Endovascular treatment of 300 consecutive middle cerebral artery aneurysms: clinical and radiologic outcomes

Flow Diversion for the Treatment of Middle Cerebral Artery Aneurysms

The invention of flow diverting stents (FDS) is a novel milestone in the field of endovascular aneurysm therapy, promoting physiological healing of the vessel segment contrary to prior deconstructive treatment strategies, such as coiling. The effects of FDS are based on changes in flow patterns, segmental wall stabilization, and the growth of a neointima. Although flow diversion is already well established for cerebral aneurysms in proximal segments, peripheral locations remain challenging. Especially the middle cerebral artery (MCA) with its predominance of non-collateralized perforators and functional end arteries that supply the eloquent areas of the brain is of major concern.The literature was reviewed for flow diversion of the MCA and antiplatelet therapy.Resulting from the special anatomical characteristics of the MCA, FDS implantation in this territory is completely different from the proximal vessel segments. Still, flow diversion represents an effective endovascular strategy, especially in otherwise non-accessible or sufficiently treatable lesions. However, the risk of ischemic adverse events might be increased. Special attention to the individual decision regarding device selection, antiplatelet regimen, and exact definition of the proximal and distal landing zone considering the jailed side branches is essential for a good angiographic and clinical outcome. · MCA aneurysms can be sufficiently treated by FDS.. · The anatomic and hemodynamic characteristics of the MCA result in an increased risk of thromboembolism.. · Individual device selection and antiplatelet regimen are essential for treatment success.. · Schüngel M, Wohlgemuth WA, Elolf E et al. Review: Flow Diversion for the Treatment of Middle Cerebral Artery Aneurysms. Rofo 2025; DOI 10.1055/a-2343-0046.

Microsurgical clipping remains a viable option for the treatment of coilable ruptured middle cerebral artery aneurysms in the endovascular era

Although many institutions increasingly perform endovascular coiling instead of microsurgical clipping as the primary treatment for ruptured aneurysms, there remains ongoing debate regarding the optimal treatment strategy for ruptured middle cerebral artery (MCA) aneurysms. Therefore, we compared the outcomes of clipping and coiling for treating ruptured MCA aneurysms. A total of 155 ruptured MCA aneurysms that were deemed eligible for both clipping and coiling were retrospectively reviewed. We compared patient characteristics, radiological results, clinical outcomes, and perioperative complications between patients who received clipping and those receiving coiling. Furthermore, we analyzed the potential risk factors for perioperative complications that differed between the two groups. 59 (38.1%) aneurysms were treated using coiling, and 96 (61.9%) received clipping. The clipping group showed a significantly higher rate of immediate complete occlusion and a lower rate of neck remnants compared with the coiling group (p = 0.006). These radiological results persisted at the 12-month angiographic follow-up, with a significantly higher complete occlusion rate (p = 0.038) and a lower recanalization rate (p = 0.033) in the clipping group. The clinical outcomes were comparable between the two groups. Patients treated with coiling showed a higher rate of permanent shunting than those treated with clipping (18.6% vs. 8.3%, p = 0.058). Coiling was independently associated with shunt-dependent hydrocephalus in multivariate analysis. Microsurgical clipping provides comparable clinical outcomes, better occlusion, and superior durability for treating ruptured MCA aneurysms compared with endovascular coiling. Therefore, clipping remains a viable option for treating ruptured MCA aneurysms, even in aneurysms suitable for coiling.

Efficacy and safety of endovascular coil embolization for unruptured middle cerebral artery aneurysms: middle-term clinical and imaging outcomes with 3 years mean follow-up periods, a 16-year experience

The anatomical characteristics of middle cerebral artery aneurysms make endovascular treatment difficult. This study evaluated the efficacy and safety of endovascular treatment of unruptured middle cerebral artery aneurysm in preventing rupture. A retrospective review of patients who underwent coil embolization for unruptured middle cerebral artery aneurysm between 2006 and 2022 at Nagoya University Hospital with at least 12 months followed up was conducted. Imaging and clinical outcomes were described using the Raymond classification and the modified Rankin Scale, respectively. Good imaging outcome was defined as complete occlusion or neck remnant and clinical outcome as modified Rankin Scale score of 0-2. Patients were divided into initial and recurrent group based on the number of treatments, pre- and post-stent groups based on when stents became available in Japan. A total of 77 patients (80 with aneurysms) were included in the final analysis. Their average age was 60.3 years, and their average follow-up period was 38 months. Favorable clinical outcomes were achieved for 96.2% among 66 (97.0%) initial and 11 (91.7%) recurrent aneurysms. Furthermore, good imaging outcomes were obtained in 90.0 %, and 5% had permanent symptomatic ischemic complications. The pre-stent group had a significantly higher proportion of patients with narrow-neck aneurysms than the post-stent group. There were no significant differences in terms of imaging and clinical outcomes or complication rates. The present study demonstrated that endovascular treatment of unruptured middle cerebral artery aneurysm was safe and effective in preventing rupture. The wide-neck aneurysm was also well embolized by using adjunctive technique.

Coil embolization of the middle cerebral artery bifurcation aneurysms: Feasibility and durability

OBJECTIVE

To evaluate the feasibility and durability of coil embolization for MCAB aneurysms by analyzing clinical and radiological results.

METHODS

From January of 2008 to June of 2018, we treated a total of 1785 aneurysms using coil embolization. The aneurysms were treated by both coiling and stent-assisted coiling. Among these cases, 223 MCAB aneurysms were analyzed retrospectively. Clinical and radiological assessments were conducted at admission, after treatment, at discharge, and at last clinical follow-up.

RESULTS

Coil embolization was performed on 223 MCAB aneurysms in 217 patients. Peri-procedural ischemic, hemorrhagic, and other complications within 30 days after coil embolization occurred at rates of 8.0 %, 8.0 %, and 2.0 %, respectively, in the ruptured group and at 2.9 %, 1.2 %, and 0 %, respectively, in the unruptured group. The overall morbidity and mortality rates associated with complications were 2.3 % and 2.0 %. The cumulative major recurrence rates were 5.1 % at 12 months, 7.1 % at 18 months, and 11.9 % at three years after coil embolization. The mean follow-up period was 33.27 ± 25.48 months. Independent risk factors for major recurrence after coil embolization for MCAB aneurysms were a ruptured aneurysm, initial incomplete occlusion, the aneurysm size, and the neck size.

CONCLUSION

Coil embolization is a good alternative treatment option for MCAB aneurysms compared to surgical clipping. Considering the risk factors for major recurrence, the follow-up angiography should continue up to three years after coil embolization.

Changes in treatment of intracranial aneurysms during the last decade in a large European neurovascular center

OBJECTIVE

Treatment modality for ruptured and unruptured intracranial aneurysms has shifted during the last two decades from microsurgical treatment towards endovascular treatment. We present how this transition happened in a large European neurovascular center.

METHODS

We conducted a retrospective observational study consecutive patients treated for an unruptured or ruptured intracranial aneurysm at Helsinki University Hospital during 2012-2022. We used Poisson regression analysis to report age-adjusted treatment trends by aneurysm location and rupture status.

RESULTS

A total of 2491 patients with intracranial aneurysms were treated (44% ruptured, 56% unruptured): 1421 (57%) surgically and 1070 (43%) endovascularly. A general trend towards fewer treated aneurysms was noted. The proportion of patients treated surgically decreased from 90% in 2012 to 20% in 2022. The age-adjusted decrease of surgical versus endovascular treatment was 6.9%/year for all aneurysms, 6.8% for ruptured aneurysms, and 6.8% for unruptured aneurysms. The decrease of surgical treatment was most evident in unruptured vertebrobasilar aneurysms (10.8%/year), unruptured communicating artery aneurysms (10.1%/year), ruptured communicating artery aneurysms (10.0%/year), and ruptured internal carotid aneurysms (9.0%/year). There was no change in treatment modality for middle cerebral artery aneurysms, of which 85% were still surgically treated in 2022. A trend towards an increasing size for treated ruptured aneurysms was found (p = 0.033).

CONCLUSION

A significant shift of the treatment modality from surgical to endovascular treatment occurred for all aneurysm locations except for middle cerebral artery aneurysms. Whether this shift has affected long-term safety and patient outcomes should be assessed in the future.

Prognostic Factors for Anterior Cerebral Artery Aneurysms: A Single-Center Series

OBJECTIVE

The aim of the present study is to summarize the characteristics of anterior cerebral artery aneurysms and to explore the prognostic factors of microsurgical clipping treatment for anterior cerebral artery aneurysms.

MATERIALS AND METHODS

A total of 90 anterior cerebral artery aneurysms (ACAAs) are reviewed from January 2000 to July 2019. Patients are categorized into good outcome group and poor outcome group according to Glasgow outcome scale scores. Multiple factors, including clinical characteristics and aneurysms' characteristics, are evaluated to identify the independent risk factors associated with prognosis of ACAAs.

RESULTS

This analysis reveals that in the ACAAs database the number of SAH (P=0.01), high H-H grade (P<0.001) and high Fisher grade (P<0.001) are correlated with prognosis of ACAAs. Finally, age (P=0.007, odds ratio=1.124, 95% CI: 1.033-1.223) and Hunt-Hess (grade III-V, P=0.022, odds ratio =59.77, 95% CI: 1.794-1991.298) are found to be independent risk factors for prognosis.

CONCLUSIONS

The age and high Hunt-Hess grade seem to be important factors affecting the prognosis of ACAAs.

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.

Outflow angle: a risk factor for thromboembolic complications in coil embolisation for treating unruptured middle cerebral artery bifurcation aneurysms

BACKGROUND

Thromboembolic complications are a relevant risk in coil embolisation of cerebral aneurysms. This retrospective study aimed to assess the treatment outcomes of unruptured middle cerebral artery (MCA) bifurcation aneurysms and the predictors for thromboembolic complications based on the aneurysm morphological characteristics. We examined the following three features: inflow angle, outflow angle (OA), and bifurcation angle, formed by the aneurysm and neighbouring blood vessels.

METHODS

A total of 32 MCA bifurcation aneurysms were retrospectively investigated in 32 patients treated consecutively at our institute between April 2008 and March 2019. The predictors for thromboembolic complications were analysed in two groups: patients with and without thromboembolic complications.

RESULTS

Perioperative thromboembolic complications were detected in six patients (18.8%), including two and six intra- and post-procedural thromboembolic complications, respectively; all cases were resolved. Regarding the aneurysms' morphological characteristics, the group with thromboembolic complications showed a significantly smaller OA (55.58° ± 14.05° vs. 86.04° ± 28.58°, P = 0.01) than the group without complications. Multivariate analysis revealed that smoking habits and OA < 70° were significant predictors of thromboembolic complications (smoking habits: P = 0.01, odds ratio [OR]: 6.89, 95% confidence interval [CI]: 3.78-12.62; OA < 70°: P = 0.04, OR: 3.19, 95% CI: 1.52-6.56).

CONCLUSIONS

Our findings indicate significant pre-procedural predictors of thromboembolic complications to consider for safe treatment; clipping should be preferred to coil embolisation in high-risk patients. The method of choice should be considered in each case to allow the safe treatment of unruptured MCA aneurysms.

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.

Endovascular Treatment of Ruptured Middle Cerebral Artery Aneurysms With a Low-Profile Visualized Intraluminal Support Device

Objective: Stenting in ruptured middle cerebral artery (MCA) aneurysms was reported with a high perioperative complication rate. However, the treatment devices and physician's experience have continued to evolve. We performed this retrospective study to evaluate the safety and efficacy of LVIS stent-assisted coiling for ruptured MCA aneurysms.

Methods: Patients with acutely ruptured MCA aneurysms treated between November 2014 and October 2019 were retrospectively reviewed. Clinical and angiographic data of those treated with LVIS stents were collected from a prospectively maintained database.

Results: A total of 40 patients with 40 ruptured MCA aneurysms were enrolled, which comprised 26.3% (40/152) of all the ruptured MCA aneurysms at the same time. All stents were successfully deployed except for one (2.5%), which had a poor stent opening. Ischemic procedure-related complications were encountered in three patients (7.5%). One patient died of complications related to high-grade SAH on admission. Follow-up (mean 15.9 months) angiography was performed for 36 patients, which showed 33 (91.7%) aneurysms were completely occluded, 1 (2.8%) was improved, 1 (2.8%) was stable, and 1 (2.8%) was recanalized. Clinical follow-up (mean 29.6 months) was available for all survived patients, which showed 38 (95.0%) patients had favorable neurologic outcomes (mRS score 0–2), and 2 (5.0%) patients had poor neurologic outcomes.

Conclusion: The use of LVIS stents is feasible, safe, and effective with glycoprotein IIb/IIIa inhibitor for the treatment of ruptured MCA aneurysms in the acute setting. Prospective, multicenter studies with larger sample sizes are still required to further evaluate the safety and long-term efficacy.

Patterns of care for ruptured aneurysms of the middle cerebral artery: analysis of a Swiss national database (Swiss SOS)

OBJECTIVE

The objective of this study was to determine patterns of care and outcomes in ruptured intracranial aneurysms (IAs) of the middle cerebral artery (MCA) in a contemporary national cohort.

METHODS

The authors conducted a retrospective analysis of prospective data from a nationwide multicenter registry of all aneurysmal subarachnoid hemorrhage (aSAH) cases admitted to a tertiary care neurosurgical department in Switzerland in the years 2009-2015 (Swiss Study on Aneurysmal Subarachnoid Hemorrhage [Swiss SOS]). Patterns of care and outcomes at discharge and the 1-year follow-up in MCA aneurysm (MCAA) patients were analyzed and compared with those in a control group of patients with IAs in locations other than the MCA (non-MCAA patients). Independent predictors of a favorable outcome (modified Rankin Scale score ≤ 3) were identified, and their effect size was determined.

RESULTS

Among 1866 consecutive aSAH patients, 413 (22.1%) harbored an MCAA. These MCAA patients presented with higher World Federation of Neurosurgical Societies grades (p = 0.007), showed a higher rate of concomitant intracerebral hemorrhage (ICH; 41.9% vs 16.7%, p < 0.001), and experienced delayed cerebral ischemia (DCI) more frequently (38.9% vs 29.4%, p = 0.001) than non-MCAA patients. After adjustment for confounders, patients with MCAA were as likely as non-MCAA patients to experience DCI (aOR 1.04, 95% CI 0.74-1.45, p = 0.830). Surgical treatment was the dominant treatment modality in MCAA patients and at a significantly higher rate than in non-MCAA patients (81.7% vs 36.7%, p < 0.001). An MCAA location was a strong independent predictor of surgical treatment (aOR 8.49, 95% CI 5.89-12.25, p < 0.001), despite statistical adjustment for variables traditionally associated with surgical treatment, such as (space-occupying) ICH (aOR 1.73, 95% CI 1.23-2.45, p = 0.002). Even though MCAA patients were less likely to die during the acute hospitalization (aOR 0.52, 0.30-0.91, p = 0.022), their rate of a favorable outcome was lower at discharge than that in non-MCAA patients (55.7% vs 63.7%, p = 0.003). At the 1-year follow-up, 68.5% and 69.6% of MCAA and non-MCAA patients, respectively, had a favorable outcome (p = 0.676).

CONCLUSIONS

Microsurgical occlusion remains the predominant treatment choice for about 80% of ruptured MCAAs in a European industrialized country. Although patients with MCAAs presented with worse admission grades and greater rates of concomitant ICH, in-hospital mortality was lower and long-term disability was comparable to those in patients with non-MCAA.

Endovascular Treatment for Middle Cerebral Artery Aneurysms: Single-Center Experience and Review of Literatures

Objective

The efficacy of endovascular treatment for middle cerebral artery (MCA) aneurysms remains controversial. However, recent studies have reported the safety of endovascular treatment for MCA aneurysms. In this study, we studied the efficacy and clinical outcomes of endovascular treatment for MCA aneurysms in our hospital and the morphology and anatomy of MCA aneurysms that were suitable for endovascular treatment.

Methods

We retrospectively analyzed 26 cases of MCA aneurysms which had undergone endovascular treatment at our institution between January 2015 and October 2018. We studied sizes and shapes of the aneurysms, clinical and angiographical outcomes one year after the treatment, and complications in these 26 patients. We also compared the differences in these parameters of the 26 patients with those of 61 other patients who were treated with clipping during the same period.

Results

The median aneurysm size was 6.1 mm (1.8-29.9 mm), with the shapes of the aneurysms irregular in 8, and round in the other 18 cases. Four cases (15.4%) had ruptured aneurysms. All aneurysms were treated with assist techniques; 8 (30.8%) were treated by stent-assisted technique and 18 (69.2%) were treated by balloon-assisted technique and endovascular treatment was successfully performed in all (100%) cases. While the aneurysms were completely obliterated in 22 of them (84.6%), the remaining 4 cases (15.4%) had neck remnants. We observed periprocedural complications in 5 of the 26 (19.2%) aneurysms, all of which were transient and completely recovered during the follow-up period. The efficacy and complication rates were not different from the MCA aneurysms treated with clipping. All MCA aneurysms arising from the M1 trunk were treated with endovascular treatment, and those with a round shape with the axis not deviating from M1 were also treated with endovascular treatment.

Conclusion

Endovascular treatment for MCA aneurysms is safe and effective together with adjunctive techniques such as balloon-assisted technique or stent-assisted technique. Thus, M1 trunk aneurysms and MCA bifurcation aneurysms with a round shape along the same axis of MCA may be good indications for endovascular treatment. However, long-term clinical and angiographical outcomes remain unknown. Thus, further studies are needed to address the existing limitations.

Outcome and Prognostic Factors of Ruptured Middle Cerebral Artery Aneurysms Treated via Endovascular Approach: A Single-Center 11-Year Experience

OBJECTIVE

To investigate outcomes and prognostic factors of ruptured middle cerebral artery (MCA) aneurysms, treated via endovascular approach, with improving treatment materials and techniques.

PATIENTS AND METHODS

A total of 185 consecutive patients, admitted with acutely ruptured MCA aneurysms and treated by endovascular methods between 2006 and 2016, were retrospectively reviewed. Their baseline characteristics, procedure-related complications, and angiographic and clinical outcomes were collected. Univariate analysis and logistic regression analysis were completed to identify any association between procedure-related complications or clinical outcomes and potential risk factors.

RESULTS

Procedure-related complications occurred in 28 patients (15.1%), including aneurysm rebleeding in 7 (3.8%), hematoma expansion in 10 (5.4%), and ischemia in 13 (7.0%) (concurrent hemorrhage and ischemia in 2 patients), which resulted in morbidity/mortality of 7% and 1.4%. Final evaluations indicated that 153 patients (82.7%, 153/185) had a good outcome (modified Rankin Scale score 0-2). Among 120 (69.4%) who underwent angiographic follow-up, 89 (74.2%) were completely occluded and 20/120 (16.7%) were recanalized. Multivariate analysis of clinical outcome indicated that a high preoperative Hunt and Hess grade (IV-V), intrasylvian/intracerebral hematoma, and early period treatment (2006-2013) were associated with unfavorable outcomes.

CONCLUSIONS

Endovascular treatment for patients with ruptured middle cerebral artery aneurysms may offer favorable clinical and angiographic outcomes. With the evolution of treatment materials and updated techniques, treatment complications have become less common than previously reported in literature, and clinical outcomes have been improved in recent years.

Long-term results of middle cerebral artery aneurysm clipping in the Barrow Ruptured Aneurysm Trial

Objective

A direct comparison of endovascular versus microsurgical treatment of ruptured middle cerebral artery (MCA) aneurysms in randomized trials is lacking. As endovascular treatment strategies continue to evolve, the number of reports of endovascular treatment of these lesions is increasing. Herein, the authors report a detailed post hoc analysis of ruptured MCA aneurysms treated by microsurgical clipping from the Barrow Ruptured Aneurysm Trial (BRAT).

Methods

The cases of patients enrolled in the BRAT who underwent microsurgical clipping for a ruptured MCA aneurysm were reviewed. Characteristics of patients and their clinical outcomes and long-term angiographic results were analyzed.

Results

Fifty patients underwent microsurgical clipping of a ruptured MCA aneurysm in the BRAT, including 21 who crossed over from the endovascular treatment arm. Four patients with nonsaccular (e.g., dissecting, fusiform, or blister) aneurysms were excluded, leaving 46 patients for analysis. Most (n = 32; 70%) patients presented with a Hunt and Hess grade II or III subarachnoid hemorrhage, with a high prevalence of intraparenchymal blood (n = 23; 50%), intraventricular blood (n = 21; 46%), or both. At the last follow-up (up to 6 years after treatment), clinical outcomes were good (modified Rankin Scale score 0–2) in 70% (n = 19) of 27 Hunt and Hess grades I–III patients and in 36% (n = 4) of 11 Hunt and Hess grade IV or V patients. There were no instances of rebleeding after the surgical clipping of aneurysms in this series at the time of last clinical follow-up.

Conclusions

Microsurgical clipping of ruptured MCA aneurysms has several advantages over endovascular treatment, including durability over time. The authors report detailed outcome data of patients with ruptured MCA aneurysms who underwent microsurgical clipping as part of a prospective, randomized trial. These results should be used for comparison with future endovascular and surgical series to ensure that the best results are being achieved for patients with ruptured MCA aneurysms.

Endovascular Treatment of Ruptured Middle Cerebral Artery Aneurysms: A Single-Arm Meta-Analysis and Systematic Review

OBJECTIVE

The use of endovascular treatment for ruptured middle cerebral artery (MCA) aneurysms, which have been more likely to be recommended for neurosurgical clipping because of the complex anatomic configuration, remains controversial. In the present study, the angiographic and clinical outcomes of endovascularly treated ruptured MCA aneurysms were systematically reviewed.

METHODS

Online databases, including Cochrane, Medline, Web of Science, and Embase, were retrospectively and systematically searched. The primary outcomes were the immediate complete occlusion rate, mortality, complication-related mortality, and procedure-related complication rate. Meta-analysis was performed using a random or fixed effect model based on heterogeneity.

RESULTS

A total of 14 studies with 1004 ruptured MCA aneurysms were included. The procedure-related mortality rate at discharge was 1.8% (95% confidence interval [CI], 0.9%-2.7%; I² = 0.0%; P = 0.623). The favorable clinical outcome rate at discharge was 65.4% (95% CI, 54.8%-76.0%; I² = 94.2%; P < 0.001) and had progressively increased to 73.2% (95% CI, 59.9%-86.5%; I² = 80.9%; P < 0.001). The overall complication rate was 22.7% (95% CI, 15.1%-30.3%; I² = 75.5%; P < 0.001).

CONCLUSION

Endovascular treatment of MCA aneurysms was related to a high incidence of procedure-related complications but a low rate of procedure-related mortality. The overall angiographic and clinical outcomes were comparable and warrant further investigation comparing clipping versus coiling for ruptured MCA aneurysms.

Meta-Analysis of Clipping versus Coiling for the Treatment of Unruptured Middle Cerebral Artery Aneurysms: Direct Comparison of Procedure-Related Complications

BACKGROUND

Endovascular coiling and surgical clipping are routinely used to treat unruptured middle cerebral artery aneurysms (MCAAs). However, the optimal treatment for unruptured MCAAs is controversial. We aimed to systematically and comprehensively compare the clinical outcomes between endovascular coiling and surgical clipping for the treatment of MCAAs.

METHOD

This meta-analysis retrieved academic articles comparing the clinical outcomes between endovascular coiling and surgical clipping for unruptured MCAAs from the Cochrane Library, Medline, PubMed, and EMBASE databases. The reference articles of the identified studies were carefully reviewed to ensure that all available articles were represented in the study. The meta-analysis was conducted in accordance with the acknowledged the prioritized reported items for systematic review and meta-analysis (PRISMA) guidelines.

RESULTS

A total of 6 studies, which enrolled a total of 789 participants, were included in our analysis. Of these 789 patients with MCAAs, 144 were assigned to an endovascular coiling group, and 645 were assigned to a surgical clipping group. Our results demonstrated that endovascular coiling was associated with a higher rate of retreatment (OR = 104.926; 95% CI: 12.931 to 851.379; P<0.001) and postoperative complications (OR = 3.157; 95% CI: 1.239 to 8.048; P= 0.016) than surgical clipping, especially for postoperative thrombus without infarction (OR = 4.905, 95% CI: 1.097 to 21.933; P = 0.037). Furthermore, surgical clipping was related to a higher rate of complete occlusion (OR = 0.349, 95% CI: 0.140 to 0.872; P = 0.024) and Glasgow Outcome Scale (GOS) ≥4 (OR = 0.250; 95% CI: 0.072 to 0.867; P= 0.029) than endovascular coiling after the operation. However, there was no significant difference in the rate of death, the proportion of patients with modified Rankin Scale (mRS)>2, infarction, or bleeding.

CONCLUSION

Although this study has inherent limitations, surgical clipping of unruptured MCAAs resulted in significantly higher complete aneurysm occlusion and GOS≥4 rates and was associated with a lower incidence of retreatment and complication, especially for postoperative thrombus without infarction. Therefore, the effect induced by surgical clipping of unruptured MCAAs remains superior to that induced by endovascular coiling; surgical clipping should be regarded as the first choice of treatment for unruptured MCAAs.

Endovascular treatment of middle cerebral artery aneurysm with a (LVIS) device: Comparison of LVIS stent and non-LVIS stent

Middle cerebral artery (MCA) aneurysm is a serious medical condition mainly occurring in the proximal and bifurcation tracts. Evidence has indicated that endovascular treatment is an effective surgical method for patients with MCA aneurysm. In the present study, the efficacy of endovascular treatment with low-profile visualized intraluminal support (LVIS) stent for MCA aneurysms was evaluated in comparison with that using a non-LVIS stent device. A total of 92 patients who underwent endovascular treatment of MCA aneurysms with LVIS stent or non-LVIS stent were included in the present study. The clinical presentation, aneurysmal characteristics, technical feasibility, procedural complications, as well as angiographic and clinical follow-up results were analyzed. The computed tomography scan demonstrated that endovascular treatment with LVIS stent markedly reduced pre-operative and intra-operative ruptures. It was indicated that endovascular treatment with LVIS stent resulted in less post-operative symptoms and cases of disability according to the modified Rankin scale score. In conclusion, the present outcomes provide evidence that endovascular treatment with an LVIS stent is an efficient method for the treatment of MCA aneurysm.

Coiling Versus Microsurgical Clipping in the Treatment of Unruptured Middle Cerebral Artery Aneurysms: A Meta-Analysis

BACKGROUND

Open microsurgical clipping of unruptured intracranial aneurysms has long been the gold standard, yet advancements in endovascular coiling techniques have begun to challenge the status quo.

OBJECTIVE

To compare endovascular coiling with microsurgical clipping among adults with unruptured middle cerebral artery aneurysms (MCAA) by conducting a meta-analysis.

METHODS

A systematic search was conducted from January 2011 to October 2015 to update a previous meta-analysis. All studies that reported unruptured MCAA in adults treated by microsurgical clipping or endovascular coiling were included and cumulatively analyzed.

RESULTS

Thirty-seven studies including 3352 patients were included. Using the random-effects model, pooled analysis of 11 studies of microsurgical clipping (626 aneurysms) revealed complete aneurysmal obliteration in 94.2% of cases (95% confidence interval [CI] 87.6%-97.4%). The analysis of 18 studies of endovascular coiling (759 aneurysms) revealed complete obliteration in 53.2% of cases (95% CI: 45.0%-61.1%). Among clipping studies, 22 assessed neurological outcomes (2404 aneurysms), with favorable outcomes in 97.9% (95% CI: 96.8%-98.6%). Among coiling studies, 22 examined neurological outcomes (826 aneurysms), with favorable outcomes in 95.1% (95% CI: 93.1%-96.5%). Results using the fixed-effect models were not materially different.

CONCLUSION

This updated meta-analysis demonstrates that surgical clipping for unruptured MCAA remains highly safe and efficacious. Endovascular treatment for unruptured MCAAs continues to improve in efficacy and safety; yet, it results in lower rates of occlusion.

Treatment of Large and Giant Middle Cerebral Artery Aneurysms: Risk Factors for Unfavorable Outcomes

OBJECTIVE

This study aimed to assess the clinical and radiologic outcomes after neurosurgical treatment of large and giant aneurysms of the middle cerebral artery (MCA). In addition, we aimed to identify risk factors for unfavorable outcomes.

METHODS

This retrospective study included 105 patients with 106 large or giant MCA aneurysms treated with neurosurgical methods, including microsurgery and endovascular treatment, over a 15-year period.

RESULTS

The mean aneurysm size was 15.3 ± 7.1 mm. Ten (9.4%) were giant aneurysms. The MCA bifurcation was the most common aneurysm site, followed by the MCA trunk and distal MCA. Aneurysm clipping was the most common treatment method, followed by clipping or trapping with bypass surgery and endovascular treatment. However, acute cerebral infarction was the most common complication (16.0%), poor outcomes (modified Rankin Scale score, 3-6) developed in 12.3% of aneurysms after treatment, and 6.6% of treated aneurysms needed retreatment. Multivariate analysis showed that independent risk factors for acute cerebral infarction after treatment were aneurysms located on the MCA trunk and 2 or more underlying diseases. Initial presentation with subarachnoid hemorrhage and complications during treatment were independent risk factors for poor outcomes. In addition, endosaccular coiling was an independent risk factor for retreatment.

CONCLUSIONS

Neurosurgical management should be considered a priority for large and giant MCA aneurysms because of the high rupture rate and clinical symptoms. However, treatment outcomes remain unsatisfactory. Therefore, tailored management with consideration of risk factors for unfavorable outcomes should be implemented.

Flow Diversion for the Treatment of MCA Bifurcation Aneurysms-A Single Centre Experience

Background

Intracranial aneurysms located at the bifurcation of the middle cerebral artery (MCA) can often be challenging for the neurointerventionalist. We aimed to evaluate the efficacy and safety of flow diverting stents (FDS) in the treatment of these aneurysms.

Materials and methods

We retrospectively reviewed our prospectively maintained database to collect information for all patients with unruptured saccular bifurcation MCA aneurysms treated with FDS between January 2010 and January 2016. In addition to demographic data, we recorded the location, aneurysm characteristics, previous treatments, number and type of FDS, complications, and clinical and angiographic follow-up.

Results

Our search identified 13 patients (7 males) with an average age of 61.7 years (47–74 years). All patients had a single bifurcation aneurysm of the MCA, and none of the aneurysms were acutely ruptured. The average fundus size of the saccular aneurysms was 3 mm (range 1.5–10 mm). Follow-up studies were available for 12 patients. Based on the most recent follow-up angiograms, six aneurysms (50%) were totally occluded; five aneurysms (41.7%) showed only a small remnant; and one aneurysm (8.3%) remained unchanged. One patient suffered from an ischemic stroke with resultant permanent hemiparesis (mRS 3). In another case, there was an in-stent thrombosis during the intervention, which resolved upon intra-arterial infusion of Eptifibatide (mRS 0). There were no intra-operative vessel or aneurysm ruptures and no mortalities. Angiography of the covered MCA branches showed no change in the caliber or flow of the vessel in six (50%), a reduction in caliber in five (41.7%), and a complete occlusion in one (8.3%). All caliber changes and occlusions of the vessels were asymptomatic.

Conclusion

In our series, 91.7% of treated MCA bifurcation aneurysms were either completely occluded or showed only a small remnant with a good safety profile. Flow diversion of MCA bifurcation aneurysms should be considered as an alternative treatment strategy when microsurgical clipping or alternative endovascular treatment options are not feasible.

Stent-assisted Embolization of a Giant Aneurysm of the Middle Cerebral Artery Using Small and Large Coils (Penumbra Coil 400)

Giant aneurysms have been treated with endovascular approaches like general, balloon-assisted and stent-assisted coiling, and flow diverter stent-assisted techniques. Few cases have been reported to be treated with both normal and large coils. Despite the mass effect, an adequate revascularization has been reported. An initial use of these coils is being reported in the current study. This is a case which has been successfully treated using a stent-assisted coiling with both small and large coils i.e., Penumbra Coil 400 (Penumbra, Inc., Alameda, California). 

Treatment of ruptured middle cerebral artery aneurysms by endovascular approach: a single-center experience

PURPOSE

The optimal treatment modalities of ruptured middle cerebral artery aneurysm are still controversial. The objective of this study is to analyze the outcomes of patients with ruptured middle cerebral artery aneurysms treated by endovascular coiling.

MATERIALS AND METHODS

From October 2011 to October 2015, 67 patients with 71 ruptured middle cerebral artery aneurysms received endovascular coiling in our hospital. We retrospectively reviewed the clinical, radiologic records and outcomes.

RESULTS

Of all the 71 aneurysms (67 patients), 42 were treated by coil embolization merely, 27 by stent-assisted coiling and 2 unruptured aneurysms in patients with bilateral middle cerebral artery aneurysms without receiving treatment. Complete occlusion was achieved in 82.6% (57/69) of all the procedures. Each of incomplete and partial occlusion rates was 8.7% (6/69). Intraoperative rupture of aneurysms occurred in two procedures (2.9%). Thrombogenesis occurred in eight procedures (11.6%). Brain infarction occurred in eight patients (11.9%). Post-operative rebleeding occurred in seven patients (10.4%). Sixty-three patients were followed at a mean follow-up of 8.24 ± 7.16 months. The mortality and good outcome rate were 3.2% and 90.5%, respectively. Aneurysm recurrence occurred in 6 (13.3%) of the 45 aneurysms at a mean follow-up of 8.44 ± 7.83 months.

CONCLUSIONS

Endovascular coiling is effective for patients with ruptured middle cerebral artery aneurysms. Individualized treatment should be assessed by experienced specialist. It is essential to perform randomized large trials to confirm the efficiency of endovascular coiling.

Three-Dimensional Angiographic Evaluation of Middle Cerebral Artery Trunk Aneurysms: Demonstration of the Close Relationship Between the Early Frontal Cortical Branches and Lateral Lenticulostriate Arteries

BACKGROUND

For the treatment planning of a patient with a middle cerebral artery (MCA) trunk aneurysm, understanding the anatomic relationship among the aneurysm, branching vessels, and lenticulostriate arteries (LSAs) is important. We aimed to demonstrate the branching-vessel anatomy related to an MCA trunk aneurysm using 3-dimensional (3D) angiography.

METHODS

We retrospectively reviewed 3D angiographic findings of 64 cases of MCA trunk aneurysms using a 3D workstation with various postprocessing conditions. We classified the aneurysms into 4 groups (early frontal cortical branch [EFCB], early temporal cortical branch [ETCB], LSA, and nonbranching aneurysms) and analyzed the relationship between the branching vessels and the LSAs.

RESULTS

There were 30 EFCB aneurysms, 25 ETCB aneurysms, 7 LSA aneurysms, and 2 nonbranching aneurysms. Twenty-six (86.7%) of the 30 EFCB aneurysms shared common origins and were associated with the LSAs, but none of the 25 ETCB aneurysms were. Three of 24 patients who received clipping for an EFCB aneurysm experienced a postoperative infarction in the LSA territory. In these 3 patients, the LSA originated from the EFCB and was closely related with the aneurysm.

CONCLUSIONS

We have identified a clinically important anatomic relationship between the MCA trunk aneurysm and branching vessels, including the LSAs. EFCB aneurysms show a close relationship with the LSAs. Pretreatment identification of the origin of the LSAs is important to obviate any perforator injury in EFCB aneurysms.

[Aneurysmal subarachnoid haemorrhage: Results after introducing endovascular therapy in a medium-low volume centre]

OBJECTIVE

To evaluate the impact of introducing endovascular therapy for patients with aneurysmal subarachnoid haemorrhage (aSAH) in a medium-low volume centre.

MATERIAL AND METHODS

A retrospective observational study was conducted by comparing the clinical outcome of patients with aSAH before and after introducing endovascular therapy in our centre. The main variables analysed were: type of treatment, hospital and late mortality, intra-procedural morbidity, rate of re-bleeding and vasospasm, and clinical outcome according to the Glasgow Outcome Score (GOS).

RESULTS

Seventy-one patients were treated in two periods: 2010-2011 (32 patients; 19 clipped, 6 coiled, 7 untreated), and 2012-2013 (39 patients, 3 clipped, 34 coiled, 2 untreated). No significant differences were found in age, sex, clinical grade at admission, type and location of aneurysm, Fisher score, or in hospital mortality (28.1% vs 25.6%, P=.35), GOS (except for GOS 5: 43.37% vs 53.8%, P=.045), rate of hydrocephalus and rate of vasospasm. The second cohort obtained better results for aggregated GOS 1+2+3 (36.3% vs 43.75%, P=.034) and for GOS 4+5 (61.5% vs 56.25%, P=.078). The percentage of patients left untreated was significantly lower in the second period (5.1% vs 21.8%, P<.01), as well as the rate of re-bleeding (0% vs 9.4%, P<.01). Patients were treated earlier (2.51 vs 3.95 days), and hospital and total stay were lower (15.2 and 24.6 vs 10.3 and 18 days) in the second period, these differences not reaching statistical significance.

CONCLUSIONS

Endovascular therapy allowed treating more patients with aSAH, and with a lower re-bleeding rate. This led to a modest reduction in morbidity and mortality.

"Clip first" policy in management of intracranial MCA aneurysms: Single-centre experience with a systematic review of literature

BACKGROUND

The results of microsurgical treatment for middle cerebral artery (MCA) aneurysms (ANs) have been highly satisfying for decades, notoriously posing a challenge for interventional neuroradiologists. Following the International Subarachnoid Aneurysm Trial (ISAT) study results, most centres across Europe and the USA switched to a "coil first" policy. The purpose of this study is to evaluate and critically review the substantiation of this change.

METHODS

The authors conducted a single-institution retrospective study of MCA AN treatment between January 2000 and December 2013 maintaining a "clip first" policy. The results are supplied with a literature review.

RESULTS

A total of 315 MCA ANs were treated in 288 consecutive patients (209 females, 79 males). Microsurgical treatment was performed for 238 AN patients (116 ruptured, 122 unruptured) and 77 AN patients (46 ruptured, 31 unruptured) who underwent a coiling procedure. Treatment-related morbidity and mortality (MM) for unruptured ANs was 2.8 % in the microsurgical group and 10.3 % in the endovascular group. The percentage of patients with no/minor permanent neurological deficits after SAH in a good initial clinical state (HH 1-2) was 93 % in the microsurgical and 76 % in the endovascular group. A literature review identified 21 studies concerning MCA AN treatment with a specified decision-making algorithm. Microsurgery seemed superior to endovascular management regarding both clinical and radiological outcomes, although several aspects of the analysed reports might appear questionable.

CONCLUSION

Although this study has its inherent limitations, the effect brought about by microsurgical clipping of MCA ANs remains superior to that of endovascular embolisation and it should be sustained as the first treatment choice. The decision about the treatment strategy should be made by a multi-disciplinary team consisting of specialists from both teams, bearing in mind the higher occlusion rate and longevity of the surgical treatment.

Improvement in patient outcomes following endovascular treatment of WFNS grade V subarachnoid haemorrhage from 2000 to 2014

Patient outcomes following grade V subarachnoid haemorrhage (SAH) have been dismal, although they may have improved following recent technological advances in endovascular treatment (EVT). A single-centre, retrospective study was conducted to evaluate whether outcomes have improved from 2000 to 2014 for patients with World Federation of Neurosurgical Societies (WFNS) grade V SAH. Coiling has been the preferred first-line treatment for grade V SAH patients in our institution since 2000. Patients who underwent EVT (n=115) were grouped on the basis of their hospital admission year: 2000-2004 (n=44), 2005-2009 (n=37) and 2010-2014 (n=34). Patient demographics, outcomes and in-hospital mortality rates were compared between the groups. Patient outcomes at discharge were evaluated using the Glasgow Outcome Scale (GOS), with GOS scores of 4-5 defined as favourable outcomes. There were no significant intergroup differences in patient demographics. In addition, there were no significant differences in the frequencies of favourable outcomes (14% in 2000-2004, 16% in 2005-2009 and 26% in 2010-2014). Mortality rates were 52% in 2000-2004, 43% in 2005-2009 and 24% in 2010-2014, with a significantly lower mortality rate in 2010-2014 than in 2000-2004 (p=0.01). Both perioperative rebleeding and delayed cerebral ischaemia decreased over time; however, multivariate regression analysis showed that the former contributed more to the decrease in mortality. Age was the only variable associated with favourable outcomes. The results of this study indicate that EVT is an appropriate therapeutic option for grade V SAH patients. However, multi-centre, prospective trials are required to provide evidence-based verification of the efficacy of EVT.

Validity of the Meyer Scale for Assessment of Coiled Aneurysms and Aneurysm Recurrence

BACKGROUND AND PURPOSE

Both the Meyer and Raymond scales are commonly used to report angiographic outcomes following coil embolization of intracranial aneurysms. The objectives of this study were the following: 1) to assess the interobserver agreement of the Meyer and Raymond scales, and 2) to evaluate and compare their performance in predicting major recurrence at follow-up.

MATERIALS AND METHODS

A retrospective series of 120 coiled aneurysms was included. Four investigators independently graded DSA images immediately posttreatment and at follow-up according to the Meyer and Raymond scales. On follow-up DSA, readers also evaluated recurrence outcome. Interobserver agreement was assessed via the intraclass correlation coefficient. The ability of posttreatment Meyer and Raymond scales to predict major recurrence was modeled by using logistic regression and assessed by using receiver operating characteristic analysis.

RESULTS

For the Meyer scale, interobserver intraclass correlation coefficients were 0.58 (95% CI, 0.46-0.68) on posttreatment and 0.78 (95% CI, 0.72-0.83) on follow-up evaluations. For the Raymond scale, interobserver intraclass correlation coefficients were 0.50 (95% CI, 0.39-0.61) and 0.69 (95% CI, 0.62-0.76), respectively, for posttreatment and follow-up. The areas under the curve for the receiver operating characteristic analyses regarding the performance to predict major recurrence at follow-up were 0.69 (95% CI, 0.60-0.79) for the Meyer and 0.70 (95% CI, 0.61-0.78) for the Raymond scale.

CONCLUSIONS

The Meyer scale appears consistent and reliable with observer agreement as high or higher than that of the Raymond scale. Performance of both scales in predicting the risk of major recurrence at follow-up is adequate, with no statistical difference between the scales.