Unruptured Basilar Tip Aneurysm Research Articles

Compartment syndrome associated with vascular avulsion caused by transradial access in neurointervention for unruptured intracranial aneurysm: illustrative case.

Transradial access (TRA) has a lower risk of access-site complications than transfemoral access but can cause major puncture-site complications, including acute compartment syndrome (ACS). The authors report a case of ACS associated with radial artery avulsion after coil embolization via TRA for an unruptured intracranial aneurysm. An 83-year-old woman underwent embolization via TRA for an unruptured basilar tip aneurysm. Following embolization, strong resistance was felt during removal of the guiding sheath due to vasospasm of the radial artery. One hour after neurointervention via TRA, the patient complained of severe pain in the right forearm, with motor and sensory disturbance of the first 3 fingers. The patient was diagnosed with ACS causing diffuse swelling and tenderness over the entire right forearm due to elevated intracompartmental pressure. The patient was successfully treated by decompressive fasciotomy of the forearm and carpal tunnel release for neurolysis of the median nerve. TRA operators should be aware that radial artery spasm and the brachioradial artery pose a risk of vascular avulsion and resultant ACS and warrant precautionary measures. Prompt diagnosis and treatment are essential because ACS can be treated without the sequelae of motor or sensory disturbance if properly addressed.

Comparison of angiographic outcomes and complication rates of WEB embolization and coiling for treatment of unruptured basilar tip aneurysms

Endovascular coiling represents the standard treatment for basilar tip aneurysms. Some of these aneurysms are not amenable to conventional coiling due to a complex aneurysm geometry, hence, novel devices such as the Woven Endobridge (WEB) have been developed. We retrospectively compared WEB embolization and coiling for the treatment of unruptured basilar tip aneurysms. Patients treated with WEB or coiling at four centers were reviewed. Procedure-related complications, clinical outcome and angiographic results were retrospectively evaluated and compared. Forty patients treated with the WEB and 35 patients treated by coiling were included. Stent-assistance was more often necessary for coiling than for WEB embolization (71% vs 2.5%, p < 0.001). The technical success rates were 100% for both methods. The overall complication rates were not significantly different between groups (WEB: 5%, coil: 11%, p = 0.409). Procedural morbidity rates were 9% in the coiling group and 2.5% in the WEB group (p = 0.334). There was no mortality. Treatment duration was shorter for WEB implantation than for coiling (p = 0.048). At mid-term follow-up, complete occlusion, neck remnants and aneurysm remnants were observed in 89%, 4% and 7% for the WEB, respectively, and in 100%, 0% and 0% for coiling. While complication rates and mid-term angiographic outcome was comparable between the groups, the WEB was associated with a shorter treatment duration and required stent-assistance less frequently. The choice of the treatment modality should be made based on the specific aneurysm characteristics, the individual experience of the neurointerventionalist and patient preference.

Endovascular treatment for large (> 10mm) basilar tip aneurysms: a retrospective case series.

To report the long-term clinical and angiographic outcomes of the endovascular treatment of large/giant basilar tip aneurysms (BTAs) in our institutions. We retrospectively reviewed cases of BTA larger than 10mm that received endovascular treatment between January 2009 and December 2019. Data on the demographic and clinical characteristics and radiologic severity were obtained from the patients' medical records. The collected clinical follow-up data included neurological evaluation. Magnetic resonance angiography (MRA) was performed 6 to 12months after the procedure, followed by once every 1 to 2years as needed. A total of 12 patients with BTA were included in this study. The median age was 60.08years (27-80years), and the mean clinical follow-up was 66.78months (19.00-142.87months). Almost half of the patients presented with unruptured BTAs (58.33%, n = 7). The median maximum aneurysm diameter was 13.00mm (10.46-20.90mm) and the mean neck size was 8.34mm (4.82-13.04mm). A Modified Raymond Roy Classification (MRRC1) of 1 or 2 was observed in 66.67% of the patients (n = 8) immediately after the first procedure. Procedural morbidity and mortality were 33.33% and 8.33%, respectively. Major recanalization occurred in two patients, one of whom underwent additional coiling with the other being merely observed due to older age. It is very difficult to cure a large BTA completely at once and recanalization occurred often after endovascular treatment. Conducting long-term follow-up studies at short intervals is warranted, as well as improving existing treatment methods and developing new approaches.

Hemodynamic and Morphologic Factors Related to Coil Compaction in Basilar Artery Tip Aneurysms

Coil compaction is directly related to the degree of cerebral aneurysmal recanalization. The degree of recanalization (DoR) was quantified by measuring the volume vacated by coil deformation. The purpose of this study was to clarify the hemodynamic and morphologic factors associated with coil compaction. Computational fluid dynamics simulations were performed on 28 middle-size (5-10 mm) unruptured basilar artery tip aneurysms. The DoR was measured by comparing the coil mass shape obtained from three-dimensional digital subtraction angiography data immediately after coil embolization and again within 1-2 years of follow-up. Deployed coils were modeled using a virtual coiling technique for computational fluid dynamics simulations. Hemodynamic and morphologic factors to predict the DoR were derived using multiple linear regression. Aneurysmal neck area, the maximum pressure generated on the neck surface after coil embolization, and the high-pressure position on the neck surface predicted DoR with statistic significance (P < 0.001, P < 0.001, P= 0.004, respectively). The DoR tended to increase when the neck areawas large, the pressure generated on the coils was high, and the high-pressure position was close to the center of the neck surface. The volume embolization ratio was not statistically relevant for the DoR in the cases of this study. Coil compaction occurs in cerebral aneurysms with a wide neck, high pressure generated on the coils, and high pressure in the center of the neck surface. Establishing the DoR can contribute to the prediction of recanalization after coil embolization.

The Analysis of Morphoradiological Parameters in Predicting Risk of Basilar Artery Tip Aneurysm Rupture: A Retrospective Cohort Study.

PurposeBasilar artery tip aneurysms can have fatal consequences and poor prognostic outcomes in case of rupture. We investigated the standard parameters used to evaluate aneurysmal morphology to predict aneurysm rupture.Patients and MethodsWe measured the differences between ruptured and unruptured basilar bifurcation aneurysms in terms of morphological features, including aneurysm size, size ratio, aneurysm height, perpendicular height, aneurysm width, bottleneck ratio, aspect ratio, and present daughter domes, using 3D angiography.ResultsAmong 34 patients, 21 (61.8%) and 13 (38.2%) had ruptured and unruptured basilar tip aneurysms, respectively. In the ruptured group, the mean aneurysm size, and aspect, size, and bottleneck ratios were 6.8 ± 1.9 mm, 3.2 ± 1.0, 2.3 ± 0.5, and 2.2 ± 0.4, respectively, compared to 4.5 ± 1.5 mm, 4.4 ± 2.0, 1.6 ± 0.4, and 2.7 ± 0.7, respectively, in the non-ruptured group. Univariate analysis showed a larger aneurysmal cross-sectional diameter (odds ratio [OR], 0.50; 95% confidence interval [CI], 0.5–5.392; p < 0.05), a larger size ratio (OR, 21.375; 95% CI, 3.283–139.177; p < 0.05), and presence of a daughter dome (OR, 72.0; 95% CI, 6.7–776.5; p < 0.05) with ruptured basilar artery tip aneurysms.ConclusionA larger aneurysm size and size ratio, and the presence of a daughter dome were significantly associated with increased rupture risk in basilar tip aneurysms.

Subtemporal, Transapical, and Transcavernous Approach to Clip Low-Lying Basilar Tip Aneurysm: 2-Dimensional Operative Video.

Basilar tip aneurysm clipping is technically challenging because of the depth of operative corridor, rarity in presentation, and important perforators supplying deep, critical structures. Two major approaches to basilar tip aneurysms include (1) a frontotemporal (transorbital) trans-sylvian approach for most aneurysms and (2) a modified subtemporal approach for aneurysms with low-lying necks. A 53-yr-old woman presented to our institution with a large unruptured basilar tip aneurysm notable for a low, broad neck (6.4 mm). After discussion of risks and benefits of endovascular vs surgical options, the patient consented to operative intervention. She underwent a right frontotemporal craniotomy with zygomatic osteotomy, intradural petrous apicectomy, elective sectioning of the fourth cranial nerve (CN IV), and intracavernous removal of the dorsum sellae and posterior clinoid process to provide more space for aneurysm dissection. After temporary clipping of the basilar artery, the perforating arteries were dissected free from the aneurysm and the aneurysm occluded with 2 fenestrated clips. Important technical nuances of the approach include (1) achieving ample working room for temporary occlusion aneurysm dissection, (2) careful dissection of the perforators and contralateral P1, and (3) utilization of 2 fenestrated clips to accommodate and preserve the ipsilateral P1 segment. Postoperative angiogram showed complete aneur-ysmal occlusion. Postoperatively, the patient demonstrated mild cognitive impairment and a right CN IV palsy. At 6-wk follow-up, cognition recovered to normalcy. More recently, at 12-mo follow-up, the patient noted intermittent diplopia. Formal neuro-ophthalmologic assessment confirmed persistence of a CN IV palsy treated with prism lenses but no other neurological deficits.

Intentional Stent Herniation Technique Using Neuroform Atlas Stent System for Embolization of a Wide-Necked Basilar Tip Aneurysm.

Endovascular treatment for complex wide-necked basilar tip aneurysms is challenging. Multiple stenting may be an option to deal with such aneurysms; however, the risk of ischemic complications is reported to be relatively high. Here, we report a case of unruptured basilar tip aneurysm treated using the intentional stent herniation technique to preserve the aneurysmal neck branches. A 65-year-old woman presented with a growing unruptured basilar tip aneurysm associated with bilateral posterior cerebral arteries (PCAs) arising from the aneurysmal dome. We intentionally selected a large-sized Neuroform Atlas stent (Stryker, Kalamazoo, MI, USA) compared to the parent artery and deployed it along the right PCA to the basilar artery. The stent was herniated into the aneurysmal dome near the origin of the left PCA, resulting in the preservation of the left PCA. Successful coil embolization was achieved with acceptable obliteration. The intentional stent herniation technique may be an effective approach to treat complex wide-necked basilar tip aneurysms.

Anterior temporal approach and clipping of a high-riding basilar tip aneurysm: Case report and review of the surgical technique

Basilar apex aneurysms constitute 5%–8% of all intracranial aneurysms. Microsurgical clipping of basilar tip aneurysms is still advocated for as it is safe, especially for unruptured basilar tip aneurysms which have a low risk of postoperative mortality or morbidity. Careful patient preparation is needed preoperatively because the risk of intraoperative rupture is significant. Good surgical techniques should be applied. The skill will need to be preserved as endovascular surgery becomes more popular. This is a case of basilar tip aneurysm managed by clipping through the anterior temporal approach, followed by a review of the literature.

Multimodality Techniques in Microsurgical Clipping as the Gold Standard Treatment in the Management of Basilar Tip Aneurysm: A Case Series.

Introduction:Basilar aneurysms represent 5%–7% of all intracranial aneurysms. The main goal of open surgery is to achieve complete obliteration of the aneurysmal sac using minimal invasive technique while emphasizing on avoidance of complication.Materials and Methods:We performed a retrospective cohort study of nine cases of unruptured basilar tip aneurysm referred to the Fujita Health University Banbuntane-Hotokukai Hospital, Japan. The objective of the study was to analyze the surgical outcomes of unruptured basilar tip aneurysm.Results:Nine patients with unruptured basilar tip aneurysm were referred to our hospital between 2015 and 2017. The median size of the aneurysm and age were 4.00 mm (interquartile range [IQR] = 3.25–6.75 mm) and 58 years (IQR = 54–70 years), respectively. Five patients (55.6%) were presented with multiple intracranial aneurysms. Surgical adjuncts such as intraoperative neuromonitoring, intraoperative indocyanine green (ICG) angiography with dual-image videoangiography (DIVA), and neuroendoscope were used. Two patients developed transient postoperative oculomotor nerve palsy which resolved spontaneously. The median duration of surgery and days of hospitalization were 292 min (IQR = 237.5–350.5 min) and 12 days (IQR = 12–25 days), respectively. There was no mortality recorded in this case series.Conclusion:Microsurgical clipping of basilar tip aneurysm is safe in unruptured basilar tip aneurysm with a low risk of postoperative mortality or morbidity. All complications reported in this case series were transient with no long-term sequalae. The improved safety profile of microsurgical technique is due to the availability of intraoperative neuromonitoring, neuroendoscope, ICG, and DIVA. The application of multimodality technique in neurovascular surgery has also helped to achieve complication avoidance. The obliteration of the aneurysmal sac helps to restore the laminar blood flow in the bifurcation and distal blood vessels and improves the brain perfusion.

A computational fluid dynamics (CFD) study of WEB-treated aneurysms: Can CFD predict WEB “compression” during follow-up?

BackgroundRecent reports have revealed a worsening of aneurysm occlusion between WEB treatment baseline and angiographic follow-up due to “compression” of the device. ObjectiveWe utilized computational fluid dynamics (CFD) in order to determine whether the underlying mechanism of this worsening is flow related. MethodsWe included data from all consecutive patients treated in our institution with a WEB for unruptured aneurysms located either at the middle cerebral artery or basilar tip. The CFD study was performed using pre-operative 3D rotational angiography. From digital subtraction follow-up angiographies patients were dichotomized into two groups: one with WEB “compression” and one without. We performed statistical analyses to determine a potential correlation between WEB compression and CFD inflow ratio. ResultsBetween July 2012 and June 2015, a total of 22 unruptured middle cerebral artery or basilar tip aneurysms were treated with a WEB device in our department. Three patients were excluded from the analysis and the mean follow-up period was 17months. Eleven WEBs presented “compression” during follow-up. Interestingly, device “compression” was statistically correlated to the CFD inflow ratio (P=0.018), although not to aneurysm volume, aspect ratio or neck size. ConclusionThe mechanisms underlying the worsening of aneurysm occlusion in WEB-treated patients due to device compression are most likely complex as well as multifactorial. However, it is apparent from our pilot study that a high arterial inflow is, at least, partially involved. Further theoretical and animal research studies are needed to increase our understanding of this phenomenon.

The role of endovascular treatment in unruptured basilar tip aneurysms.

Objective This study was to evaluate the safety and efficiency of endovascular treatment of unruptured basilar tip aneurysms. Methods We retrospectively reviewed consecutive 79 cases of unruptured basilar tip aneurysms in our center between 2009 and 2014. The patients' clinical and imaging information were recorded. Complications, initial occlusion rate, clinical outcomes and the predictors were retrospectively analyzed. Results Thirty-five cases received conservative treatment and 44 cases were treated by endovascular embolization. In the conservative treatment group, six (19.4%) of 31 basilar tip aneurysms ruptured and resulted in five deaths (16.1%) during the mean 18.1-month follow-up (range from 1 to 60 months). Among the endovascularly treated cases, 24 (54.5%) achieved initial complete occlusion and no delayed hemorrhagic events occurred during the mean 33.6-month follow-up (range from 10 to 68 months). For 20 (45.5%) incompletely occluded cases, five postoperative or delayed hemorrhagic events and two mass effect events resulted in six deaths. There were no statistical significant differences in hemorrhagic events ( p = 0.732) and mortality ( p = 0.502) between the incomplete occlusion group and untreated group. Large aneurysm size (≥10 mm) was an independent predictor for incomplete occlusion ( p = 0.002), which had a potential risk of postoperative or delayed hemorrhage. On univariate analysis, initial occlusion rate and aneurysm size were found to be associated with clinical outcomes ( p = 0.042 and 0.015). Conclusion Complete occlusion for unruptured basilar tip aneurysm proved to be a safe and effective therapeutic method that could eliminate the potential risk of postoperative or delayed hemorrhage.

Unruptured Basilar Tip Aneurysm with Internal Septation: Coiling Implications?

An internal septum within a basilar artery aneurysm is an infrequent anomaly and is very rarely reported in the literature. We report a 62-year-old lady that was incidentally diagnosed with basilar tip aneurysm. Further imaging with magnetic resonance imaging (MRI) revealed internal septation within this aneurysm which was later confirmed with digital subtraction angiography (DSA). She underwent coil embolisation, which involved technical manipulation of the microcatheter and the balloon to enable coiling of each separate aneurysm compartment. We present this case to illustrate the effect of this anatomical variation on the selection of endovascular treatment strategy.

Spontaneous thrombosis of a basilar tip aneurysm after ventriculoperitoneal shunting

We present a case of a large unruptured basilar tip aneurysm with concomitant hydrocephalus. Complete thrombosis of the aneurysm was observed after ventriculoperitoneal shunting. Analyzing preoperative and postoperative MRI and...

Headache and ptosis for four months: potential mimickers of intraparenchymal hemorrhage

Computed tomography demonstrated a hyperdense collection in the left thalamus (Fig. 1), originally thought to represent hemorrhage. Computed tomographic angiography, however, showed that the collection represented an unruptured basilar tip aneurysm (Fig. 2). The patient underwent uncomplicated surgical clipping. Cerebral aneurysms commonly arise at bifurcations within the Circle of Willis. Upwards of 90 % arise within the anterior circulation, while approximately 10 %, as demonstrated in this case, arise within the posterior circulation, with an overall incidence of 2.3 % [1]. Individuals with unruptured aneurysms are usually asymptomatic. Cranial neuropathies and thromboembolic events are rare. Unruptured aneurysms containing thrombus will appear hyperdense on unenhanced computed tomography of the head, potentially mimicking acute hemorrhage [1]. Differentiating aneurysm and hemorrhage is critical as management of the two conditions varies drastically. Computed tomographic angiography is the imaging modality of choice, with 95 % sensitivity for detecting aneurysms greater than 2 mm [2].

Transfundal stent placement for treatment of complex basilar tip aneurysm: technical note

We describe a case where a complex unruptured basilar tip aneurysm was treated with a unique method of stent-assisted coil embolization. The aneurysm was considered to have a complex anatomy...

Basilar Tip Aneurysms

Endovascular therapy has largely replaced microsurgical clipping for the treatment of basilar tip aneurysms. We describe the variables our center evaluates when choosing to clip or coil basilar tip aneurysms and our outcomes. Four case illustrations are presented. All patients with ruptured or unruptured basilar tip aneurysms from 2005 to April 2012 were examined. The patients were treated by 2 interventional neuroradiologists and 2 dually trained neurosurgeons. There were 63 ruptured (clipped 38%, coiled 62%) and 37 unruptured (clipped 35%, coiled 65%) aneurysms in this 100-patient study. Seventy percent of the patients with ruptured aneurysms and 92% of the patients with unruptured aneurysms had a good outcome (modified Rankin scale 0-2) at 3 months. For ruptured aneurysms, there was a statistically significant difference in clipping and coiling with respect to age and treatment modality (clip 48.8 years, coil 57.6 years). Patients in the coiled group had higher dome-to-neck (1.3 vs 1.1) (P = .01) and aspect ratios (1.6 vs 1.2) (P = .007). In the ruptured coiling group, 69.5% achieved a Raymond 1 radiographic outcome, 28% Raymond 2, and 2.5% Raymond 3. Eleven (17.4%) patients required re-treatment, and 3 (4.4%) patients were re-treated more than twice. Coiling of unruptured aneurysms resulted in 75% Raymond 1. There were no residual lesions for unruptured clipped aneurysms. There were no differences in outcome between clipping and coiling in the ruptured and unruptured group. In our current management of basilar tip aneurysms, the majority can be treated via endovascular means, albeit with the expectation of a higher percentage of residual lesions and recurrences. Microsurgery is still appropriate for aneurysms with complex neck morphologies and in young patients desiring a more durable treatment.

The Woven EndoBridge Cerebral Aneurysm Embolization Device (WEB II): initial clinical experience

The Woven Endobridge (WEB II) device (Sequent Medical, Inc., Aliso Viejo, CA, USA) is an intra-saccular, oblate, braided-wire embolization device designed to provide flow disruption at the aneurysm neck-parent artery interface. The purpose of this study was to evaluate the acute and short-term performance of the WEB II device regarding the immediacy, degree, and durability of aneurysm occlusion in two patients. The WEB II device was implanted in one patient with an unruptured MCA trifurcation aneurysm and one patient with an unruptured basilar tip aneurysm. The degree of intra-aneurysmal flow disruption was graded based on serial digital subtraction aneurysm angiography performed over 30min immediately following device implantation and at 8weeks. Immediate and 8-week post-treatment CT and 3-T MRI studies were also performed. Delivery and deployment of the WEB II device was technically straightforward and achieved without complications. Neither device required retrieval or repositioning after full deployment. There were no peri-procedural thrombembolic or hemorrhagic complications. In both cases, complete aneurysm occlusion was observed within minutes of device deployment. Short-term angiographic follow-up confirmed stable complete occlusion at 8weeks. Early technical and clinical results from the first WEB II cases have been encouraging and suggest that the intra-saccular deployment of self-expanding, compliant, cylindrical, high-density, braided metallic mesh constructs may represent a feasible approach for the endovascular treatment of cerebral aneurysms.

未破裂脳底動脈先端部動脈瘤の自然経過と外科治療

未破裂脳底動脈先端部動脈瘤の自然経過と外科治療

Coiling of Very Large and Giant Basilar Tip Aneurysms: Midterm Clinical and Angiographic Results

The purpose of this study was to report the midterm clinical and angiographic results of coiling of very large (>15 mm) and giant basilar tip aneurysms. Between January 1995 and October 2005, 44 very large and giant basilar tip aneurysms in 44 patients were coiled. There were 13 men (30%) and 31 women (70%) with a mean age of 51.4 years (median, 51 years; range, 34-72 years). Mean aneurysm size was 19.6 mm (range, 15-30 mm). Of 44 aneurysms, 33 (75%) had ruptured. Of 11 unruptured basilar tip aneurysms, 7 were incidentally discovered, 1 was additional to another ruptured aneurysm, and 3 were symptomatic by mass effect. Procedural mortality was 2/44 (4.6%, 95% confidence interval (CI), 0.4%-16%) and morbidity 1/44 (2.3%, 95% CI, 0.01%-13%). Of 33 patients with ruptured aneurysms, mean clinical follow-up was 5.2 years (range, 0.5-11.5 years). Two patients had a rebleeding from the coiled basilar tip aneurysm leading to death in 1 patient and to dependency in the other patient (annual rebleeding rate, 1.1%) One other patient died 2 years later of progressive brain stem compression. Mean angiographic follow-up in 41 of 42 surviving patients was 3.1 years. Nineteen aneurysms reopened and were coiled for a second time. Of these, 9 repeatedly reopened with time and were repeatedly coiled up to 6 times. Additional treatments were without complications. Coiling of very large and giant basilar tip aneurysms is associated with reasonably low morbidity. Although additional treatment during follow-up is frequently necessary, rebleeding is uncommon.

Intraoperative jugular bulb desaturation during acute aneurysmal rupture

To describe an episode of acute jugular venous desaturation during intraoperative rupture of a cerebral aneurysm. A 57-yr-old patient was scheduled for clipping of a large unruptured basilar tip aneurysm. Abrupt bulging of the brain was observed after bone flap removal, but before dura was opened. This was associated with concurrent development of systemic hypertension to 200/120 mmHg and jugular venous bulb (S(jv)O(2)) desaturation to 13%. Rupture of aneurysm was confirmed by frank blood in cerebrospinal fluid drainage from the lumbar subarachnoid catheter. Abrupt S(jv)O(2) desaturation prior to dural opening may suggest an acute increase in intracranial pressure, which in our case followed aneurysmal rupture; the systemic response to increased intracranial pressure (Cushing's response) may be ineffective in maintaining cerebral perfusion.