Outcome for unruptured middle cerebral artery aneurysm treatment: surgical and endovascular approach in a single center

Systematic Review and Meta-Analysis of Endovascular Therapy Effectiveness for Unruptured Saccular Intracranial Aneurysms

Background

Currently, endovascular treatment of intracranial aneurysms (ICAs) is limited by low complete occlusion rates. The advent of novel endovascular technology has expanded the applicability of endovascular therapy; however, the superiority of novel embolic devices over the traditional Guglielmi detachable coils (GDCs) is still debated. We performed a systematic review of literature that reported Raymond-Roy occlusion classification (RROC) rates of modern endovascular devices to determine their immediate and follow-up occlusion effectiveness for the treatment of unruptured saccular ICAs.

Methods

A search was conducted using electronic databases (PUBMED, Cochrane, ClinicalTrials.gov, Web of Science). We retrieved studies published between 2000-2022 reporting immediate and follow-up RROC rates of subjects treated with different endovascular ICA therapies. We extracted demographic information of the treated patients and their reported angiographic RROC rates.

Results

A total of 80 studies from 15 countries were included for data extraction. RROC rates determined from angiogram were obtained for 21,331 patients (72.5% females, pooled mean age: 58.2 (95% CI: 56.8-59.6), harboring 22,791 aneurysms. The most frequent aneurysm locations were the internal carotid artery (46.4%, 95% CI: 41.9%-50.9%), the anterior communicating artery (26.4%, 95% CI: 22.5%-30.8%), the middle cerebral artery (24.5%, 95% CI:19.2%-30.8%) and the basilar tip (14.4%, 95% CI:11.3%-18.3%). The complete occlusion probability (RROC-I) was analyzed for GDCs, the Woven EndoBridge (WEB), and flow diverters. The RROC-I rate was the highest in balloon-assisted coiling (73.9%, 95% CI: 65.0%-81.2%) and the lowest in the WEB (27.8%, 95% CI:13.2%-49.2%). The follow-up RROC-I probability was homogenous in all analyzed devices.

Conclusions

We observed that the coil-based endovascular therapy provides acceptable rates of complete occlusion, and these rates are improved in balloon-assisted coils. Out of the analyzed devices, the WEB exhibited the shortest time to achieve >90% probability of follow-up complete occlusion (~18 months). Overall, the GDCs remain the gold standard for endovascular treatment of unruptured saccular aneurysms.

Long-term outcomes of surgical clipping of saccular middle cerebral artery aneurysms: a consecutive series of 92 patients

Despite advances in endovascular treatment, microsurgical clipping of middle cerebral artery (MCA) aneurysms remains appropriate. We review the high occlusion rate and treatment durability seen with surgical clipping of MCA aneurysms. We retrospectively reviewed patients who underwent microsurgical clipping of saccular MCA aneurysms by a single surgeon. Outcomes included aneurysm occlusion rate and durability, modified Rankin scale (mRS), and postoperative neurological morbidities. Ninety-two patients with 92 saccular MCA aneurysms were included, 50% of which were ruptured aneurysms. The mean follow-up period was 59 months. Complete aneurysm occlusion was achieved in all except one patient (99%) with near-complete occlusion. MCA aneurysm clipping was durable, with only one patient (1%) requiring retreatment after 4 years due to regrowth. Of the cohort, 79.3% achieved mRS 0-2 at last follow-up, including all with unruptured aneurysms. Poor outcome at discharge was associated with age > 65 (p = .03), postoperative neurological morbidities (p = .006), and aneurysm rupture (p < .001). Older age remained the single correlate for poor long-term outcome (p = .04). For ruptured aneurysms, predictors of poor long-term outcome included hemiparesis on presentation (p = .017), clinical vasospasm requiring treatment (p = .026), and infarction related to vasospasm (p = .041). Older age (p = .046) and complex anatomy (p = .036) were predictors of new postoperative neurological morbidities in the unruptured group. MCA aneurysm clipping is safe, durable, and should be considered first-line treatment for patients with saccular MCA aneurysms, especially in centers with abundant surgical experience.

Microsurgical clipping and endovascular intervention for middle cerebral artery aneurysm: A meta-analysis

BACKGROUND

The purpose of this study is to compare the prognosis and effective rate of interventional embolization and surgical clipping in the treatment of middle cerebral artery aneurysms, to provide evidence-based basis for the selection of clinical treatment.

METHODS

By searching PubMed, Cochrane library, Medline, Embase and other databases, we collected the related studies interventional embolization and surgical clipping in the treatment of middle cerebral artery aneurysms, whether it was a randomized controlled trial or not. According to the relevant inclusion and exclusion criteria, 2 researchers independently screened and extracted the relevant data. Quality of life, residual neck and recurrence rate, incidence of ischemic cerebral infarction, intracranial infection rate, incidence of vasospasm and rebleeding rate were measured. Revman5.4 software was used for Meta-analysis.

RESULTS

There were 3658 patients included in 30 literatures, including 1478 patients treated with interventional embolization and 2180 patients treated with surgical clipping. The rate of low quality of life (odds ratio [OR] = 1.68, 95% confidence interval [CI]: 1.36-2.07, P < .00001) and intracranial infection rate (OR = 8.79,95% CI: 4.47-17.27, P < .00001) in the interventional embolization group were lower than those in the surgical clipping group. The postoperative rebleeding rate (OR = 0.46, 95% CI: 0.29-0.73, P = .0009), residual neck and recurrence rate (OR = 0.32, 95% CI: 0.24-0.43, P < .00001) in the interventional embolization group were higher than those in the surgical clipping group. The heterogeneity of residual neck and recurrence rate were high, so subgroup analysis was performed. We divide them into short-term group (OR = 0.68, 95% CI: 0.40-1.13, P = .13) and long-term group (OR = 0.23, 95% CI: 0.16-0.33, P < .00001). The results showed that the residual neck and recurrence rate in the interventional embolization group were higher than those in the surgical clipping group. There was no significant difference in the incidence of cerebral vasospasm (OR = 1.09, 95% CI: 0.64-1.86, P = .74) and ischemic stroke (OR = 0.87, 95% CI: 0.63-1.19, P = .37) between the 2 treatments.

CONCLUSION

According to the current clinical research evidence, compared with interventional embolization in the treatment of middle cerebral artery aneurysms, the quality of life of patients after clipping is lower, the incidence of intracranial infection is higher, but the residual neck, and recurrence rate are reduced. The risk of rebleeding is also reduced. There was no significant difference in the incidence of vasospasm and ischemic stroke between the 2 groups.

Has intraoperative neuromonitoring changed the surgery for unruptured middle cerebral artery aneurysms? A retrospective comparative study

Intraoperative neurophysiological monitoring (IONM) represents one of the available technologies able to assess ischemia and aimed to improve surgical outcome reducing the treatment related morbidity in surgery for intracranial aneurysms. Many studies analyzing the impact of IONM are poised by the heterogeneity bias affecting the cohorts. We report our experience with IONM for surgery of unruptured middle cerebral artery (MCA) aneurysm in order to highlight its influence on functional and radiological outcome and surgical strategy. We retrospectively reviewed all MCA unruptured aneurysms treated between January 2013 and June 2021 by our institutional neurovascular team. Patients were divided into 2 groups according to the use of IONM. A total of 153 patients were included in the study, 52 operated on without IONM and 101 with IONM. The groups did not differ preoperatively regarding clinical status and aneurysm characteristics. Patients operated with IONM had better functional outcomes at discharge as well as at follow-up (p= 0.048, p=0.041) due to lower symptomatic ischemia and better radiological outcome due to lower rate of unexpected aneurysmal remnants (p= 0.0173). The introduction of IONM changed the use of temporary clipping (TeC), increasing its average duration (p= 0.01) improving the safety of dissecting and clipping the aneurysm. IONM in surgery for unruptured MCA aneurysm could improve the efficacy and safety of clipping strategy in the way it showed a role in changing the use of TeC and was associated to the reduction of unexpected aneurysmal remnants' rate and improvement in both short- and long-term patient's outcome.

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.

Procedural complications in patients undergoing microsurgical treatment of unruptured intracranial aneurysms: a single-center experience with 1923 aneurysms

BACKGROUND

With the growing use of endovascular therapy (EVT) to manage unruptured intracranial aneurysms (IAs), detailed information regarding periprocedural complication rates of microsurgical clipping and EVT becomes increasingly important in determining the optimal treatment for individual cases. We report the complication rates associated with open microsurgery in a large series of unruptured IAs and highlight the importance of maintaining surgical skill in the EVT era.

METHODS

We reviewed all cases of unruptured IAs treated with open microsurgery by a single neurosurgeon between July 1997 and June 2019. We analyzed surgical complications, deaths, and patient-reported outcomes.

RESULTS

A total of 1923 unruptured IAs in 1750 patients (mean age 44 [range: 6-84], 62.0% [1085/1750] female) were treated surgically during the study period. Of the aneurysms treated, 84.9% (1632/1923) were small, 11.1% (213/1923) were large, and 4.1% (78/1923) were giant. Aneurysm locations included the middle cerebral artery (44.2% [850/1923]), internal carotid artery (29.1% [560/1923]), anterior cerebral artery (21.0% [404/1923]), and vertebrobasilar system (5.7% [109/1923]). The overall mortality rate was 0.3% (5/1750). Surgical complications occurred in 7.4% (129/1750) of patients, but only 0.4% (7/1750) experienced permanent disability. The majority of patients were able to return to their preoperative lifestyles with no modifications (95.9% [1678/1750]).

CONCLUSIONS

At a high-volume, multidisciplinary center, open microsurgery in carefully selected patients with unruptured IAs yields favorable clinical outcomes with low complication rates. The improvement of EVT techniques and the ability to refer cases for EVT when a high complication rate with open microsurgery was expected have contributed to an overall decrease in surgical complication rates. These results may serve as a useful point of reference for physicians involved in treatment decision-making for patients with unruptured IAs.

Microsurgical and endovascular treatment of un-ruptured cerebral aneurysms by European hybrid neurosurgeons to balance surgical skills and medical staff management

Background

In Europe, aneurysm treatment performed by dually trained neurosurgeons is extremely scarce. We provide outcome data for un-ruptured aneurysm patients treated at a European hybrid center to prove that hybrid neurosurgeons achieve clinical and angiographical results allowing to integrate hybrid neurosurgery into routine aneurysm treatment. This will not only help to maintain neurovascular microsurgical skills but will influence staff costs in related hospitals.

Methods

We retrospectively analyzed all consecutively treated un-ruptured aneurysm patients between 2000 and 2016. The decision-making took into account the pros and cons of both modalities and considered patient and aneurysm characteristics. Clinical outcome was assessed by the modified Rankin scale (mRS). Occlusion rates were stratified into grade I for 100%, grade II for 99–90%, and grade III for <90% occlusion. To account for the introduction of stents, two treatment periods (p1, 2000 to 2008; p2, 2009 to 2016) were defined.

Results

The study population consisted of 274 patients (median age 55 years) harboring 338 un-ruptured aneurysms. Microsurgery (MS) was performed in 51.8% and endovascular therapy (EVT) in 43.1%; 5.1% required combined treatment. Overall, 93% showed a favorable clinical outcome (mRS 0–2), 94.3% after MS and 91.5% after EVT. Grade I aneurysm occlusion was achieved in 82.6% patients, 91.9% after MS and 72.9% after EVT. Procedure-related complications occurred after MS in 5.6% and after EVT in 4.4% patients. Mortality was recorded for five (1.8%) patients, one patient after MS and four after EVT. For the EVT cohort, significant improvement from p1 to p2 was seen with clinical outcomes (P=0.030, RR = 0.905, CI: 0.8351–0.9802) and occlusion rates (P=0.039, RR = 0.6790, CI: 0.499–0.923).

Conclusion

Hybrid neurosurgeons achieve qualified clinical and angiographic results. Dual training will allow to maintain neurovascular caseloads and preserve future aneurysm treatment within neurosurgery. Furthermore economic benefits could be observed in hospital management.

Endovascular coiling versus surgical clipping for the treatment of unruptured cerebral aneurysms: Direct comparison of procedure-related complications

BACKGROUND

Endovascular coiling and surgical clipping are routinely used to treat unruptured cerebral aneurysms (UCAs). However, the evidence to support the efficacy of these approaches is limited. We aimed to analyze the efficacy of endovascular coiling compared with surgical clipping in patients with UCAs.

METHOD

A systematic search of 4 databases was conducted to identify comparative articles involving endovascular coiling and surgical clipping in patients with UCAs. We conducted a meta-analysis using the random-effects model when I> 50%. Otherwise, a meta-analysis using the fixed-effects model was performed.

RESULTS

Our results showed that endovascular coiling was associated with a shorter length of stay (WMD: -4.14, 95% CI: (-5.75, -2.531), P < .001) and a lower incidence of short-term complications compared with surgical clipping (OR: 0.518; 95% CI (0.433, 0.621); P < .001), which seems to be a result of ischemia complications (OR: 0.423; 95% CI (0.317, 0.564); P < .001). However, surgical clipping showed a higher rate of complete occlusion after surgery, in both short-term (OR: 0.179, 95% CI (0.064, 0.499), P = .001) and 1-year follow-ups (OR: 0.307, 95% CI (0.146, 0.646), P = .002), and a lower rate of short-term retreatment (OR: 0.307, 95% CI (0.146, 0.646), P = .002). Meanwhile, there was no significant difference in postoperative death, bleeding, and modified Rankin Scale (mRS) > 2 between the 2 groups.

CONCLUSIONS

The latest evidence illustrates that surgical clipping resulted in lower retreatment rates and was associated with a higher incidence of complete occlusion, while endovascular coiling was associated with shorter LOS and a lower rate of complications, especially ischemia.

Microsurgical treatment of unruptured middle cerebral artery aneurysms: a large, contemporary experience

OBJECTIVE

Advances in endovascular therapy for the treatment of middle cerebral artery (MCA) aneurysms have led to scrutiny of its benefits compared with microsurgical repair. To provide information regarding complication rates and outcomes, the authors reviewed the results of a large series of unruptured MCA aneurysms treated with open microsurgery.

METHODS

The authors included all patients who underwent surgical repair of an unruptured MCA aneurysm between 1997 and 2015. All surgical procedures, including clipping, wrapping, bypass, and parent artery occlusion, were performed by a single neurosurgeon. Aneurysm occlusion was assessed using intraoperative digital subtraction angiography (DSA) or DSA and indocyanine green videoangiography in all cases. Postoperatively, all patients were monitored in a neurointensive care unit overnight. Clinical follow-up was scheduled for 2-4 weeks after surgery, and angiographic follow-up was performed in those patients with subtotally occluded aneurysms at 1, 2, and 5 years postoperation.

RESULTS

The authors treated 750 unruptured MCA aneurysms in 716 patients: 649 (86.5%) aneurysms were small, 75 (10.0%) were large, and 26 (3.5%) were giant. Most aneurysms (n = 677, 90%) were treated by primary clip reconstruction. The surgical morbidity rate was 2.8%, and the mortality rate was 0%. Complete angiographic aneurysm occlusion was achieved in 92.0% of aneurysms. At final follow-up, 713 patients had a modified Rankin Scale (mRS) score of 0, 2 patients had an mRS score of 2 or 3, and 1 had an mRS score of 4.

CONCLUSIONS

In high-volume centers, microsurgical management of MCA aneurysms can be performed with very low morbidity rates. Currently, microsurgical repair appears to be a highly effective method of treating MCA aneurysms.

Relative health-related quality of life after treatment of unruptured intracranial aneurysms: long-term outcomes and influencing factors

Health-related quality of life (HRQOL) is an important clinical outcome parameter. Its analysis is particularly meaningful to patients with minor functional impairment. The main goal of this study was to assess long-term data of HRQOL and their variables for patients undergoing treatment for unruptured intracranial aneurysms (UIAs). Therefore, a cross-sectional study of HRQOL (SF-36 questionnaire) was conducted in patients treated for UIA using a telephone survey assessing numerous medical and sociodemographic variables. A total of 96 patients with a follow up longer than 36 months post-treatment were included. HRQOL results were compared with the German reference population. Uni- and multivariate analyses were performed to detect variables with an impact on outcome. After a mean follow up of 57.75 ± 13.56 months, patients with treated UIAs showed a significant decrease in the mental health domains ‘role emotional’ and ‘social functioning’ and the ‘mental health component score’ (MHCS) compared with the age- and sex-matched reference population. Overall, 47% of the patients showed a clinically and psychosocially relevant decrease compared with the mean MHCS of the reference population. Multivariate analysis suggests that mainly the treatment modality (coiling versus clipping) and additional remaining untreated UIAs negatively impacted mental HRQOL. In conclusion, the partly significant losses in HRQOL identify the necessity for less-wearing treatment strategies and a better prediction of risk of UIA rupture. Our results indicate that certain factors in the guidance and management of patients undergoing endovascular treatment may negatively affect their mental HRQOL. The relevance of additional UIAs remaining untreated on HRQOL is a new finding that should be considered in the counseling of patients with multiple UIAs.

Procedural Clinical Complications, Case-Fatality Risks, and Risk Factors in Endovascular and Neurosurgical Treatment of Unruptured Intracranial Aneurysms: A Systematic Review and Meta-analysis

Importance

The risk of procedural clinical complications and the case-fatality rate (CFR) from preventive treatment of unruptured intracranial aneurysms varies between studies and may depend on treatment modality and risk factors.

Objective

To assess current procedural clinical 30-day complications and the CFR from endovascular treatment (EVT) and neurosurgical treatment (NST) of unruptured intracranial aneurysms and risk factors of clinical complications.

Data Sources

We searched PubMed, Excerpta Medica Database, and the Cochrane Database for studies published between January 1, 2011, and January 1, 2017.

Study Selection

Studies reporting on clinical complications, the CFR, and risk factors, including 50 patients or more undergoing EVT or NST for saccular unruptured intracranial aneurysms after January 1, 2000, were eligible.

Data Extraction and Synthesis

Per treatment modality, we analyzed clinical complication risk and the CFR with mixed-effects logistic regression models for dichotomous data. For studies reporting data on complication risk factors, we obtained risk ratios (RRs) or odds ratios (ORs) with 95% CIs and pooled risk estimates with weighted random-effects models.

Main Outcomes and Measures

Clinical complications within 30 days and the CFR.

Results

We included 114 studies (106 433 patients with 108 263 aneurysms). For EVT (74 studies), the pooled clinical complication risk was 4.96% (95% CI, 4.00%-6.12%), and the CFR was 0.30% (95% CI, 0.20%-0.40%). Factors associated with complications from EVT were female sex (pooled OR, 1.06 [95% CI, 1.01-1.11]), diabetes (OR, 1.81 [95% CI, 1.05-3.13]), hyperlipidemia (OR, 1.76 [95% CI, 1.3-2.37]), cardiac comorbidity (OR, 2.27 [95% CI, 1.53-3.37]), wide aneurysm neck (>4 mm or dome-to-neck ratio >1.5; OR, 1.71 [95% CI, 1.38-2.11]), posterior circulation aneurysm (OR, 1.42 [95% CI, 1.15-1.74]), stent-assisted coiling (OR, 1.82 [95% CI, 1.16-2.85]), and stenting (OR, 3.43 [95% CI, 1.45-8.09]). For NST (54 studies), the pooled complication risk was 8.34% (95% CI, 6.25%-11.10%) and the CFR was 0.10% (95% CI, 0.00%-0.20%). Factors associated with complications from NST were age (OR per year increase, 1.02 [95% CI, 1.01-1.02]), female sex (OR, 0.43 [95% CI, 0.32-0.85]), coagulopathy (OR, 2.14 [95% CI, 1.13-4.06]), use of anticoagulation (OR, 6.36 [95% CI, 2.55-15.85]), smoking (OR, 1.95 [95% CI, 1.36-2.79]), hypertension (OR, 1.45 [95% CI, 1.03-2.03]), diabetes (OR, 2.38 [95% CI, 1.54-3.67]), congestive heart failure (OR, 2.71 [95% CI, 1.57-4.69]), posterior aneurysm location (OR, 7.25 [95% CI, 3.70-14.20]), and aneurysm calcification (OR, 2.89 [95% CI, 1.35-6.18]).

Conclusions and Relevance

This study identifies risk factors for procedural complications. Large data sets with individual patient data are needed to develop and validate prediction scores for absolute complication risks and CFRs from EVT and NST modalities.

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.

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.

Monolateral Pterional Keyhole Approaches to Bilateral Cerebral Aneurysms: Anatomy and Clinical Application

OBJECTIVE

To study the anatomy and clinical application of monolateral pterional keyhole approaches for treating bilateral cerebral aneurysms.

METHODS

Twelve formalin-fixed cadaveric heads underwent right pterional keyhole approaches for management of simulative contralateral aneurysms. The length of the contralateral middle cerebral artery (MCA), distal internal carotid artery (DICA), anterior cerebral artery, and ophthalmic segment of the internal carotid artery (OICA) was recorded. The operability of contralateral aneurysms was assessed using a modified numeric grading system. A total of 16 patients (12 patients with ruptured aneurysms) with bilateral cerebral aneurysms undergoing contralateral pterional keyhole approaches were included.

RESULTS

The contralateral A1 segment of the anterior cerebral artery, proximal A2 segment, M1 segment of the MCA, DICA, and OICA was exposed via pterional keyhole approaches. An additional 2 mm of the OICA was exposed after incision of the falciform dural fold was completed. Contralateral aneurysms of the M1 segment (posterior), M2 segment, MCA bifurcation (inferior), A2 segment (lateral), DICA (posterior and lateral), and OICA (superior, inferior, and lateral) could not be fully exposed to perform simulated surgical clipping (operability rate <75%). A total of 36 aneurysms underwent adequate surgical clipping via unilateral pterional keyhole approaches, whereas 1 aneurysm of the A3 segment did not.

CONCLUSIONS

Contralateral aneurysms of the M1 segment (anterior, superior, and inferior), MCA bifurcation (superior and lateral), A1 segment, A2 segment (anterior, posterior, and medial), internal carotid artery bifurcation, DICA (anterior and medial), and OICA (medial) were fully exposed from different angles and surgical maneuvers were performed via pterional keyhole approaches, including in patients presenting with subarachnoid hemorrhage.

Risk factors for angiographic recurrence after treatment of unruptured intracranial aneurysms: Outcomes from a series of 178 unruptured aneurysms treated by regular coiling or surgery

BACKGROUND

Long-term stability after intracranial aneurysm exclusion by coiling is still a matter of debate; after surgical clipping little is known.

OBJECTIVE

To study outcome after endovascular and surgical treatments for unruptured intracranial aneurysms in terms of short- and long-term angiographic exclusion and risk factors for recanalization.

METHODS

From 2004 and 2009, patients treated for unruptured berry intracranial aneurysms by coiling or clipping were reviewed. Aneurysmal exclusion was evaluated using the Roy-Raymond grading scale; immediate clinical outcome was also assessed. Clinical outcome, recanalization, risk factors for recurrence and bleeding during the follow-up period were analyzed by groups; "surgery" and "embolization".

RESULTS

From 2004 to 2009, 178 consecutive unruptured aneurysms were treated. The post-procedure angiographic results for "surgery" were: total exclusion 75.6%; residual neck 13.5%; residual aneurysm 10.8%. For "embolization", the results were, respectively: 72%; 20.7%; and 7.2%. Morbidity was 3% for "surgery" and 1.6% for "embolization" (P=0.74); mortality was nil. Mean clinical and angiographic follow-up was 5years. Recurrence rate was of 11.5% for "surgery" vs. 44% for "embolization" with a mean follow-up of 4 and 5.75years, respectively (P=1.10-5). The retreatment rate was 8.4%. Two significant risk factors for recanalization were identified: maximum diameter of the aneurysm sac (P=0.0038) and pericallosal location (P=0.0388). No bleeding event occurred.

CONCLUSION

Both techniques are safe. The rate of aneurismal recurrence was significantly higher for embolization, especially for large diameter aneurysms and pericallosal locations. No bleeding event occurred after recanalization.

Analysis of endovascular treatment of ruptured aneurysms of the middle cerebral artery compared to other anatomical locations

OBJECTIVE

The objective of this article is to compare the results of endovascular treatment of ruptured middle cerebral artery (MCA) aneurysms with ruptured aneurysms of other anatomic locations.

METHODS

Fifty consecutive ruptured aneurysms of the MCA and 209 aneurysms at other anatomical locations were selected retrospectively. We compared epidemiological, clinical and radiological variables, prognosis and complications.

RESULTS

The MCA aneurysms had a greater size and a poor dome/neck ratio. There were no significant differences in endovascular technique complications, occlusion rate or rebleeding between the two groups (p > 0.1). There were no significant differences in the mortality and number of dependent patients after one month.

CONCLUSION

The endovascular treatment of ruptured MCA aneurysms without hematoma is as safe and effective as other aneurysm localizations. Complication rates, occlusion rates and rebleeding of ruptured MCA aneurysms are comparable to other locations.

Factors for Achieving Safe and Complete Treatment for Unruptured Saccular Aneurysm Smaller Than 10 mm by Simple Clipping or Simple Coil Embolization

OBJECTIVE

Reducing complications from unruptured aneurysms (UAs) treatment is important. We clarify the criteria for achieving safe and complete treatment for UAs ≤10 mm by clipping or coil embolization.

METHODS

This study included 59 newly treated UAs in the past 2 years. We prospectively decided on criteria to recommend active treatment. UAs ≤10 mm and in ≤75 year-olds, located at in the internal carotid artery at the paraclinoid portion and the posterior circulation aneurysms except for a vertebral artery-inferior posterior cerebellar artery aneurysm were mainly treated by coil embolization, and those in the internal carotid artery except at the paraclinoid portion, in the anterior or middle cerebral artery, and in the vertebral artery-inferior posterior cerebellar artery were treated preferably by clipping. UAs with a height/neck ratio or a dome/neck ratio ≤1.4 were treated preferentially by clipping. Specific preoperative imaging and careful manipulation were adopted for clipping.

RESULTS

Fifty-seven (96.6%) achieved modified Rankin scale (mRS) 0-1, 2 (3.4%) mRS 2-5, and 0 had mRS 6. Fifty-three UAs (89.8%) achieved complete occlusion (CO) and 7 (10.1%) had neck remnants (NR). Forty-one UAs (100%) within the criteria achieved mRS 0-1, 40 (98%) achieved CO, and 1 (2%) NR. The odds ratio of NR for those outside the criteria was 18.5 (95% confidence interval, 1.83-186.6) (P < 0.05). CO treated within the criteria was 39 and NR was 1. CO treated outside the criteria was 14 and NR was 5 (P < 0.05). The mRS 0-1 with age ≤75 years was 55 and the mRS 2-6 was 0. The mRS 0-1 with age ≥76 years was 2 and the mRS 2-6 was 2 (P < 0.01).

CONCLUSIONS

The treatment for UAs within the criteria, with the most recent points of concern, can lead to safe and complete results.

Clinical outcome after surgical clipping or endovascular coiling for cerebral aneurysms: a pragmatic meta-analysis of randomized and non-randomized trials with short- and long-term follow-up

BACKGROUND

Two randomized trials have evaluated clipping and coiling in patients with ruptured aneurysms. Aggregated evidence for management of ruptured and unruptured aneurysms is missing.

OBJECTIVE

To conduct a meta-analysis evaluating clinical outcome after aneurysm treatment.

METHODS

PubMed, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov were searched for studies evaluating aneurysm treatment. The primary outcome measure was an independent clinical outcome (modified Rankin scale 0-2, Glasgow Outcome Scale 4-5, or equivalent). Secondary outcomes were poor outcome and mortality. ORs were calculated on an intention-to-treat basis with 95% CIs. Outcome heterogeneity was evaluated with Cochrane's Q test (significance level cut-off value at <0.10) and I² (significance cut-off value >50%) with the Mantel-Haenszel method for dichotomous outcomes. A p value <0.05 was regarded as statistically significant.

RESULTS

Searches yielded 18 802 articles. All titles were assessed, 403 abstracts were evaluated, and 183 full-text articles were read. One-hundred and fifty articles were qualitatively assessed and 85 articles were included in the meta-analysis. Patients treated with coiling (randomized controlled trials (RCTs)) had higher independent outcome at short-term follow-up (OR=0.67, 95% CI 0.57 to 0.79). Independent outcome was favored for coiling at intermediate and long-term follow-up (RCTs and observational studies combined-OR=0.80, 0.68 to 0.94 and OR=0.81, 0.71 to 0.93, respectively). Independent outcome and lower mortality was favored after coiling in unruptured aneurysms (database registry studies) at short-term follow-up (OR=0.34, 0.29 to 0.41 and OR=1.74, 1.52 to 1.98, respectively).

CONCLUSIONS

This meta-analysis evaluating clinical outcome after coiling or clipping for intracranial aneurysms, indicates a higher independent outcome and lower mortality after coiling.

"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.

Contralateral Approach to Bilateral Middle Cerebral Artery Aneurysms: Comparative Study, Angiographic Analysis, and Surgical Results

BACKGROUND

Bilateral aneurysms located between the 2 middle cerebral artery (MCA) bifurcations may be approachable through a single unilateral approach.

OBJECTIVE

To identify anatomic parameters based on imaging that would favor a contralateral approach.

METHODS

From January 1998 to December 2013, we retrospectively identified 173 patients with bilateral intracranial aneurysms. Fifty-one patients had bilateral MCA aneurysms. A total of 38 patients underwent a single craniotomy with a contralateral microsurgical approach (group 1 or contralateral group) and 13 patients underwent bilateral craniotomies (group 2 or bilateral group). For both groups, we analyzed aneurysm characteristics, morphology, size, projections, and distance to the contralateral corridor, as well as surgical time, outcome, and postoperative complications.

RESULTS

All aneurysms approached contralaterally were unruptured and without wall calcifications. Of the contralaterally approached aneurysms, 97% were smaller than 14 mm. The median length of the contralateral A1 was 13.2 mm (range: 6-19.8 mm) and the median length of the contralateral M1 was 14.2 mm (range: 4.6-21 mm). The contralateral group had a good postoperative outcome (modified Rankin Scale 0-3) in 80% of ruptured cases and 86% of unruptured cases. The median surgical time was 120 minutes (range: 75-255 minutes), 43% shorter than the bilateral group.

CONCLUSION

The contralateral approach for bilateral MCA aneurysms in selected patients is feasible in experienced hands, with acceptable morbidity and mortality. The contralateral approach requires a meticulous preoperative analysis of the characteristics of the aneurysms to be clipped and of the anatomic constraints of the microsurgical operative corridor.

ABBREVIATIONS

A1, anterior cerebral artery proximal segmentbMCA, bilateral middle cerebral arteryCTA, computed tomographic angiographyHH, Hunt-Hess scaleIA, intracranial aneurysmsICA, internal carotid arteryICAbif, internal carotid artery bifurcationMCA, middle cerebral arteryM1, middle cerebral artery proximal segmentmRS, modified Rankin ScaleSAH, subarachnoid hemorrhage.