AcomA Aneurysms Research Articles

Anatomic Predictors of Unruptured Anterior Communicating Artery Aneurysm Growth.

Anatomic variations of the anterior communicating artery (ACOM) complex have been shown to influence ACOM aneurysm morphology. It is not known whether these variations predispose unruptured ACOM aneurysms to grow over time. We retrospectively reviewed the course of patients with untreated, unruptured ACOM aneurysms monitored with serial imaging at our institution. The primary outcome of interest was aneurysm growth. Predictors of aneurysm growth were determined using a Cox proportional hazards model. There were 81 patients with an unruptured ACOM aneurysm who were included in our study. Growth occurred in 9 (11.1%) patients, yielding a yearly growth rate of 2.8%. Aneurysms that grew were larger on initial detection than were those that remained stable in size (8.3 mm vs. 6.2 mm; P= 0.031). The ratio of the diameter of A1 segments was greater in patients with aneurysms that grew (2.1 vs. 1.4; P= 0.003), as was the frequency of patients with an A1 ratio >2.3 (25.0% vs. 6.6%; P= 0.023). Among aneurysms that grew, location at the A1-A2 junction was more common than origination solely from the ACOM (88.9% vs. 11.1%). When follow-up time was adjusted for, increasing aneurysm size (unit relative risk [RR] 1.25, 95% confidence interval [CI] 1.06-1.45; P= 0.011) and location at the A1-A2 junction (RR 6.15, 95% CI1.12-114.49;P= 0.035) were significant predictors of aneurysm growth. We identify several anatomic characteristics that may be associated with increased risk of ACOM aneurysm growth. These data could influence management strategies of unruptured ACOM aneurysms.

Early retreatment after surgical clipping of ruptured intracranial aneurysms.

Although a rerupture after surgical clipping of ruptured intracranial aneurysms is rare, it is associated with high morbidity and mortality. The causes for retreatment and rupture after surgical clipping are not clearly defined. From a prospectively maintained database of 244 patients who had undergone surgical clipping of ruptured intracranial aneurysms, we selected patients who experienced retreatment or rerupture within 30days after surgical clipping. Aneurysm occlusions were examined by microvascular Doppler ultrasonography and indocyanine green video-angiography. Indications for retreatment included rerupture and partial occlusion. We analyzed the characteristics and causes of early retreatment. Six patients (2.5%, 95% CI 0.9 to 5.3%) were retreated within 30days after surgical clipping, including two patients (0.8%, 95% CI 0.1 to 2.9%) who experienced a rerupture. The retreated aneurysms were found in the anterior communicating artery (AcomA) (n=5) and basilar artery (n=1). Retreatment of the AcomA (7.5%) was performed significantly more frequently than that of other arteries (0.56%) (p<0.01). A laterally projected AcomA aneurysm (17.4%) was more frequently retreated than were other aneurysm types (2.3%). Cases of laterally projecting AcomA aneurysms tended to result from an incomplete clip placed using a pterional approach from the opposite side of the aneurysm projection. Despite developments, the rates of retreatment and rerupture after surgical clipping remain similar to those reported previously. Retreatment of the AcomA was significantly more frequent than was retreatment of other arteries. Patients underwent retreatment more frequently when they were originally treated for lateral type aneurysms using a pterional approach from the opposite side of the aneurysm projection. The treatment method and evaluation modalities should be considered carefully for AcomA aneurysms in particular.

The pCONus Device for Treatment of Complex Wide-Neck Anterior Communicating Artery Aneurysms

Anterior communicating artery (AcomA) aneurysms with a wide neck are often not feasible for endovascular coiling. Emerging devices for neck protection, such as the pCONus stent, are promising forendovascular treatment of challenging intracranial aneurysms. We report the preliminary results with pCONus in the treatment of wide-neck AcomA aneurysms. All consecutive patients harboring AcomA aneurysms treated with pCONus in 3 European centers were retrospectively reviewed. Thirty-six patients (mean age, 61 years) harboring 36 saccular AcomA aneurysms (mean dome size, 7.3 mm; mean neck size, 5.4 mm) were included, of which 7 were treated in the setting of subarachnoid hemorrhage. Aprocedural angiographic complication was reported in 3 patients without clinical impact at 3 months. Five patients presented a postoperative neurological deficit without angiographic complication. Procedure-related permanent morbidity and mortality rates were 11% (3/33) and 0 at 3 months, respectively. Postoperative angiographic results showed a complete aneurysm occlusion in 56% (20/36), a neck remnant in 25% (9/36), and an aneurysm remnant in 19% (7/36) of cases. Four patients were retreated after early angiographic follow-up (mean, 3.2 months). Twenty-two patients were followed (mean, 12.9 months), and a complete aneurysm occlusion was observed in 59% of patients (13/22), and a neck remnant in 41% (9/22). There was no in-stent stenosis or jailed branch occlusion. Recanalization rate was 9%. The pCONus device allows endovascular coiling of wide-necked AcomA aneurysms.

Abstract WP83: Wall Shear Stress Strength Over the Cerebral Aneurysm is Drastically Affected by Aneurysm Location While the Magnitude of Disturbed Flow is Closely Related to Aneurysm Size and Surface Area

Background and purpose: The rupture rate of cerebral aneurysms varies according to the aneurysm size and location. Although several reports suggest hemodynamic involvement in the mechanisms, there still remains to be clarified. Using computational fluid dynamics, we elucidated here differences in hemodynamics according to size and location of human cerebral aneurysms. Methods: Patient-specific inflow velocities and arterial geometries of 39 MCA aneurysms and anterior communicating artery (Acom) aneurysms were acquired from patients who consented to participate in the multi-institutional prospective clinical study, CFD ABO Study. Pulsatile blood flow was simulated using ANSYS-CFX, based on the Navier-Stokes equations for incompressible fluid. Aneurysms were divided into 3 groups by their size; less than 5mm, less than 7mm and more than 5mm, and more than 7mm. Results: Wall shear stress (WSS) was significantly lower in Acom aneurysms than MCA aneurysms (p=0.00075) while there was no significant difference in WSS according to aneurysm size. In contrast, indicators for disturbed flow, oscillatory shear index (OSI) and normalized transverse WSS (NtransWSS) were significantly higher over the aneurysms of the size less than 7mm and more than 5mm compared to those less than 5mm (p=0.021 and 0.014, respectively). Moreover, there were strong or moderate positive correlations between aneurysm surface area and OSI and NtransWSS, but not WSS. However, there was no significant difference in OSI or NtransWSS between MCA and Acom aneurysms. Conclusions: The data suggest that WSS strength over the cerebral aneurysm is drastically affected by the aneurysm location while the magnitude of disturbed flow is closely related to aneurysm size and surface area. A significant lower WSS in Acom aneurysms compared to MCA aneurysms may be associated with higher rupture rate in Acom aneurysms. In contrast, disturbed flow may be involved in aneurysm enlargement.

Small versus Large Ruptured Intracranial Aneurysm: Concerns with the Site of Aneurysm

Background: Although size is one of the strongest predictors, small aneurysms often rupture. We compared the characteristics of small and large ruptured intracranial aneurysms (RIAs) according to their location to find the factors associated with small RIAs in each location. Methods: Patients with subarachnoid hemorrhage due to saccular RIAs were consecutively enrolled. The sizes were dichotomized as small (<5 mm) or large, and the location was classified as paraclinoid-distal internal carotid artery, sidewalls of anterior or middle cerebral artery (MCA; sidewall), MCA-bifurcation, anterior or posterior communicating artery (Acom or Pcom, respectively), and posterior circulation RIAs. Independent factors associated with small RIAs compared to large RIAs were investigated in each location. Results: Small RIAs were observed in 384 of 791 patients (48.5%), and were most commonly located at Acom (17.1%) followed by Pcom (9.0%) and sidewalls (7.2%). Female sex (OR 3.038; 95% CI 2.099-4.395), young age (OR 0.971; 95% CI 0.958-0.985), hypertension (OR 1.412; 95% CI 1.033-1.930) and multiple aneurysms (OR 1.942; 95% CI 1.335-2.824) were associated with small RIAs. By location, sidewall aneurysms (OR 2.183; 95% CI 1.049-4.542) were associated with small RIAs, whereas MCA-bifurcation (OR 0.318; 95% CI 0.168-0.599) and Pcom aneurysms (OR 0.511; 95% CI 0.277-0.944) were associated with large RIAs. The presence of multiple aneurysms (OR 4.69; 95% CI 1.45-21.19) was associated with small RIAs at sidewalls, and young age, female sex, hypertension and the presence of bilateral A1 (OR 1.85; 95% CI 1.09-3.13) were associated with small RIAs at Acom. Acom RIAs with bilateral A1 was smaller than those with unilateral A1 (4.7 ± 2.1 vs. 5.8 ± 2.6 mm; p < 0.001). Conclusions: Intracranial aneurysms which rupture below 5 mm are not uncommon, and the factors associated with small-sized RIAs differ according to location. Sidewall aneurysms, with multiple aneurysms and Acom aneurysms with bilateral A1 may rupture even at small size.

前交通動脈瘤手術におけるmini orbitozygomatic approachの有用性の検討

Introduction: The mini orbitozygomatic approach (mOZA) can relieve frontal lobe retraction and is beneficial for clipping anterior communicating artery (Acom) aneurysms, especially high-position Acom aneurysms. The Acom can easily be observed through the mOZA. In this study, we evaluated the usefulness of the mOZA for Acom aneurysm clipping by comparing various aneurysm orientations.Materials and Methods: Aneurysm neck position (height and anteroposterior position) and maximum diameter, patient age and sex, and incidence of previous subarachnoid hemorrhage were compared between 5 cases treated via the mOZA and 13 cases treated via the pterional approach (PA) for Acom aneurysm clipping. Furthermore, the appropriateness of the two approaches was assessed by reviewing the intraoperative video.Results: The mean ages of the mOZA and PA groups were 64.0 and 59.8 years (p = 0.552), respectively. There were 3 male patients (60%) in the mOZA group and 7 (53.8%) in the PA group (p = 1.000). Two patients (40%) in the mOZA group and 8 (61.5%) in the PA group had a previous subarachnoid hemorrhage (p = 0.608). The mean maximum aneurysm diameter was 5.4 mm in the mOZA group and 5.7 mm in the PA group (p = 0.811). The mean height of the aneurysmal neck was significantly higher in the mOZA group (8.3 mm) than in the PA group (5.5 mm; p = 0.045). The mean anteroposterior position was not different between the two groups (8.5 mm vs 5.1 mm, p = 0.216). When the aneurysm neck was located at a height of between 8 and 10 mm from the planum sphenoidale and anteriorly located 10 mm from the jugum sphenoidale, mOZA was considered to be useful for Acom aneurysm clipping on the basis of the review of the intraoperative video.Conclusion: Understanding the positional relationship between the height and the anteroposterior position of the aneurysm neck is a key factor in considering the mOZA for Acom aneurysms. The approach is especially useful in cases where the aneurysm neck is located at a high level anteriorly.

Horizontal distance of anterior communicating artery aneurysm neck from anterior clinoid process is critically important to predict postoperative complication in clipping via pterional approach.

Background:The difficulty of clipping aneurysm of the anterior communicating artery (AcomA) depends on the size, direction, positional relationship with the parent artery, and height from the anterior frontal base. Cases of clipping unruptured AcomA aneurysm through pterional approach were analyzed to investigate the importance of the horizontal distance from the base of the anterior clinoid process.Methods:Twenty-six consecutive unruptured AcomA aneurysms were treated by clipping through pterional approach in 10 males and 11 females aged 37–77 years (mean 61.8 years). Size and direction of the aneurysm, and vertical distance from the anterior frontal base and horizontal distance from the base of the anterior clinoid process were measured by preoperative three-dimensional computed tomography angiography (3D-CTA). Correlations with occurrence of clinical complications and computed tomography (CT) abnormalities after operation were investigated.Results:The aneurysms had a mean size of 4.7 mm (range 2.1–8.9 mm). Three patients suffered complications and all had anosmia. Three patients had CT abnormality and all were contusion. The mean horizontal distance from the base of the anterior clinoid process was −4.7 mm (range −12.3–3.5 mm). The patients were divided into the anterior and posterior groups with the boundary set at −5 mm. There were no significant complications between two groups (P = 0.26). There were statistically significant CT abnormalities in posterior group (P = 0.025).Conclusion:The horizontal distance from the base of the anterior clinoid process is important to predict CT abnormalities and complications in clipping of AcomA aneurysm through pterional approach.

A 16 Year Experience with Modified Lateral Supraorbital Approach for Ruptured Cerebral Aneurysms

Objectives: Upto now, most authors reported the supraorbital approach for unruptured aneurysm and small and less complex aneurysm. The authors devised the Modified Lateral Supraorbital (MLSO) approach. We present a 16 year experience with MLSO approach for ruptured anterior circulation aneurysms and some parts of posterior circulation aneurysms. Materials and Methods: Aneurysm clipping surgery through the MLSO approach was performed on a total 323 patients. Baseline demographics, operative time, procedural complications, and clinical outcomes at 6 months and 1 year were retrospectively analyzed. Results: For patients treated MLSO approach, 293 had single aneurysms and 30 had multiple aneurysms. The proportion of small, medium, large, and giant aneurysms were 64% (206/323), 31% (101/323), 4.7% (15/323), and 0.3% (1/323). Mean operation time was 219.6 minutes. Procedural complications occurred in 21 cases (6.5%). Five patients died from severe brain swelling and refusal of additional treatment, while 1 patient died from tonsilar herniation due to lumbar catheter drainage. Favorable clinical outcomes, Glasgow Outcome Scale IV or V, were observed in 82.6% (267/293) and 83.6% (270/293) at 6 months and one year follow-up. The MLSO approach has the following advantages: less brain retraction, good surgical field for high positioned A-com or basilar tip aneurysm surgery, short operation time, small skin incision, minimizing temporal muscle manipulation and good cosmetic appearance. Conclusions: The MLSO approach can be considered as a useful approach for neurosurgeons for cases of general ruptured aneurysm, except those with a large amount of intracerebral hemorrhage and severe brain swelling.

T-microstent-assisted coiling in the management of ruptured wide-necked anterior communicating artery aneurysms: Choosing between Y, X and T

Anterior communicating artery aneurysms frequently present wide necks and incorporate parent vessels. They are associated with significant variations in vascular anatomy, especially hypoplasia or aplasia of one of the proximal anterior cerebral arteries. Safe and complete endovascular occlusion of these aneurysms usually requires the assistance of complex approaches including dual stenting. We describe a technique for T-configured stent-assisted coiling in the management of ruptured wide-necked AcomA aneurysms by means of two simultaneous microsystems that allowed placement of two nitinol self-expandable Leo+ Baby stents (Balt Therapeutics, Montmorency, France) followed by coiling. Technical details and comparison to other dual stent configurations were presented and briefly discussed.

Elderly age associated with poor functional outcome after rupture of anterior communicating artery aneurysms

The effect of age on patient outcomes after rupture of the anterior communicating artery (Acom) aneurysms is not well-defined. We performed a retrospective cohort study of patients presenting to our institution with a ruptured Acom aneurysm between 2003 and 2012. Patients were divided into two groups on the basis of age at presentation, with patients 65years and older categorized as the elderly group. The effect of elderly age on patient outcomes was then evaluated using multivariate logistic regression analysis. There were 147 patients presenting with a ruptured Acom aneurysm. Of these, 41 (27.9%) were 65years or older. Patients in the elderly group were more likely to be female (68.3% vs. 40.6%, p=0.0026), and less likely to be active smokers (22.0% vs. 60.4%, p<0.0001) or to abuse alcohol (7.3% vs. 21.7%, p=0.0404). Elderly patients were more likely to have a history of hypertension (70.7% vs. 52.8%, p=0.0487) and coronary artery disease (19.5% vs. 2.8%, p=0.0006). Elderly patients were more likely to require a ventriculostomy (61.0% vs. 37.7%, p=0.0109) and ultimately to require permanent cerebrospinal fluid diversion (36.6% vs. 17.0%, p=0.0106). On adjusted analysis, age 65 years or older was associated with a greater likelihood of poor outcome at last follow-up within 1year of aneurysmal subarachnoid hemorrhage (odds ratio=3.76, 95% confidence interval: 1.30–11.78, p=0.0144). Our results suggest that elderly age is an independent risk factor for poor functional outcome after rupture of an Acom aneurysm.

A1 segment hypoplasia associated with cerebral infarction after anterior communicating artery aneurysm rupture.

Congenital hypoplasia or absence of the A1 segment of the anterior cerebral artery (ACA) has been associated with increased incidence of berry aneurysms at the anterior communicating artery (Acom) complex. It is not known, however, whether this anatomic variant also predisposes patients to complications after aneurysmal subarachnoid hemorrhage. Patients were included for analysis if they presented to our institution for clipping or coiling of an Acom aneurysm between the years of 2001 and 2013. Patients were deemed to have cerebral infarction if a new hypodensity in a vascular distribution was visualized on CT imaging. The association between A1 segmental abnormalities and radiologic infarction was subsequently evaluated in a risk-adjusted manner using stepwise multivariable logistic regression analysis. Of 145 patients who presented with aneurysmal subarachnoid hemorrhage after rupture of an Acom aneurysm, 31 (21.4%) had a hypoplastic or absent A1 segment. On univariate analysis, there was a trend toward an increased rate of radiologic infarction in patients with A1 segment abnormalities (OR=2.11, 95% CI: 0.93-4.79; P=0.0757). On multivariable analysis, a hypoplastic or absent A1 segment was significantly associated with an increased rate of radiologic infarction (OR=2.54, 95% CI: 1.02-6.43; P=0.0466). Our results suggest that a hypoplastic or absent A1 segment is associated with cerebral infarction following subarachnoid hemorrhage from ruptured Acom aneurysms, indicating a potential need for heightened vigilance and a reduced threshold for therapeutic intervention in patients harboring this abnormality.

Pentaxial access platform for ultra-distal intracranial delivery of a large-bore hyperflexible DIC (distal intracranial catheter): A technical note

Abstract Background Intracranial access techniques in modern neurointervention are shifting towards more robust access platforms. We present in this report a novel method of navigating a 5 French distal intracranial catheter (DIC) deep within the intracranial circulation in an atraumatic fashion via a pentaxial access system. Methods We retrospectively reviewed all neurointerventions performed at two author institutions identifying all aneurysm treatments where the pentaxial system was used to build the catheter support for intracranial positioning of a 5 French DIC. Procedural data collected include parent artery tortuosity, use of vasodilator, intra-procedural DIC position, and peri-procedural complications. Results The pentaxial access platform provided ultra-distal intracranial navigation of the 5 French DIC in the following 11 neurointerventions for treatment of anterior circulation aneurysms: Pipeline embolization device (PED) for anterior communicating artery (ACom) aneurysm, n = 2; surpass for large internal carotid artery (ICA) aneurysm, n = 4; Woven EndoBridge (WEB) device for ACom aneurysm, n = 5. Mean patient age was 55 ± 11 years (range 40–75 years). Mean aneurysm size was 6.7 mm ± 3.8 mm (range 2–16 mm). Mean fluoroscopy time was 29 ± 16.7 min. Intra-procedural DIC positions achieved included supraclinoid ICA (n = 6), M1 (n = 4), and A1 (n = 1). No significant catheter-related complications occurred. Conclusion Distal intracranial catheters can achieve ultra-distal intracranial positions safely with the pentaxial access platform. This technique is a near no step-off, atraumatic method of navigating a DIC in a stepwise fashion over de-escalating smaller diameter catheters via a microwire. Familiarity with catheter specifications including diameters and length is essential for the success of this system.

Closed-Cell Stent-Assisted Coiling of Intracranial Aneurysms: Evaluation of Changes in Vascular Geometry Using Digital Subtraction Angiography.

BackgroundStent-assisted coil embolization (SACE) plays an important role in the treatment of intracranial aneurysms. The purpose of this study was to investigate geometrical changes caused by closed-cell design stents in bifurcation and sidewall aneurysms.Methods31 patients with 34 aneurysms underwent SACE with closed-cell design stents. Inflow angle α, determined by aneurysm neck and afferent vessel, and angle between afferent and efferent vessel close to (δ1), respectively, more remote from the aneurysm neck (δ2) were graphically determined in 2D angiography projections.ResultsStent assisted coiling resulted in a significant increase of all three angles from a mean value (±SEM) of α = 119° (±6.5°) pretreatment to 130° (±6.6°) posttreatment (P ≤ .001), δ1 = 129° (±6.4°) to 139° (±6.1°), (P ≤ .001) and δ2 = 115° (±8.4°) to 126° (±7.5°), (P ≤ .01). Angular change of δ1 in AcomA aneurysms was significant greater compared to sidewall aneurysms (26°±4.9° versus 8°± 2.3°, P ≤ .05). The initial angle of δ1 and δ2 revealed a significantly inverse relationship to the angle increase (δ1: r = -0.41, P ≤ .05 and δ2: r = -0.47, P ≤ .01). Moreover, angle δ1 was significantly higher in unruptured compared to ruptured aneurysms (135°±7.1° versus 103°±10.8°, P ≤ .05).ConclusionStent deployment modulates the geometry of the aneurysm-vessel complex, which may lead to favorable hemodynamic changes more similar to unruptured than to ruptured aneurysms. Our findings also suggest that the more acute-angled aneurysm-vessel anatomy, the larger the angular change. Further studies are needed to investigate whether these changes improve the clinical outcome.

Twin-like appearance of an unruptured intracerebral anterior communicating artery (ACom) aneurysm in a male sibling of a patient with a ruptured ACom aneurysm

Increased risk of intracranial aneurysm rupture with subsequent subarachnoid haemorrhage (SAH) is related to several possible factors, including first-grade familial aneurysms. Here we present a case of one ruptured and one unruptured identical twin-like anterior communicating artery (ACom) aneurysm present in two male siblings, without any proven genetic predisposition. According to evidence-based scores, aneurysm rupture risk for the younger (51years old) sibling (with an unruptured ACom aneurysm) would be low, leaving the decision for either treatment or clinical follow-up to the discretion of the treating physician. From a clinical neurosurgical perspective, however, especially since his older brother suffered an aneurysmal SAH at age 57 (i.e. 6 life-years later) from a twin-like-appearing ACom aneurysm, in our opinion rupture seems almost inevitable, thus prompting treatment at an early stage.

The Implication of Anterior Communicating Complex Rotation and 3-Dimensional Computerized Tomography Angiography Findings in Surgical Approach to Anterior Communicating Artery Aneurysms

To investigate the usefulness of 3-dimensional computerized tomography angiography (3D-CTA) in the microsurgical management of anterior communicating artery (AcomA) aneurysms. Twenty-six consecutive patients with AcomA aneurysms (22 ruptured) underwent microsurgical clipping. Detailed angioanatomic assessment of the AcomA complex and operative approach was based on the 3D-CTA. The 3D-CTA showed a dominant proximal anterior cerebral artery (A1) segment in 61% and symmetric A1s in 39% of aneurysms. Dominant A1 segments presented with rotation of the AcomA complex toward the contralateral side in 63%, toward the ipsilateral side in 25%, and without rotation in 12%. With symmetric A1s, the AcomA was parallel to the coronal plane in 90% and a right-sided approach was carried out in these patients. In rotated AcomA complexes, the virtual 3D views were compared to determine the side of the approach. For superior projecting aneurysms, we determined that the approach from the side in which the A1-distal anterior cerebral artery (posterior communicating) angle was posterior was more favorable. For posterior projecting aneurysms, the approach from the side where the A1-distal anterior cerebral artery (posterior communicating) angle was more anterior was more favorable. For anteroinferior projecting aneurysms, an approach from the dominant A1 side was chosen regardless of AcomA complex rotation. Postoperative 3D-CTA showed complete exclusion of 24 aneurysms (>92%) and 2 small remnants (<2 mm). Outcome was excellent or good (modified Rankin score 0-2) in 88% of patients. Rotation of the AcomA complex and dome projection are important angioanatomic elements in determining the surgical exposure and side of the approach. This study illustrates the role of 3D-CTA in the management of these difficult lesions by individualizing the surgical approach.

Abstract WP88: Hemodynamic Localizations in Anterior Communicating Artery Aneurysms in Comparison With Middle Cerebral Artery Aneurysms With Computational Fluid Dynamics Analysis

Introduction: In a series of reports using an animal model of experimentally induced cerebral aneurysms (CAs), we have proposed that an increase in wall shear stress (WSS)-related hemodynamics initiates CA development. Although several studies tried to clarify detailed hemodynamic stress in human CAs with computational fluid dynamics (CFD), the results so far are controversial. Thus, we started the multi-institutional prospective clinical trial to examine hemodynamics-related factors for CA development, enlargement, and rupture with CFD, named CFD ABO Study. We have proposed “normalized transverse WSS” (NtransWSS); a newly modified indicator based on transWSS for multi-directional disturbed flow, and indicated significant importance of WSS-associated disturbed flow in CA formation. We show here the interim report of the trial. Hypothesis: Unlike MCA aneurysms, anterior communicating artery (Acom) aneurysms usually have inlet flow from both sides of internal carotid arteries, which may cause more complicated hemodynamic circumstances, contributing to higher rupture rate of Acom aneurysms. In order to clarify this hypothesis, we elucidated differences in hemodynamics between Acom and MCA aneurysms. Methods: Three-dimensional CT angiographic images of human CAs and patient-specific flow velocities as inlet boundary conditions were used for CFD analysis. Results and Conclusions: In Acom aneurysms, WSS was lower over the entire aneurysm than neighboring arteries (p=0.02), but higher at neck of the CA (p=0.02). WSS gradient was higher at the neck (p=0.02). NtransWSS and OSI were higher over the entire aneurysm (p=0.02) and at the neck (p=0.02 and 0.04, respectively). Although distributions of some hemodynamic metrics in MCA aneurysms were statistically similar in Acom aneurysms, OSI at the neck was not significantly higher. In addition, WSS over the entire aneurysms of Acom was much lower as compared with MCA aneurysms (p=0.03). At the neck of Acom aneurysms compared with MCA aneurysms, NtransWSS and OSI were higher while WSS was lower (not significant). High WSS under disturbed flow may be involved in CA development, and low WSS with turbulences in rupture. Markedly lower WSS in Acom aneurysms may be associated with higher rupture rate in this site.

Transient Bilateral Oculomotor Nerve Palsy (TOP) Associated with Ruptured Anterior Communicating Artery Aneurysm: A Case Report

Oculomotor nerve palsy has been recognized as a localizing sign due to aneurysms along the internal carotid artery, resulting from direct pressure on the nerve. There were only two case reports of an anterior communicating artery (AcomA) aneurysm rupture followed by bilateral oculomotor nerve palsy. We experienced the rare finding of a patient with transient bilateral oculomotor nerve palsy unrelated to consciousness disturbance that started about 38 hours after subarachnoid hemorrhage (SAH) due to AcomA aneurysm rupture. Without raised intracranial pressure, bilateral mydriasis resolved spontaneously 22 hours later. A thick clot Fisher group 3 SAH occupying perimesencephalic, interhemispheric, and sylvian cisterns bilaterally,remained in CT scans afterthe operation. Reconstructed MRI data of the oculomotor nerve were converted to a curved multiplanar reconstruction (MPR) image suggested that subarachnoid blood occupying the perimesencephalic cisterns bilaterally induced compression on the oculomotor nerves directly, and the subsequent local edema caused transient bilateral palsy.

Small and medium size intracranial aneurysms - a 5 years retrospective analysis trial and multimodal treatment

Abstract Clinical context. Subarachnoid hemorrhage (SAH) due to rupture of an aneurysm is one of the most common neurosurgical emergencies who account for onethird of stroke .In the SAH cases , aneurysms accounted for 70%. Aneurysms had a bleeding rate of 12 per 100,000 population per year, and in particular between 50 to 60 years of age with a high morbidity and mortality, especially in the first episode of bleeding at about 43% of cases (1, 4, 14). Surgery is indicated to prevent rebleeding. 2.5% of patients in the general population may have unbroken aneurysms with a prevalence of 0.65%, with a preponderance of aneurysms in a 2: 1 in women. ACI aneurysms are more common in women and Acom aneurysms are more common in men and in 15-30% of patients with presence of multiple aneurysms. Surgical timing, the assessment in each individual case for rebleeding usage of endovascular techniques (3, 12), neurological status, the presence or absence of intraparenchymal hematoma or intraventricular hemorrhage with or without vasospasm, have an influence on the result. Over a period of 5 years from January 2010 to November 2014, 317 cases of patients with intracranial aneurysms in four clinics of neurosurgery in Bagdasar -Arseni hospital have been studied. The follow up period range between 6 month and 4 years and 3 month.

A Reappraisal of Anterior Communicating Artery Aneurysms: A Case for Stent-Assisted Embolization.

Wide-necked anterior communicating artery aneurysms represent a subset of lesions with challenging endovascular treatment despite new endoluminal and intrasaccular devices. To assess the long-term clinical and angiographic outcomes of stent-assisted embolization for wide-necked anterior communicating artery aneurysms. Between March 2008 and March 2014, 32 patients with unruptured wide-necked AComm aneurysms were treated using stent-assisted embolization. The Glasgow Outcome Scale was reviewed at the time of discharge and at latest follow-up. Ischemic and hemorrhagic events were also recorded and analyzed. Aneurysm occlusion was evaluated post-intervention and on subsequent follow-up evaluations. Successful stent deployment was achieved in all cases, but in 1 patient the coils could not be contained inside the aneurysm, and the procedure was aborted without complications. The distal segment of the stent was positioned in the ipsilateral A2 in 16 patients, in the contralateral A2 in 15 patients, and in the contralateral A1 in 1 patient. There were no periprocedural thromboembolic or hemorrhagic complications. The rate of major complications was 6%. One patient developed intracranial hemorrhage related to antiplatelet therapy and another had ischemic events due to in-stent stenosis. Angiographic follow-up was available for 26 aneurysms and during a mean follow-up of 22 months, 81% of the lesions were completely occluded and 8% had a small residual neck. The retreatment rate for residual aneurysms was 3%. Our long-term results suggest that stent-assisted embolization for anterior communicating artery aneurysms may be considered an excellent treatment option with an adequate combination of safety profile and effectiveness.

Morphological risk factors for the rupture of anterior communicating artery aneurysms: the significance of fenestration.

The purpose of this study was to evaluate morphological factors associated with rupture in anterior communicating artery (AcomA) aneurysms and to investigate the significance of AcomA fenestration as a risk factor for aneurysm rupture. The clinical and radiologic findings of 255 patients with AcomA aneurysms treated with coil embolization between January 2005 and March 2014 were retrospectively reviewed. We performed univariate and multivariate analyses to evaluate the associations between morphological variables and rupture status. The number of patients with AcomA fenestration was 17 out of 255 (6.6%). There were no statistically significant differences between the fenestration group and non-fenestration group in clinical and morphological characteristics. Multivariate logistic regression tests showed that superior direction of aneurysm dome (OR 2.802, p = 0.023), presence of a bleb (OR 5.998, p < 0.001), high aspect ratio (OR 3.138, p = 0.009), size greater than 7mm (OR 3.356, p = 0.013), and AcomA fenestration (OR 4.135, p = 0.026) were significantly associated with AcomA aneurysm rupture. The results of this study demonstrated that a fenestrated AcomA is associated with risk of aneurysm rupture. Therefore, AcomA fenestration can be considered as an important morphological risk factor for rupture, along with other known risk factors such as the direction of aneurysm dome, a bleb, high aspect ratio, and size.