Surgery Versus Endovascular Treatment for Proximal Anterior Cerebral Artery Aneurysms: A Meta-Analysis.

BACKGROUND: Proximal anterior cerebral artery (PACA) aneurysms account for less than 1% of all intracranial aneurysms. These aneurysms possess a challenge to surgeons due to their small size, wide base, fragile wall, and accompanying vascular anomalies. Surgery and endovascular treatment are both effective treatment options for PACA aneurysms but there is currently no consensus on which is the method of choice. OBJECTIVE: A systematic review and meta-analysis was conducted to investigate treatment strategies for aneurysms at proximal anterior cerebral artery. MATERIAL AND METHODS: The Cochrane Library, EMBASE, PubMed, and Web of Science databases were systematically searched for studies published between January 01, 2000 and December 01, 2020 that investigated surgery and/or endovascular treatment for patients with PACA. RESULTS AND CONCLUSIONS: Nineteen retrospective studies involving 358 patients met the inclusion criteria. Among these patients, 150 were treated surgically and 208 were treated using an endovascular technique. Preoperative morbidity was significantly greater in the surgical patients compared with the endovascular treated patients but there was no difference between groups in procedural related morbidity. The rates of favorable clinical outcome at time of discharge and at follow-up were statistically significantly greater in the endovascular group compared with the surgical group. Procedural related mortality was 8.7% for the surgical group and 1% in the endovascular group. In summary, our meta-analysis emphasized the safety and efficiency of endovascular treatment, and concluded that it was superior to surgery in acquiring favorable clinical outcome and reducing the perioperative complications. However, surgery was still the preferred treatment strategy for ruptured PACA aneurysms. Preoperative evaluation seems to be of great vital.

Safety and anatomical outcome analysis after flow diverter coverage of the anterior cerebral artery.

OBJECTIVES: Few studies on ischemic complications and flow changes after a flow diverter covering the anterior cerebral artery. The purpose of the study was to explore the ischemic complications and anatomical alterations associated with the flow diverter after it covers the anterior cerebral artery. MATERIALS AND METHODS: In this single-center study, patients treated with FD covering the anterior cerebral artery at the First Affiliated Hospital of Zhengzhou University were retrospectively collected. The primary endpoint was ischemic complications related to the anterior cerebral artery. Secondary endpoints were anatomical changes in the anterior cerebral artery postoperatively and at follow-up. RESULTS: A total of 59 patients were included in this study. Four (6.8%) patients presented with ischemic stroke symptoms. Immediately after the procedure, complete occlusion of A1 and decreased blood flow was observed in 13 (22.0%) and 21 patients (35.6%), respectively. At follow-up, A1 artery was occluded in 34 patients (57.6%) and decreased blood flow was observed in 10 patients (16.9%). Symptoms of neurological deficits related to the anterior cerebral artery were not observed in all patients at follow-up. CONCLUSION: Coverage of A1 is safe, with a low incidence of ischemic stroke, when using an FD to treat aneurysms. Risk of reduced perfusion of the anterior cerebral artery postoperatively even if the anterior communicating artery is open. In cases with A1 occlusion, the blood flow in the distal the anterior cerebral artery can be adequately compensated by opening the anterior communicating artery and good vascular anastomoses.

Risk Factors for the Recurrence of Distal Anterior Cerebral Artery Aneurysms After Endovascular Treatment.

OBJECTIVE: We aimed to investigate risk factors for the recurrence of distal anterior cerebral artery (DACA) aneurysms after endovascular treatment (EVT). METHODS: The clinical and radiologic outcomes of DACA aneurysms treated with endovascular methods at a single tertiary hospital from September 2008 to December 2021 were retrospectively reviewed. We measured the angle between 2 distal branches of DACA aneurysms and categorized the angle as follows: 1) wide-angle (≥180°), and 2) narrow-angle type configuration (<180°). Univariate and multivariate analyses were performed to demonstrate the relationships between characteristics of DACA aneurysm and recurrence risk. RESULTS: In total, 132 DACA aneurysms were treated in our institution. Among these, 47 DACA aneurysms after EVT were included in this study. Forty patients underwent coil embolization without stent, 7 for stent-assisted coil embolization. At the last follow-up (mean 30.2 ± 24.2 months), overall recurrence rate was 23.4% (n = 11). Recurrence rate of the wide-angle type (9 of 23, 39.1%) was significantly greater than narrow-angle type (2 of 24, 8.3%) (P = 0.041; odds ratio 8.174, 95% confidence interval 1.094-61.066). Irregular shape of the DACA aneurysm also showed significantly greater recurrence rate (P = 0.011; odds ratio 10.663, 95% confidence interval 1.701-66.838) after endovascular treatment. CONCLUSIONS: The wide-angle between 2 distal branches of DACA aneurysm and irregular shape might be independent risk factors for the recurrence after endovascular treatment for DACA aneurysms.

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.

Effect of revascularization surgery on cerebral hemodynamics in adult moyamoya disease.

OBJECTIVE: Few studies have reported local hemodynamic changes after revascularization surgery. This study aimed to identify regional hemodynamic changes after combined revascularization surgery for moyamoya disease using single-photon emission computed tomography with N-isopropyl-p-123I-iodoamphetamine. METHODS: A total of 46 adults with moyamoya disease who underwent combined revascularization surgery from August 2009 to July 2021 at our facility were enrolled. The combined bypass procedure comprised a single direct bypass to the motor area and encephalo-duro-arterio-myo-synangiosis. The preoperative and postoperative cerebral blood flow (CBF) and cerebral vascular reserve (CVR) in the genu; precentral, central, parietal, angular, temporal, and posterior regions; splenium; hippocampus; and cerebellum were measured. To modify the examination variability, the cerebral-to-cerebellar activity ratio (CCR) was calculated by dividing the counts in the region by those in the cerebellum (CBF-CCR and CVR-CCR). RESULTS: Postoperatively, asymptomatic cerebral infarction occurred in three (6.5%) patients. The CBF-CCR and CVR-CCR improved in the precentral, parietal, and temporal regions and in the overall middle cerebral artery (MCA) territory. Sub-analysis of anterior cerebral artery (ACA) and posterior cerebral artery (PCA) territory hemodynamics revealed that patients with normal preoperative hemodynamics showed no changes in the CBF-CCR and CVR-CCR postoperatively, whereas patients with preoperative perfusion impairment exhibited improved CVR-CCR in the ACA territory (0.13-0.3, p=0.019) and CBF-CCR in the PCA territory (0.93-0.96, p=0.0039). CONCLUSION: Combined revascularization surgery with single bypass to the motor area improved hemodynamics in the primary targeted MCA territory and in the ACA and PCA territories among patients with preoperative hemodynamic impairment.

Risk factor analysis of changes in blood flow in the A1 segment of the anterior cerebral artery after flow-diverter coverage of it.

Few studies have explored the effect of a flow-diverter device (FD) on blood flow in the A1 segment of the anterior cerebral artery (ACA), after treatment of intracranial aneurysms in the bifurcation region of the internal carotid artery (ICA). The main objective of this article is to investigate the factors that affect A1 blood flow after FD covers the A1 artery. This is a single-center, retrospective study. Data were collected retrospectively from our center, and patients whose FDs were placed for treatment from the terminal of the ICA to the M1 segment were analyzed. A total of 42 patients were included in the study. Immediate post-procedural angiography following device placement revealed decreased blood flow in the A1 of 15 (35.7%) patients and complete occlusion of the A1 segment in 11 (26.2%) patients. During an average follow-up period of 9.8 months, the A1 segment was ultimately occluded in 25 patients (59.5%) and decreased blood flow in 4 patients (9.5%). When using FD to cover the A1 artery for the treatment of intracranial aneurysms, patients with preoperative opening of the anterior communicating artery (AcomA) are more prone to occlusion or decreased blood flow of the A1 artery, compared to patients without opening.

The biportal transorbital approach: quantitative comparison of the anterior subfrontal craniotomy, bilateral transorbital endoscopic, and microscopic approaches.

OBJECTIVE: The aim of this study was to assess the surgical use and applicability of a biportal bitransorbital approach. Single-portal transorbital and combined transorbital transnasal approaches have been used in clinical practice, but no study has assessed the surgical use and applicability of a biportal bitransorbital approach. METHODS: Ten cadaver specimens underwent midline anterior subfrontal (ASub), bilateral transorbital microsurgery (bTMS), and bilateral transorbital neuroendoscopic surgery (bTONES) approaches. Morphometric analyses included the length of the bilateral cranial nerves I and II, the optic tract, and A1; the area of exposure of the anterior cranial fossa floor; craniocaudal and mediolateral angles of attack (AOAs); and volume of surgical freedom (VSF; maximal available working volume for a specific surgical corridor and surgical target structure normalized to a height of 10 mm) of the bilateral paraclinoid internal carotid arteries (ICAs), bilateral terminal ICAs, and anterior communicating artery (ACoA). Analyses were conducted to determine whether the biportal approach was associated with greater instrument freedom. RESULTS: The bTMS and bTONES approaches provided limited access to the bilateral A1 segments and the ACoA, which were inaccessible in 30% (bTMS) and 60% (bTONES) of exposures. The average total frontal lobe area of exposure (AOE) was 1648.4 mm2 (range 1516.6-1958.8 mm2) for ASub, 1658.9 mm2 (1274.6-1988.2 mm2) for bTMS, and 1914.9 mm2 (1834.2-2014.2 mm2) for bTONES exposures, with no statistically significant superiority between any of the 3 approaches (p = 0.28). The bTMS and bTONES approaches were significantly associated with decreases of 8.7 mm3 normalized volume (p = 0.005) and 14.3 mm3 normalized volume (p < 0.001) for VSF of the right paraclinoid ICA compared with the ASub approach. No statistically significant difference in surgical freedom was noted between all 3 approaches when targeting the bilateral terminal ICA. The bTONES approach was significantly associated with a decrease of 105% in the (log) VSF of the ACoA compared with the ASub (p = 0.009). CONCLUSIONS: Although the biportal approach is intended to improve maneuverability within these minimally invasive approaches, these results illustrate the pertinent issue of surgical corridor crowding and the importance of surgical trajectory planning. A biportal transorbital approach provides improved visualization but does not improve surgical freedom. Furthermore, although it affords impressive anterior cranial fossa AOE, it is unsuitable for addressing midline lesions because the preserved orbital rim restricts lateral movement. Further comparative studies will elucidate whether a combined transorbital transnasal route is preferable to minimize skull base destruction and maximize instrument access.

Endovascular treatment of patients with stroke caused by anterior cerebral artery occlusions.

BACKGROUND: Occlusion of the anterior cerebral artery (ACA) is uncommon but may lead to significant disability. The benefit of endovascular treatment (EVT) for ACA occlusions remains uncertain. METHODS: We included patients treated with EVT and compared patients with ACA occlusions with patients who had internal carotid artery (ICA) or proximal (M1/M2) middle cerebral artery (MCA) occlusions from the MR CLEAN Registry. Primary outcome was the modified Rankin Scale score (mRS). Secondary outcomes were functional independence (mRS 0-2), National Institutes of Health Stroke Scale (NIHSS) score, delta-NIHSS (baseline minus NIHSS score at 24-48 h), and successful recanalization (expanded thrombolysis in cerebral infarction (eTICI) score 2b-3). Safety outcomes were symptomatic intracranial hemorrhage (sICH), periprocedural complications, and mortality. RESULTS: Of 5193 patients, 11 (0.2%) had primary ACA occlusions. Median NIHSS at baseline was lower in patients with ACA versus ICA/MCA occlusions (11, IQR 9-14; versus 15, IQR 11-19). Functional outcome did not differ from patients with ICA/MCA occlusions. Functional independence was 4/11 (36%) in patients with ACA versus 1949/4815 (41%) in ICA/MCA occlusions; median delta-NIHSS was - 1 (IQR - 7 to 2) and - 4 (IQR - 9 to 0), respectively. Successful recanalization was 4/9 (44%), versus 3083/4787 (64%) in ICA/MCA occlusions. Mortality was 3/11 (27%) versus 1263/4815 (26%). One patient with ACA occlusion had sICH; no other complications occurred. CONCLUSION: In this cohort ACA occlusions were uncommon. Functional outcome did not differ between patients with ACA occlusions and ICA/MCA occlusions. Prospective research is needed to determine feasibility, safety, and outcomes of EVT for ACA occlusions.

Dominant A1 Direction as an Additional Factor for Deciding Surgical Approach for A1 Bifurcation Aneurysms.

BACKGROUND AND OBJECTIVE: Clipping of aneurysms located in the anterior communicating artery (AcomA) is considered a critical surgical procedure for neurosurgeons worldwide because of the complexity of the surgical area. The present study was conducted to discuss the importance of the geometric curvatures and the direction of the dominant A1 artery and their impact on aneurysmal growth direction and choice of side selection of the pterional surgical approach side. METHODS: The present study enrolled 183 patients with ruptured AcomA-located aneurysms. The aneurysms were all treated surgically through a pterional approach. Because of multiple dominant A1 directions, we divided the artery into 2 segments, and based on the second segment direction, we categorized the patients into ascending A1, descending A1, and horizontal A1 groups. The ascending group includes the superiorly projecting aneurysms, whereas the horizontal and descending groups include the anteriorly and inferiorly projecting aneurysms, respectively. A contralateral pterional approach to the dominant A1 was chosen for aneurysms with an ascending artery. However, the ipsilateral pterional approach was conducted in the horizontal and descending A1 dominant groups. RESULTS: The aneurysmal growth projection axis always follows the direction of the second dominant A1 segment. Full neck control with satisfactory inspection of perforators was achieved through the contralateral approach in most cases of an ascending A1, especially if ipsilateral A2 was posterior to the neck. The A1 segment can be satisfactorily seen from the contralateral exposure before the aneurysmal neck is exposed in ascending A1 geometries. CONCLUSIONS: A1 direction is an important additional factor that is to be considered for side selection when deciding pterional exposure of A1 bifurcation aneurysms. Accessing the contralateral dominant ascending A1 has better visualization of the neck than entering from an ipsilateral approach, especially if the ipsilateral A2 was posterior to the neck.

Anatomical Variations and Anomalies of the Anterior Communicating Artery Complex.

BACKGROUND: Intracranial arteries have a high rate of variation, but a clear schematic overview is lacking. In this pictorial review we classify and depict all variations and anomalies within the anterior communicating artery complex. METHODS: PubMed was searched with the terms "Anterior Communicating Artery" AND "Variations" OR "Anomalies." Articles were selected based on their description of variants. Cross-referencing was used to broaden the range of variations. Surgical view during pterional craniotomy and transsylvian approach was used as a baseline for schematic drawings of the variations. RESULTS: A total of 42 variants were identified, schematically drawn and classified into A1-A2 segment, anterior communicating artery, and the recurrent artery of Heubner. CONCLUSIONS: The anterior communicating artery complex consists of the anterior cerebral artery, anterior communicating artery and the recurrent artery of Heubner. An overview of these variations may be helpful in distinguishing pathology from anatomical variations, assist neurosurgeons during clipping of cerebral aneurysms, and support interventional radiologists during endovascular treatments. This article summarizes the current knowledge of anatomical variations within the anterior communicating artery complex, their prevalence and clinical relevance. A total of 42 variants were identified and schematically depicted. We encourage all who diagnose, treat, and study the anterior communicating artery complex to use this overview for a uniform and better understanding of its anatomy.

Fusiform aneurysms of anterior cerebral artery: center experience and systematic literature review.

Fusiform aneurysms of the anterior cerebral artery (ACA) are uncommon, and the natural history of this entity is poorly characterized. Along with our center experience, we conducted a systematic literature review to help shed light on the clinical course of ACA fusiform aneurysms. We queried our institutional database to identify cases with fusiform aneurysms of ACA. In addition, following the PRISMA algorithm, we identified all reported cases published in the English literature from the inception of PubMed until December 2022. We categorized clinical presentations into three categories: (i) traumatic/iatrogenic, (ii) spontaneous symptomatic ruptured/unruptured, and (iii) spontaneous asymptomatic aneurysms. We utilized descriptive statistics. We identified seven cases from our center along with 235 patients from published literature. Blunt trauma was responsible for the development of 19 aneurysms. Sixty-three percent of these aneurysms tend to rupture within 2 weeks from the initial trauma, and despite treatment, only 74% of these patients had good clinical outcomes. Spontaneous symptomatic presentation occurred in 207 patients and was often associated with previous/concomitant ACA dissection. Subarachnoid hemorrhage from ruptured aneurysms was the most common presentation. Spontaneous symptomatic fusiform aneurysm is rapidly evolving lesions, and treatment is necessary. Three of our own cases were treated with an endovascular flow diverter (pipeline) stenting with good outcomes. Spontaneous asymptomatic aneurysms were reported in nine patients. These lesions are often associated with other vascular abnormalities. Treatment included surgical clipping with good clinical outcomes. Instead, four patients from our center database were managed conservatively with equally good outcomes. Our study demonstrates good clinical outcomes when fusiform aneurysms of ACA, especially when symptomatic, are treated promptly with either reconstructive or deconstructive therapies.

Superficial temporal artery interposition bypass for the treatment of complex intracranial aneurysms: Flexible and creative options for flow preservation bypass.

PURPOSE: Flow-preservation bypass is a treatment option for complex intracranial aneurysms (IAs) that cannot be managed with microsurgical clipping or endovascular treatment. Various bypass methods are available, including interposition grafts such as the radial artery or saphenous vein. Size discrepancy, invasiveness, and procedure complexity must be considered when using interposition grafts. We describe our experience of treating complex IAs using a superficial temporal artery (STA) interposition bypass. METHODS: We retrospectively reviewed the medical records and operative videos of all patients who were treated for complex IAs at our center from January 2009 to December 2021 using cerebral revascularization. Clinical, radiological, and surgical findings of the cases that underwent STA interposition bypass were investigated. RESULTS: Seventy-six bypass procedures were performed of which seven (9.2%) complex IAs were managed using STA interposition bypass. Of these 5 cases were of anterior cerebral artery, 1 of middle cerebral artery, and 1 of posterior inferior cerebellar artery aneurysm. There were no postoperative ischemic complications. Revision surgery for postoperative pseudomeningocele was performed in one case. The long-term bypass patency rate was 85.7% (6 out of 7) and good long-term aneurysm control was achieved in all cases, with a mean follow-up of 64 months. CONCLUSIONS: When treating complex IAs, creative revascularization strategies are needed in selective cases for favorable outcomes. STA interposition graft bypass which can reduce the size discrepancy between the donor and recipient may be a less invasive, flexible, and practical option for treating complex IAs.

Left anterior cerebral artery arising from a right internal carotid artery: a rare case of carotid-anterior cerebral artery anastomosis.

Carotid-anterior cerebral artery anastomosis (carotid-ACA anastomosis) is described as infrequent vascular connections between the pre-ophthalmic segment of the internal carotid artery (ICA) and the A1 segment of the anterior cerebral artery (ACA). The embryological origin of these variant is still unclear and they are often associated to other vascular anomalies of the circle of Willis, as well as to the presence of aneurysms. Carotid-ACA anastomosis is often right-sided although left and bilateral cases have also been described. We report a rare case by MR angiography of a carotid-ACA anastomosis in which the abnormal vessel arises from the right ICA and takes an infraoptic course to join the A2 segment of the contralateral ACA, making this vascular anomaly function as a 'left ACA with an origin at the right ICA'. The A1 segment of the left ACA is absent and both A2 segments of the ACAs present fenestration. To our knowledge, no similar cases have been reported in English literature so far.

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.

Selective clipping of giant anterior communicating artery aneurysms remains a reliable therapeutic option.

BACKGROUND: Giant anterior communicating artery (AcomA) aneurysm represent a significant surgical challenge. Our study aimed to discuss the therapeutic strategy in patients with a giant AcomA aneurysm treated by selective neck clipping through a pterional approach. METHODS: Among all operated patients from an intracranial aneurysm between January 2015 and January 2022 (n = 726) in our institution, three patients with a giant AcomA aneurysm treated by neck clipping were included. Early (<7days) outcome was noted. Early postoperative CT scan was performed in all patients to detect any complications. Early DSA was also performed to confirm giant AcomA aneurysm exclusion. The mRS score was recorded 3 months after treatment. The mRS≤ 2 was considered as a good functional outcome. Control DSA was performed one year after treatment. RESULTS: In the three patients, after a large frontopterional approach, a selective exclusion of their giant AcomA aneurysm was obtained after a partial pars orbitalis of the inferior frontal gyrus resection. Ischemic lesion was noted in 1 patient and chronic hydrocephalus in 2 patients with ruptured aneurysm. The mRS score after 3 months was good in 2 patients. Long term complete occlusion of the aneurysm were noted in the three patients. CONCLUSION: Selective clipping of a giant AcomA aneurysm is a reliable therapeutic option after a careful evaluation of local vascular anatomy. An adequate surgical exposure is frequently obtained through an enlarged pterional approach with an anterior basifrontal lobe resection, especially in an emergency situation and/or in case of high position of anterior communicating artery.

Contralateral transfalcine approach for resection of right medial frontal AVM.

Brain arteriovenous malformations (AVMs) are high flow vascular lesions that can cause significant morbidity and mortality [1-6]. We present a case of a 23-year-old woman who initially presented to an outside institution with a ruptured right medial frontal Spetzler Martin grade II AVM. An EVD was placed and a diagnostic angiogram with partial embolization was performed. She was then transferred to our institution two months post rupture for further care. On arrival, she was trached with eyes opening to voice and localizing in bilateral upper extremities and withdrawing in bilateral lower extremities. Diagnostic angiogram demonstrated arterial supply from the right pericallosal and callosomarginal artery, right posterior cerebral artery callosomarginal branch, distal left anterior cerebral artery (ACA) branches with venous drainage via a cortical vein to the superior sagittal sinus. The patient underwent preoperative embolization of the ACA feeders followed by a contralateral interhemispheric transfalcine approach. An interhemispheric dissection was performed down to the corpus callosum and AVM feeders and draining veins were identified. The falx was then incised to expose the right medial frontal lobe. The AVM was circumferentially dissected and resected. Postoperative imaging demonstrated complete resection of the AVM. She remained at her neurological baseline immediately postoperatively and was discharged to inpatient rehab. The patient made a remarkable recovery and at three months follow up, she no longer required a tracheostomy and was neurologically intact with no complaints except for mild memory difficulties. In this video, we demonstrate the step-by-step surgical technique and review the benefits of the contralateral transfalcine approach for resection of a ruptured right medial frontal Spetzler Martin grade II AVM. The patient consented to the procedure and to the publication of her imaging in this surgical video.

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.