% at 12 mo. Average follow-up was 11.8 mo. Fusiform or dissecting morphology and large or giant aneurysm size were predictors of aneurysm persistence at 6 mo on multivariate logistic regression. This is a large single-institution series of Pipeline (Medtronic Inc) for posterior circulation aneurysms and demonstrates acceptable safety and effectiveness in these challenging cases.

Analysis of Surgical Freedom Variation Across the Basilar Artery Bifurcation: Towards a Deeper Insight Into Approach Selection for Basilar Apex Aneurysms

The orbitozygomatic approach is generally advocated over the pterional approach for basilar apex aneurysms. However, the impact of the extensions of the pterional approach on the obtained maneuverability over multiple vascular targets (relevant to basilar apex surgery) has not been studied before. To analyze the patterns of surgical freedom change across the basilar bifurcation between the pterional, orbitopterional, and orbitozygomatic approaches. Surgical freedom was assessed for 3 vascular targets important in basilar apex aneurysm surgery (ipsilateral and contralateral P1-P2 junctions, and basilar apex), and compared between the pterional, orbitopterional, and orbitozygomatic approaches in 10 cadaveric specimens. Transitioning from the pterional to orbitopterional approach, the surgical freedom increased significantly at all 3 targets (P<.05). However, the gain in surgical freedom declined progressively from the most superficial target (60% for ipsilateral P1-P2 junction) to the deepest target (35% for contralateral P1-P2 junction). Conversely, transitioning from the orbitopterional to the orbitozygomatic approach, the gain in surgical freedom was minimal for the ipsilateral P1-P2 and basilar apex (<4%), but increased dramatically to 19% at the contralateral P1-P2 junction. The orbitopterional approach provides a remarkable increase in surgical maneuverability compared to the pterional approach for the basilar apex target and the relevant adjacent arterial targets. However, compared to the orbitopterional, the orbitozygomatic approach adds little maneuverability except for the deepest target (ie, contralateral P1-P2 junction). Therefore, the orbitozygomatic approach may be most efficacious with larger basilar apex aneurysms limiting the control over of the contralateral P1 PCA.

Comprehensive Anatomic Assessment of the Pterional, Orbitopterional, and Orbitozygomatic Approaches for Basilar Apex Aneurysm Clipping.

The pterional approach, along with its orbitopterional and orbitozygomatic extensions, is among the most common surgical approaches for tackling challenging aneurysms of the basilar artery apex (BAX). There is general consensus that the orbitozygomatic approach provides the best exposure for these lesions. However, there is little objective evidence to support approach selection for surgical treatment of BAX aneurysms. To compare different features regarding surgical treatment of BAX aneurysms between the pterional, orbitopterional, and orbitozygomatic approaches. The pterional, orbitopterional, and orbitozygomatic approaches were sequentially completed on 10 cadaveric specimens. The visibility of perforators, lengths of exposure, and safe clipping for major BAX branches, surgical area of exposure, and the surgical freedom for the BAX target were assessed. The orbitopterional approach provided significantly greater values than the pterional approach in all variables, except for exposure of the bilateral P1 posterior cerebral artery (PCA) perforators. When compared to the orbitopterional approach, the orbitozygomatic approach did not provide a statistically significant increase in (1) surgical freedom through the carotid-oculomotor triangle, (2) area of exposure, (3) ipsilateral, and (4) contralateral P1 PCA perforator visibility, and (5) ipsilateral PCA exposure and (6) clipping lengths. The orbitopterional approach provides significantly greater surgical exposure to BAX than the pterional approach. The orbitopterional approach is less invasive while providing similar surgical access to the BAX compared to the orbitozygomatic. The results of this study show that the orbitopterional approach may be optimal for the treatment of most BAX aneurysms, particularly to reduce morbidity resulting from the full orbitozygomatic approach.

Embryological basilar apex disposition as a risk factor of basilar apex aneurysm

The pathogenesis of basilar apex aneurysm (BAA) are still poorly understood. Embryologically, basilar apex anatomical disposition is formed by the fusion of both caudal internal carotid divisions on the midline. To compare basilar apex morphology by embryological classification among patients with BAAs, anterior circulation aneurysms (ACAs), and controls. Prospectively collected data of 47 consecutive patients with unruptured BAAs (42 females and five males), age- and gender-matched 47 patients with unruptured ACAs, and 47 controls without any aneurysms were analyzed. Based on embryology, basilar apex morphology was classified into symmetric cranial fusion (SCrF), symmetric caudal fusion, and asymmetric fusion type. Posterior communicating artery (Pcom) was classified into hypoplastic, adult, or fetal type. The asymmetrical Pcom was defined as bilaterally different type Pcom. The ACAs located at the anterior communicating artery (n = 18), paraclinoid portion (n = 12), middle cerebral artery (n = 8), anterior cerebral artery (n = 5), the top of internal carotid artery (n = 2), and anterior choroidal artery (n = 2). Compared with the ACA group and controls, smoking, asymmetrical Pcom (fetal and adult type), and SCrF type were more prevalent in patients with BAAs by residual analysis. The multinomial logistic regression comparative analysis demonstrated that SCrF type was associated with BAAs (vs. ACA group; odds ratio, 13; 95% confidence interval, 3.8–41 and vs. controls; odds ratio, 25; 95% confidence interval, 5.4–121). The assessment of basilar apex morphology may aid in the understanding of the pathogenesis of BAA and the prediction of BAA formation.

Comparative Analysis of Orbitozygomatic and Subtemporal Approaches to the Basilar Apex: A Cadaveric Study

The subtemporal and orbitozygomatic approaches are the most commonly used surgical approaches for the treatment of basilar artery apex (BAX) aneurysms. Relative advantages and disadvantages are generally reported based on surgeons' experience. This study was performed to provide a detailed comparison between the subtemporal and orbitozygomatic approaches based on cadaveric dissection analysis for the treatment of BAX aneurysms. Subtemporal and orbitozygomatic approaches were performed on 5 cadaveric heads (10 sides), and the following variables were assessed and compared between the 2 approaches: 1) number of exposed perforators on P1-posterior cerebral arteries (PCA); 2) lengths of exposure and clipping for bilateral PCA, superior cerebellar arteries (SCA), and basilar trunk; 3) surgical area of exposure; and 4) surgical freedom at the BAX. Number of perforators exposed on P1-PCA was not different between the subtemporal and orbitozygomatic approaches. Exposure and clipping of ipsilateral SCA and PCA were superior using the subtemporal approach, and better for contralateral SCA and PCA using the orbitozygomatic approach, all reaching statistical significance. The orbitozygomatic approach provided greater exposure and clipping length for the proximal basilar trunk. Although the surgical area of exposure was similar between the 2 approaches, the overall surgical freedom was greater in the orbitozygomatic approach. The orbitozygomatic approach provides a greater number of surgical corridors to the BAX and is superior regarding multiple surgically relevant anatomic parameters. Importantly, control over the basilar trunk and over the contralateral SCA and PCA (blind spots) is superior with the orbitozygomatic approach.

Wide-neck bifurcation aneurysms of the middle cerebral artery and basilar apex treated by endovascular techniques: a multicentre, core lab adjudicated study evaluating safety and durability of occlusion (BRANCH)

Background and purposeBRANCH (wide-neck bifurcation aneurysms of the middle cerebral artery and basilar apex treated by endovascular techniques) is a multicentre, retrospective study comparing core lab evaluation of angiographic outcomes...

Assessment of the endoscopic endonasal approach to the basilar apex region for aneurysm clipping.

The expanded endoscopic endonasal approach (EEA) has shown promising results in treatment of midline skull base lesions. Several case reports exist on the utilization of the EEA for treatment of aneurysms. However, a comparison of this approach with the classic transcranial orbitozygomatic approach to the basilar apex (BAX) region is missing.The present study summarizes the results of a series of cadaveric surgical simulations for assessment of the EEA to the BAX region for aneurysm clipping and its comparison with the transcranial orbitozygomatic approach as one of the most common approaches used to treat BAX aneurysms. Fifteen cadaveric specimens underwent bilateral orbitozygomatic craniotomies as well as an EEA (first without a pituitary transposition [PT] and then with a PT) to expose the BAX. The following variables were measured, recorded, and compared between the orbitozygomatic approach and the EEA: 1) number of perforating arteries counted on bilateral posterior cerebral arteries (PCAs); 2) exposure and clipping lengths of the PCAs, superior cerebellar arteries (SCAs), and proximal basilar artery; and 3) surgical area of exposure in the BAX region. Except for the proximal basilar artery exposure and clipping, the orbitozygomatic approach provided statistically significantly greater values for vascular exposure and control in the BAX region (i.e., exposure and clipping of ipsilateral and contralateral SCAs and PCAs). The EEA with PT was significantly better in exposing and clipping bilateral PCAs compared to EEA without a PT, but not in terms of other measured variables. The surgical area of exposure and PCA perforator counts were not significantly different between the 3 approaches. The EEA provided better exposure and control if the BAX was located ≥ 4 mm inferior to the dorsum sellae. For BAX aneurysms located in the retrosellar area, PT is usually required to obtain improved exposure and control for the bilateral PCAs. However, the transcranial approach is generally superior to both endoscopic approaches for accessing the BAX region. Considering the superior exposure of the proximal basilar artery obtained with the EEA, it could be a viable option when surgical treatment is considered for a low-lying BAX or mid-basilar trunk aneurysms (≥ 4 mm inferior to dorsum sellae).

The ’bendy' basilar: progressive aneurysm tilting and arterial deformation can be a delayed outcome after coiling of large basilar apex aneurysms

BackgroundMorphological changes in the basilar artery and the artery-aneurysm relationship following coiling of large basilar apex aneurysms may induce morbidity.MethodsThe basilar artery radius-of-curvature was measured along its center line on...

Microsurgical Clipping of Basilar Apex Aneurysms: A Systematic Historical Review of Approaches and their Results.

Neck clipping remains a valuable treatment option for basilar apex aneurysms, especially in those with complex morphology, such as incorporation of branching vessels or large size, and young patient age. Several approaches have proved to give effective exposure for various types of lesion morphologies. Our historic literature review from 1976 to the present systematically compares the outcomes and complications of the key surgical approaches in the treatment of basilar apex aneurysms. We searched PubMed for articles with at least 5 patients, data on neurologic outcome, and procedure-associated complications for the following approaches: pterional or orbitozygomatic transsylvian, subtemporal (with or without zygomatic osteotomy), pretemporal (with or without transcavernous extension), and transpetrous. n-Weighted averages for clinical outcome, aneurysm occlusion rates, morbidity, mortality, and aneurysm morphology were compared. Of 35 articles selected, 2041 patients with 722 ruptured aneurysms underwent microsurgery, including 1131 transsylvian, 241 pretemporal, 375 subtemporal, and 17 transpetrous approaches. Comparing these 4 approaches in n-weighted averages, respectively, we noted good neurologic outcomes (81%, 85%, 81%, and 58%), surgical morbidity (14%, 10%, 34%, and 53%), surgical mortality (4%, 1%, 0, and 1%), and complete occlusion rates (95%, 94%, 86%, and 75%). Transsylvian, pretemporal, and subtemporal approaches showed favorable neurologic outcomes at similar rates and were applied for aneurysms located between-1mm and+7mm in relation to the posterior clinoid process. The pretemporal approach was preferably applied to large and giant aneurysms with good outcome; the transsylvian approach was most frequently used for ruptured aneurysms.

Flow Diversion for the Treatment of Basilar Apex Aneurysms.

Flow diversion for basilar apex aneurysms has rarely been reported. To assess flow diversion for basilar apex aneurysms in a multicenter cohort. Retrospective review of prospectively maintained databases at 8 academic institutions was performed from 2009 to 2016 to identify patients with basilar apex aneurysms treated with flow diversion. Clinical and radiographic data were analyzed. Sixteen consecutive patients (median age 54.5 yr) underwent 18 procedures to treat 16 basilar apex aneurysms with either the Pipeline Embolization Device (Medtronic Inc, Dublin, Ireland) or Flow Redirection Endoluminal Device (Microvention, Tustin, California). Five aneurysms (31.3%) were treated in the setting of subarachnoid hemorrhage. Seven aneurysms (43.8%) were treated with flow diversion alone, while 9 (56.2%) underwent flow diversion and adjunctive coiling. At a median follow-up of 6 mo, complete (100%) and near-complete (90%-99%) occlusion was noted in 11 (68.8%) aneurysms. Incomplete occlusion occurred more commonly in patients treated with flow diversion alone compared to those with adjunctive coiling. Patients with partial occlusion were significantly younger. Retreatment with an additional flow diverter and adjunctive coiling occurred in 2 aneurysms with wide necks. There was 1 mortality in a patient (6.3%) who experienced posterior cerebral artery and cerebellar strokes as well as subarachnoid hemorrhage after the placement of a flow diverter. Minor complications occurred in 2 patients (12.5%). Flow diversion for the treatment of basilar apex aneurysms results in acceptable occlusion rates in highly selected cases. Both primary flow diversion and rescue after failed clipping or coiling resulted in a modified Rankin Scale score that was either equal or better than at presentation and the technology represents a viable alternative or adjunctive option.

Transcavernous Approach to the Basilar Apex: A Cadaveric Prosection.

The transcavernous approach to the basilar artery, as initially described by Dolenc, is one of the most common and elegant approaches to the region. It affords a generous working and viewing angle, but it can be technically challenging and requires attention to detail at each step. We investigate this approach in this report via a cadaveric prosection with a focus on the value of each of the component steps in improving surgical view and exposure. The transcavernous approach steps are divided into extradural stages: orbitozygomatic osteotomy (a modern adjunct to Dolenc’s original description), drilling of the lesser sphenoid wing, and anterior clinoidectomy; and intradural stages: wide splitting of the Sylvian fissure, unroofing of the oculomotor and trochlear nerves, and posterior clinoidectomy. The surgical windows afforded by each step in the approach are illustrated using microscopic images taken during the cadaveric prosection of a donor who happened to harbor a basilar apex aneurysm. An illustrative case and artist illustrations are used to emphasize the relative value of each step of the transcavernous exposure.

Extended Endoscopic Endonasal Clipping of Basilar Apex Aneurysms: Anatomical Comparative Study and Surgical Simulation

Extended Endoscopic Endonasal Clipping of Basilar Apex Aneurysms: Anatomical Comparative Study and Surgical Simulation

Should we still consider clips for basilar apex aneurysms? A critical appraisal of the literature.

Background:Basilar apex aneurysms constitute 5–8% of all intracranial aneurysms, and their treatment remains challenging for both microsurgical and endovascular approaches. The perceived drawback of the microsurgical approach is its invasiveness leading to increased surgical morbidity. However, many high-volume centers have shown excellent clinical results with better occlusion rates compared to endovascular treatment. With endovascular therapy taking a larger role in the management of cerebral aneurysms, the future role of microsurgery for basilar apex aneurysm treatment is unclear.Methods:We performed a literature search to review the microsurgical and endovascular outcomes for basilar apex aneurysms.Results:Many studies have examined the efficacy of microsurgical and endovascular treatment for intracranial aneurysms, including large randomized trials such as ISAT and BRAT, prospective observational series such as ISUIA, and many single-center retrospective reviews. The recruitment number for posterior circulation aneurysms, specifically for basilar apex aneurysms, was limited in most prospective trials, thus failing to offer clear guidance on basilar apex aneurysm treatment. Recent single-center series report good clinical outcomes between 57–92% for surgical series and 73–96% in endovascular series. The durability of aneurysm occlusion remains superior in surgical cases. The techniques and devices in endovascular treatment have improved treatment aneurysm occlusion rates but more follow-up is needed to confirm long-term durability.Conclusions:Both microsurgical and endovascular approaches should be complementing each other to treat basilar apex aneurysms. Although endovascular therapy has taken a larger role in the treatment of basilar apex aneurysms, many indications still exist for the use of microsurgery. Advancements in microsurgical techniques and good case selection will allow for acceptably low morbidity after surgical treatment while maintaining its superior durability.

Surgical treatment of unruptured distal basilar artery aneurysm: durability and risk factors for neurological worsening.

Distal basilar artery aneurysms (DBAs) consist of basilar apex and basilar artery-superior cerebellar artery bifurcation (BA-SCA) aneurysms. The authors aimed to investigate clinical and radiological differences between two locations and to evaluate the 12-month surgical outcome in unruptured DBAs. Fifty-six consecutive patients who underwent surgical treatment (37 basilar apex and 19 BA-SCA aneurysms) between April 2012 and February 2016 were retrospectively evaluated. In patients with a preoperative modified Rankin Scale score (mRS) of more than 1, neurological worsening (NW) was defined as an increase in one or more mRS. In patients without symptoms, NW was defined as mRS ≥2. The mean age of the patient population was 64±9.6years, and 48 (86%) were female. Mean follow-up period was 2.6 ± 0.94years. An excellent (mRS 0 to 1) outcome was archived in 31 (55%), 45 (82%), and 48 (87%) patients at 30 days, 6 months, and 12 months, respectively. Clinical and radiological characteristics showed no differences between two locations. One early death (1.8%) and one severe morbidity (1.8%) due to rupture were observed. The postoperative annual rupture rate was 1.4% overall (145 patient-years). After adjustment for age and location, large or giant DBA was related to 30-day and 12-month NW [n=22 (39%) and n=6 (11%); p=0.009 and 0.002, respectively], aneurysm localization in the interpeduncular cistern (LIC) and perforator territory infarction were related to 30-day NW (p=0.002 and 0.002), and DBA that needed bypass surgery and previously treated recurrent DBA were related to NW at 12 months (p=0.017 and 0.001). Multivariate analysis showed that LIC was significantly related to perforator territory infarction (p=0.003). Clinical and radiological characteristics were not different between basilar apex and BA-SCA aneurysms; therefore, they should not be discussed separately. To avoid neurological worsening, results of surgical treatment for unruptured DBAs should be improved.

Large Basilar Apex Aneurysms Treated with Flow-Diverter Stents.

The treatment of wide-neck, large basilar apex aneurysms is challenging with either an endovascular or a surgical approach. The aim of the present study was to report our experience treating basilar apex aneurysms with flow-diverter stents and to evaluate their efficacy and safety profile in this specific anatomic condition. We retrospectively analyzed data from all consecutive patients treated with flow-diverter stents at our institution between January 2011 and January 2015. Patients with large basilar apex aneurysms treated with a flow-diverter stent were included in the study. Clinical presentations, technical details, intra- and perioperative complications, and clinical and angiographic outcomes were recorded, with a midterm follow-up. Of the 175 aneurysms treated with flow-diverter stents at our institution, 5 patients (2 women and 3 men; age range, 44-58 years) received flow-diverter stent for basilar apex aneurysms. The mean follow-up after stent deployment was 21 months (range, 15-24 months). One patient died on day 31 from an early postprocedural midbrain hemorrhage. One patient had a right cerebellar hemispheric ischemic lesion with a transient cerebellar syndrome resolved within 24 hours without neurologic sequelae at the latest follow-up. The mRS was 0 in 4 patients and 6 in 1 patient at last follow-up. Flow diversion is a feasible technique with an efficacy demonstrated at a midterm follow-up, especially in the case of basilar apex aneurysm recurrences after previous endovascular treatments. Concern about its safety profile still exists.

Outcome of the Treatment of Basilar Apex Aneurysms Using Advanced Transcavernous Microsurgical Clipping155

Outcome of the Treatment of Basilar Apex Aneurysms Using Advanced Transcavernous Microsurgical Clipping155

Surgical Clipping of a Basilar Tip Aneurysm: Case Report and Literature Review

Basilar tip aneurysms account for 5% - 8% of all intracranial aneurysms. They are known to rupture more frequently than aneurysms in other locations. Surgical clipping of basilar apex aneurysms however challenging; remains the treatment of choice in Ivory Coast due in part, to multiple technical barriers. A 60-year-old right-handed patient presented to our Neurosurgical Unit in February 2nd 2013 after a sudden onset of altered consciousness. Neurological examination revealed both an upper motor neuron and meningeal syndromes with a Glasgow Coma Scale of 12. Brain NECT scan and a subsequent brain CT angiography showed a subarachnoid haemorrhage and a 3.8 mm (height) × 5.2 mm (width) basilar tip aneurysm respectively. Surgical clipping of the aneurysm was indicated but due to multiple technical barriers, surgery was delayed and the patient underwent surgery after the critical vasospasm period. The patient developed a hospital acquired pneumonia after surgery and was successfully treated with antibiotics. Since her discharge, she has been asymptomatic. We sought to report this case of a basilar apex aneurysm successfully occluded with non-ferromagnetic SUGITA clips and to share our experience of clipping these lesions through the frontotemporal approach. The patient was informed that non identifying information from the case would be submitted for publication, and she provided consent.

Quantitative analysis of the trajectory of simulated basilar apex aneurysms through the internal carotid artery to assess the need for an orbitozygomatic approach

BackgroundThe aim of this study was to identify the correlation between the location of the internal carotid artery (ICA) and the need for an orbitozygomatic approach (OZA) when approaching a basilar apex (BX) aneurysm.Materials and methodsBy imaging the virtual trajectory to access the basilar artery (BA) through the ICA, the correlations among the height of the BX, the height and lateral breadth of the bifurcation of the ICA, and the need for removal of the orbital rim or zygomatic arch were investigated using three-dimensional computed tomography angiography (3DCTA) data of approximately 80 random samples not limited to BX aneurysms. Furthermore, the utility of 3D simulation to determine the need for the OZA was verified using data from five patients with BX aneurysms.ResultsThe height of the bifurcation of the ICA was inversely correlated and the height of the BX was positively correlated with the need for the OZA (both p < 0.017). Among patients undergoing surgery, clipping was successfully performed without the OZA in two patients in whom the distance from the simulated skull point on the extended line from the BX through the bifurcation of the ICA was more than 4 cm from the zygoma and orbital rim.ConclusionsIt is necessary to determine the spatial relationship between the basilar artery and the ICA to decide whether the OZA is needed for surgery. Correlations of the height of the ICA and BX with the need for the OZA were not very strong individually, though they were significant. Therefore, simulation using 3DCTA appears to be important for planning the surgical approach for the treatment of BX aneurysms.

The effect of basilar artery bifurcation angle on rates of initial occlusion, recanalization, and retreatment of basilar artery apex aneurysms following coil embolization.

Arterial bifurcations are common locations for aneurysm development given the altered hemodynamic forces and shear stress variations present at these locations. Recent reports indicate that a wide basilar artery bifurcation angle is an independent predictor of aneurysm development, growth, and subsequent rupture. To determine the effect of basilar artery bifurcation angle on rates of initial occlusion, recanalization, and retreatment of basilar artery apex aneurysms following coil embolization, the records of 46 patients with basilar artery apex aneurysms treated with endovascular coil embolization from 2007 to 2013 were analyzed. A wide basilar artery bifurcation angle was associated with a Raymond-Roy Occlusion Classification (RROC) III occlusion in univariate analysis, but was not a statistically significant factor in multivariate modeling. An increasing basilar artery bifurcation angle was not associated with aneurysm recanalization or retreatment following coil embolization. Increasing packing density (p < .01) was the only statistically significant predictor of a RROC I or II closure. The initial RROC designation was the most powerful predictor of both eventual aneurysm recanalization (p = .01) and retreatment (p = .02). While increasing aneurysm size (p < .01), increasing aneurysm volume (p < .01), and increasing neck size (p < .01) were associated with wide basilar artery bifurcation angles, neck size (p = .03) was the only statistically significant predictor of basilar artery bifurcation angle on multivariate analyses. Basilar artery bifurcation angle fails to predict rates of initial occlusion, recanalization, and retreatment on multivariate modeling in our series. Basilar artery apex aneurysm neck size independently correlates with basilar artery bifurcation angle.