Coil Embolization of the Azygos Anterior Cerebral Artery Aneurysm: Three Case Reports.

The azygos anterior cerebral artery (ACA) is a rare anatomical anomaly. Clipping surgery has been conducted in approximately 30 reported cases because it is frequently associated with aneurysms. However, few cases in which coil embolization was performed have been reported. We report three cases of coil embolization for distal ACA aneurysms with distal azygos ACA at our institution in 7 years. All patients were over 65-year-old women with saccular aneurysms larger than 7 mm; two with subarachnoid hemorrhage and one with an unruptured aneurysm. No patient had surgical complications associated with coil embolization. Coil embolization is also useful for large aneurysms in the distal azygos ACA, and its indication for treatment could be broadened.

Fenestrated Anterior Cerebral Artery, Anterior Communicating Artery, with Accessory Middle Cerebral Artery-A Conglomeration of Embryologically Different Entities in a Single Individual.

Cerebral arterial fenestrations are anatomic variants of undetermined significance where there is a division of a single vessel into at least 2 channels, each having endothelial and muscular layers, that coalesce to a single lumen in the distal course of the vessel. The basilar artery is the most common site, followed by the anterior communicating artery. The accessory middle cerebral artery is defined as the anomalous origin of the vessel from the anterior cerebral artery and its further course along the sylvian fissure parallel to the middle cerebral artery. The embryologic basis of all these has been explained by studies on human embryological development by Padget et al. However, simultaneous existence of all 3 anomalies in a single individual has never been reported. Here we present a case of medial sphenoid wing meningioma with these incidental findings during workup and further delineation of anatomy following surgical resection of meningioma.

Unreported branching pattern of the triplicated anterior cerebral artery associated with multiple bilateral variants of the superior cerebellar artery detected by computed tomography angiography and 3D modeling.

A 26-year-old patient underwent a successful ablation of Grade 2 diffuse astrocytoma of the right parietal lobe. The postoperative computed tomography angiography with 3D modeling revealed a residual avascular porencephalic cyst. Otherwise, multiple arterial variants have been encountered. First, the left A1 segment was fenestrated, and three A2 segments arose from the anterior communicating artery. The middle A2 segment was dominant and supplied left callosomarginal and both pericallosal territories. The right A2 segment supplied the right callosomarginal territory, while the left A1 was limited to the left orbitofrontal and frontopolar territories. This configuration represents a triplicated anterior cerebral artery with an unusual branching pattern not included in the classification of Baptista. In addition, on both sides, superior cerebellar artery duplication was present, with one arising from the basilar artery and the other from the P1 segment of the ipsilateral posterior cerebral artery. The left lower superior cerebellar artery was early bifurcated. It is the first time such a cerebrovascular configuration has been reported. Because of the several clinical and surgical applications of the anterior cerebral artery and superior cerebellar artery variants, this case report is of utmost interest to anatomists, radiologists, and neurosurgeons.

The application of high-resolution vessel wall imaging in the in situ bypass surgeries for complex anterior cerebral artery aneurysms.

OBJECTIVE: Complex anterior cerebral artery (ACA) aneurysms are still technically challenging to treat. Bypass surgery is needed to achieve aneurysm obliteration and ACA territory revascularization. Severe atherosclerosis of aneurysm walls can cause clip slippage, intraoperative rupture, postoperative ischemic events. How to assess the atherosclerotic changes in vascular walls by high-resolution vessel wall magnitude resonance imaging (VWI) is the key question in complex ACA aneurysm surgical management. METHODS: This retrospective single-center study included eight patients diagnosed with complex anterior cerebral arteries admitted to our hospital for bypass surgery from January 2019 to April 2022. We discussed the application of VWI in aneurysms treated with in situ bypass and reviewed previous experience of revascularization strategies for complex ACA aneurysms. RESULTS: In this study, we treated 8 cases of complex ACA aneurysms (3 communicating aneurysms/5 postcommunicating aneurysms) over the prior one year. In situ side-to-side anastomosis (1 A2-to-A2/6 A3-to-A3) was performed in seven cases, and trapping combined with excision was performed in another case. Following bypass, complete trapping was performed in 4 cases, and proximal clipping was performed in 3 cases. No surgery-related neurological dysfunctions were observed. The final modified Rankin scale was 0 in seven of the eight cases and 2 in one case. CONCLUSION: High-resolution VWI, as a favorable preoperative assessment tool, provides insight into patient-specific anatomy and microsurgical options before operations, which can help neurosurgeons develop individualized and valuable surgical plans.

Bihemispheric Right Anterior Cerebral Artery, Fenestrated Origin of the Left Pericallosal Artery, Fenestrated Basilar Artery, Double Right Posterior Cerebral Artery.

Anatomical variations of the cerebral vasculature are frequently encountered. The archived magnetic resonance angiogram of a 62-year-old male patient was studied anatomically on planar slices and 3-dimensional volume renderings. Numerous anatomical variants were found in that single case. In the vertebrobasilar system were found: the proximal basilar artery fenestration, with a unilateral origin from that fenestration of an anterior inferior cerebellar artery, and the unilateral origin of the superior cerebellar artery from the P1 segment of the main posterior cerebral artery (PCA). There were also unilateral variants of the right internal carotid artery (ICA): a subvariant of an accessory PCA leaving the ICA as a hyperplastic anterior choroidal artery and united to the main PCA by a short communicating branch, distinctive of the posterior communicating artery in that side (unilateral double PCA); a right bihemispheric anterior cerebral artery (ACA) but with complete agenesis of the contralateral A1 ACA segment; from the right ACA continued an anatomically normal ipsilateral A2 segment and a short transverse contralateral A2 that, in turn, sent off long pericallosal and callosomarginal arteries; and fenestrated origin of the left pericallosal artery. Therefore, an arterial variant in one of the main cerebral circulations could not exclude anatomical variants in the other cerebral circulatory beds.

False Absence of the Anterior Communicating Artery and a Median Artery of Corpus Callosum.

The anterior communicating artery (AComA) normally joins the anterior cerebral arteries (ACAs) when they change their directions from horizontal to vertical. Each postcommunicating segment of the ACAs commonly sends off the callosomarginal artery (CMA) and continues as the pericallosal artery. While documenting the archived computed tomography angiogram of a 61-year-old male patient, a rare anatomic variant was found to be associated with a previously unreported one. Both ACAs had symmetrical horizontal and vertical segments, but the AComA was absent from the usual location. The right ACA continued as CMA without sending off a pericallosal artery. A median artery of corpus callosum (MACC) left from the horizontal segment of the left ACA. Then the left ACA continued as CMA. At 1.9 cm from its origin, the MACC was united to the right CMA by a high, interhemispheric AComA. Therefore, an AComA should be regarded as absent only after documenting the bilateral anastomoses within the interhemispheric fissure. A third interhemispheric main artery, such as a rarely occurring MACC, could be accurately documented by computed tomography angiogram to avoid unpleasant intraoperative hemorrhage or to establish a personalized endovascular route to the anterior cerebral system.

Microsurgical anatomy of the anterior cerebral artery and the arterial supply of the cingulate gyrus.

PURPOSE: The cingulate gyrus is a potential surgical area to treat tumours, psychiatric diseases, intractable pain and vascular malformations. The aim of the study was to define the topographic anatomy and arterial supply of the cingulate gyrus located on the medial surface of the cerebral hemisphere. METHODS: We studied thirty-six hemispheres, each hemisected in the midsagittal plane. The vertical thickness of the cingulate gyrus was measured at the anterior commissure (AC), posterior commissure (PC), and genu levels of the corpus callosum. The branches of the anterior and posterior cerebral arteries supplying each zone were noted separately. The arterial pathways were transformed to digital data in AutoCAD to identify the condensation and reduction areas. RESULTS: The mean AC-PC distance was 27.17 ± 1.63 mm. The thinnest region was the genu level of the corpus callosum (10.29 mm). The superior internal parietal artery (SIPA), inferior internal parietal artery (IIPA) and pericallosal artery (PrCA) supplied all zones of the cingulate gyrus. The anterior zone received the greatest supply. The arterial condensation and reduction areas on both sides of cingulate gyrus and its x, y, and z coordinates specified. CONCLUSIONS: The target cingulotomy (TC) area was determined for anterior cingulotomy. The properties of the TC area are that the thinnest region of the cingulate gyrus is supplied relatively less than other areas and is close to the anterior cingulotomy areas in the literature. The arterial reduction area (ARA) was found to be suitable for corpus callosotomy in terms of avoiding haemorrhage.

Cerebrovascular Reserve Impairment in the Anterior Cerebral Artery Territory Predicts Deep Temporal Artery Enlargement After Combined Revascularization Surgery in Moyamoya Disease.

OBJECTIVE: A combined surgery of direct and indirect revascularization has been frequently performed in patients with moyamoya disease, though the efficacy of indirect revascularization surgery in adult patients with moyamoya disease has not been established. This study aimed to evaluate superficial temporal artery (STA) and deep temporal artery (DTA) diameters 1 day and 3 months after combined revascularization surgery in patients with moyamoya disease. We also investigated clinical factors related to DTA enlargement after surgery. METHODS: We examined 78 cerebral hemispheres in 57 adult and pediatric patients with moyamoya disease who underwent combined revascularization surgery [STA-MCA bypass and encephalo-duro-myo-synangiosis] in our institution. STA and DTA diameters were measured on axial magnetic resonance angiography images at 1 day and 3 months after surgery. RESULTS: DTA diameter increased in 64 hemispheres (82.1%). DTA diameter increase in association with STA diameter decrease was found in 39 hemispheres (50%). The proportion of hemispheres with a reduction in STA diameter was significantly higher in hemispheres with DTA enlargement than in hemispheres with DTA reduction (P = 0.0088). Among the 64 hemispheres with DTA enlargement, 51 (79.7%) showed cerebrovascular reserve (CVR) impairment in the anterior cerebral artery (ACA) territory before surgery. CVR impairment in the ACA territory was the only clinical factor related to DTA enlargement (P < 0.001). CONCLUSION: The DTA frequently enlarges after combined revascularization surgery, even in adult patients with moyamoya disease. In patients with impaired CVR in the ACA territory, blood supply from the DTA to the ACA territory can be expected after combined revascularization surgery.

How I do it: left posterior cerebral artery P1-2 segment dissecting aneurysm distal clipping via an A1-RAG-P2 bypass.

BACKGROUND: Posterior cerebral artery (PCA) P1-2 segment dissecting aneurysms are difficult because regular craniectomy aneurysm clipping or intravascular interventional therapy is not applicable. METHOD: We report distal clipping of a PCA P1-2 segment dissection aneurysm with an anterior cerebral artery (ACA) A1-radial artery graft-PCA P2 bypass. CONCLUSION: This case demonstrates the value of an ACA-RAG-PCA bypass in the therapy of a PCA dissecting aneurysm.

Surgical Treatment of Large and Giant Anterior Cerebral Artery Aneurysms in the Endovascular Era: Analysis of Large Clinical Series.

OBJECTIVE: Analysis of results of surgical treatment of 112 patients with large and giant anterior cerebral artery (ACA) aneurysms. METHODS: This is the largest clinical series of large and giant ACA aneurysms ever reported. Retrospective analysis of medical charts, radiographic studies, and intraoperative videos was performed. Univariate and multivariate analysis of relations among 3 types of outcomes (complete aneurysm occlusion, ischemic complications, and clinical outcomes) and predicting factors was performed. RESULTS: Most aneurysms were communicant (84.8%). Aneurysms of the A1 segment and distal segments (A2-A5) were encountered rarely. Complete aneurysm occlusion (class I) was shown in 95 cases (90.5%). In 4 patients, only exploration and wrapping were performed because of severe atherosclerosis and chronic intraluminal thrombi. Partial occlusion (class III) was shown in 2 patients, and neck residual (class II) in 4 patients. Cerebral ischemia developed in 29 patients postoperatively. Occlusion or injury of the A1 segment and anterior communicating artery perforators and recurrent branch of Heubner were the most common reason for ischemic complications. At follow-up, 97 patients (86.6%) had favorable outcomes. Ten patients (8.9%) had unfavorable outcomes because of postoperative complications. CONCLUSIONS: Microsurgery provides effective and relatively safe occlusion of complex ACA aneurysms. Direct clipping can be applied in most cases independent of their precise location. In certain cases, alternative methods can be safely used. According to multivariate analysis, giant aneurysm size, aneurysm-related mass effect, involvement of large arterial branches in the aneurysm wall, and intraoperative complications were significant predicting factors for ischemic complications.

Occlusion of the Anterior Cerebral Artery Mimicking a Cerebral Aneurysm: Clinical Presentation and Literature Review.

BACKGROUND: Intracranial aneurysms may be misdiagnosed with other vascular lesions such as vascular loops, infundibulum, or the stump of an occluded artery (very rare and reported compromising only the middle cerebral artery and the posterior circulation territory). Our aim was to describe a unique case of occlusion of an anterior cerebral artery mimicking a cerebral aneurysm in a probable moyamoya disease patient, and to highlight its clinical presentation, diagnosis, and management, and to perform an extensive literature review. CASE: A 67-year-old man suffering from recurrent dizziness for 3 months. Previous medical history was unremarkable. Brain magnetic resonance angiography (MRA) and digital subtraction angiography (DSA) demonstrated occlusion of the right middle cerebral artery (MCA) associated with a "probable moyamoya disease" and an aneurysm-like shadow protruding lesion at the anterior communicating artery (AcomA). Perfusion images showed ischemia along the right temporo-occipital lobe. Due to MCA occlusion with perfusion deficits and unspecific symptoms, we offered a right side encephalo-duro-myo-synangiosis (EDMS) and clipping of the AcomA aneurysm in one session. Intraoperatively, there was no evidence of the AcomA aneurysm; instead, this finding corresponded to the stump of the occluded right anterior cerebral artery (A1 segment). This segment appeared to be of yellowish color due to atherosclerosis and lacked blood flow. The patient underwent as previously planned a right side EDMS and the perioperative course was uneventful without the presence of additional ischemic attacks. CONCLUSION: Arterial branch occlusions can sometimes present atypical angiographic characteristics that can mimic a saccular intracranial aneurysm. It is relevant to consider this radiographic differential diagnosis, especially when aneurysm treatment is planned.

Unilateral agenesis of internal carotid artery with interparaclinoid and contralateral carotid-anterior cerebral artery anastomoses diagnosed by magnetic resonance angiography: a case report.

PURPOSE: Unilateral agenesis of the internal carotid artery (ICA) is a rare anatomical variant. We identified a case of unilateral ICA agenesis with interparaclinoid and contralateral carotid-ACA anastomoses. METHODS: A 65-year-old female with a long history of depressive episodes underwent MR imaging including MR angiography at National Hospital Organization Kyushu Medical Center. MR imaging was performed using a 3.0-T MR scanner to rule out vascular Parkinsonism, although drug-induced Parkinsonism was suspected from her medical history. RESULTS: The proximal left ICA was not visible on MR angiography, and an anterior communicating artery (ACoA) aneurysm was identified. The left middle cerebral artery was supplied from the right ICA via an interparaclinoid anastomosis. This interparaclinoid anastomosis showed no communication with the basilar, posterior communicating, or posterior cerebral arteries. A communicating artery connecting the interparaclinoid anastomosis and anterior cerebral artery (ACA) branched off from the presumed transition point between the interparaclinoid anastomosis and left ICA. Both right and left ophthalmic arteries (OAs) originated from the clinoid segment of the ICA. The communicating artery connecting the interparaclinoid anastomosis and ACA arose proximal to the left OA, and the communicating artery was identified as the carotid-ACA anastomosis. CONCLUSION: Neuroradiologists, physicians, and neurosurgeons need to be aware of this extremely unusual anatomical variant to determine appropriate treatment strategies in cases of aneurysmal growth or anterior cranial base surgery.

Surgical Resection of an Arteriovenous Malformation of the Orbital Surface of the Frontal Lobe with Olfactory Tract Preservation: 2-Dimensional Operative Video.

Medial orbitofrontal area arteriovenous malformations (AVMs) are located in the noneloquent cortex and typically drain superficially into Sylvian veins or the superior sagittal sinus, making them favorable for surgical treatment. However, while typically supplied by pial/cortical branches of the anterior cerebral artery (ACA), they can incorporate the recurrent artery of Heubner and other ACA perforators on their way to the anterior perforated substance located just posterior. We present a case of a 30-year-old female admitted with sudden collapse and intraventricular hemorrhage from a ruptured medial orbitofrontal area AVM. She was admitted to the intensive care unit and an external ventricular drain was placed to treat acute hydrocephalus. Catheter angiography demonstrated an AVM located just anteromedial to the termination of the internal carotid artery with a compact nidus and an associated intranidal flow aneurysm. Arterial supply originated from the orbitofrontal artery off the ACA, with medial lenticulostriates seen coursing past the nidus. Additional supply from the recurrent artery of Heubner could not be excluded. However, a hypodensity in the inferior frontal lobe seen on the presentation computed tomography scan was suggestive of a prior orbitofrontal infarct and thus cortical, rather than perforator, supply. In our practice, treatment of ruptured AVMs is dictated by the patients' clinical recovery and associated high-risk features (e.g., flow aneurysms). In this case, despite the presence of a flow aneurysm, treatment was delayed 18 days due to slow neurologic recovery and family preference. The patient remained in the intensive care unit under close neurologic observation. She was extubated on day 10, and the external ventricular drain was removed on day 12 after confirming resolution of intraventricular hemorrhage. Preoperatively the patient recovered to a Glasgow Coma Scale score of 15. Risks of treatment were discussed, and informed consent was obtained. The patient was treated using a standard pterional craniotomy. We describe the anatomic location of the lesion in the medial orbitofrontal area, the relationship to the olfactory tract and olfactory stria. We demonstrate olfactory tract dissection from its arachnoid cistern between the orbitofrontal lobe and gyrus rectus in order to access the lesion. Indocyanine green angiography is used to help surgical dissection and for quality control at the end of the procedure. We do not perform intraoperative angiography routinely; however, it can be a useful adjunct in deep and/or eloquent locations, which are difficult to image using videoangiography. Nevertheless, in the absence of intraoperative angiography close dissection directly over the nidus on the eloquent side ensures preservation of functional brain. We describe the microsurgical techniques of surgical treatment of AVMs, in particular the "cone" dissection technique of the AVM in order to allow identification of all feeding vessels and tracing "en passant" vessels from proximal to distal, as well as the use of intraoperative videoangiography to elucidate the nidus morphology and immediate postoperative quality control (Video 1, available at https://drive.google.com/file/d/1IXuLg84MwyMek1_Z1f1n7qssLThimvdx/view?usp=sharing).

Impact of subcallosal artery origin and A1 asymmetry on surgical outcomes of anterior communicating artery aneurysms.

BACKGROUND: Surgical clipping of anterior communicating artery (ACoA) aneurysms remains challenging due to their complex anatomy. Anatomical risk factors for ACoA aneurysm surgery require further elucidation. The aim of this study is to investigate whether proximity of the midline perforating artery, subcallosal artery (SubCA), and associated anomaly of the ACoA complex affect functional outcomes of ACoA aneurysm surgery. METHODS: A total of 92 patients with both unruptured and ruptured ACoA aneurysms, who underwent surgical clipping, were retrospectively analyzed from a multicenter, observational cohort database. Association of ACoA anatomy with SubCA origin at the aneurysmal neck under microsurgical observation was analyzed in the interhemispheric approach subgroup (n = 56). Then, we evaluated whether anatomical factors associated with SubCA neck origin affected surgical outcomes in the entire cohort (both interhemispheric and pterional approaches, n = 92). RESULTS: In the interhemispheric approach cohort, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was stratified to have the highest probability of the SubCA neck origin by a decision tree analysis. Then, among the entire cohort using either interhemispheric or pterional approach, combination of A1 asymmetry and aneurysmal size ≥ 5.0 mm was significantly associated with poor functional outcomes by multivariable logistic regression analysis (OR 6.76; 95% CI 1.19-38.5; p = 0.03) as compared with A1 symmetry group in the acute subarachnoid hemorrhage settings. CONCLUSION: Combination of A1 asymmetry and larger aneurysmal size was significantly associated with SubCA aneurysmal neck origin and poor functional outcomes in ACoA aneurysm surgery. Interhemispheric approach may be proposed to provide a wider and unobstructed view of SubCA for ACoA aneurysms with this high-risk anatomical variant.

Morphologic Variations in the Circle of Willis as a Risk Factor for Aneurysm Rupture in the Anterior and Posterior Communicating Arteries.

BACKGROUND: Intracranial aneurysms are acquired abnormal vascular dilations. The most dangerous complication of a cerebral aneurysm is its rupture, with a high rate of mortality. This study aimed to determine whether there is an association between anatomic variations in the circle of Willis and ruptured aneurysms in the anterior and posterior communicating arteries. METHODS: A cross-sectional study of adult patients with a diagnosis of intracranial aneurysm was carried out between March 2015 and March 2019. The patients were divided into groups of ruptured or unruptured aneurysm in the anterior and posterior communicating arteries. RESULTS: A total of 132 patients with anterior and posterior communicating artery aneurysms were included. The presence of anatomic variation in the circle of Willis presented a statistically significant association with ruptured aneurysms (odds ratio [OR], 2.28; 95% confidence interval [CI], 1.11-4.65; P = 0.024). There was a statistically significant difference between the presence of nonspherical aneurysm and rupture (OR, 6.9; 95% CI, 3.12-15.48; P < 0.0001). Multivariate logistic regression observed smoking (OR, 2.4; 95% CI, 1.01-5.9; P = 0.4), anterior complex variations (OR, 2.68; 95% CI, 1.01-7.18; P < 0.04), and nonspherical morphology (OR, 4.7; 95% CI, 1.93-11.45; P = 0.001) presented a statistically significant association with the rupture. CONCLUSIONS: Our results suggest that the studied variations of the circle of Willis and nonspherical morphology, in addition to playing a role in the development of cerebral aneurysms, may contribute to their rupture.

Endovascular treatment of anterior cerebral artery occlusions.

There are limited data on endovascular treatment (EVT) for anterior cerebral artery (ACA) occlusions. This review focuses on aspects related to ACA EVT: ACA anatomy, clinical and imaging findings, prognosis of ACA stroke, and ACA thrombectomy techniques. The ACA anatomy, and the regions supplied by the ACA, are highly variable; frequent anatomical variants include azygos ACA, triplicated ACA and fenestrations of the anterior communicating artery. ACA occlusions can be classified based on occlusion location, their continuity with other vessel occlusions (isolated ACA occlusion vs ACA occlusion as part of a carotid T occlusion) and etiology (primary-spontaneous ACA occlusion, vs secondary-spontaneous or iatrogenic due to clot fragmentation/migration). Symptoms of ACA stroke differ in severity and nature due to large inter-individual variations in territorial ACA blood supply. Generally, ACA strokes are severely disabling, and the typical clinical hallmark is a motor deficit of the contralateral lower extremity. Advanced imaging (CT perfusion, multiphase CT angiography) increases the likelihood of the correct diagnosis of ACA stroke and should be obtained on routine basis.Available data for ACA EVT suggest its feasibility and safety while clinical outcomes are often unfavorable with conservative management. Therefore, the potential benefit of EVT seems obvious. An optimized endovascular approach for ACA thrombectomy comprises the development and use of smaller and softer devices that can be delivered through small microcatheters with an optimized vector of force. Ultimately, generating high-level evidence for ACA EVT from randomized trials remains warranted.

Traumatic Distal Anterior Cerebral Artery Aneurysms - Pathomechanism and Revascularisation Strategies.

Traumatic intracranial aneurysms (TICA) of the distal anterior cerebral artery (dACA) are exceptionally rare and display therapeutic challenges due to their angioanatomical characteristics. The objective of this work was to discuss the mechanisms of TICA formation of the dACA and to elucidate the best treatment and revascularization strategies in these patients based on two illustrative cases. Case 1: 20-year-old patient with a traumatic, partially thrombosed 14 × 10 mm aneurysm of the right pericallosal artery (rPericA), distal to the origin of the right callosomarginal artery (rCMA). Complete trapping of the right dissection A3 aneurysm and flow replacement extra-to-intracranial (EC-IC) bypass (STA - radial artery - A4) was performed. Case 2: 16-year-old patient with a traumatic polylobulated, partially thrombosed 16 × 10 mm aneurysm of the rPericA. Microsurgical excision of the A3- segment harboring the aneurysm and flow replacement intra-to-intracranial (IC-IC) bypass via reimplantation of the right remaining PericA on the contralateral PericA (end-to-side anastomosis) was performed (in situ bypass). TICA of the dACA are exceptionally rare. Mechanical vessel wall injury and aneurysm formation of the dACA in blunt head trauma is very likely due to the proximity of the dACA with the rigid free edge of the falx. Given their nature as dissecting (complex) aneurysm, trapping and revascularization is a very important strategy. The interhemispheric cistern offers multiple revascularization options with its numerous donor vessels. The IC-IC bypass is often the simplest revascularization construct.

Comparison of Clinical Outcomes After Stent-Assisted Coiling with 3 Types of Self-Expanding Laser-Cut Stents in Patients with Wide-Necked Intracranial Aneurysms.

OBJECTIVE: We report the clinical outcomes of stent-assisted coiling for wide-necked intracranial aneurysms using 3 low-profile laser-cut stents and compare the results according to stent type. METHODS: All patients treated with stent-assisted coiling for their intracranial aneurysms at our hospital between July 2010 and September 2019 were reviewed. We selected patients with Enterprise, Neuroform EZ, or Neuroform Atlas stents who underwent imaging follow-up and investigated aneurysm and stent features, stent-related complications, recanalization, and retreatment rates. We compared the retreatment risk among the patients treated with the 3 stent types using Kaplan-Meier survival analysis and Cox regression analysis. RESULTS: We evaluated 364 consecutive cases (103 Enterprise, 105 Neuroform EZ, and 156 Neuroform Atlas stents). Neuroform Atlas was more frequently used in distal vessels: 8 (7.8%) Enterprise, 2 (1.9%) Neuroform EZ, and 41 (26.3%) Neuroform Atlas cases, respectively. The median follow-up durations were 6.49, 4.91, and 1.24 years for the Enterprise, Neuroform EZ, and Neuroform Atlas cases, respectively, and retreatment was performed in 11 (10.1%), 9 (8.6%), and 6 (3.8%) cases. In the first 2 years of follow-up, the estimated retreatment risk ratios for Neuroform EZ and Neuroform Atlas with Enterprise as reference were 0.63 (95% confidence interval, 0.24-1.65; P = 0.35) and 0.54 (95% confidence interval, 0.18-1.59; P = 0.26), respectively. CONCLUSIONS: Neuroform Atlas stents were more frequently deployed in small-caliber vessels compared with the other 2 types of stents. The complication rate and retreatment risk until at least 1 year after the aneurysm treatment appeared to be similar for the 3 stent types.

Management of Proximal Segment of the Anterior Cerebral Artery Aneurysms.

ABSTRACT: The authors reported 2 cases with proximal anterior cerebral artery (A1) aneurysms, and one was treated with aneurysm clipping, whereas another was treated with coil embolization. The authors suggest both endovascular surgery and aneurysm clipping are good options for A1 aneurysms.