Microneurosurgical management of anterior communicating artery aneurysms

Multidimensional Comparison of Microsurgical Clipping and Endovascular Techniques for Anterior Communicating Artery Aneurysms: Balancing Occlusion Rates and Periprocedural Risks

Background and Objectives: The anterior communicating artery is a common location for intracranial aneurysms. Anterior communicating artery aneurysms (AcomA) pose a significant risk of rupture. Treatment options include microsurgical clipping and endovascular techniques, but the optimal approach remains controversial. This study aims to compare the outcomes of these two treatment modalities in a single-center patient cohort using a comprehensive matching process based on clinical and morphological parameters. Materials and Methods: A retrospective analysis was conducted on 1026 patients with 1496 intracranial aneurysms treated between 2000 and 2018. After excluding cases lacking 3D angiography or aneurysms in other locations or without treatment, 140 AcomA were selected. The study matched 24 surgically treated AcomA cases with 116 endovascularly treated cases based on 21 morphological and clinical criteria, including age, sex, Hunt and Hess score, and Fisher grade. Results: The microsurgical clipping group demonstrated a significantly higher rate of complete aneurysm occlusion compared to the endovascular group (p = 0.007). However, this was associated with a higher incidence of postoperative ischemic complications in the surgical group (13 out of 24 cases) compared to the endovascular group (2 out of 116 cases). Despite these complications, no significant differences were found in clinical outcomes at discharge or follow-up, as measured by the modified Rankin Scale (p > 0.999). Both groups had comparable rates of hydrocephalus, vasospasm, and delayed cerebral ischemia. Conclusions: Microsurgical clipping resulted in higher aneurysm occlusion rates but carried an increased risk of ischemic complications compared to endovascular treatment. Clinical outcomes were comparable between the two modalities, suggesting that treatment decisions should be individualized based on aneurysm characteristics and patient factors. Further prospective studies are warranted to optimize treatment strategies for AcomA.

The basal cisternostomy for management of severe traumatic brain injury: A retrospective study

PURPOSE

Traumatic brain injury (TBI) is a significant public health issue that impacts individuals all over the world and is one of the main causes of mortality and morbidity. Decompressive craniectomy is the usual course of treatment. Basal cisternostomy has been shown to be highly effective as an alternative procedure to decompressive craniectomy.

METHODS

We conducted a retrospective cohort of patients who received surgery for severe TBI between January 2019 and March 2023. Inclusion criterias were patients between the ages of 18 and 70 years who met the diagnostic criteria for severe TBI at first presentation and who underwent surgical intervention. The exclusion criteria were patients who have severe multiple injuries at the time of admission; preoperative intracranial pressure > 60 mmHg; cognitive impairment before the onset of the disease; hematologic disorders; or impaired functioning of the heart, liver, kidneys, or other visceral organs. Depending on the surgical approach, the patients were categorized into decompressive craniectomy group as well as basal cisternostomy group. General data and postoperative indicators, including Glasgow coma scale, intracranial pressure, etc., were recorded for both groups of patients. Among them, the Glasgow outcome scale extended assessment at 6 months served as the primary outcome. After that, the data were statistically analyzed using SPSS software.

RESULTS

The trial enrolled 41 patients (32 men and 9 women) who met the inclusion criteria. Among them, 25 patients received decompressive decompressive craniectomy, and 16 patients received basal cisternostomy. Three days postoperative intracranial pressure levels were 10.07 ± 2.94 mmHg and 17.15 ± 14.65 mmHg (p = 0.013), respectively. The 6 months following discharge Glasgow outcome scale extended of patients was 4.73 ± 2.28 and 3.14 ± 2.15 (p = 0.027), respectively.

CONCLUSION

Our study reveals that basal cisternostomy in patients with surgically treated severe TBI has demonstrated significant efficacy in reducing intracranial pressure as well as patient prognosis follow-up and avoids removal of the bone flap. The efficacy of cisternostomy has to be studied in larger, multi-clinical center randomized trials.

The morphological, clinical, and prognostic factors in the management of giant anterior communicating artery aneurysms: A systematic review of cases

Introduction

Giant intracranial aneurysms (GIAs) of the anterior communicating artery (AComm) are rare and challenging to treat due to their distinct angioarchitecture.

Research question

To review demographic, morphological, clinical, and prognostic factors in the treatment of giant AComm aneurysms to inform decision-making.

Materials and methods

Medline, Scopus, and Cochrane databases were searched for records examining cases diagnosed with giant AComm aneurysms. The study type, sample size, patient age, aneurysm site, aneurysm size, presenting complaints, and treatment modality were tabulated, and methodological quality was assessed. Additionally, two cases from our institution were included.

Results

The data from 24 retrieved records, including 45 cases (60% treated with direct clipping/clip reconstruction, 20% with surgical bypass±trapping, and 16% with endovascular/combined methods) were obtained. The mean age was 52 years with an overall male preponderance (3:1). 73% presented with symptoms; mostly visual impairment/loss and subarachnoid hemorrhage. 82% had favorable outcomes (mRS 0-2). 56% had a mean maximum diameter between 25 and 30 mm. Cases treated by direct clipping/reconstruction were primarily ruptured, while cases treated by surgical bypass/trapping were unruptured or asymptomatic. Endovascular/combined methods were utilized for only few cases.

Discussion and conclusion

Immediate suspicion is warranted for visual impairment with headaches in adults or seizures in the elderly. Direct clipping is the first-line treatment for ruptured cases closely followed by surgical bypass and trapping for unruptured cases. There is limited data on endovascular/combined methods. Evidence from case reports/series should be interpreted with caution. Both inter-modality and intra-modality nuances exist.

The prevalence and anatomy of recurrent artery of Heubner: a meta analysis with neurosurgical considerations

BACKGROUND

The recurrent artery of Heubner (RAH) is typically the largest medial lenticulostriate branch of the anterior cerebral artery (ACA). Neurosurgical procedures such as aneurysm treatment on the anterior part of the circle of Willis can result in damage of the RAH leading to neurological deficits. The aim of this study was to identify the gaps and provide comprehensive data on the prevalence and anatomical characteristics of the RAH with neurosurgical considerations.

METHODS

The major electronic databases were thoroughly searched to identify the eligible studies. The information concerning study type, geographical origin, prevalence of the RAH, course and origin of the RAH, symmetry of origin and number of RAHs in each hemisphere, and morphometric data were extracted. The PRISMA guidelines were rigorously followed throughout the study. The AQUA tool was used to evaluate the reliability of included studies.

RESULTS

A total of 34 studies (n = 3645 hemispheres) were included in the meta-analysis. The analysis revealed that the RAH was present in 97.5% (95%CI: 95.5-98.6) of the hemispheres, originating most frequently from the A2 segment (42.2%, 95%CI: 35.0-49.7) or the ACoA-ACA junction (41.6%, 95%CI: 34.0-49.6), and coursing anteriorly (47.6%, 95%CI: 38.7-56.6) or superiorly (43.9%, 95%CI: 34.4-53.8) in relation to ACA. Almost a quarter of patients had more than one RAH, which was on average 22.82 mm (SD: 1.35, 95%CI: 20.16-25.47; I2 = 99.1%, p < 0.01) long and reached 0.76 mm (SD: 0.05, 95%CI: 0.66-0.85; I2 = 99.4%, p < 0.01) in diameter.

CONCLUSIONS

As the RAH is present in the majority of the population, it is important to be aware of the wide variations in its anatomy. This will help to prevent postoperative neurological deficits by avoiding undesirable complications during surgeries that are performed in close proximity to the anterior segment of the circle of Willis.

Anterior interhemispheric vs. pterional approach in the microsurgical management of anterior communicating artery aneurysms: a comparative analysis employing a novel multidimensional matching-tool

The surgical management of anterior communicating artery aneurysms (AcomA) is challenging due to their deep midline position and proximity to complex skull base anatomy. This study compares the pterional craniotomy with the interhemispheric approach based on the specific aneurysm angulation. A total of 129 AcomA cases were analyzed, with 50 undergoing microsurgical clipping via either the pterional or interhemispheric approach. All selected cases had computed tomography-angiography with sagittal imaging slices and 2D-angiography. Using an interactive tool, 14 cases treated via the interhemispheric approach were matched with 14 cases approached pterionally based on clinical and morphological parameters, emphasizing intracranial aneurysm (IA) dome angulation relative to the frontal skull base. Outcomes included IA occlusion, temporary clipping incidence, intraoperative rupture, postoperative strokes, hemorrhages, hydrocephalus, vasospasm, and patient functionality. Matched cohorts had consistent demographics. Both approaches resulted in similar IA occlusion rates, but the interhemispheric approach led to improved clinical outcomes, measured by the modified Rankin Scale. It also had a lower incidence of hydrocephalus and reduced need for permanent ventriculoperitoneal shunt placement. Vasospasms and postoperative infarction rates were comparable between the groups. Our findings suggest potential advantages of the interhemispheric approach in managing AcomA, depending on aneurysm angulation. Despite a small sample size, the results highlight the importance of customized surgical decision-making based on the unique traits of each aneurysm and the surgeon's expertise.

Tailoring fenestrated aneurysm clips intraoperatively: Instant solution for a difficult problem

The anterior communicating artery (AcoA) aneurysms represent the most complex aneurysms of the anterior circulation. For years, surgical challenges including the intricate anatomy and narrow surgical corridor have been overcome using supplementary techniques including extended craniotomies, wide opening of the cisterns, gyrus rectus resection and special clips like fenestrated clips. However, imaginative solutions such as intraoperative clip modification may be inevitable in particular cases for safe clipping. We retrospectively analyzed clinical records of two patients who required clip modification intraoperatively. Case #1 underwent microsurgical clipping of a ruptured, 4-mm AcoA aneurysm. Unfortunately, given the short distance between the two A2s, it was not possible to clip the aneurysm without a compromise to the contralateral A2 with the available shortest 3mm-fenestrated clip. We then used the clip modification technique intraoperatively by shortening the clip tips with mesh-plaque cutter and smoothening the remaining sharp ends using cautery sanding. Eventually, the aneurysm was clipped successfully with the modified-fenestrated clip. Post-clipping imagings confirmed complete occlusion of the aneurysm and patency of parent arteries. Case 2# underwent microsurgical clipping for a ruptured, 1-mm AcoA aneurysm. Like Case 1#, the initial clipping attempt with the available shortest 4mm-fenestrated clip failed given the excessive length of the tips. The patient, thus, required clip modification as described above. The aneurysm was then clipped successfully using the modified-fenestrated clip, protecting bilateral A2s. Post-clipping imagings demonstrated patency of parent arteries with no residual aneurysm filling. Clip modification seems to be an effective option in clipping the AcoA aneurysms when available clips are too long to secure them safely.

Comparative analysis of supra-orbital keyhole approach and pterional approach for surgical clipping of intracranial anterior circulation aneurysms in patients with favorable Hunt and Hess grades

INTRODUCTION

Traditional large craniotomies have been the standard for aneurysm surgery. However, minimally invasive "keyhole" approaches have gained popularity for aneurysm clipping in recent years. This study focuses on Supra-Orbital Keyhole Approach (SOKHA),its use in clipping of aneurysms of the anterior Circle of Willis. Here we share the experiences of a tertiary care center regarding aneurysm clipping using SOKHA.

MATERIALS AND METHODS

We retrospectively reviewed 166 cases involving aneurysm clipping, with 62 patients undergoing SOKHA and 104 patients undergoing the pterional approach. Factors evaluated included patient demographics, aneurysm characteristics, incidence of intraoperative complications, temporary-clipping usage, and postoperative clinical outcomes. Glasgow Outcome Scale scores were utilized to assess clinical outcomes.

RESULTS

The study found that both the SOKHA and pterional approaches were similar in terms of age distribution, Hunt and Hess grades, and the incidence of hydrocephalus. The majority of aneurysms in both groups were anterior communicating artery aneurysms.Hydrocephalus was observed in 14.5 % of SOKHA cases and 13.5 % of pterional cases. Intraoperative aneurysm rupture occurred in 8.1 % of SOKHA cases and 7.7 % of pterional cases. There were no mortalities in the SOKHA group, while the pterional group had 1.92 % mortality rate. At the last follow-up, 77.4 % of SOKHA cases and 75.9 % of pterional cases had a favorable outcome (Glasgow Outcome Scale IV and V), with no significant difference.

CONCLUSION

SOKHA offers the advantage of potential cosmetic benefit with neurological outcomes comparable to those of the traditional pterional approach, in properly selected patients.

Optimizing surgical approaches for anterior communicating artery aneurysms: Development and internal validation of a novel surgical scoring system

BACKGROUND

The objective was to provide comprehensive preoperative information on both the aneurysm orientation and the side and method of surgical approach for optimal preoperative information and safe clipping using 3D imaging modalities. This was achieved by making an objective risk assessment on the surgical side/method and evaluating its effectiveness with internal validation.

MATERIALS AND METHODS

Radiologic data of 61 ACoA aneurysm patients between 2012 and 2020 were retrospectively analyzed. A scoring system based on five criteria; ACoA aneurysm dome orientation, A1 symmetry/control, perforating artery control, A2 trace orientation, and A2 fork symmetry was developed. The system is designed to align with the most common surgical approaches in ACoA aneurysm surgery. The patients were categorized into three groups based on the scoring results to determine the most appropriate surgical method. Group I was recommended, Group II was less recommended, and Group III was least recommended. Internal validation was performed to assess the system's effectiveness. Outcomes and complication rates were statistically evaluated.

RESULTS

When the scoring system was utilized, the mean score difference between the first group and the other groups was 2.71 and 4.62, respectively. There was a homogeneous distribution among the groups in terms of age, sex, WFNS, and Fisher scores. Complication occurred in three patients in Group I and nine patients each in Group II and Group III. The further the deviation from the first option, the higher the complication rate (p = 0.016), and a significant cause-effect relationship was identified (p = 0.021). The ROC curve established a cut-off value of 12.5 points for complications and outcomes.

CONCLUSION

Our study introduces a new scoring system for ACoA aneurysms, enhancing the use of 3D CTA in daily practice and providing internal validation for the proposed approach. By evaluating objective criteria, this scoring system helps predict surgical risks, prevent complications, and supports personalized evaluation and selection of the surgical approach based on objective criteria.

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.

Endovascular Treatment in Precommunicating Segment Aneurysms of Posterior Cerebral Artery

BACKGROUND

Precommunicating (P1) segment aneurysms of the posterior cerebral artery are rare, with few studies reported to date. Herein, we address the clinical and radiologic outcomes of their endovascular treatment.

METHODS

For this study, we retrieved prospectively collected data on 35 consecutive patients with 37 P1 aneurysms, analyzing the clinical ramifications and morphologic outcomes of treatment. All subjects received endovascular interventions between January 2001 and October 2021.

RESULTS

There were 16 aneurysms (43.2%) of P1 segment sidewalls and 21 (56.8%) at P1/posterior communicating artery junctions. Five (13.5%) were fusiform, and 14 (37.8%) were ruptured. In 14 patients (40%), 16 aneurysms (43%) were associated with intracranial arterial occlusive disease of the anterior circulation. Selective coiling was undertaken in 34 aneurysms (91.9%), using single (n = 24) or double (n = 4) microcatheters, microcatheter protection (n = 2), or stents (n = 4); and trapping was done in 3 (8.1%). No procedure-related morbidity or mortality resulted. Excluding the trapped lesions, angiographic follow-up of 29 aneurysms obtained >6 months after embolization (mean, 12.4 month) revealed stable occlusion in 21 (72.4%), with some recanalization in the other 8 (minor: 3/29, 10.4%; major: 5/29, 17.2%).

CONCLUSIONS

Aneurysms of P1 segment (vs. other locations) are strongly associated with intracranial arterial occlusive disease of the anterior circulation and thus are likely flow related. Endovascular treatment of such lesions seems safe and efficacious, despite the array of technical strategies that their distinctive anatomic configurations impose.

Development of a comprehensive and clinically applicable novel projection classification system for anterior communicating artery aneurysms

Various surgical and anatomical classifications have been proposed to date related to ACoA aneurysm projection. Nonetheless, a universally accepted classification system is yet to be established. This study is aimed at establishing a standardized classification system for ACoA aneurysms with utilization 3D technology and defining reference lines for their projections. The goal is to create a simple, understandable, surgically beneficial, and reliable classification system based on neurovascular structures in the region, including safe and hazardous zones. The radiologic data of 96 patients with ACoA aneurysm who were treated in our university hospital between 2012 and 2020 were retrospectively analyzed, and a planned classification scale was developed with the data obtained. The classification aimed to create 9 main projection groups in the sagittal plane: superior, inferior, anterior, and posterior in linear orientation, and anterosuperior, posterosuperior, anteroinferior, posteroinferior, and complex in quadrant orientation. The coronal and axial planes included medial, lateral, and midline classifications, resulting in a 3-dimensional classification system with 25 projections. Among the 96 patients, 32 had linear and 64 had quadrant projections. In the sagittal plane, the linear projection breakdown was as follows: superior (28%), inferior (6.25%), anterior (53%), and posterior (12.5%). For the quadrant projection, the distribution was as follows: anterosuperior (53%), posterosuperior (12.5%), anteroinferior (21.87%), posteroinferior (3.12%), and complex (9.37%). Overall, 35.4% aneurysms were anterosuperior, 17.7% anterior, 14.58% anteroinferior, 9.37% superior, 8.3% posterosuperior, 6.25% complex, 4.16% posterior, 2.08% posteroinferior, and 2.08% inferior projection. Our study proposes a projection classification that utilizes 3D technology for safe surgery based on neurovascular structures in the region and thus better reveals safe and hazardous zones, including three plans, three dimensions, and two orientations. The use of this classification system offers valuable guidance for daily practice in the treatment of ACoA aneurysms.

Clipping of Anterior Circulation Aneurysms: Operative Instructions and Safety Rules for Young Cerebrovascular Surgeons

INTRODUCTION

Due to the constant development of the technique, in the last 30 years, the endovascular treatment of the intracranial aneurysms (IAs) has gradually superseded the traditional surgery in the majority of centers. However, clipping still represents the best treatment for some anterior circulation IAs according to their angioarchitectural, topographical, and hemodynamic characteristics. Thus, the identification of residual indications for clipping and the maintenance of training programs in vascular neurosurgery appear nowadays more important than ever.

MATERIALS AND METHODS

We reviewed our last 10-year institutional experience of ruptured and unruptured IAs clipping. We appraised in detail all technical refinements we adopted during this time span and analyzed the difficulties we met in teaching the aneurysm clipping technique to residents and fellows. Then, we described the algorithm of safety rules we used to teach young neurosurgeons how to surgical approach anterior circulation IAs and develop a procedural memory, which may intervene in all emergency situations.

RESULTS

We identified seven pragmatic technical key points for clipping of the most frequent anterior circulation IAs and constructed a didactic approach to teach young cerebrovascular surgeons. In general, they concern craniotomy; cisternostomy; obtaining proximal control; cranial nerve, perforator, and vein preservation; necessity of specific corticectomy; aneurysm neck dissection; and clipping.

CONCLUSION

In the setting of an IA clipping, particularly when ruptured, the young cerebrovascular surgeon needs to respect an algorithm of safety rules, which are essential not only to avoid major complications, but they may intervene during the difficulties helping to manage potentially life-tethering conditions.

Endovascular Treatment of Anterior Communicating Artery Aneurysms: A Single-Center Experience from a Developing Country

Objective  In recent years, endovascular methods have been developed to treat intracranial aneurysms. To date, results of endovascular treatment (EVT) for anterior communicating aneurysms (ACoAs) have never been investigated in Iran. Thus, we sought to assess the mid-term angiographic and clinical outcomes of patients with ACoAs who underwent EVT in a tertiary center. Materials and Methods  Electronic health documents of patients with ACoAs who underwent EVT from March 2019 to July 2021 were retrospectively reviewed. Demographic and clinical characteristics of patients, procedural and clinical complications along with immediate and 12 months' postprocedural angiographic and clinical results were included in the analysis. Aneurysm occlusion status was classified based on the Raymond-Roy Occlusion Classification (RROC), and clinical outcomes were assessed using the modified Rankin Scale (mRS). Results  Of 38 patients with 38 ACoAs, 32 patients (84.21%) presented with subarachnoid hemorrhage of whom 23 (60.52%) had ruptured ACoAs. EVT included simple coiling in 29 patients (76.32%), balloon-assisted coiling in 6 (15.79%), and stent-assisted coiling in 3 (7.89%). Immediate and 12-month postprocedural angiograms demonstrated complete/near-complete occlusion (RROC I and II) in 32 (84.21%) and 35 patients (97.22%), respectively. Periprocedural complications occurred in five patients (13.15%), and the mortality rate was 5.26%. Thirty-two patients (84.21%) had favorable outcomes (mRS 0-2) at the last follow-up. Conclusion  EVT is a safe and beneficial procedure with favorable mid-term clinical and angiographic outcomes for ACoAs. Our results can lay the foundation for further studies in developing countries and are satisfactory enough for neurointerventionists to put EVT on the therapeutic agenda of ACoAs.

Circulation remodeling after flow diversion of an anterior communicating artery aneurysm: A case report

Anterior communicating artery aneurysms are the most common intracranial aneurysm and have a high risk of rupture which can lead to morbidity and mortality. Traditionally, intracranial aneurysms were treated by clipping with neurosurgical access. However, certain patients may prefer less invasive approaches or not represent open surgical candidates. Flow diverters, including flow-redirection endoluminal devices (FRED), are new-generation stents that are placed endovascularly by transfemoral or transradial access. Recent studies have demonstrated that FRED is both safe and effective, with complete occlusion of aneurysms in over 90% of patients. This case highlights an interesting phenomenon of post-flow diversion circulatory remodeling, where flow diverter treatment can alter the circle of Willis anatomy and physiology.

The risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms: anatomical consideration and infarction territory

PURPOSE

An anterior communicating artery is a common location for both ruptured and unruptured intracranial aneurysms, and microsurgery is sometimes necessary for their successful treatment. However, postoperative infarction should be considered during clipping due to the complex surrounding structures of anterior communicating artery aneurysms. This study aimed to evaluate the risk factors of postoperative infarction after surgical clipping of unruptured anterior communicating artery aneurysms and its clinical outcomes.

METHODS

The data of patients who underwent microsurgical clipping of an unruptured anterior communicating artery aneurysm in our hospital between January 2008 and December 2020 were retrospectively analyzed. The patients' demographic data, anatomical features of the anterior communicating artery complex and aneurysm, surgical technique, characteristics of postoperative infarction, and its clinical course were evaluated.

RESULTS

Notably, among 848 patients, 66 (7.8%) and 34 (4%) patients had radiologic and symptomatic infarctions, respectively. Univariate and multivariate logistic regression analyses showed that hypertension (odds ratio (OR), 1.99; [Formula: see text]), previous stroke (OR, 3.89; [Formula: see text]), posterior projection (OR, 5.58; [Formula: see text]), aneurysm size (OR, 1.17; optimal cut-off value, 6.14 mm; [Formula: see text]), and skull base-to-aneurysm distance (OR, 1.15; optimal cut-off value, 11.09 mm; [Formula: see text]) were associated with postoperative infarction. In the pterional approach, a closed A2 plane was an additional risk factor (OR, 1.88; [Formula: see text]). Infarction of the subcallosal and hypothalamic branches was significantly associated with symptomatic infarction ([Formula: see text]).

CONCLUSION

Hypertension, previous stroke, posteriorly projecting aneurysms, aneurysm size, and highly positioned aneurysms are independent risk factors for postoperative infarction during surgical clipping of an unruptured anterior communicating artery aneurysm. Additionally, a closed A2 plane is an additional risk factor of postoperative infarction in patients undergoing clipping via the pterional approach.

Impact of Very Small Aneurysm Size and Anterior Communicating Segment Location on Outcome after Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Very small anterior communicating artery aneurysms (vsACoA) of <5 mm in size are detected in a considerable number of patients with aneurysmal subarachnoid hemorrhage (aSAH). Single-center studies report that vsACoA harbor particular risks when treated.

OBJECTIVE

To assess the clinical and radiological outcome(s) of patients with aSAH diagnosed with vsACoA after aneurysm treatment and at discharge.

METHODS

Information on n = 1868 patients was collected in the Swiss Subarachnoid Hemorrhage Outcome Study registry between 2009 and 2014. The presence of a new focal neurological deficit at discharge, functional status (modified Rankin scale), mortality rates, and procedural complications (in-hospital rebleeding and presence of a new stroke on computed tomography) was assessed for vsACoA and compared with the results observed for aneurysms in other locations and with diameters of 5 to 25 mm.

RESULTS

This study analyzed n = 1258 patients with aSAH, n = 439 of which had a documented ruptured ACoA. ACoA location was found in 38% (n = 144/384) of all very small ruptured aneurysms. A higher in-hospital bleeding rate was found in vsACoA compared with non-ACoA locations (2.8 vs 2.1%), especially when endovascularly treated (2.1% vs 0.5%). In multivariate analysis, aneurysm size of 5 to 25 mm, and not ACoA location, was an independent risk factor for a new focal neurological deficit and a higher modified Rankin scale at discharge. Neither very small aneurysm size nor ACoA location was associated with higher mortality rates at discharge or the occurrence of a peri-interventional stroke.

CONCLUSION

Very small ruptured ACoA have a higher in-hospital rebleeding rate but are not associated with worse morbidity or mortality.

Understanding anterior communicating artery aneurysms: A bibliometric analysis of top 100 most cited articles

Bibliometric analysis is of paramount importance in assessing the research impact wherein studies are ranked on the basis of citations received. It also brings out the excellent contribution of authors and journals in adding evidence for future research. This study aimed at evaluating the top 100 most cited articles on anterior communicating artery (ACoA) Aneurysms. Scopus database was searched using title specific search for the aneurysm of ACoA and top 100 most cited articles along with their authors, author IDs, affiliated institutions, countries and funding bodies were identified. Search yielded 841 articles and top 100 articles were identified to include in this analysis which secured 5615 citations. Citations per year was also calculated to minimize the risk of bias. Maximum citations by any article were 242. The United States was the major contributor to the number of articles while Kessler Institute for Rehabilitation became the highest contributing institution. DeLuca J proved to be a pioneer in this specialized area as he penned 6 studies being first author in 4 of them, making him the most frequent author. National Institutes of Health and the U.S. Department of Health and Human Services were the main funding bodies. Subcategory analysis revealed, 50% studies provided evidence for the treatment and the surgical outcome of the aneurysm. Studies like these can aid in better neurological and neurosurgical management in decision making of ACoA aneurysm.

The Lateral Supraorbital Craniotomy Approach for Anterior Circulation Aneurysms: A Modern Surgical Case Series in the Endovascular Era

BACKGROUND

The lateral supraorbital (LSO) approach is a minimally invasive modification of the standard pterional approach to anterior circulation aneurysms. This study aimed to describe a dual-trained cerebrovascular neurosurgeon's first 18-month experience with the LSO approach, including decision-making criteria and lessons learned.

METHODS

This retrospective case series analyzed 50 consecutive patients treated with LSO craniotomy for aneurysm clipping by a single surgeon. Aneurysms were separated into 3 categories by location: internal carotid artery, anterior communicating artery, and middle cerebral artery. Surgical characteristics were evaluated for differences by location and rupture status.

RESULTS

Aneurysm clipping via LSO was performed on 57 aneurysms in 50 patients. Fixed retraction was employed less often in patients with internal carotid artery aneurysms than in patients with anterior communicating artery, middle cerebral artery, or multiple aneurysms (10% vs. 68.2%, 45.5%, and 42.9, P = 0.02). Of patients, 26 (52%) presented with subarachnoid hemorrhage; the majority of patients (92.3%) had Hunt and Hess grade I-III. No differences were noted in intraoperative rupture rates, fixed retractor use, operative duration, or estimated blood loss by rupture status. Adverse events included permanent frontalis nerve palsy in 1 patient (2%), temporalis atrophy in 1 patient, and transient aphasia in 1 patient. No postoperative hematomas or strokes were observed.

CONCLUSIONS

The LSO approach can safely and effectively treat anterior circulation aneurysms and should be considered a viable minimally invasive option for aneurysm clipping. Further studies comparing the LSO approach with other cranial approaches are needed.

Fast Transition from Open Surgery to Endovascular Treatment of Unruptured Anterior Communicating Artery Aneurysms-A Retrospective Analysis of 128 Patients

OBJECTIVE

Anterior communicating artery aneurysms (ACoAAs) are challenging to treat both surgically and endovascularly. In this study, we evaluate the treatment-related morbidity and clinical outcome of microsurgical clipping and endovascular treatment for a consecutive series of unruptured ACoAAs while the treatment paradigm was in transition from surgical to endovascular first.

METHODS

We retrospectively reviewed clinical and radiologic data of adult patients who underwent microsurgical clipping or endovascular treatment of an unruptured ACoAA at a high-volume academic neurovascular center (Helsinki University Hospital) during 2012-2019. During this period, a transition from microsurgical clipping to endovascular treatment took place. Regarding outcome, we focused on treatment-related complications, discharge-to-home rates, functional performance (modified Rankin Scale score), and obliteration rates.

RESULTS

Of 128 treated ACoAAs, 81 (64%) were treated surgically and 47 (36%) endovascularly. There was no difference in major complications, intracranial hemorrhagic complications or ischemic complications, discharge-to-home rates, or functional performance between the surgically and endovascularly treated patients. With time, a decrease in major complications was observed in the surgical cases (from 29% to 17%), whereas the major complication rate increased in the endovascularly patients (from 0% to 25%). Cerebral ischemia was the most frequent complication in both groups. The risk for permanent neurologic deficit remained low in both groups (9% for endovascular and 5% for surgery).

CONCLUSIONS

We did not find any major differences regarding complications and outcomes after the treatment paradigm shift from clipping to endovascular of unruptured ACoAAs. Prospective studies evaluating durability of treatments are needed to compare overall effectiveness.

Intra-procedural complications, success rate, and need for retreatment of endovascular treatments in anterior communicating artery aneurysms: a systematic review and meta-analysis

In recent years, intracranial aneurysms have been widely treated with endovascular methods. The anterior communicating artery (Acom) is the most common site of intracranial aneurysms. Despite its effectiveness, endovascular interventions can be associated with various intra-procedural and post-procedural complications. A systematic review of the literature was performed through PubMed, Embase, Scopus, and Web of Sciences databases up to March 18, 2022. The pooled rates of intra-procedural complications, mortality, procedure-related morbidities, the immediate and late aneurysm occlusion, and also the necessity for retreatment were calculated by applying random-effects models. A total of 41 articles with 4583 patients were included in the meta-analysis. The pooled rate of overall intra-procedural complications was 9.6% (95% CI: 7.7 to 11.8%). The initial rupture status and also type of EVT procedure did not affect the overall complication rate. The pooled rate of intra-procedural thrombosis, aneurysm rupture, coil prolapse, and early aneurysm rebleeding were 6.1% (95% CI: 4.5 to 8.2%); 4.2% (95% CI: 3.4 to 5.2%), 4.7% (95% CI: 3.2 to 6.7%), and 2.2% (95% CI: 1.5 to 3.2%), respectively. Our analysis showed that intra-procedural mortality occurred in 1.7% (95% CI: 1.1 to 2.5%) and procedure-related permanent morbidities in 3.3% (95% CI: 2.3 to 4.7%) of patients. Endovascular methods achieved complete and near to complete aneurysm occlusion (Raymond-Roy occlusion classification 1 and 2) in 89.2% (95% CI: 86.4 to 92.5%) of cases post-procedure, and 9.5% (95% CI: 7.3 to 12.4%) of patients needed retreatment due to recanalization in follow-ups. Endovascular treatment can serve as an acceptable method for Acom aneurysms. However, improved endovascular treatment equipment and new techniques provide more satisfactory outcomes for complicated cases.

Factors affecting global neurocognitive status and frontal executive functions in the early stage after surgical clipping of unruptured anterior circulation aneurysms with respect to keyhole clipping and conventional clipping

PURPOSE

This study investigated the most significant factor for the preservation of the global neurocognitive status and frontal executive functions in the surgical clipping of unruptured anterior circulation aneurysms, specifically in keyhole and conventional clipping procedures.

METHODS

The prospective study that was performed to examine the effects of aneurysm surgery on the patient's global neurocognitive status and frontal executive functions started on April 2016. After exclusion posterior circulation aneurysms, anterior communicating aneurysms treated by interhemispheric approach, giant aneurysms, and paraclinoid aneurysms, 23 patients who were enrolled before May 2017 were treated by conventional clipping, and 18 patients who were enrolled after June 2017 were treated by keyhole clipping. Two patients were excluded from each group due to missing data. Finally, 21 and 16 patients in each group were analyzed, respectively. Three-tesla magnetic resonance imaging was performed before and after surgery to detect the presence of perioperative cerebral infarctions and brain edema. The Mini-Mental State Examination, Frontal Assessment Battery, and Self-Rating Depression Scale scores were obtained before and 1 month after surgery.

RESULTS

Logistic regression analyses indicated that anterior communicating and internal carotid artery aneurysms were the most significant factors for poor outcomes and that keyhole clipping for these two types of aneurysm was the most significant factor for the preservation of patient global neurocognitive status. Keyhole clipping was also the most significant factor for the preservation of frontal executive functions in patients.

CONCLUSIONS

Keyhole clipping may be more favorable than conventional clipping for the preservation of the global neurocognitive status and frontal executive functions. Moreover, it may be the most effective factor for preservation of global neurocognitive status when it is indicated for anterior communicating or internal carotid artery aneurysms.

Variations of perforating arteries of anterior communicating artery in cases with anterior communicating artery aneurysms: a cadaveric anatomical study

PURPOSE

In terms of postoperative morbidity and mortality, preservation of the perforating arteries branching from the anterior communicating artery (ACoA) during clipping is particularly imperative in patients with ACoA aneurysm. In the present study, we aimed to investigate whether perforating arteries originated from ACoA were pushed away in a different location in patients with ACoA aneurysm. Furthermore, if they did so, we aimed to identify the direction in which they were dislocated and how the perforating arteries could be preserved during clipping.

METHODS

Herein, we categorized 40 brains obtained from cadavers into two groups. The first (n = 26) and second (n = 14) groups included cases without and with ACoA aneurysms, respectively. After completing the preparation procedure, the brains were dissected using surgical microscope and the relevant anatomical region was examined and photographed. Finally, statistical analyses were performed on the data and the results were documented.

RESULTS

In the aneurysms with posterior and superior projections, the perforators appeared to be pushed away inferiorly and were frequently noted at the anteroinferior part of the aneurysm neck. Most of the cases, where one of the A1s was larger at one side, the perforating arteries arose from the larger A1 side.

CONCLUSION

The mortality and morbidity associated with damage to the perforators can be reduced by approaching the patient from the dominant A1 side and pursuing the perforators primarily at the anteroinferior part of the aneurysm neck in the aneurysms with superior and posterior projections.

Clipping Could Be the Best Treatment Modality for Recurring Anterior Communicating Artery Aneurysms Treated Endovascularly

BACKGROUND

The anterior communicating artery (AcoA) is the most common location for intracranial aneurysms.

OBJECTIVE

To present occlusion outcomes, complication rate, recurrence rate, and predictors of recurrence in a large cohort with AcoA aneurysms treated primarily with endosaccular embolization. We also attempt to present data on the most effective treatment modality for recurrent AcoA aneurysms.

METHODS

This is a retrospective, single-center study, reviewing the outcomes of 463 AcoA aneurysms treated endovascularly between 2003 and 2018.

RESULTS

The study cohort consisted of 463 patients. Adequate immediate occlusion was achieved in 418 (90.3%). Independent functional status at discharge was observed in 269 patients (58.0%), and the mortality rate was 6.8% (31). At 6 months, adequate occlusion was achieved in 418 (90.4%). Of all the patients, recurrence was observed in 101 cases (21.8%), and of those, 98 (22.4%) underwent retreatment. The combined frequency of retreatment for the coiling group was 42.4%, which was significantly higher than the 0 incident of retreatment in the clipping group (P < .0001). Among the retreatment cohort, there was a significantly higher subsequent retreatment rate in the endovascular group (0% in the clipping group vs 42.4% in the endovascular group, P < .0001).

CONCLUSION

Coiling with and without stent/balloon assistance is a relatively safe and effective modality for the treatment of AcoA aneurysms; however, in the setting of recurrence, microsurgical reconstruction leads to improved outcomes regarding durable occlusion, thus avoiding the potential for multiple interventions in the future.

Microsurgical clipping versus newer endovascular techniques in treatment of unruptured anterior communicating artery-complex aneurysms: a meta-analysis and systematic review

The aim of this study is to compare occlusion rate, complication rate, and clinical outcome of microsurgical clipping (MC) and advanced endovascular techniques (EVT) in unruptured anterior communicating artery-complex aneurysms (ACoCAs). We reviewed the scientific literature reporting occlusion rate, time of occlusion assessment, and clinical outcome of MC and EVT in patients with unruptured ACoCAs, from January 2009 to December 2019. We included in our analysis 25 studies and 872 patients with unruptured ACoCAs (434 treated with endovascular techniques and 438 with MC). Ninety-three (10.7%), 320 (36.7%), 21 (2.4%), and 438 (50.2%) were treated with flow diverter (FD), stent-assisted coiling (SAC), endosaccular devices (ES), and microsurgical clipping (MC) respectively. FD, SAC, ES, and MC subgroups presented minor complications in 11.8%, 3.8%, 14.3%, and 7.1% of cases (p=.016), and major complications in 3.2%, 4.4%, 0%, and 7.1% (p=.136) of patients. A total occlusion rate post-treatment has been achieved in 4.3%, 87.1%, 47.6%, and 98.2% of cases (p=.000), while at 12 months' follow-up in 50%, 66%, 83.3%, and 80% of patients (p=.001). FD, SAC, ES, and MC subgroups had a good clinical outcome at 12 months in 93.5%, 90.5%, 100%, and 67.8% of cases. MC is associated with higher post-treatment total occlusion rate, but higher complication and lower good clinical outcome rates. EVT are promising in treating unruptured anterior cerebral artery aneurysms with high margin of safety and good clinical outcome, despite the lower total occlusion rate.

Clinicoradiological Profile and Outcome of Microsurgical Clipping of Ruptured Anterior Circulation Aneurysms: A Single-Institute Experience

Introduction:

Prevalence of intracranial aneurysms is estimated to be from 1% to 5% of population, most of them are small and located in the anterior circulation. The real danger is when an aneurysm ruptures, leading to a subarachnoid hemorrhage (SAH). SAH is a catastrophic event with a mortality rate of 25% to 50%. Permanent disability occurs in nearly 50% of the survivors. Fifteen percent of patients expire before reaching the hospital and 25% die within 24 h. The purpose of our study is to report the clinicoradiological data and outcome of microsurgical clipping of ruptured anterior circulation aneurysms in our center.

Materials and Methods:

This study included ruptured anterior circulation aneurysms admitted to tertiary care hospital in northern India from January 2018 to June 2020. The final outcome of patients was analyzed with Glasgow Outcome Score (GOS) at the time of discharge from the hospital.

Results:

A total of 53 patients with ruptured anterior circulation aneurysm underwent microsurgical clipping comprising 25 (47.2%) males and 28 (52.8%) females. The mean neck size of all aneurysms was 3.43 ± 1.66 mm. The mean hospital stay was longer in patients having preoperative intraventricular hemorrhage (IVH) (35.96 ± 27.27 days) and postoperative complications (43.36 ± 29.76 days) compared to patients who did not have IVH (21.10 ± 15.47 days) and postoperative complications (18 ± 6.54 days). P value was ≤0.05. Patients with preoperative hydrocephalus had GOS 3.44 ± 1.20 at discharge compared to nonhydrocephalus who had GOS 4.32 ± 1.07 (P = 0.009). Patients with Intracerebral Hemorrhage (ICH) and non-ICH had GOS 3.31 ± 1.38 and 4.28 ± 1.01, respectively (P = 0.009).

Conclusion:

Poor outcome at the time of discharge after the surgical treatment of anterior circulation aneurysms was associated with poor world federation of neurological surgeons grade on admission, presence of IVH, hydrocephalus, intracerebral hemorrhage, and postoperative cerebral infarcts.

Postoperative Clipping Status after a Pterional versus Interhemispheric Approach for High-Positioned Anterior Communicating Artery Aneurysms

OBJECTIVE

When treating high-positioned anterior communicating artery (ACoA) aneurysms, pterional-transsylvian and interhemispheric approaches are both viable options, yet comparative studies of these two surgical approaches are rare. Accordingly, this retrospective study investigated the surgical results of both approaches.

METHODS

Twenty-four patients underwent a pterional approach (n=11) or interhemispheric approach (n=13), including a unilateral low anterior interhemispheric approach or bifrontal interhemispheric approach, for high-positioned ACoA aneurysms with an aneurysm dome height >15 mm and aneurysm neck height >10 mm both measured from the level of the anterior clinoid process. The clinical and radiological data were reviewed to investigate the surgical results and risk factors of incomplete clipping.

RESULTS

The pterional patient group showed a significantly higher incidence of incomplete clipping than the interhemispheric patient group (p=0.031). Four patients (36.4%) who underwent a pterional approach showed a postclipping aneurysm remnant, whereas all the patients who experienced an interhemispheric approach showed complete clipping. In one case, the aneurysm remnant was obliterated by coiling, while follow-up of the other three cases showed the remnants remained limited to the aneurysm base. A multivariate analysis revealed that a pterional approach for a large aneurysm with a diameter >8 mm presented a statistically significant risk factor for incomplete clipping.

CONCLUSION

For high-positioned ACoA aneurysms with a dome height >15 mm and neck height >10 mm above the level of the anterior clinoid process, a large aneurysm with a diameter >8 mm can be clipped more completely via an interhemispheric approach than via a pterional approach.

Partial Gyrus Rectus Resection as a Technique to Improve the Exposure to the Anterior Communicating Artery Complex through the Junctional Triangle: A Quantitative Study

Objective  The junctional triangle, formed by the distal A1 anterior cerebral artery (ACA) segment, the proximal A2 ACA segment, and the medial surface of gyrus rectus (GR), is a corridor of access to superiorly and posteriorly projecting anterior communicating artery (AComA) aneurysms that is widened by GR retraction or resection. Exposure of the AComA complex through the junctional triangle after GR resection has not been previously quantitatively evaluated. Design  GR resection extent and increase in artery exposure through the junctional triangle were assessed in this study. Setting  This study was conducted in the laboratory with a pterional approach, exposing the AComA complex. Participants  Ten sides of five cadaveric heads were considered. Main Outcome Measures  Exposure extent of ipsilateral and contralateral A1, A2, and AComA and accessibility of branches coming off the AComA complex were measured before and after GR resection. The GR was resected until sufficient bilateral A2 and contralateral A1 exposures were achieved. GR resection span was measured. Results  The mean (standard deviation) resected span of GR was 7 ± 3.9 mm. After GR resection, the exposed span of the ipsilateral A2 increased from 2 ± 0.7 mm to 4 ± 1.1 mm ( p  = 0.001); contralateral A2 exposure increased from 3 ± 1.5 mm to 4 ± 1.1 mm ( p  = 0.03). Contralateral recurrent artery of Heubner (RAH) and orbitofrontal artery were accessible in five and eight specimens, respectively, before GR resection and in all 10 after resection. Conclusion  GR resection improves exposure of bilateral A2 segments through the junctional triangle. Exposure improvement is greater for the ipsilateral A2 than contralateral A2. The junctional triangle concept is enhanced by partial GR resection during surgery for superior and posterior AComA aneurysms.

MISIAN (Minimally Invasive Surgery for Treatment of Unruptured Intracranial Aneurysms): A Prospective Randomized Single-Center Clinical Trial With Long-Term Follow-Up Comparing Different Minimally Invasive Surgery Techniques with Standard Open Surgery

BACKGROUND

Unruptured intracranial aneurysms (UIAs) are increasingly diagnosed but treatment is still controversial. Although the descriptions and use of minimally invasive surgery (MIS) have increased, comparative studies with standard approaches are rare.

OBJECTIVE

MISIAN (Minimally Invasive Surgery for Treatment of Unruptured Intracranial Aneurysms) is a prospective randomized single-center clinical trial with long-term follow-up comparing different MIS techniques with standard open surgery for treatment of UIAs.

METHODS

We randomly allocated a standard pterional approach (PtA) or MIS (1:2) to 111 patients with UIAs of the anterior circulation (mean dome diameter, 6.4 mm; range, 3-20 mm). Patients selected for MIS underwent a second randomization between a transeyelid approach (TelA) or nanopterional approach (NPtA) (1:1).

RESULTS

Forty-one patients were randomized to and treated with the PtA, 36 with the TelA, and 34 with the NPtA. Only patients treated with PtA had permanent facial nerve palsy (n = 4 [10%]; P = 0.032). MIS cosmetic results were considered better than those of PtA by independent observers (P < 0.001), and less temporal atrophy in the MIS group was also observed (P = 0.0034). The proportion of excellent results was higher in the TelA group than in the NPtA group (86% vs. 67.6%; P = 0.039). Patients undergoing MIS also reported consistently higher satisfaction and quality-of-life scores (P < 0.001).

CONCLUSIONS

MIS is superior to standard PtA for microsurgical clipping of small UIAs of the anterior circulation in terms of cosmetic, satisfaction, and quality-of-life outcomes. The TelA or NPtA for UIAs did not show significant outcome differences at 12-18 months.

Surgical Treatment of Middle Cerebral Artery Aneurysms: Hints and Precautions for Young Cerebrovascular Surgeons

BACKGROUND AND OBJECTIVE

 Clipping is still considered the treatment of choice for middle cerebral artery (MCA) aneurysms due to their angioarchitectural characteristics as they are often bifurcation dysplasias, needing a complex reconstruction rather than a simple exclusion. Thus, maintaining this surgical expertise is of paramount importance to train of young cerebrovascular surgeons. To balance for the increasingly limited experience due the worldwide general inclination toward the endovascular approaches, it is important to provide to the young neurosurgeons rules and operative nuances to guide this complex surgery. We describe the technical algorithm we use to teach our residents to approach ruptured and unruptured MCA aneurysms, which may help to develop a procedural memory useful to perform an effective and safe surgery.

MATERIALS AND METHODS

 We reviewed our last 10 years' institutional experience of about 400 cases of ruptured and unruptured MCA aneurysms clipping, analyzing our technical refinements and the difficulties in residents and young neurosurgeons teaching, to establish fundamental key-points and design a didactic algorithm that includes operative instructions and safety rules.

RESULTS

 We recognized seven pragmatic technical key points regarding craniotomy, sylvian fissure opening, basal cisternostomy, proximal vessel control, lenticulostriate arteries preservation, aneurysm neck microdissection, and clipping to use as a didactic algorithm for teaching residents, and as operative instructions for inexperienced neurosurgeons.

CONCLUSION

 In the setting of clipping MCA aneurysms, respect for surgical rules is of paramount importance to perform an effective and safe procedure, ensure the best aneurysm exclusion, and preserve the flow in collaterals and perforators.

The Rise of Inflow Cisternostomy in Resource-Limited Settings: Rationale, Limitations, and Future Challenges

Low- and middle-income countries (LMICs) bear most of the global burden of traumatic brain injury (TBI), but they lack the resources to address this public health crisis. For TBI guidelines and innovations to be effective, they must consider the context in LMICs; keeping this in mind, this article will focus on the history, pathophysiology, practice, evidence, and implications of cisternostomy. In this narrative review, the author discusses the history, pathophysiology, practice, evidence, and implications of cisternostomy. Cisternostomy for the management of TBI is an innovation developed in LMICs, primarily for LMICs. Its practice is based on the cerebrospinal fluid shift edema theory that attributes injury to increased pressure within the subarachnoid space due to subarachnoid hemorrhage and subsequent dysfunction of glymphatic drainage. Early reports of the technique report significant improvements in the Glasgow Outcome Scale, lower mortality rates, and shorter intensive care unit durations. Most reports are single-center studies with small sample sizes, and the technique requires experience and skill. These limitations have led to criticisms and slow adoption of the technique. Further research is needed to establish the effect of cisternostomy on TBI outcomes.

Impact of Virtual Reality in Arterial Anatomy Detection and Surgical Planning in Patients with Unruptured Anterior Communicating Artery Aneurysms

Anterior-communicating artery (ACoA) aneurysms have diverse configurations and anatomical variations. The evaluation and operative treatment of these aneurysms necessitates a perfect surgical strategy based on review of three-dimensional (3D) angioarchitecture using several radiologic imaging methods. We analyzed the influence of 3D virtual reality (VR) reconstructions versus conventional computed tomography angiography (CTA) scans on the identification of vascular anatomy and on surgical planning in patients with unruptured ACoA aneurysms. Medical files were retrospectively analyzed regarding patient- and disease-related data. Preoperative CTA scans were retrospectively reconstructed to 3D-VR images and visualized via VR software to detect the characteristics of unruptured ACoA aneurysms. A questionnaire was used to evaluate the influence of VR on the identification of aneurysm morphology and relevant arterial anatomy and on surgical strategy. Twenty-six patients were included and 520 answer sheets were evaluated. The 3D-VR modality significantly influenced detection of the aneurysm-related vascular structure (p = 0.0001), the recommended head positioning (p = 0.005), and the surgical approach (p = 0.001) in the planning of microsurgical clipping. Thus, reconstruction of conventional preoperative CTA scans into 3D images and the spatial presentation in VR models enabled greater understanding of the anatomy and pathology, provided realistic haptic feedback for aneurysm surgery, and influenced operation planning and strategy.

Result of coiling versus clipping of unruptured anterior communicating artery aneurysms treated by a hybrid vascular neurosurgeon

OBJECTIVE

This study will evaluate the outcomes of coiling versus clipping of unruptured anterior communicating artery (A-com) aneurysms treated by a hybrid vascular neurosurgeon to suggest the best protocol of management for these conditions.

METHODS

We retrospectively reviewed the records of 70 patients with an unruptured A-com aneurysm treated with coiling or clipping performed by a hybrid vascular neurosurgeon between March 2012 and December 2019. The patients were dichotomized, into the coil group or clip group. Treatment-related complications, clinical and radiological results were evaluated.

RESULTS

Of the 70 patients identified, 37 underwent coiling and 33 clipping. Procedure-related symptomatic complications occurred in 2 patients (5.4%) in the coil group and 3 patients (9.1%) in the clip group. Poor clinical outcome (modified Rankin Scale [mRS] of 3 to 6) at 6 months of follow-up was seen in only one patient (2.7%) for the coil group, and none for the clip group. The one poor outcome was the result of intra-procedural rupture during coiling. Follow-up conventional angiography data (mean duration, 15.0 months) revealed that the major recanalization rate is 5.6% for the coil group and 10.0% for the clip group.

CONCLUSIONS

Management of A-com aneurysms requires more collaboration between microsurgical clipping and endovascular therapy. Evaluation of patient and aneurysm characteristics by considering the advantages and disadvantages of both techniques could provide an optimal treatment modality. A hybrid vascular neurosurgeon is expected to be a proper solution for the management of these conditions.

Microsurgical Treatment of Unruptured Anterior Communicating Artery Aneurysms: Approaches and Outcomes in a Large Contemporary Series and Review of the Literature

BACKGROUND

With advances in endovascular techniques, the relative roles of microsurgery and endovascular therapy in the management of intracranial aneurysms have become less clear, and data regarding treatment-specific outcomes are increasingly important.

OBJECTIVE

To describe our experience with microsurgery in a large series of unruptured anterior communicating artery aneurysms (ACOMMAAs) and detail our treatment decision-making process based on individual aneurysm morphology.

METHODS

We retrospectively reviewed unruptured ACOMMAAs treated microsurgically at our center between 1997 and 2018, recording aneurysm size, surgical approach, occlusion rates, neurological outcomes, and complications.

RESULTS

We treated 300 unruptured ACOMMAAs in 300 patients, mean age 49 yr, 180 (60.0%) female, including 245 (81.7%) small, 50 (16.7%) large, and 5 (1.7%) giant aneurysms. Most underwent a pterional approach (253, 84.3%), with orbitozygomatic or anterior interhemispheric approaches in 35 (11.7%) and 12 (4%), respectively. Greater than 95% occlusion was achieved in 284 (94.7%), 90% to 95% occlusion in 13 (4.3%), and 3 (1.0%) underwent wrapping. Serious complications occurred in 3 patients (1.0%) resulting in 2 deaths (0.7%), and minor complications in 12 (4.0%). At final follow-up, good neurological outcome was observed in 297 (99.0%) patients.

CONCLUSION

Given clinical equipoise regarding optimal treatment of unruptured ACOMMAAs, this work provides a benchmark for achievable microsurgical outcomes. Future surgical/endovascular studies should separate results of ruptured and unruptured lesions and describe aneurysm morphology to allow for better comparison of outcomes between treatments. We suggest that open microsurgery represents an important option for select, morphologically complex ACOMMAAs, and that a multidisciplinary approach offers optimal patient outcomes.

Comparative Analysis of Pterional, Supraorbital, Extended Supraorbital, and Transtubercular-Transplanum Approaches for Exposing the Anterior Communicating Artery Complex: A Cadaveric Study

OBJECTIVE

We aimed to quantify and compare surgical exposure and freedom at the anterior communicating artery (ACoA) complex using pterional (PT), supraorbital (SO), extended supraorbital withorbital osteotomy (SOO), and endonasal endoscopic transtubercular-transplanum (EEATT) approaches.

METHODS

Right-sided PT, SO, SOO, and EEATT approaches were performed using 10 cadaveric heads. Surgical exposure and freedom (horizontal and vertical attack angle) at the ACoA complex were measured. The farthest clipping distance from ACoA to A1 (precommunicating segment of the anterior cerebral artery)/A2 (postcommunicating segment of the anterior cerebral artery) was also quantified.

RESULTS

There was a significantly greater exposure length of right A1 in the PT approach (12.20 ± 2.48 mm) compared with the EEATT approach (9.52 ± 2.09 mm; P = 0.029). Among the 4 approaches, EEATT provided the shortest clipping distance for right A1 (6.56 ± 1.33 mm; P = 0.001) and the longest clipping distance for right A2 (3.36 ± 1.24 mm; P = 0.003). SO, SOO, and PT approaches (2.9 ± 0.9) had more observations on perforators from ACoA than did the EEATT approach (2.0 ± 0.66; P = 0.029). The EEATT approach (50.90 ± 17.45 mm²) provided better exposure of the superior part of the ACoA complex compared with the SO approach (29.37 ± 17.27 mm²; P = 0.05). PT and SOO approaches provided the greatest horizontal (36.88° ± 5.85°) and vertical (19.37° ± 4.70°) attack angle, respectively.

CONCLUSIONS

The SO, SOO, and PT approaches provided a better hemilateral view of the ACoA complex and similar surgical exposure, whereas the EEATT approach offered greater exposure in the upper part of the ACoA complex, with relatively limited exposure of perforators from ACoA and surgical freedom. The EEATT approach can play a role in exposure of lesion involving the ACoA complex.

Surgical Treatment of Anterior Communicating Artery Aneurysms: Hints and Precautions for Young Cerebrovascular Surgeons

Background Anterior communicating artery (AComA) aneurysms are the most common intracranial aneurysm, accounting for 25 to 38% of all cases. In spite of the advent of modern neurointerventional treatments, they still represent a strong indication for clipping in certain anatomical and clinical conditions. However, AComA aneurysms are the deepest located aneurysms of the anastomotic circle of Willis, with a complex spatial orientation, and they are fed by bilateral branches of the anterior circulations. Although, on one hand, these aneurysms represent the most complex ones of the anterior circulation, on the other hand, the experience of young neurosurgeons is increasingly limited. Therefore, respecting operative guidelines is crucial to achieve the best aneurysm exclusion and avoid fatal intraoperative complications.

Study Objective We describe the technical algorithm we use to teach young neurosurgeons how to approach AComA aneurysms and help them to develop a procedural memory needed to perform an efficient and safe surgery.

Materials and Methods We reviewed our last 10 years of institutional experience of > 200 cases of clipping ruptured and unruptured AComA aneurysms, analyzing our technical refinements and the difficulties in teaching residents and young neurosurgeons how to establish fundamental key points and design a didactic algorithm that includes operative instructions and safety rules.

Results We identified seven pragmatic technical key points regarding craniotomy, cisternostomy, gyrus rectus corticectomy, proximal control, perforators and Heubner preservation, aneurysm neck dissection, and clipping to use in a didactic algorithm for teaching residents and as operative instructions for inexperienced neurosurgeons.

Conclusion In the setting of clipping AComA aneurysms, respect for surgical rules is of paramount importance to perform an efficacious and safe procedure and ensure the best aneurysm exclusion and preservation of neurovascular structures.

Interhemispheric Approach with Early A1 Exposure for Clipping Anterior Communicating Artery Aneurysms: Operative Techniques and Outcomes

BACKGROUND

The interhemispheric approach (IHA) provides an excellent surgical corridor for clipping anterior communicating artery aneurysms (AcoAAs). However, an important disadvantage of the approach is obtaining proximal control at A1 in the last stage of dissection, especially in anterior or superior projecting AcoAAs and ruptured cases. We describe and evaluate the microsurgical clipping of AcoAAs using the IHA with early A1 exposure.

METHODS

This was a retrospective descriptive study in patients with AcoAA who received microsurgical clipping through the IHA with early A1 exposure between April 2016 and May 2019. Aneurysm morphology, projection, completeness of clipping, surgical complications, and outcomes were collected from medical records.

RESULTS

Twenty-five patients with AcoAA received microsurgical clipping via the IHA with early A1 exposure. Twenty-three patients (92%) presented with subarachnoid hemorrhage. Intraoperative rupture while dissecting the interhemispheric fissure occurred in 2 cases, for which proximal control via subfrontal route was effectively performed. Of the patients, 100% achieved complete obliteration of their aneurysms. Postoperative anosmia was detected in 22.7%. In ruptured cases, 16 (88.9%) of the good grade patients achieved a good outcome (Glasgow Outcome Scale scores of 4 and 5) at 3 months after the operation.

CONCLUSIONS

The IHA with early A1 is safe and effective for clipping AcoAAs.

Comparison of Minimally Invasive and Pterional Craniotomies for Ruptured Anterior Circulation Aneurysms: A Propensity Score Matched Analysis

BACKGROUND

Minimally invasive craniotomy (MIC) for ruptured aneurysm remains a debatable issue because of unclear information regarding its safety and efficacy compared with standard approaches. Here, we compared the outcomes between MIC and pterional craniotomy (PTC) for the treatment of ruptured anterior circulation aneurysms.

METHODS

A database of patients with ruptured anterior circulation aneurysm who were treated with surgical clipping was reviewed. With the use of propensity score matching to balance the baseline characteristics of MIC and PTC groups, outcomes of the 2 groups were compared. Clinical predictors of favorable outcomes (modified Rankin scale score 0-2) were evaluated by using uni- and multivariate analyses.

RESULTS

A total of 102 matched pairs were identified. MIC resulted in a significantly shorter operative time (2.8 ± 0.9 vs. 4.2 ± 0.7 hours; P = 0.004) and hospital stay (14.2 ± 5.9 vs. 19.2 ± 9.1 days; P < 0.001), respectively. Both MIC and PTC had similar mortality and complication rates except for the incidences of intracranial hemorrhage (2% vs. 9.8%; P = 0.039) and brain injury (9.8% vs. 27.5%; P = 0.036), respectively. Use of MIC instead of standard surgery and lower World Federation of Neurosurgical Societies (WFNS) grade and absence of hydrocephalus were significant predictors of favorable outcome at 1 month, whereas higher WFNS grade and higher Fisher grade were significantly associated with a poor outcome at 6 months.

CONCLUSIONS

For the treatment of ruptured anterior circulation aneurysms, MIC was comparable with PTC and presented additional advantage in terms of earlier recovery. Therefore, MIC can be considered an alternative surgical treatment in this setting.

Factors determining the side of approach for clipping ruptured anterior communicating artery aneurysm via supraorbital eyebrow keyhole approach

PURPOSE

The purpose of this study was to review the microsurgical anatomy and clipping of ruptured anterior communicating artery (AComA) aneurysms and to plan and avoid complications before operation.

METHODS

A total of 523 cases of cerebral aneurysms admitted to the neurosurgery department of the Third Affiliated Hospital of Sun Yat-Sen University from September 2010 to October 2018 were analyzed retrospectively. Among them, 85 patients had ruptured AComA aneurysms. This study was limited to 85 of these cases, whose satisfactory preoperative angiographic diagnostic films can be retrieved from the hospital database system because of the need for detailed review.

RESULTS

We performed supraorbital eyebrow keyhole approach (SOEK) craniotomy in 85 patients to clip 85 AComA aneurysms, in the setting of subarachnoid hemorrhage (SAH). Patients' mean age was (52.69 ± 9.94) years (range, 28-78 years). The proportions of small, medium and large aneurysms were 83.5%, 15.3%, and 1.2%, respectively. The average size of the aneurysms was (5.07 ± 2.36) mm. There were 77.8% of patients with inferior aneurysms and 81.3% of patients with superior aneurysms achieved good results. There was a significant correlation between A1 dominance and operation method (p < 0.001). There was no significant relationship between surgical approach and aneurysm projection or A2 plane (p = 0.157 &p = 0.318).

CONCLUSION

Regardless of whether the A2 plane is open or closed, the A1 dominant side is still a better choice for accessing AComA aneurysms to avoid dangerous premature bleeding.

Quantitative measurement of the surgical freedom for anterior communicating artery complex-a comparative study between the frontotemporal pterional and supraorbital craniotomy; a laboratory study

OBJECTIVE

To quantitatively measure surgical degree of freedom (SDF) to the anterior communicating artery (AComA) complex via removal of the orbital rim. Comparisons of SDF quadrants were made between a supraorbital and standard frontotemporal pterional craniotomy according to the surgeons' geometric microscope compass-based views.

METHODS

Eleven latex-injected formalin-fixed cadaveric heads; 14 sides (eight unilateral and three bilateral) were dissected. Standard frontotemporal pterional and subsequent supraorbital craniotomy approaches were conducted in each specimen. Point "0" was allocated as a point 1 cm distal to the ipsilateral A1 and A2 junction of AComA. The tip of a 10-cm long pointer was used to locate point 0. The base of the pointer stick was maneuvered outside the craniotomy in eight compass directions, with the most peripheral points expressed as target points 1-8. The center of this octagon was attributed point C. A pyramid was established by connecting the points 0, C, and 2 neighboring target points. A frameless stereotaxic instrument was used as a three-dimensional digitizer to measure pyramid volume. Each neighboring two pyramids form a hexagonal cone and was expressed as a surgical freedom quadrant (cm³). The quadrants are depicted counterclockwise (surgeons view) as orbital-nasal, vertex-nasal, vertex-temporal, and orbital-temporal.

RESULTS

Total SDF obtained via supraorbital and pterional approaches were 122.8 ± 109.66 and 159.94 ± 93.65, respectively (mean ± SD cm³; supraorbital < pterional by 30.2%). Supraorbital to pterional, in the orbital-nasal quadrant was 21.9 ± 35.5 and 13.04 ± 8.7, vertex-nasal 31.3 ± 28.5 and 16.7 ± 13.7, vertex-temporal 39.5 ± 42.14 and 60.4 ± 4.7, and orbital-temporal 30.14 ± 42.14 and 70.01 ± 42.14, respectively (mean ± SD cm³). In the vertex-nasal quadrant, the supraorbital approach provides a 47.3% increase in SDF compared to the standard frontotemporal pterional craniotomy approach.

CONCLUSION

Given that the AComA complex is located more nasally and the surgeon's view is more vertex, we propose that a supraorbital craniotomy allows a more contralateral portion of the AComA complex to be visualized during dissection.

Clinical and morphological profile of aneurysms of the anterior communicating artery treated at a neurosurgical service in Southern Brazil

Background:

The aim of the study was to characterize the clinical profile of patients with anterior communicating artery (ACoA) aneurysms and examine potential correlations between clinical findings, aneurysm morphology, and outcome.

Methods:

A review of medical records and diagnostic neuroimaging reports of patients treated at a neurosurgical service in Porto Alegre, Brazil, between August 2008 and January 2015 was performed.

Results:

During the period, 100 patients underwent surgery for ACoA aneurysms. Fifteen had unruptured aneurysms and 85 had ruptured aneurysms. Ruptured aneurysms had a higher aspect ratio than unruptured ones (2.37 ± 0.71 vs. 1.93 ± 0.51, P = 0.02). Intraoperative rupture occurred in 3%, and temporary clipping was performed in 15%. Clinical vasospasm occurred in 43 patients with ruptured aneurysms (50.6%). Overall, mortality was 26%; 25 patients in the ruptured group (29.4%) and one in the unruptured group (6%). The Glasgow Outcome Scale (GOS) was favorable (GOS 4 or 5) in 54% of patients, significantly more so in those with unruptured aneurysms (P = 0.01). In patients with ruptured aneurysms, mortality was associated with preoperative Hunt and Hess (HH) score (P < 0.001), hydrocephalus (P < 0.001), and clinical complications (P < 0.001). Unfavorable outcomes were associated with HH score (P < 0.001), Fisher grade (P = 0.015), clinical vasospasm (P = 0.012), external ventricular drain (P = 0.015), hydrocephalus (P < 0.001), and presence of clinical complications (P = 0.001). In patients with unruptured aneurysms, presence of clinical complications was the only factor associated with mortality (P < 0.001).

Conclusion:

Despite advances in the management of subarachnoid hemorrhage and surgical treatment of aneurysms, mortality is still high, especially due to clinical complications.

Extended Endoscopic Endonasal Clipping of Intracranial Aneurysms: An Anatomic Feasibility Study

BACKGROUND

Intracranial aneurysms (IAs) located in the midline region represent formidable challenge owing to their deep location. The objective of this study was to assess feasibility and identify the limitations of endoscopic endonasal clipping of IAs. We further aimed to describe the locations and characteristics of aneurysms that may be amenable for endoscopic endonasal clipping; thus outlining the indications of these approaches.

METHODS

Fifteen latex-injected cadaveric heads were used for endoscopic endonasal exposure of anterior and posterior cerebral circulations. An aneurysm simulator model with 2 different sizes was used at the common sites for IAs to emulate a real surgery. Key measured parameters included "exposure of vessels and their respective perforators," "ability to gain proximal/distal control," and "possibility of clip placement" according to the size, direction, and location of the aneurysm model. Maneuverability of instruments and the need for pituitary gland transposition were assessed and recorded as well.

RESULTS

Exposure of the anterior communicating artery complex and the common sites of posterior circulation aneurysms were feasible. The size, location, and direction of the aneurysm model had an impact on obtaining proximal and/or distal control, and the ability of clip placement.

CONCLUSIONS

Clipping of midline aneurysms of the posterior circulation is feasible via endoscopic endonasal approach. Small-sized ventrally and medially directed aneurysm models carried a better probability of getting proximal and/or distal control, as well as better overall ability to place a clip. The endonasal route seems to provide a limited condition for proper management of anterior circulation aneurysms.

Neural Crest Cell Failure as Embryogenesis for Fusiform Aneurysm of the Anterior Communicating Artery: Case Report and Review of the Literature

BACKGROUND

Pure fusiform aneurysms of the anterior communicating artery (AcomA) are rare. We report a unique case of a patient with an AComA fusiform aneurysm in the setting of several unusual cranial neurocristopathies, including a hypoplastic internal carotid artery (ICA), persistent craniopharyngeal canal, transsphenoidal encephalocele, and ectopic, duplicated pituitary gland. We also review the literature on cranial base neurocristopathies and AComA fusiform aneurysms.

CASE DESCRIPTION

This 46-year-old patient had a history of short stature, osteoporosis, obesity, cleft lip, decreased libido, congenital left eye blindness, headaches, and chronic nasal congestion. Magnetic resonance imaging revealed a 25 × 25 × 33 mm heterogenous soft tissue mass with an ectopic pituitary gland extending transsphenoidally and a duplicated pituitary stalk. A hormone panel revealed undetectable insulin-like growth factor 1 and growth hormone, central hypogonadism, and elevated prolactin. Before presentation, computed tomography angiography (CTA) had revealed a congenitally hypoplastic right ICA and 4.7 × 10.7 mm fusiform aneurysm of the AComA. Digital subtraction angiography confirmed stable morphology after 9 years. Nonoperative management of aneurysm and cephalocele was elected, with repeat CTA in 1 year.

CONCLUSIONS

This case provides evidence that inherent arterial wall defects can contribute to fusiform aneurysm formation in the AComA. We propose that small AComA fusiform aneurysms without sclerotic or symptomatic features can be safely observed by describing the longest reported conservative management for this type of aneurysm. A high degree of suspicion for cerebrovascular anomalies should be maintained in patients who present with cranial neurocristopathy.

Flow diversion treatment of aneurysms of the complex region of the anterior communicating artery: which stent placement strategy should 'I' use? A single center experience

BACKGROUND

Aneurysms of the anterior communicating artery (ACoA) are difficult to treat with coiling or clipping because of the anatomical variation in this region. Flow diversion represents a feasible treatment, but no consensus exists as to which stent deployment technique is more suitable.

METHODS

All patients with ACoA aneurysms treated with flow diverters between April 2014 and November 2018 were retrospectively analyzed. Aneurysm characteristics, follow-up results, and clinical outcome data were recorded, and a new classification comparing the diameters of both A1 segments is proposed: H1=same diameters; H2=<50% difference in diameters; H3= ≥50% difference; and Y=no A1 segment.

RESULTS

We analyzed 30 procedures in 30 patients with ACoA aneurysms, including 16 ruptured aneurysms treated with coiling embolization and 4 previously unruptured aneurysms (two Medina and two Woven EndoBridge devices). Adequate aneurysm occlusion occurred in 86.9%; one patient (3.3%) experienced symptomatic ischemic stroke. The global thromboembolic complications for each group were 17.6% (H1), 25% (H2), and 60% (H3).

CONCLUSION

Flow diversion treatment in this region is safe, feasible, and effective. The most suitable anatomical configuration for flow diverter treatment seems to be the H1 configuration where the 'I technique' is suitable (from an A1 segment to the ipsilateral A2). There is a tendency that the H3 configuration is not a good indication for flow diverter treatment. However, further studies are needed to evaluate the feasibility of this anatomical classification and the reproducibility of our findings.

Flow-Diversion Treatment of Unruptured Saccular Anterior Communicating Artery Aneurysms: A Systematic Review and Meta-Analysis

BACKGROUND

Flow diversion for anterior communicating artery aneurysms required further investigation.

PURPOSE

Our aim was to analyze outcomes after treatment of anterior communicating artery aneurysms with flow-diverter stents.

DATA SOURCES

A systematic search of 3 data bases was performed for studies published from 2008 to 2018.

STUDY SELECTION

According to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we included studies reporting anterior communicating artery aneurysms treated with flow diversion.

DATA ANALYSIS

Random-effects meta-analysis was used to pool the following: aneurysm occlusion rate, complications, and factors influencing the studied outcomes.

DATA SYNTHESIS

We included 14 studies and 148 unruptured saccular anterior communicating artery aneurysms treated with flow diversion. The long-term complete/near-complete (O'Kelly-Marotta C-D) occlusion rate was 87.4% (91/105; 95% CI, 81.3%-93.6%; I² = 0%) (mean radiologic follow-up of 11 months). The treatment-related complication rate was 8.6% (14/126; 95% CI, 4%-13.1%; I² = 0%), with morbidity and mortality rates of 3.5% (5/126; 95% CI, 2%-7%; I² = 0%) and 2.5% (2/148; 95% CI, 0.3%-5%; I² = 0%), respectively. Most complications were periprocedural (12/126 = 7%; 95% CI, 3%-11%; I² = 0%). Thromboembolic events were slightly higher compared with hemorrhagic complications (10/126 = 6%; 95% CI, 2%-10%; I² = 0% and 4/126 = 3%; 95% CI, 1%-6%; I² = 0%). Branching arteries (A2 or the recurrent artery of Heubner) covered by the stent were occluded in 16% (7/34; 95% CI, 3.5%-28%; I² = 25%) of cases. Pre- and posttreatment low-dose and high-dose of antiplatelet therapy was not associated with significantly different complication and occlusion rates.

LIMITATIONS

We reviewed small and retrospective series.

CONCLUSIONS

Flow diversion for unruptured saccular anterior communicating artery aneurysms appears to be an effective alternative treatment for lesions difficult to treat with coiling or microsurgical clipping. The treatment-related complication rate was relatively low. However, larger studies are needed to confirm these results.

Analysis for risk factors of 12-month neurological worsening in patients with surgically treated small-to-moderate size unruptured intracranial aneurysms

The risk associated with surgical treatment for small-to-moderate size unruptured intracranial aneurysms (SMUIAs, defined as <15 mm) has not been well characterized. Authors aimed to investigate risk factors for poor outcome in surgical treatment of SMUIAs. The data of prospectively collected 801 consecutive patients harboring 971 surgically treated SMUIAs was evaluated. Neurological worsening (NW) was defined as an increase in 1 or more modified Rankin Scale at 12-month. Clinical and radiological characteristics were compared. Neurological worsening was observed in 45 (4.6%). In multivariate analysis, only perforator territory infarction (PTI) on postoperative diffusion-weighted imaging (odds ratio (OR), 13; 95% confidence interval (CI), 4.9-32, p < 0.0001), and aneurysm locations (paraclinoid (OR, 6.9; 95% CI, 3.1-15, p < 0.0001), basilar artery (OR, 4.5; 95% CI, 1.5-14, p = 0.008), vertebral artery (OR, 11; 95% CI, 3.3-34, p < 0.0001)) were related to neurological worsening. Multivariate analysis showed that statin use (OR, 12; 95% CI, 3.8-39, p < 0.0001) and aneurysm locations (internal carotid artery-posterior communicating artery (OR, 3.9; 95% CI, 1.8-8.2, p < 0.0001) and basilar artery (OR, 6.3; 95% CI, 2.3-17, p = 0.008)), and aneurysm size >10 mm (OR, 5.3; 95% CI, 1.8-15, p = 0.003) were related to PTI. Although all SMUIAs should be carefully considered whether to be treated, those with statins, specific locations, and larger sizes should perhaps be more meticulously contemplated, and neurosurgeons should continue to avoid PTI.