Microsurgical Clipping Compared with New and Most Advanced Endovascular Techniques in the Treatment of Unruptured Middle Cerebral Artery Aneurysms: A Meta-Analysis in the Modern Era

Surgical clipping and endovascular treatments for small or very small anterior communicating artery aneurysms: A comparative pooled analysis

INTRODUCTION

Small and very small anterior communicating artery (ACoA) aneurysms pose a complex challenge in neurosurgery and interventional neuroradiology due to their critical location and potential for severe consequences upon rupture. Surgical clipping has been a traditional approach, but it presents challenges requiring precision and expertise. Endovascular treatment has emerged as an alternative, offering minimally invasive techniques with potential advantages. This study aims to comprehensively compare outcomes and efficacy between surgical clipping and endovascular treatment for small or very small ACoA aneurysms.

OBJECTIVES

We aimed to perform a meta-analysis of small or very small anterior communicating artery aneurysms comparing surgical clipping and endovascular treatments.

METHODS

A systematic review and meta-analysis were conducted, including studies reporting on both treatment modalities. Eligible studies were identified through PubMed, Cochrane Library, and Embase databases. Pooled analyses with 95% confidence intervals were used to compare treatment effects, and statistical analysis followed PRISMA guidelines.

RESULTS

Thirteen studies with 637 patients were included. Endovascular treatment, predominantly coiling, was performed in 60.3% of patients, while 39.7% underwent surgical management. Endovascular treatment exhibited an 18% retreatment rate, contrasting with 0% in the surgery group. Mortality rates were 3% and 6% for endovascular and surgical treatments, respectively. Overall complications occurred in 1.8% of patients, with intraoperative rupture and cerebral infarction being the most common.

CONCLUSION

In summary, our study indicates a comparable outcome between surgical clipping and endovascular treatment for small ACoA aneurysms, with the former showing a lower retreatment rate. Decision factors include surgeon expertise, healthcare context, and patient age. Further research is needed to refine treatment strategies, considering variations in aneurysm status and evolving techniques.

Microsurgical clipping versus endovascular therapy for treating patients with middle cerebral artery aneurysms presenting with neurological ischemic symptoms

Studies comparing different treatment methods in patients with middle cerebral artery (MCA) aneurysms in different subgroups of onset symptoms are lacking. It is necessary to explore the safety and efficacy of open surgical treatment and endovascular therapy in patients with MCA aneurysms in a specific population. This study aimed to compare microsurgical clipping versus endovascular therapy regarding complication rates and outcomes in patients with MCA aneurysms presenting with neurological ischemic symptoms. This was a retrospective cohort study in which 9656 patients with intracranial aneurysms were screened between January 2014 and July 2022. Further, 130 eligible patients were enrolled. The primary outcome was the incidence of serious adverse events (SAEs) within 30 days of treatment, whereas secondary outcomes included postprocedural target vessel-related stroke, disabling stroke or death, mortality, and aneurysm occlusion rate. Among the 130 included patients, 45 were treated with endovascular therapy and 85 with microsurgical clipping. The primary outcome of the incidence of SAEs within 30 days of treatment was significantly higher in the clipping group [clipping: 23.5%(20/85) vs endovascular: 8.9%(4/45), adjusted OR:4.05, 95% CI:1.20-13.70; P = 0.024]. The incidence of any neurological complications related to the treatment was significantly higher in the clipping group [clipping:32.9%(28/85) vs endovascular:15.6%(7/45); adjusted OR:3.49, 95%CI:1.18-10.26; P = 0.023]. Postprocedural target vessel-related stroke, disabling stroke or death, mortality rate, and complete occlusion rate did not differ significantly between the two groups. Endovascular therapy seemed to be safer in treating patients with MCA aneurysms presenting with neurological ischemic symptoms compared with microsurgical clipping, with a significantly lower incidence of SAEs within 30 days of treatment and any neurological complications related to the treatment during follow-up.

Complex intracranial aneurysms: a DELPHI study to define associated characteristics

PURPOSE

Intracranial aneurysms present significant health risks, as their rupture leads to subarachnoid haemorrhage, which in turn has high morbidity and mortality rates. There are several elements affecting the complexity of an intracranial aneurysm. However, criteria for defining a complex intracranial aneurysm (CIA) in open surgery and endovascular treatment could differ, and actually there is no consensus on the definition of a "complex" aneurysm. This DELPHI study aims to assess consensus on variables defining a CIA.

METHODS

An international panel of 50 members, representing various specialties, was recruited to define CIAs through a three-round Delphi process. The panelists participated in surveys with Likert scale responses and open-ended questions. Consensus criteria were established to determine CIA variables, and statistical analysis evaluated consensus and stability.

RESULTS

In open surgery, CIAs were defined by fusiform or blister-like shape, dissecting aetiology, giant size (≥ 25 mm), broad neck encasing parent arteries, extensive neck surface, wall calcification, intraluminal thrombus, collateral branch from the sac, location (AICA, SCA, basilar), vasospasm context, and planned bypass (EC-IC or IC-IC). For endovascular treatment, CIAs included giant size, very wide neck (dome/neck ratio ≤ 1:1), and collateral branch from the sac.

CONCLUSIONS

The definition of aneurysm complexity varies by treatment modality. Since elements related to complexity differ between open surgery and endovascular treatment, these consensus criteria of CIAs could even guide in selecting the best treatment approach.

Long-Term Follow-Up of Cerebral Aneurysms Completely Occluded at 6 Months After Intervention with the Woven EndoBridge (WEB) Device: a Retrospective Multicenter Observational Study

The Woven EndoBridge (WEB) device has been widely used to treat intracranial wide neck bifurcation aneurysms. Initial studies have demonstrated that approximately 90% of patients have same or improved long-term aneurysm occlusion after the initial 6-month follow up. The aim of this study is to assess the long-term follow-up in aneurysms that have achieved complete occlusion at 6 months. We also compared the predictive value of different imaging modalities used. This is an analysis of a prospectively maintained database across 13 academic institutions. We included patients with previously untreated cerebral aneurysms embolized using the WEB device who achieved complete occlusion at first follow-up and had available long-term follow-up. A total of 95 patients with a mean age of 61.6 ± 11.9 years were studied. The mean neck diameter and height were 3.9 ± 1.3 mm and 6.0 ± 1.8 mm, respectively. The mean time to first and last follow-up was 5.4 ± 1.8 and 14.1 ± 12.9 months, respectively. Out of all the aneurysms that were completely occluded at 6 months, 84 (90.3%) showed complete occlusion at the final follow-up, and 11(11.5%) patients did not achieve complete occlusion. The positive predictive value (PPV) of complete occlusion at first follow was 88.4%. Importantly, this did not differ between digital subtraction angiography (DSA), magnetic resonance angiography (MRA), or computed tomography angiography (CTA). This study underlines the importance of repeat imaging in patients treated with the WEB device even if complete occlusion is achieved short term. Follow-up can be performed using DSA, MRA or CTA with no difference in positive predictive value.

Comparison of endovascular interventional embolization and microsurgical clipping for ruptured cerebral aneurysms: impact on patient outcomes

OBJECTIVE

To compare the therapeutic efficacy of endovascular interventional embolization and microsurgical clipping in patients with ruptured cerebral aneurysms and investigate their subsequent influence on inflammatory indices, neurological function, prognosis, and recovery.

METHODS

The two groups were compared in terms of surgery duration, hospital stay, Hunt-Hess classification, and inflammatory indices before and after the surgery, as well as National Institutes of Health Stroke Scale (NIHSS), Baethel Index (BI), and one-year prognosis of patients affected.

RESULTS

The surgery duration and hospital stay of the intervention group were (116.27 ± 12.32) min and (19.82 ± 2.26) d, respectively, and those of the clipping group was (173.87 ± 10.39) min and (24.11 ± 2.33) d, respectively (both p < 0.05). Neither the intervention nor the microscopic approach had a significant impact on the severity of the patients' conditions in terms of Hunt-Hess classification (p > 0.05). In the intervention group, CRP was changed to (5.31 ± 1.22) mg/L and PCT decreased to (1.17 ± 0.39) μg/L after the surgery, while the corresponding values in clipping group were (9.78 ± 2.35) mg/L and (2.75 ± 0.81) μg/L (p > 0.05). After surgery, both groups' NIHSS scores declined dramatically, with the intervention group scoring lower than the microscopy group (6.81 ± 1.22 vs 8.72 ± 1.27) (p < 0.05).

CONCLUSION

The findings of this study support the potential advantages of endovascular interventional embolization (coiling) over microsurgical clipping for the management of ruptured cerebral aneurysms. These advantages include shorter surgical duration, reduced hospital stay, lower inflammatory response, improved neurological and functional outcomes, and better long-term prognosis.

Mortality After Microsurgical Treatment of Unruptured Intracranial Aneurysms in the Modern Era

BACKGROUND

The incidence of mortality after treatment of unruptured intracranial aneurysms (UIAs) has been described historically. However, many advances in microsurgical treatment have since emerged, and most available data are outdated. We analyzed the incidence of mortality after microsurgical treatment of patients with UIAs treated in the past decade.

METHODS

The medical records of all patients with UIAs who underwent elective treatment at our large quaternary center from January 1, 2014, to December 31, 2020, were reviewed retrospectively. We analyzed mortality at discharge and 1-year follow-up as the primary outcome using univariate to multivariable progression with P < 0.20 inclusion.

RESULTS

During the 7-year study period, 488 patients (mean [SD] age = 58 [12] years) had UIAs treated microsurgically. Of these patients, 61 (12.5%) had a prior subarachnoid hemorrhage. One patient (0.2%) with a dolichoectatic vertebrobasilar aneurysm died while hospitalized, and 7 other patients (8 total; 1.6%) were determined to have died at 1-year follow-up (1 trauma, 2 myocardial infarction, 2 cerebrovascular accident, 1 pulmonary embolism, and 1 subdural hematoma complicated by abscess). On univariate analysis, significant risk factors for mortality at follow-up included diabetes mellitus, preoperative anticoagulant or antiplatelet use, aneurysm calcification, nonsaccular aneurysm, and higher American Society of Anesthesiologists grades (all P < 0.03). On multivariable logistic regression analysis, only nonsaccular aneurysms and higher American Society of Anesthesiologists grades were predictors of mortality.

CONCLUSIONS

A low mortality rate is associated with recent microsurgical treatment of UIAs. However, nonsaccular aneurysms and higher American Society of Anesthesiologists grades appear to be predictors of mortality.

Endovascular treatment of middle cerebral artery aneurysms: current status and future prospects

Middle cerebral artery (MCA) aneurysms are complex and widely distributed throughout the course of the MCA. Various types of aneurysms can occur in the MCA. Ruptured as well as unruptured MCA aneurysms may require treatment to avoid bleeding or rebleeding. Currently, clipping is regarded as the first-line choice for the treatment of MCA aneurysms. However, endovascular treatment (EVT) is emerging as an alternative treatment in selected cases. EVT techniques vary. Therefore, it is necessary to review EVT for MCA aneurysms. In this review, the following issues were discussed: MCA anatomy and anomalies, classifications of MCA aneurysms, the natural history of MCA aneurysms, EVT status and principle, deployments of traditional coiling techniques and flow diverters (FDs), and deployments and prospects of intrasaccular flow disruptors and stent-like devices. According to the review and our experience, traditional coiling EVT is still the preferred therapy for most MCA aneurysms. FD deployment can be used in selective MCA aneurysms. Parent artery occlusion (PAO) can be used to treat distal MCA aneurysms. In addition, new devices can be used to treat MCA aneurysms, such as intrasaccular flow disruptors and stent-like devices. In general, EVT is gaining popularity as an alternative treatment option; however, there is still a lack of evidence regarding EVT, and longer-term data are not currently available for most EVT devices.

Anterior circulation location-specific results for stent-assisted coiling - carotid versus distal aneurysms: 1-year outcomes from the Neuroform Atlas Stent Pivotal Trial

BACKGROUND

The Neuroform Atlas Stent System is an established treatment modality for unruptured anterior and posterior circulation intracranial aneurysms. Location-specific results are needed to guide treatment decision-making. However, it is unclear whether there are differences in safety and efficacy outcomes between carotid and more distal anterior circulation aneurysms.

METHODS

The ATLAS IDE trial was a prospective, multicenter, single-arm, open-label interventional study that evaluated the safety and efficacy of the Neuroform Atlas Stent System. We compared differences in efficacy and safety outcomes of proximal internal carotid artery (ICA) versus distal and bifurcation anterior circulation aneurysms.

RESULTS

Of 182 cases, there were 70 aneurysms in the ICA and 112 in the distal anterior circulation (including ICA terminus/bifurcation). There were no significant differences in the primary efficacy endpoint (85.5% vs 83.9%, p=0.78) and complete aneurysm occlusion rates (88.7% vs 87.9%, p=0.78) between proximal ICA aneurysms and distal aneurysms, respectively. Complications were more often encountered in distal and bifurcation aneurysms, but the overall rate of major safety events was low and comparable between the two groups (1.4% vs 6.3%, p=0.14). Recanalization and retreatment rates were also similar between the groups.

CONCLUSION

The results of this study suggest that the Neuroform Atlas Stent System is a safe and efficacious treatment modality for unruptured anterior circulation intracranial aneurysms, regardless of aneurysm location.

TRIAL REGISTRATION NUMBER

NCT02340585.

Trends in Ruptured and Unruptured Aneurysmal Treatment from 2010 to 2020: A Focus on Flow Diversion

OBJECTIVE

Flow diverters are a promising new tool in the neurosurgeon's arsenal for aneurysm management. We sought to quantify the trends of flow diversion in comparison to traditional endovascular coiling and surgical clip ligation techniques in the United States from 2010 to 2020 with an emphasis on aneurysm location and preferences in usage for ruptured versus unruptured aneurysms.

METHODS

In this large cross-sectional study, patients aged 18 and older within the MARINER database were analyzed. Descriptive characteristics were calculated for all included patients. χ2 tests were used to compare categorical variables. P values < 0.05 were statistically significant.

RESULTS

A total of 45,542 procedures were conducted in the United States from 2010 to 2020 (clipping: 14,491; coiling: 28,840; flow diversion: 2211). The Southern United States had the largest operative volume across all 3 intervention types, closely followed by the Midwest. Aneurysms of the middle cerebral artery were mostly clipped, whereas coiling and flow diversion techniques were most utilized for anterior communicating and posterior communicating artery aneurysms. Flow diversion is growing most rapidly in the treatment of unruptured aneurysms, though there were also significant increases in usage for ruptured aneurysm treatment from 2019 to 2020.

CONCLUSIONS

Flow diverters have gained significant traction in the treatment for both unruptured and ruptured aneurysms. In the coming years, the indications and use of flow diversion will undoubtedly grow further, but excitement over their application should be tempered by the safety and efficacy data that continues to emerge.

Radiological follow-up of endovascularly treated intracranial aneurysms: a survey of current practice in the UK and Ireland

PURPOSE

Due to the risk of intracranial aneurysm (IA) recurrence and the potential requirement for re-treatment following endovascular treatment (EVT), radiological follow-up of these aneurysms is necessary. There is little evidence to guide the duration and frequency of this follow-up. The aim of this study was to establish the current practice in neurosurgical units in the UK and Ireland.

METHODS

A survey was designed with input from interventional neuroradiologists and neurosurgeons. Neurovascular consultants in each of the 30 neurosurgical units providing a neurovascular service in the UK and Ireland were contacted and asked to respond to questions regarding the follow-up practice for IA treated with EVT in their department.

RESULTS

Responses were obtained from 28/30 (94%) of departments. There was evidence of wide variations in the duration and frequency of follow-up, with a minimum follow-up duration for ruptured IA that varied from 18 months in 5/28 (18%) units to 5 years in 11/28 (39%) of units. Young patient age, previous subarachnoid haemorrhage and incomplete IA occlusion were cited as factors that would prompt more intensive surveillance, although larger and broad-necked IA were not followed-up more closely in the majority of departments.

CONCLUSIONS

There is a wide variation in the radiological follow-up of IA treated with EVT in the UK and Ireland. Further standardisation of this aspect of patient care is likely to be beneficial, but further evidence on the behaviour of IA following EVT is required in order to inform this process.

Treatment of unruptured middle cerebral artery aneurysms: Systematic review in an attempt to perform a network meta-analysis

Objective

Open surgical clipping has been generally considered the best treatment option for unruptured middle cerebral artery aneurysms (uMCAAs). However, this type of aneurysm is being treated endovascularly with the appearance of new devices. We have carried out a systematic review of randomized and quasi-experimental studies to conduct a network meta-analysis (NMA) to assess the safety and efficacy of the different treatment methods currently used in uMCAAs.

Methods

The literature was searched by using PubMed and Google Scholar databases. Eligibility criteria were randomized or quasi-experimental studies including at least five cases per arm and reporting duration of follow-up and number of lost cases. The end points were: angiographic success, final neurological outcome, and the need for retreatments.

Results

We could only analyze four quasi-experimental studies with 398 uMCAAs. All of them compared clipping vs. coiling. Clipping showed better results than coiling in all analyzed end points. We could not conduct the proposed NMA because of the absence of randomized or quasi-experimental studies. Instead, a systematic review is further discussed.

Conclusions

There is an urgent need for comparative studies on the treatment of uMCAAs.

Endovascular therapy versus microsurgical clipping of unruptured wide-neck aneurysms: a prospective multicenter study with propensity score analysis

OBJECTIVE

Numerous techniques have been developed to treat wide-neck aneurysms (WNAs), each with different safety and efficacy profiles. Few studies have compared endovascular therapy (EVT) with microsurgery (MS). The authors' objective was to perform a prospective multicenter study of a WNA registry using rigorous outcome assessments and to compare EVT and MS using propensity score analysis (PSA).

METHODS

Unruptured, saccular, not previously treated WNAs were included. WNA was defined as an aneurysm with a neck width ≥ 4 mm or a dome-to-neck ratio (DTNR) < 2. The primary outcome was modified Rankin Scale (mRS) score at 1 year after treatment (good outcome was defined as mRS score 0-2), as assessed by blinded research nurses and compared with PSA. Angiographic outcome was assessed using the Raymond scale with core laboratory review (adequate occlusion was defined as Raymond scale score 1-2).

RESULTS

The analysis included 224 unruptured aneurysms in the EVT cohort (n = 140) and MS cohort (n = 84). There were no differences in baseline demographic characteristics, such as proportion of patients with good baseline mRS score (94.3% of the EVT cohort vs 94.0% of the MS cohort, p = 0.941). WNA inclusion criteria were similar between cohorts, with the most common being both neck width ≥ 4 mm and DTNR < 2 (50.7% of the EVT cohort vs 50.0% of the MS cohort, p = 0.228). More paraclinoid (32.1% vs 9.5%) and basilar tip (7.1% vs 3.6%) aneurysms were treated with EVT, whereas more middle cerebral artery (13.6% vs 42.9%) and pericallosal (1.4% vs 4.8%) aneurysms were treated with MS (p < 0.001). EVT aneurysms were slightly larger (p = 0.040), and MS aneurysms had a slightly lower mean DTNR (1.4 for the EVT cohort vs 1.3 for the MS cohort, p = 0.010). Within the EVT cohort, 9.3% of patients underwent stand-alone coiling, 17.1% balloon-assisted coiling, 34.3% stent-assisted coiling, 37.1% flow diversion, and 2.1% PulseRider-assisted coiling. Neurological morbidity secondary to a procedural complication was more common in the MS cohort (10.3% vs 1.4%, p = 0.003). One-year mRS scores were assessed for 218 patients (97.3%), and no significantly increased risk of poor clinical outcome was found for the MS cohort (OR 2.17, 95% CI 0.84-5.60, p = 0.110). In an unadjusted direct comparison, more patients in the EVT cohort achieved a good clinical outcome at 1 year (93.4% vs 84.1%, p = 0.048). Final adequate angiographic outcome was superior in the MS cohort (97.6% of the MS cohort vs 86.5% of the EVT cohort, p = 0.007).

CONCLUSIONS

Although the treatments for unruptured WNA had similar clinical outcomes according to PSA, there were fewer complications and superior clinical outcome in the EVT cohort and superior angiographic outcomes in the MS cohort according to the unadjusted analysis. These results may be considered when selecting treatment modalities for patients with unruptured WNAs.

Intrasaccular Flow Disruptor-Assisted Coiling of Intracranial Aneurysms Using the Novel Contour Neurovascular Systems and NEQSTENT: A Single-Center Safety and Feasibility Study

Background: Intrasaccular flow disruptors (IFD) have been introduced in the treatment of intracranial aneurysms (IAs) to overcome the low aneurysm occlusion rate and the high recanalization rate of the coiling technique. Among them, the Contour Neurovascular System (CNS) and the Neqstent (NQS) were designed to reconstruct the aneurysmal neck and both can be used as assisting coiling devices. We aimed to report our preliminary experience with the flow disruptor-assisted coiling (IFD-AC) technique. Methods: We performed a retrospective analysis of prospectively collected data of all patients with IAs treated with the IFD-AC. Results: Between February 2021 and April 2022, we treated 15 IAs with the IFD-AC: 10 ruptured and 5 unruptured. The IFD-AC was successfully performed in 13 cases, with a post-operative RROC 1 in 12 cases (92.3%) and RROC 2 in 1 case (7.7%). There was one ischemic event (6.7%) and no hemorrhagic complications. Twelve patients underwent a mid-term radiologic follow-up: Ten IAs (83.4%) presented an adequate occlusion, while 2 (16.7%) had a recurrence. Conclusions: The IFD-AC, both with the CNS and the NQS, seems a safe technique with promising efficacy profile. The IFD-AC has proved to be safe without antiplatelet therapy in ruptured cases. Further studies are needed to confirm our preliminary results.

Woven EndoBridge versus stent-assisted coil embolization of cerebral bifurcation aneurysms

OBJECTIVE

Stent-assisted coil (SAC) embolization has been the mainstay endovascular treatment for bifurcation aneurysms. The recent introduction of the Woven EndoBridge (WEB) device has presented an alternative endovascular treatment modality for these aneurysms. Direct comparisons of outcomes between these two modalities are limited in the literature. Here, the authors compared the outcomes of bifurcation aneurysms treated with SAC and WEB devices.

METHODS

This retrospective single-center study comprised 148 bifurcation aneurysms that were treated endovascularly with SAC or WEB devices between 2011 and 2019. The primary outcome was complete occlusion of the aneurysm at 6 months on catheter angiography.

RESULTS

The SAC and WEB cohorts comprised 85 and 63 aneurysms, respectively. The baseline characteristics were well balanced after inverse probability weight (IPW) adjustment, except for smoking status. The 6-month complete occlusion rate was higher in the WEB cohort than the SAC cohort (67.4% vs 40.6%; unadjusted OR [95% CI] 3.014 [1.385-6.563], p = 0.005). However, this difference in complete occlusion rates did not remain significant after IPW adjustment and multiple imputations. The neck remnant rate was lower in the WEB cohort than the SAC cohort (20% vs 50%; OR [95% CI] 0.250 [0.107-0.584], p = 0.001), and this difference remained significant after IPW adjustment (OR [95% CI] 0.304 [0.116-0.795], p = 0.015) and multiple imputations.

CONCLUSIONS

Use of SAC and WEB demonstrated comparable 6-month complete occlusion rates for bifurcation aneurysms. WEB appeared to be associated with a lower rate of neck remnant at 6 and 12 months compared with SAC. WEB was also associated with fewer complications and decreased retreatment rates compared with SAC.

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.

Efficacy and safety of endovascular therapy versus surgical clipping for patients with unruptured middle cerebral artery bifurcation aneurysms

This study aims to evaluate the efficacy and safety of endovascular therapy versus neurosurgical clipping carried out for patients with unruptured middle cerebral artery bifurcation aneurysms (MCABAs). Patients diagnosed with MCABAs were enrolled in this prospective study according to the inclusion and exclusion standard. Enrolled patients were divided into a study group (endovascular therapy) and a control group (neurosurgical clipping), with 65 cases in each group. In terms of efficacy, we found that the proportion of Glasgow Outcome Scale (GOS) grade 1 after treatment in the study group was significantly higher than in the control group (p<0.001), while the proportion of GOS grades 2, 3, and 4 after treatment was significantly lower in the study group than in the control group (p<0.05). The postoperative brain injury indicators neuron-specific enolase and S100β in the study group were significantly lower than in the control group (p<0.001), and the postoperative life activity score of patients in the study group was significantly higher than in the control group (p<0.001). In terms of safety, the postoperative hospital stay of patients in the study group was significantly shorter than in the control group (p<0.001), and the incidence rate of postoperative pulmonary and intracranial infections in the study group was significantly lower than in the control group (p<0.05). Endovascular therapy for patients with unruptured MCABAs may be effective in improving outcomes and has better safety profile compared with neurosurgical clipping, but may increase the risk of postoperative recurrence.

Early Exposure of the Dorsal Surface of M1 Segment via the Distal Transsylvian Approach for Clipping of Anteroinferior-Projecting Middle Cerebral Artery Bifurcation Aneurysms

Background Middle cerebral artery bifurcation (MCAB) aneurysms are common intracranial aneurysms. Anteroinferior-projecting MCAB aneurysms, with M1 segment usually embedded into the deep part of the Sylvian fissure, cause some surgical challenges. The distal transsylvian approach (DTSA) allows M1 exposure from the dorsal surface for proximal control in the early step. Therefore, this study aimed to demonstrate the efficacy and safety of DTSA for clipping anteroinferior-projecting MCAB aneurysms.

Methods Among 97 patients with MCA aneurysms, 13 with anteroinferior-projecting MCAB aneurysms who underwent aneurysm clipping via the DTSA between June 2018 and January 2021 were retrospectively evaluated for the aneurysm obliteration rate, surgical complications, and outcomes.

Results Ten patients (76.9%) had ruptured MCAB aneurysms and three (23.1%) had incidentally discovered unruptured MCAB aneurysms. Favorable outcome was achieved in 100% of patients with good grade. The complete aneurysm obliteration rate was 100% without intraoperative lenticulostriate artery injury. Twelve (92.3%) patients had early identified distal M1 segment for proximal control, and one (7.7%) patient had premature rupture of aneurysm that achieved favorable outcome at 3 months postoperatively. Difficult M1 exposure and premature rupture occurred in the patient with MCAB located above the Sylvian fissure line. Permanent postoperative neurological deficit was detected in one patient due to severe vasospasm.

Conclusion DTSA, which simplify the early exposure of the dorsal surface of distal M1, is safe and effective for clipping anteroinferior-projecting MCAB aneurysms without extensive Sylvian fissure dissection. High-positioned MCAB requires careful dissection of the aneurysm neck with consideration of tentative clipping preparation.

Pipeline embolization of proximal middle cerebral artery aneurysms: A multicenter cohort study

BACKGROUND AND PURPOSE

Flow diversion of aneurysms located in the M1 segment and middle cerebral artery bifurcation with Pipeline embolization device is sometimes performed, but further study is needed to support its regular use in aneurysm treatment. Here, we report measures of safety and efficacy for Pipeline embolization in the proximal middle cerebral artery in a multi-center cohort.

MATERIALS AND METHODS

Clinical and angiographic data of eligible patients were retrospectively obtained from participating centers and assessed for key clinical and angiographic outcomes. Additional details were extracted for patients with complications.

RESULTS

In our multi-center cohort, complete aneurysm occlusion was achieved in 71% (17/24) of treated aneurysms. There were no deaths or disabling strokes, but non-disabling ischemic strokes occurred in 8% (2/24) of patients. For aneurysms in the M1 segment, complete aneurysm occlusion was observed in 75% (12/16) of aneurysms, aneurysm volume reduction was observed in 100% (16/16) of aneurysms, and non-disabling ischemic strokes occurred in 13% (2/16) of patients. For aneurysms at the middle cerebral artery bifurcation, complete aneurysm occlusion was observed in 63% (5/8) of aneurysms, aneurysm volume reduction occurred in 88% (7/8) of aneurysms, and ischemic or hemorrhagic complications occurred in 0% (0/8) of patients.

CONCLUSION

Pipeline embolization of cerebral aneurysms in the M1 segment and middle cerebral artery bifurcation demonstrated a 71% rate of complete aneurysm occlusion. There were no deaths or disabling strokes, but there was an 8% rate of non-disabling ischemic strokes.

Middle Cerebral Artery Aneurysm Trial (MCAAT): A randomized care trial comparing surgical and endovascular management of MCA aneurysm patients

BACKGROUND

Whether the best management of middle cerebral artery (MCA) aneurysm patients is surgical or endovascular remains uncertain, with little evidence to guide decision-making. A randomized care trial offering MCA aneurysm patients a 50% chance of surgical and a 50% chance of endovascular management may optimize outcomes in the presence of uncertainty.

METHODS

The Middle Cerebral Artery Aneurysm Trial (MCAAT) is an investigator-initiated, multi-center, parallel group, prospective, 1:1 randomized controlled clinical trial. All adult patients with MCA aneurysms, ruptured or unruptured, amenable to surgical and endovascular treatment can be included. The composite primary outcome is 'Treatment Success': i) occlusion or exclusion of the aneurysm using the allocated treatment modality; ii) no intracranial hemorrhage during follow-up; iii) no retreatment of the target aneurysm during follow-up, iv) no residual aneurysm on angiographic follow-up and v) independence (mRS <3) at 1 year. The trial tests two versions of the same hypothesis (one for ruptured and one for unruptured MCA aneurysm patients): Surgical management will lead to a 15% absolute increase in the proportion of patients reaching Treatment Success from 55% to 70% (ruptured) or from 75% to 90% (unruptured aneurysm patients) compared to endovascular treatment (any method). In this pragmatic trial, outcome evaluations are by treating physicians, except for 1 year angiographic results which will be core lab assessed. The trial will be monitored by an independent data safety monitoring committee to assure safety of participants. MCAAT is registered at clinicaltrials.gov: NCT05161377.

CONCLUSION

Patients with MCA aneurysms can be optimally managed within a care trial protocol.

Endoluminal flow diverting stents for middle cerebral artery bifurcation aneurysms: multicenter cohort

BACKGROUND

Data regarding the safety and efficacy of flow diverting stents (FDS) in the treatment of middle cerebral artery (MCA) bifurcation aneurysms are scarce and limited to small single center series, with particular concern for increased risk of ischemic complications with jailing one of the M2 branches.

METHODS

Prospectively-maintained databases at six North American and European centers were queried for patients harboring MCA bifurcation aneurysms undergoing treatment with FDS (2011-2018). The pertinent clinical and radiographic data were collected and analyzed.

RESULTS

87 patients (median age 60 years, 69% females) harboring 87 aneurysms were included. The majority of aneurysms were unruptured (79%); 75.9% were saccular with a median maximal diameter of 8.5 mm. Radiographic imaging follow-up was available in 88.5% of cases at a median of 16.3 months post-treatment, showing complete occlusion in 59% and near complete occlusion (90-99%) in 18% of aneurysms. The overall rate of ischemic and hemorrhagic complications was 8% and 1.1%, respectively. Symptomatic and permanent complications were encountered in 5.7% and 2.3% of patients respectively, with retreatment pursued in 2.3% of patients. Jailed branch occlusion was detected in 11.5% of cases, with clinical sequelae in 2.3%. Last follow-up modified Rankin Scale of 0-2 was noted in 96.8% of patients. On multivariate analysis, male sex was the only independent predictor of aneurysmal persistence at last follow-up imaging (p=0.019).

CONCLUSION

FDS treatment for MCA bifurcation aneurysms is feasible, with comparable safety and efficacy profiles to other available endovascular options when utilized in carefully selected aneurysms. Jailing of M2 branches was not associated with a higher risk of post-procedural ischemic complications.

Comparison of operating room variables, radiation exposure and implant costs for WEB versus stent assisted coiling for treatment of wide neck bifurcation aneurysms

BACKGROUND

The WEB device offers another option for treating wide neck bifurcation aneurysms (WNBA). The objective was to compare procedure variables, radiation and implant cost between WEB and stent assisted coiling (SAC) for WNBA.

METHODS

A retrospective comparison of similarly sized WNBA treated with SAC or WEB over 5-years was performed. The operating room (arrival-departure), anesthesia (intubation-extubation), procedure duration (puncture-closure), fluoroscopy time and radiation dose(m-Gy) were recorded from the patients' charts. Implant cost per case of all implants (stents, coils, WEB) that were opened whether deployed or not was captured including any coils used in the WEB cases. The implant cost represented the true cost incurred by the institution.

RESULTS

There were 46 WEB and 41 SAC cases with no significant difference in aneurysm size. There were more MCA and ACOMM (p = 0.005) and more ruptured aneurysms (p = 0.02) in the WEB group. Regarding procedure variables (hours:minutes): Operating room time WEB 2:31 (±0:37) versus SAC 3:41 (±0:50) (p < 0.0001); anesthesia duration WEB 2:05 (±0:31) versus SAC 3:13 (±0:51) (p < 0.0001) and procedure duration WEB 1:16 (±0:29) versus SAC 2:09 (±0:46) (p < 0.0001). Regarding radiation: Fluoroscopy time WEB 0:34 (±0:18) versus SAC 1:06 (±0:35) (p < 0.0001) and radiation dose WEB 2392(±1086)m-Gy versus SAC 3442 (±1528)m-Gy (p = 0.0007). The implant cost was $17,028(±$5,527) for the WEB versus $23,813 (±$7,456) for the SAC group (p < 0.0001).

CONCLUSION

The WEB group had significantly shorter operating room, procedure and anesthesia duration compared to the SAC group. The radiation dose and fluoroscopy time was lower for the WEB group. The total implant cost per case was significantly lower for the WEB versus the SAC group.

Identification of Hub Genes Associated with the Pathogenesis of Intracranial Aneurysm via Integrated Bioinformatics Analysis

BACKGROUND

At present, the pathogenesis of intracranial aneurysms (IA) remains unclear, which significantly hinders the development of novel strategies for the clinical treatment. In this study, bioinformatics methods were used to identify the potential hub genes and pathways associated with the pathogenesis of IA.

METHODS

The gene expression datasets of patients with intracranial aneurysm were downloaded from the Gene Expression Database (GEO), and the different data sets were integrated by the robust rank aggregation (RRA) method to identify the differentially expressed genes between patients with intracranial aneurysm and the controls. The functional enrichment analyses of the significant differentially expressed genes (DEGs) were performed and the protein-protein interaction (PPI) network was constructed; thereafter, the hub genes were screened by cytoHubba plug-in of Cytoscape, and finally sequencing dataset GSE122897 was used to verify the hub genes.

RESULTS

The GSE15629, GSE75436, GSE26969, and GSE6551 expression profiles have been included in this study, including 34 intracranial aneurysm samples and 26 control samples. The four datasets obtained 136 significant DEGs (45 up-regulated, 91 down-regulated). Enrichment analysis showed that the extracellular matrix structural constituent and the ECM-receptor interaction were closely related to the occurrence of IA. It was finally determined that eight hub genes associated with the development of IA, including VCAN, COL1A1, COL11A1, COL5A1, COL5A2, POSTN, THBS2, and CDH2.

CONCLUSION

The discovery of potential hub genes and pathways could enhance the understanding of the molecular mechanisms associated with the development of IA. These hub genes may be potential therapeutic targets for the management and new biomarker for the diagnosis of IA.

Neuroform Atlas Stent for Treatment of Middle Cerebral Artery Aneurysms: 1-Year Outcomes From Neuroform Atlas Stent Pivotal Trial

BACKGROUND

Heterogeneous effect of endovascular aneurysm therapy has been observed across different anatomic locations. There is a paucity of data for stent-assisted coiling of middle cerebral artery (MCA) aneurysms.

OBJECTIVE

To present the results of the MCA aneurysm group from the Neuroform Atlas (Stryker Neurovascular) investigational device exemption (IDE) trial.

METHODS

The Atlas IDE trial is a prospective, multicenter, single-arm, open-label study of wide-neck aneurysms (neck ≥ 4 mm or dome-to-neck ratio < 2) in the anterior circulation treated with the Neuroform Atlas Stent and approved coils. Follow-up was obtained immediately postprocedure and 2, 6, and 12 mo postoperatively. We herein describe safety and efficacy outcomes, and functional independence of the subjects with aneurysms from all segments of MCA.

RESULTS

A total of 35 patients were included (27 MCA bifurcation, 5 M1, 3 M2). The mean aneurysm size was 6.0 ± 1.8 mm, and the mean neck was 4.4 ± 1.2 mm. Technical procedural success was achieved in all patients. A total of 26 patients had follow-up digital subtraction angiography available at 12 mo, with 80.8% (21/26) having complete aneurysm occlusion. Twelve-month safety data were collected for 91.4% (32/35), 8.5% (3/35) had primary safety endpoint, all 3 major ischemic strokes. Mortality occurred in 2 patients beyond 30 d unrelated to procedure (1 gallbladder cancer and 1 fentanyl intoxication). At 1 yr, modified Rankin Score was 0 to 2 in 84.4% (27/32), 3 in 9.4%, and 3 patients were missing. Approximately 5.7% (2/35) of patients were retreated at 12 mo.

CONCLUSION

Stent-assisted coiling with the Neuroform Atlas Stent is a viable alternative to clipping for selected MCA aneurysms. Complete aneurysm occlusion rates have improved compared to historical data. Proper case selection can lead to acceptable endovascular results.

Microsurgical Clipping versus Advanced Endovascular Treatment of Unruptured Middle Cerebral Artery Bifurcation Aneurysms After a "Coil-First" Policy

OBJECTIVE

Although intracranial aneurysms are increasingly treated endovascularly, microsurgical clipping has been the standard approach for middle cerebral artery (MCA) aneurysms. We compared microsurgical clipping and state-of-the-art endovascular treatment of unruptured MCA bifurcation aneurysms treated at a neurovascular center following a "coil-first" policy.

METHODS

This single-center study included 148 patients treated for 160 unruptured MCA bifurcation aneurysms. Technical success, complications, clinical outcome, and angiographic results were retrospectively compared.

RESULTS

Microsurgical clipping was performed for 120 MCA aneurysms (75%) and endovascular treatment for 40 (25%; conventional coiling: 8, stent-assisted coiling: 16, balloon-assisted coiling: 3, and flow-disruption: 13). Technical treatment success was higher in the clipping group (100%) than in the endovascular group (92.5%, P = 0.015). Overall, complications occurred in 16.7% for clipping and in 20.0% for endovascular treatment (P = 0.631). Major ischemic stroke rates were 4.2% in the clipping group and 7.5% in the endovascular group (P = 0.414). At 6 months, a favorable outcome was obtained by 99.2% after clipping and 95.0% after endovascular treatment (P = 0.154). The 6-month complete aneurysm occlusion rates were by trend higher in the clipping group (89.2%) than in the endovascular group (75.9%, P = 0.078).

CONCLUSIONS

Microsurgical clipping was associated with a higher technical success rate and tendentially higher complete occlusion than endovascular treatment, with no additional morbidity and similar clinical outcome. On the basis of these results, clipping proves to be the standard treatment option for MCA bifurcation aneurysms. However, endovascular treatment represents a safe and efficient alternative treatment option for patients.

Surgical or Endovascular Management of Middle Cerebral Artery Aneurysms: A Randomized Comparison

OBJECTIVE

There are few randomized data comparing clipping and coiling for middle cerebral artery (MCA) aneurysms. We analyzed results from patients with MCA aneurysms enrolled in the CURES (Collaborative UnRuptured Endovascular vs. Surgery) and ISAT-2 (International Subarachnoid Aneurysm Trial II) randomized trials.

METHODS

Both trials are investigator-led parallel-group 1:1 randomized studies. CURES includes patients with 3-mm to 25-mm unruptured intracranial aneurysms (UIAs), and ISAT-2 includes patients with ruptured aneurysms (RA) for whom uncertainty remains after ISAT. The primary outcome measure of CURES is treatment failure: 1) failure to treat the aneurysm, 2) intracranial hemorrhage during follow-up, or 3) residual aneurysm at 1 year. The primary outcome of ISAT-2 is death or dependency (modified Rankin Scale score >2) at 1 year. One-year angiographic outcomes are systematically recorded.

RESULTS

There were 100 unruptured and 71 ruptured MCA aneurysms. In CURES, 90 patients with UIA have been treated and 10 await treatment. Surgical and endovascular management of unruptured MCA aneurysms led to treatment failure in 3/42 (7%; 95% confidence interval [CI], 0.02-0.19) for clipping and 13/48 (27%; 95% CI, 0.17-0.41) for coiling (P = 0.025). All 71 patients with RA have been treated. In ISAT-2, patients with ruptured MCA aneurysms managed surgically had died or were dependent (modified Rankin Scale score >2) in 7/38 (18%; 95% CI, 0.09-0.33) cases, and 8/33 (24%; 95% CI, 0.13-0.41) for endovascular. One-year imaging results were available in 80 patients with UIA and 62 with RA. Complete aneurysm occlusion was found in 30/40 (75%; 95% CI, 0.60-0.86) patients with UIA allocated clipping, and 14/40 (35%; 95% CI, 0.22-0.50) patients with UIA allocated coiling. Complete aneurysm occlusion was found in 24/34 (71%; 95% CI, 0.54-0.83) patients with RA allocated clipping, and 15/28 (54%; 95% CI, 0.36-0.70) patients with RA allocated coiling.

CONCLUSIONS

Randomized data from 2 trials show that better efficacy may be obtained with surgical management of patients with MCA aneurysms.

The safety and outcomes of acutely ruptured intracranial aneurysms with incomplete occlusion after coiling: a case-control study

BACKGROUND

Incomplete aneurysmal occlusion is a common feature of immediate posttreatment angiography. The safety and outcomes of acutely ruptured intracranial aneurysms (RIAs) with incomplete occlusion after stent-assisted coiling (SAC) and no-stent coiling (NSC) have not been well clarified. Progressive occlusion of stents can promote the complete occlusion of intracranial aneurysms (IAs), but it remains to be determined if progressive occlusion in acutely RIAs with incomplete occlusion after coiling may be enhanced by protective stenting. This study aimed to evaluate the safety and outcomes of those aneurysms after SAC and NSC; And to discover whether the stents can promote progressive aneurysm occlusion in such lesions or not.

METHODS

We reviewed 199 patients with acutely RIAs underwent endovascular coiling and developed incomplete occlusion in the past seven years. The patients' clinical and imaging information were recorded and analyzed. Univariate and multivariate analyses were performed to determine the association of recurrence rate with potential risk factors.

RESULTS

SAC group had wider aneurysms neck (3.471 mm vs 2.830 mm, P = 0.009) and smaller dome-to-neck ratio (1.536 vs 2.111, P = 0.001) than in NSC group. There was no significant difference between the two groups in total procedure-related complications rate (31.7% vs 23.5%, P = 0.195), procedure-related mortality (6.9% vs 2.0%, P = 0.170) and modified Rankin Scale (mRS) score at 6-month follow-up (P > 0.05). However, SAC group had significantly higher ischemic complications rate (21.8% vs 8.2%, P = 0.007) and complete occlusion rate (65.6% vs 48.3%, P = 0.020), and lower recurrence rate (15.6% vs 28.1%, P = 0.042) than NSC group based on 6-month follow-up angiograms. Additionally, Multivariable analysis showed NSC was an independent risk factor for aneurysm recurrence (Odds Ratio [OR]: 4.061; P = 0.018).

CONCLUSIONS

Acutely RIAs with incomplete occlusion after SAC is associated with higher complications rate and mortality, but has an acceptable safety profile and similar clinical outcome compared to NSC, as well as gives patients superior angiography outcome by progressive occlusion of stents.