Anterior Choroidal Artery Aneurysm Research Articles

Technical Approaches for Coil Embolization of Unruptured Small Anterior Choroidal Artery Aneurysms: A Focus on Anatomical Flow Preservation of the Anterior Choroidal Artery.

The anterior choroidal artery (AChA) supplies the corticospinal tract related to the motor function of the upper and lower limbs. Aneurysms arising at the AChA are not common and exhibit various patterns of involvement of the AChA. Hence, managing an AChA aneurysm poses a high risk of neurological deficits. We report technical issues related to the outcome of coil embolization for unruptured AChA aneurysms. We obtained Institutional Review Board approval for this study. In the past 2 years, 18 consecutive patients (6 males and 12 females, aged 32-68) with unruptured AChA aneurysms were treated using embolization. We present technical details, pre- and post-procedural patient statuses, angiographic outcomes, and recurrence during a mean follow-up period of 12 months (range 3-25). The patients with AChA (n=18) underwent stent-assisted coiling (n=14), coiling (n=2), or stenting only (n=2). The technical strategy for aneurysm embolization included a low-lying approach into the aneurysm, stent-strut abutting (protecting) coil framing to block inflow and avoid compromising AChA flow, and direct intra-aneurysmal angiography via a microcatheter. Angiographic results showed complete occlusion (n=11), neck remnant (n=5), and sac remnant (n=2). During the follow-up, there were 2 recurrences, and 1 of them required a re-procedure. All patients showed no change in clinical status (modified Rankin scale score=0) and did not experience any ischemic or hemorrhagic events during the follow-up period. AChA aneurysms can be managed through embolization using various techniques. Such technical concepts may enhance the safety and improve the outcomes of AChA aneurysm embolization.

Anterior choroidal artery aneurysms: a systematic review and meta-analysis of outcomes and ischemic complications following surgical and endovascular treatment.

Anterior choroidal artery (AChA) aneurysms account for 2%-5% of all intracranial aneurysms. Treatment considerations include microsurgical clipping, flow diversion, or coiling with or without adjunctive devices. AChA aneurysms pose challenges in treatment due to the origination of the aneurysm from the origin or proximal segment of the AChA. The AChA is particularly susceptible to vasospasm and occlusion during treatment with devastating neurological deficits, including hemiparesis, hemianesthesia, lethargy, neglect, and hemianopia. In this study, the authors performed a meta-analysis to quantify the outcomes and complication rates across treatment modalities for AChA aneurysms and to identify risk factors reported in the literature. The authors performed a systematic review of AChA aneurysms treated with surgical clipping, endovascular coiling, or flow diversion and reported in the PubMed, Embase, Scopus, and Cochrane search databases. Single-arm meta-analyses of the selected outcomes were performed in RStudio. Literature review yielded 25 studies that met the inclusion criteria. In total, 1627 patients were included in the analysis, with 554 males, 1009 females, and 64 unspecified. The rate of any complication in the full cohort was 11.6%, with a rate of ischemic complications of 5.5% and a favorable recovery rate of 90.3% of all patients treated. In total, 1064 patients underwent surgical clipping, 443 were treated with coiling, and 120 patients with flow diversion. In clipped patients, the rate of total surgical complications was 17.6%, with an ischemic complication rate of 9.4%. The rate of good functional recovery, defined on the basis of a Glasgow Outcome Scale score of 4-5 or modified Rankin Scale score of 0-2, was 88.0%, and complete obliteration was achieved in 84.5% of surgically clipped aneurysms. The complication rate in coiled patients was 10.3%, with an ischemic complication rate of 3.0%. Good functional recovery was achieved in 88.6% of coiled patients and complete aneurysm obliteration in 74.1%. Flow diversion resulted in a complication rate of 1.3%, with 0.7% rate of ischemic complications. Good functional recovery was achieved in 98.4% of patients and complete aneurysm obliteration in 79.0% in the flow diversion group. Aneurysm morphological features that impacted the complication rate were also identified to augment quantitative data and to help guide treatment selection for AChA aneurysms. Flow diversion showed significantly lower total and ischemic complications and improved outcomes compared to clipping and coiling. There may be differences in outcomes between treatment types, especially when considering the varied patient presentations that guide treatment selection.

Anterior Choroidal Artery Aneurysm Clipping: Angiographic Diagnostics and Surgical Tactics Focused on Visualizing the Anterior Choroidal Artery Behind the Aneurysm

This study describes our experiences with AChA aneurysm clipping with a focus on visualizing the anterior choroidal artery (AChA) just behind the aneurysm to identify the risk factors for adhesion of the AChA or its branches to the posterior wall of the AChA aneurysm. The initial segment of the AChA just behind the aneurysm was evaluated preoperatively using 3D rotational angiography and its course was designated as posteromedial, posterior, or posterolateral. The posterior aspect of the AChA aneurysm was inspected intraoperatively using an endoscope or micromirror. Based on 3D rotational angiography, the main trunk of the AChA showed a posteromedial (n = 47, 57.3%), posterior (n = 18, 22.0%), or posterolateral (n = 17, 20.7%) course just behind the aneurysm. Intraoperatively, 14.6% (12 of 82) of the clipped AChA aneurysms revealed an AChA branch adhered to the posterior wall of the aneurysm. A multivariate analysis revealed that the posterior or posterolateral course of the initial segment of the AChA was a statistically significant risk factor for adhesion of an AChA branch to the posterior wall of the aneurysm (OR 21.083, 95% CI 2.567-173.166, p = 0.005). The initial course of the AChA just behind an AChA aneurysm can be evaluated using 3D rotational angiography. In contrast to a posteromedial course, a posterior or posterolateral course of the AChA just behind an AChA aneurysm can be a significant risk factor for adhesion of an AChA branch to the posterior wall of an AChA aneurysm.

Combination of neuroendoscopic hematoma evacuation and endovascular coil embolization for a ruptured anterior choroidal artery aneurysm in patients with moyamoya disease: illustrative cases.

The treatment strategy for hemorrhagic moyamoya disease (MMD) due to a ruptured aneurysm at the distal portion of the anterior choroidal artery remains controversial. The authors successfully treated the ruptured aneurysm with neuroendoscopic hematoma evacuation, followed by endovascular coil embolization. The authors encountered two patients with massive hemorrhagic MMD whose MMD had already been diagnosed and who had a periventricular anastomosis due to a ruptured aneurysm of the distal portion of the anterior choroidal artery involving the periventricular anastomosis. In both cases, neuroendoscopic hematoma evacuation was performed for hemorrhagic MMD in the acute phase, followed by endovascular coil embolization of the ruptured aneurysm in the chronic phase. In both endovascular treatments, the patient's condition was stabilized by hematoma evacuation, allowing a detailed preoperative evaluation of the anatomical findings of the vessel and functional findings of intraoperative neurophysiological monitoring using continuous monitoring of motor evoked potentials to preserve motor function. Combination therapy can be useful for hemorrhagic MMD in patients with diagnosed MMD with a periventricular anastomosis. Additionally, a preoperative understanding of the vascular construction and intraoperative neurophysiological monitoring will aid in the successful coil embolization of aneurysms at the distal portion of the anterior choroidal artery with hemorrhagic MMD.

Nomograms for assessing the rupture risk of anterior choroid artery aneurysms based on clinical, morphological, and hemodynamic features.

A notable prevalence of subarachnoid hemorrhage is evident among patients with anterior choroidal artery aneurysms in clinical practice. To evaluate the risk of rupture in unruptured anterior choroidal artery aneurysms, we conducted a comprehensive analysis of risk factors and subsequently developed two nomograms. A total of 120 cases of anterior choroidal artery aneurysms (66 unruptured and 54 ruptured) from 4 medical institutions were assessed utilizing computational fluid dynamics (CFD) and digital subtraction angiography (DSA). The training set, consisting of 98 aneurysms from 3 hospitals, was established, with an additional 22 cases from the fourth hospital forming the external validation set. Statistical differences between the two data sets were thoroughly compared. The significance of 9 clinical baseline characteristics, 11 aneurysm morphology parameters, and 4 hemodynamic parameters concerning aneurysm rupture was evaluated within the training set. Candidate selection for constructing the nomogram models involved regression analysis and variance inflation factors. Discrimination, calibration, and clinical utility of the models in both training and validation sets were assessed using area under curves (AUC), calibration plots, and decision curve analysis (DCA). The DeLong test, net reclassification index (NRI), and integrated discrimination improvement (IDI) were employed to compare the effectiveness of classification across models. Two nomogram models were ultimately constructed: model 1, incorporating clinical, morphological, and hemodynamic parameters (C + M + H), and model 2, relying primarily on clinical and morphological parameters (C + M). Multivariate analysis identified smoking, size ratio (SR), normalized wall shear stress (NWSS), and average oscillatory shear index (OSIave) as optimal candidates for model development. In the training set, model 1 (C + M + H) achieved an AUC of 0.795 (95% CI: 0.706 ~ 0.884), demonstrating a sensitivity of 95.6% and a specificity of 54.7%. Model 2 (C + M) had an AUC of 0.706 (95% CI: 0.604 ~ 0.808), with corresponding sensitivity and specificity of 82.4 and 50.3%, respectively. Similarly, AUCs for models 1 and 2 in the external validation set were calculated to be 0.709 and 0.674, respectively. Calibration plots illustrated a consistent correlation between model evaluations and real-world observations in both sets. DCA demonstrated that the model incorporating hemodynamic parameters offered higher clinical benefits. In the training set, NRI (0.224, p = 0.007), IDI (0.585, p = 0.002), and DeLong test (change = 0.089, p = 0.008) were all significant. In the external validation set, NRI, IDI, and DeLong test statistics were 0.624 (p = 0.063), 0.572 (p = 0.044), and 0.035 (p = 0.047), respectively. Multidimensional nomograms have the potential to enhance risk assessment and patient-specific treatment of anterior choroidal artery aneurysms. Validated by an external cohort, the model incorporating clinical, morphological, and hemodynamic features may provide improved classification of rupture states.

Treatment Outcomes in Patients with Unruptured Anterior Choroidal Artery Aneurysms: A Single-Center Experience.

Treatment of anterior choroidal artery (AChA) aneurysms is frequently associated with ischemic complications. This study aimed to report the outcomes of treatment of unruptured AChA aneurysms in our hospital. Between January 2015 and March 2022, 40 patients were treated for an unruptured AChA aneurysm in our hospital. Age, sex, aneurysm size, AChA branching type, treatment, occlusion rate, complications, modified Rankin Scale (mRS) score before surgery and after 90 days, and recurrence were investigated. The branching type was classified as internal carotid artery (ICA), neck, or dome type based on the location of the AChA origin. The mean age was 61.1 ± 1.9 years; 15 patients were men and 25 were women. The mean aneurysm diameter was 4.4 ± 0.3 mm. The branching type was ICA in four patients, neck in 35, and dome in one. Treatment was surgical clipping in 22 patients and endovascular coil embolization in 18 (14 with stent assistance). Motor-evoked potential (MEP) monitoring was used in all patients of the clipping group and 9 cases of the coiling group. Treatment complications occurred in eight patients (20%). mRS score worsened by more than one point 90 days after treatment in four patients (10%); however, the proportion of patients who experienced this did not significantly differ between the clipping and coiling groups. Although the odds of a thrombotic complication were higher with coiling than clipping, the difference was not significant (odds ratio: 10.2; P = 0.08). The rate of complete occlusion was lower in the coiling group (72.2% vs. 95.3%), but the difference was not significant. The median follow-up was 696 days (range: 99-2053). No aneurysm recurrence or rupture occurred. AChA branching type is important for treatment decision-making in patients with AChA aneurysms. Rates of complications and occlusion do not significantly differ between clipping and coiling of AChA aneurysms. MEP monitoring may be useful in preventing thrombotic complications during coil embolization.

Endovascular Treatments for Aneurysms Involving a Major Branch.

Remarkable advances have been made in the endovascular treatment of intracranial cerebral aneurysms. These advances include various adjunctive techniques, increased indications for endovascular treatment, and improved treatment results. Furthermore, the number of cerebral aneurysm treatments using flow diverters (FDs) is expected to increase. However, the reported long-term rate of branch artery occlusion after FD treatment has been reported is 15.8%. Moreover, the complete aneurysm obliteration rate is low if normal branches arise from an aneurysm neck or dome. Flow diverter placement for ophthalmic artery, posterior communicating artery, and anterior choroidal artery aneurysms is often difficult because these normal branches often arise from the aneurysm neck or dome. Therefore, in many cases, coil embolization, which can occlude the aneurysm while preserving branch vessels, should be selected. Although not yet established, various adjunctive techniques and other endovascular treatments that can be performed safely have been reported. Treatment must be planned after understanding the advantages and disadvantages of each treatment method.

Comparison of outcomes between clipping and endovascularcoiling in anterior choroidal artery aneurysm: a systematic review.

SAH (subarachnoid hemorrhage) caused by aneurysm rupture has the greatest mortality rate, with nearly 50% of patients unable to survive beyond 1month after the attack. Anterior choroidal artery (AChA) aneurysms are one of the most difficult to treat among the numerous types of aneurysms. Until now, some neurosurgeons employed shearing while others employed coiling. In this trial, researchers will compare surgical clipping and endovascular coiling treatments for anterior choroidal artery aneurysms in terms of mortality, rebleeding, retreatment, and post-procedure outcomes. Using the PubMed electronic database, the Cochrane library, the Medline Database, the Directory of Open Access Journals, and EBSCHOHOST, a systematic review compared surgical clipping and endovascular coiling in all cases of choroidal artery aneurysm. There were 17 studies that met the eligibility requirements, with a total of 1486 patients divided into groups that underwent clipping (1106) or endovascular coiling (380). The mortality rate for clipping is 1.8%, while the mortality rate for endovascular coiling is 2.34%. Rebleeding occurs in 0% of patients undergoing endovascular coiling and 0.73% of patients undergoing clipping. Retreatment of clipping was 0.27%, while endovascular coiling was 3.42%. Post-complication procedures occurred in 11.12% of patients undergoing endovascular clipping and 15.78% of patients undergoing endovascular coiling. The intervention technique of clipping has a reduced rate of mortality, reoperation, and post-operative complications. Endovascular coiling results in a reduced rate of rebleeding than clipping.

Focal drug-resistant temporal lobe epilepsy associated with an ipsilateral anterior choroidal artery aneurysm: illustrative case.

The occurrence of both an intracranial aneurysm and epilepsy, especially drug-resistant epilepsy (DRE), is rare. Although the overall incidence of aneurysms associated with DRE is unclear, it is thought to be particularly infrequent in the pediatric population. Surgical ligation of the offending aneurysm has been reported in conjunction with resolving seizure activity, although few cases have cited a combined approach of aneurysm ligation and resection of an epileptogenic focus. We present the case of a 14-year-old female patient with drug-resistant temporal lobe epilepsy and an ipsilateral supraclinoid internal carotid artery aneurysm. Seizure semiology, electroencephalography monitoring, and magnetic resonance imaging all indicated a left temporal epileptogenic focus, in addition to an incidental aneurysm. The authors recommended a combined surgery involving resection of the temporal lesion and surgical clip ligation of the aneurysm. Near-total resection and successful ligation were achieved, and the patient has remained seizure free since surgery at 1 year postoperatively. In patients with focal DRE and an adjacent intracranial aneurysm, a combined surgical approach involving both resection and surgical ligation can be used. Several surgical timing and neuroanesthetic considerations should be made to ensure the overall safety and efficacy of this procedure.

Clipping of Unruptured Anterior Choroidal Artery Aneurysms Together with Small Branches: Safety Confirmation Using Intraoperative Indocyanine Green Video-Angiography and Intraoperative Neurophysiological Monitoring

In treating anterior choroidal artery (AChA) aneurysms, preserving the AChA main trunk is of course necessary to prevent postoperative ischemic complications. However, in practice, complete occlusions are often limited by small branches. We aimed to demonstrate that even in cases where complete occlusion of the AChA aneurysm is complex due to small branches, complete occlusion can be safely achieved using indocyanine green video-angiography and intraoperative neurophysiological monitoring (IONM). We performed a retrospective review of all unruptured AChA aneurysms surgically treated at our institution from 2012 to 2021. All available surgical videos were reviewed to find AChA aneurysms clipped with small branches; clinical and radiological data were collected for these cases. Among 391 cases of unruptured AChA aneurysms treated surgically, 25 AChA aneurysms were clipped with small branches. AChA-related ischemic complications occurred in 2 cases (8%) without retrograde indocyanine green filling to the branches. These 2 cases had changes in IONM. There were no ischemic complications in the remaining cases with retrograde indocyanine green filling to the branches and no change in IONM. During an average follow-up of 47months (12-111months), a small residual neck was observed in 3 cases (12%) and recurrence or progression of the aneurysm was observed in only 1 case (4%). The surgical treatment of AChA aneurysms carries the risk of devastating ischemic complications. Even in cases where complete clip ligation seems impossible due to small branches associated with AChA aneurysms, complete occlusion can be safely achieved using indocyanine green video-angiography and IONM.

Treatment of Ruptured Anterior Choroidal Artery Aneurysms by Acute Coiling Followed by Flow Diversion

Flow-diverter treatments are successful endovascular treatments in protecting important perforating branches during aneurysm treatments. Because these treatments are performed under antiplatelet therapy, acute flow-diverter treatments in ruptured aneurysms are still controversial. Acute coiling followed by flow diversion has emerged as an intriguing and feasible treatment option for ruptured anterior choroidal artery aneurysm treatment. As a single-center retrospective case series study, this study reported the clinical and angiographic results of staged endovascular treatment in patients with a ruptured anterior choroidal aneurysm. This is a single-center retrospective case series study between March 2011 and May 2021. Patients with ruptured anterior choroidal aneurysm received flow-diverter therapy in a different session after acute coiling. Patients treated with primary coiling or only flow diversion were excluded. Preoperative demographic and presenting symptoms, aneurysm morphology, perioperative and postoperative complications, and long-term clinical and angiographic outcome as measured using the modified Rankin Scale and O'Kelly Morata Grading scale and also Raymond-Roy occlusion classification respectively. Sixteen patients underwent coiling in the acute phase to undergo flow diversion later. The mean maximum aneurysm diameter is 5.44 ± 3.39 mm. All patients had a subarachnoid hemorrhage and were treated acutely between days 0 and 3 of acute bleeding. The mean age at the presentation was 54.12 ± 12 years (32-73 years). Two patients (12.5%) had minor ischemic complications, which are seen on magnetic resonance angiography as clinically silent infarcts, after the procedure. One patient (6.2%) had a technical complication with the flow-diverter shortening and deployed a second flow diverter telescopically. No mortality or permanent morbidity was reported. The mean interval time between the 2 treatments was 24.06 ± 11.83 days. All patients were followed up with digital subtraction angiography; 14/16 patients (87.5%) had aneurysms that were completely occluded and 2/16 (12.5%) showed near-complete occlusion. Mean follow-up was 16.62 ± 3.22 months; all patients had modified Rankin Scale scores ≤2; 14/16 (87.5%) had a total occlusion 14/16 (87.5%) had near-complete occlusion. None of the patients had retreatment or rebleeding. Staged treatment of ruptured anterior choroidal artery aneurysms with acute coiling and flow-diverter treatment after recovery from subarachnoid hemorrhage is safe and effective. In this series, no cases of rebleeding occurred during the interval between coiling and flow diversion. Staged treatment should be considered a valid option in patients with challenging ruptured anterior choroidal aneurysms.

Abstract Number ‐ 199: Acute Treatment of Aneurysmal Subarachnoid Patients with Flowdiversion: A Single Center Real World Experience

Introduction Subarachnoid hemorrhage patients presenting with complex morphology, and those with dissecting /fusiform aneurysms, blister aneurysms have historically posed a challenge for acute endovascular treatment. Flow diversion as a treatment for ruptured intracranial aneurysms is a last resort given the need for dual antiplatelet therapy in the acute setting. Methods We present our single center experience, real world experience in the acute treatment of patients with subarachnoid hemorrhage with pipeline flow diversion device. Results 6 patients presented acutely with a subarachnoid hemorrhage. Two of those had saccular intracranial aneurysms, 1 with a blister aneurysm, and 3 with dissecting aneurysms. 1 patient presented with a ruptured anterior choroidal artery location dissecting aneurysm, 1 with PCA blister aneurysm, 1 with intradural vertebral artery dissecting aneurysm, 1 saccular posterior communicating artery aneurysm, and another with a ruptured complex morphology anterior choroidal artery aneurysm, and 1 with dissecting PCA aneurysm. All patients were emergently loaded with dual antiplatelet therapy consisting of either aspirin and clopidogrel, or aspirin and ticagrelor or pletal and ticagrelor. 1 patient was treated with surface modified pipeline device with shield technology. Technical success was achieved in 100% of these patients. No acute in stent thrombosis was seen in this cohort. Four patients had no residual filling or recurrence at the 1st follow‐up at a median interval of 2–12 months. 1 patient died from fulminant vaso spasm. Follow‐up is pending in 1 patient. Conclusions In carefully selected patients, flow diversion in the acute setting is tolerated and can be an alternative treatment strategy with an acceptable safety profile.

Efficacy of intraoperative neuromonitoring (IONM) and intraoperative indocyanine green videoangiography (ICG-VA) during unruptured anterior choroidal artery aneurysm clipping surgery.

The aim of this study was to investigate the efficacy of intraoperative indocyanine green videoangiography (ICG-VA) and intraoperative neuromonitoring (IONM) to prevent postoperative ischemic complications during microsurgical clipping of unruptured anterior choroidal artery (AChA) aneurysms. We retrospectively reviewed the clinical and radiological records of all patients who had undergone microsurgical clipping for unruptured AChA aneurysms at our institution between April 2001 and December 2019. We compared the postoperative complication rate of the group for which intraoperative ICG-VA and IONM were utilized (group B; n=324) with that of the group for which intraoperative ICG-VA and IONM were not utilized (group A; n=72). There were no statistically significant differences in demographic data between the two groups. Statistically significant differences were observed in the rate of overall complications (p=0.014) and postoperative ischemic complications related to AChA territory (p=0.039). All the cases (n=4) in group B who had postoperative infarctions related to AChA territory showed false-negative results of intraoperative ICG-VA and IONM. Preserving the patency of the AChA is essential to minimize postoperative complications. Intraoperative monitoring tools including ICG-VA and IONM can greatly contribute to lowering complication rates. However, their pitfalls and false-negative results should always be considered.

Treatment results of anterior choroidal artery aneurysms treated mostly with coil embolization: A single-center experience.

Anterior choroidal artery (AchA) aneurysms are usually small in diameter because of the size of the involved artery and are often wide-necked. Coil embolization of AchA aneurysm is thus challenging because of serious risks, such as thromboembolic occlusion of artery and perforation of aneurysm dome. Therefore, aneurysmal neck clipping remains widely performed despite a recent increase in the use of coil embolization for aneurysm treatment. We report the treatment results of AchA aneurysms mostly (92.3%) treated with coil embolization at our institute. The database and medical records of patients who underwent coil embolization for AchA aneurysms were retrospectively analyzed. The clinical and imaging results and procedure-related complications were investigated after coil embolization performed between January 2006 and March 2022 at our institute. In total, 96 AchA aneurysms comprising 65 unruptured and 31 ruptured aneurysms, including only 1 ruptured aneurysm (1.0%) re-embolized at postoperative day 192 because of coil compaction, were evaluated. After the initial coil embolization, complete occlusion was attained in 41, residual neck in 45, and residual aneurysm in 10 patients. Follow-up radiological studies after 6-174 months were performed for 80 aneurysms. Complete occlusion was noted in 57 patients, residual neck in 22, and residual aneurysm in 1. The dysarthria experienced by one (1.0%) patient was the only symptomatic procedure-related complication. After coil embolization, neither delayed new rupture nor re-rupture was observed. The results of this study demonstrate that coil embolization is a safe and effective treatment option for patients with AchA aneurysms.

Predictors of Ischemic Complication in Anterior Choroidal Artery Aneurysm Repair

Treatment of anterior choroidal artery (AchoA) aneurysms is challenging because of the risk of artery injury. The objective of the study was to evaluate the incidence and predictors of AchoA infarction in patients who underwent surgical or endovascular procedure. We included 123 patients with AchoA aneurysms treated by surgical clipping (n=62; 50.4%) or endovascular coiling, including flow diverter placement (n=61; 49.6%). The clinical and radiological data were retrospectively analyzed. AchoA infarction was defined as the presence of a hyperintense signal on diffusion-weighted imaging in the area of AchoA, including the posterior limb of the internal capsule. AchoA infarction was detected in 8 cases (6.5%), with similar incidence in both groups (6.5% [4/62] vs. 6.6% [4/61]). It occurred in ruptured aneurysms more frequently than in unruptured aneurysms (14.3% [6/42] vs. 2.5% [2/81], P=0.019). In the surgical group, all 4 affected patients had a non-proximal type AchoA, whereas in the non-infarction group, 9 patients (15.5%) had a non-proximal type AchoA (P=0.001). In the endovascular group, the incidence was higher in patients with ruptured aneurysms (17.3% [4/23] vs. 0% [0/38], P=0.017) and lower in patients with pre-admission antiplatelet therapy (0% [0/39] vs. 18.8% [4/22], P=0.014). Repair of an AchoA aneurysm is associated with the risk of incurring post-procedural AchoA infarction. Surgical clipping and endovascular coiling have similar complication rates, but risk factors specific to each intervention exist. Careful surgical planning to avoid these risk factors in each therapeutic modality may improve patient outcomes.

Rupture of an adjacent cerebral aneurysm following the deployment of a Pipeline embolization device: illustrative case.

BACKGROUNDAlthough the Pipeline embolization device (PED) is effective for intracranial aneurysm treatment, its impact on the surrounding vascular structure is unknown.OBSERVATIONSA 71-year-old woman was incidentally found to have a simultaneous large posterior communicating artery aneurysm and an ipsilateral small anterior choroidal artery aneurysm. She underwent flow diversion therapy for both aneurysms with a PED, but the distal shortening of the PED after deployment led to the exposure of the anterior choroidal artery aneurysm. Follow-up angiography revealed complete obliteration of the posterior communicating artery aneurysm, but the anterior choroidal artery aneurysm remained. Three years after the endovascular surgery, the patient experienced a subarachnoid hemorrhage due to the rupture of the anterior choroidal artery aneurysm. Retrospective analysis of angiographic images revealed a change in the vascular geometry surrounding the ruptured aneurysm after PED deployment; this was further accompanied by an increase in the flow velocity inside the aneurysm.LESSONSBecause PED use might induce the adverse effects on the adjacent uncovered aneurysm by changing the vascular geometry and hemodynamic stress, a cautious therapeutic strategy, such as proper placement of the stent and using a longer and appropriate-sized PED, should be chosen when deploying the PED.

Intraoperative motor-evoked potential monitoring during coil embolization for anterior choroidal artery aneurysms

Intraoperative motor-evoked potential (MEP) monitoring is widely used in the neck clipping of cerebral aneurysms. Little is known regarding the usefulness of intraoperative MEP monitoring in endovascular aneurysm surgery. The purpose of this study was to validate the feasibility of intraoperative MEP monitoring during the coil embolization of anterior choroidal artery (AChA) aneurysms. Clinical and angiographic data of consecutive patients who underwent coil embolization for unruptured AChA aneurysms with or without intraoperative MEP monitoring between January 2014 and December 2018 at our institute were abstracted and analyzed retrospectively. Twenty-three unruptured AChA aneurysms were treated. Eleven patients received MEP monitoring, and three of them experienced intraoperative reduction or disappearance of the MEP wave. Even during MEP changes, AChA filling showed no change in any of the three cases. Although one case with MEP monitoring encountered the disappearance of AChA filling, there was no change in MEP. This might be due to retrograde filling of the AChA from the anastomosis with the lateral posterior choroidal artery. AChA blood flow detected by angiography did not always reflect MEP status. When comparing the presence or absence of MEP monitoring, the volume embolization ratio of coiled aneurysms was significantly better in the MEP group. Intraoperative MEP monitoring during endovascular coiling for AChA aneurysms may be feasible. AChA blood flow detected by angiography does not always reflect MEP status.

Multiple anterior choroidal arteries and perioperative ischemic complications in unruptured anterior choroidal artery aneurysms treated with microsurgical clipping.

This study aimed to identify the association between the number of anterior choroidal arteries (AchoAs) and procedure-related ischemic complications in microsurgical clipping of unruptured AchoA aneurysms. We retrospectively reviewed the clinical, radiological, and intraoperative findings of 153 patients with unruptured AchoA aneurysms treated with microsurgical clipping between January 2012 and November 2020 in a single tertiary institution. Intraoperative video clips were reviewed, and the AchoA type was categorized into two according to the number of AchoAs: (1) single-type group with single origin and single branch and (2) multiple-type group with duplicated origin or divided multiple branches. Uni- and multivariate analyses were performed to assess the relationship between clinical and radiological factors and perioperative ischemic complications. Of the 153 patients, 52 (34%) were categorized as multiple-type group. The frequency of perioperative ischemic complications, including decreased intraoperative motor evoked potential (MEP), silent infarction, and postoperative ischemic symptoms, was significantly higher in the multiple-type group than in the single-type group (13 [25%] vs 6 [5.9%], p = 0.001). Multivariate logistic regression analysis showed that multiple-type group (odds ratio [OR], 3.725; 95% confidence interval [CI], 1.171-11.845, p = 0.026) and multilobulated shape (OR, 9.512; 95% CI, 2.093-43.224; p = 0.004) were significantly associated with perioperative ischemic complications. Among 9 patients with decreased MEP, postoperative ischemic symptoms developed in 2 patients after clip adjustment. Multiple-type AchoA aneurysms and multilobulated shape are significantly correlated with perioperative ischemic complications. Postoperative ischemic complications can be minimized by recognizing these variations and using multimodal approach with MEP monitoring.

A New Classification of Anterior Choroidal Artery Aneurysms and Its Clinical Application.

Background and Purpose: The aim of this study was to compare the different subtypes of anterior choroidal artery (AChoA) aneurysm based on a new classification and to analyze the risk factors according to individual endovascular treatment (EVT).Methods: In the new classification, AChoA aneurysms are classified into independent type (I type) and dependent type (II type) based on the relationship between the AChoA and the aneurysm. II type aneurysms have three subtypes, IIa (neck), IIb (body), and IIc (direct). We retrospectively analyzed 52 cases of AChoA aneurysm treated in our center between 2015 to 2019. There were 13 (25.0%) I type aneurysms, 24 (46.2%) IIa aneurysms, 15 (28.8%) IIb aneurysms, and no IIc type; 28 cases had a subarachnoid hemorrhage. According to our preoperative EVT plan for the different subtypes: II type should achieve Raymond-Roy Occlusion Class 1 (RROC 1) where possible. To protect the AChoA, it is best to preserve the neck of the IIa type aneurysms (RROC 2), and RROC 3 is enough for IIb type.Results: Ten asymptomatic cases with minimal aneurysms were treated conservatively. Of the other cases, 42 were treated with individualized EVT (26 with a simple coil, 6 with balloon-assisted coiling, 7 with stent-assisted coiling, and 3 by flow diverter. Different subtypes had different RROC (Z = 14.026, P = 0.001). IIb type aneurysms (χ2 = 7.54, P = 0.023) were one of the factors related to temporary or permanent AChoA injury during surgery. Overall, two patients (IIa = 1, IIb = 1) developed contralateral hemiparesis.Conclusions: The new classification diagram clearly shows the features of all types of AChoA aneurysm and makes EVT planning more explicit. The II type (particularly IIb) was a potential risk factor for AChoA injury.

Surgical Challenges Associated With Anterior Choroidal Artery Aneurysm Clipping: 2-Dimensional Operative Video.

Surgical treatment of anterior choroidal artery (AChA) aneurysms is challenging because of the constrained operative corridor and limitations imparted by the surrounding rigid structures during the exposure. The AChA most commonly arises as a single branch from the communicating (C7) segment of the internal carotid artery but has 2 to 4 branches in approximately one-third of cases, and aneurysms generally arise from the parent vessel interface with these branches. This patient experienced a sentinel headache 4 d before presenting with subarachnoid hemorrhage. The patient had a large right AChA aneurysm with a unique configuration in which the parent vessel was located anterior to the aneurysm. Endovascular therapy was aborted because there was an AChA branch at the base of the aneurysm. An orbitozygomatic craniotomy was performed that provided transsylvian access to the region of interest. Clip application was challenging because of the close proximity of the branch vessels. Intraoperative indocyanine green evaluation and postoperative angiogram showed patency of the AChA and posterior communicating artery. This video demonstrates the surgical challenge associated with AChA aneurysms because of the proximity of adjacent structures and highlights the importance of meticulous technique during clip application. The patient gave informed consent for surgery and video recording. Institutional review board approval was deemed unnecessary. Used with permission from Barrow Neurological Institute, Phoenix, Arizona.