Microsurgical Clipping of Unruptured Middle Cerebral Artery Bifurcation Aneurysms: Incidence of and Risk Factors for Procedure-Related Complications

Predictors of Extended Length of Stay After Treatment of Unruptured Intracranial Aneurysms

BACKGROUND

Despite their asymptomatic occurrence, unruptured intracranial aneurysms (UIAs) account for a significant proportion of hospital charges and healthcare resource utilization in the United States. Hospital length of stay (LOS) is a reimbursement metric utilized to incentivize value-based care. Our study identifies predictors of extended LOS (eLOS) after elective treatment of UIAs.

METHODS

This was a retrospective study of 525 patients who underwent elective treatment of an UIA at a single institution. Data were collected with regard to demographics, clinical presentation, treatment characteristics, and postoperative outcomes. The primary outcome, eLOS, was defined as hospital stay in the upper quartile of the median (≥75th percentile). Univariate and multivariate analyses were performed to identify factors predictive of eLOS in this cohort.

RESULTS

The average age of the cohort was 61.40, standard deviation=11.41. 77.3% of the cohort was female. The median duration of LOS was 2 days (interquartile range: 1-5). 11.6% experienced eLOS (≥5 days). Multivariate logistic regression identified age (OR: 1.04, 95% confidence interval [CI]: 1.01-1.07), coexistent vascular pathology (OR: 21.33, 95% CI: 8.06-56.39), open surgery (OR: 3.93, 95% CI: 1.85-8.34), and postoperative stroke (OR: 11.72, 95% CI: 3.18-43.18) as independent predictors of eLOS.

CONCLUSIONS

Our study identified predictors of eLOS that could help promote risk stratification prior to treatment of UIAs. Future research that identifies predictors of long-term outcomes based on treatment modality could help identify ways to improve healthcare resource utilization in this cohort.

A novel predictor of ischemic complications in the treatment of ruptured middle cerebral artery aneurysms: Neck-branching angle

Objective

The risk factors of procedural cerebral ischemia (CI) in ruptured middle cerebral artery (MCA) aneurysms are unclear. This study proposed the neck-branching angle (NBA), a simple quantitative indicator of the aneurysm neck and branch vessels, and analyzed its usefulness as a predictor of procedural CI in ruptured MCA aneurysms.

Methods

We retrospectively analyzed 128 patients with ruptured saccular MCA aneurysms who underwent surgical or endovascular treatment between January 2014 and June 2021. We defined the NBA as the angle formed by the MCA aneurysm neck and M2 superior or inferior branch vessel line. The superior and inferior NBA were measured on admission via three-dimensional computed tomography angiography on admission. We divided the patients into clipping (106 patients) and coiling (22 patients) groups according to the treatment. Risk factors associated with procedural CI were analyzed in each group.

Results

Both groups showed that an enlarged superior NBA was a significant risk factor for procedural CI (clipping, P < 0.0005; coiling group, P = 0.007). The receiver operating characteristic curve showed the closed thresholds of the superior NBA with procedural CI in both groups (clipping group, 128.5°, sensitivity and specificity of 0.667 and 0.848, respectively; coiling group, 130.9°, sensitivity and specificity of 1 and 0.889, respectively).

Conclusion

The NBA can estimate the procedural risk of ruptured MCA aneurysms. In addition, an enlarged superior NBA is a risk factor for procedural CI in both clipping and coiling techniques.

Improved rates of postoperative ischemia, completeness of aneurysm occlusion and neurological deficits in elective clipping of anterior circulation aneurysms over the past 20 years - association with technical improvements

BACKGROUND/PURPOSE

Several periprocedural adjuncts for elective surgical aneurysm treatment have been introduced over the last 20 years to increase safety and efficacy. Besides the introduction of IONM in the late-1990s, ICG-videoangiography (ICG-VAG) since the mid-2000s and intraoperative CT-angiography/-perfusion (iCT-A/-P) since the mid-2010s are available. We aimed to clarify whether the introduction of ICG-VAG and iCT-A/-P resulted in our department in a stepwise improvement in the rate of radiologically detected postoperative ischemia, complete aneurysm occlusion and postoperative new deficits.

METHODS

Patients undergoing microsurgical clip occlusion for unruptured anterior circulation aneurysms between 2000 and 2019 were included, with ICG-VAG since 2009 and iCT-A/-P (for selected cases) since 2016. Baseline characteristics and treatment-related morbidity/outcome focusing on differences between the three distinct cohorts (cohort-I: pre-ICG-VAG-era, cohort-II: ICG-VAG-era, cohort-III: ICG-VAG&iCT-A/-P-era) were analyzed.

RESULTS

1391 patients were enrolled (n = 74 were excluded), 779 patients were interventionally treated, 538 patients were surgically clipped by a specialized vascular team (cohort-I n = 167, cohort-II n = 284, cohort-III n = 87). Aneurysm size was larger in cohort-I (8.9 vs. 7.5/6.8 mm; p < 0.01) without differences concerning age (mean:55years), gender distribution (m: f = 1:2.6) and aneurysm location (MCA:61%, ICA:18%, ACA/AcomA:21%). There was a stepwise improvement in the rate of radiologically detected postoperative ischemia (16.2vs.12.0vs.8.0%; p = 0.161), complete aneurysm occlusion (68.3vs.83.6vs.91.0%; p < 0.01) and postoperative new deficits (10.8vs.7.7vs.5.7%; p = 0.335) from cohort-I to -III. After a mean follow-up of 12months, a median modified Rankin scale of 0 was achieved in all cohorts.

DISCUSSION

Associated with periprocedural technical achievements, surgical outcome in elective anterior circulation aneurysm surgery has improved in our service during the past 20 years.

Feasibility, Safety, and efficacy of endovascular treatment for M1 hilltop Aneurysms: A retrospective study

OBJECTIVE

This retrospective study aimed to evaluate the feasibility, safety, and efficacy of endovascular treatment (EVT) for M1 hilltop aneurysms, a specific M1 segment subtype located at the highest point of the middle cerebral artery (MCA).

METHODS

The study included 54 patients with M1 hilltop aneurysms who underwent EVT between December 2017 and [end date]. Treatment decisions were based on angiographic findings and patient characteristics. Clinical and radiological data were reviewed, and outcomes were assessed using the Raymond-Roy classification (RRC) and modified Rankin Scale (mRS). Follow-up radiological examinations were conducted at specific intervals.

RESULTS

EVT was successful in all 54 cases. Immediate postprocedural angiograms showed favorable occlusion (RRC I or II) in 59.3% and aneurysm remnants (RRC III) in 40.7%. Procedure-related complications occurred in 7.4% of patients, including thromboembolism and ICA dissection, with no permanent neurological impairment. During a mean 18.2-month follow-up, no neurological deterioration or aneurysmal rupture occurred. Most patients showed stable/improved occlusion on follow-up imaging, with a 14% recurrence rate. Retreatment was required in 2% of cases.

CONCLUSIONS

EVT appears feasible, safe, and effective for treating M1 hilltop aneurysms. It resulted in favorable occlusion and low recurrence/retreatment rates. Neck diameter and stent usage influenced immediate outcomes and recurrence. Larger studies with longer follow-ups are needed to validate these findings further.

Endoscope-assisted microsurgical clipping and reduction of post-clipping cerebral infarction: historical comparison using diffusion-weighted images

Endoscopic assistance for aneurysm clipping and its possible benefits have been suggested in previous studies, but its clinical significance has not been fully elucidated. This study aimed to present the efficacy of endoscopy-assisted clipping in reducing post-clipping cerebral infarction (PCI) and clinical outcomes via a historical comparison of patients in our institution from January 2020 to March 2022. A total of 348 patients were included, 189 of whom underwent endoscope-assisted clipping. The overall incidence of PCI was 10.9% (n = 38); it was 15.7% (n = 25) before applying endoscopic assistance and decreased to 6.9% (n = 13) after endoscope application (p = 0.010). The application of a temporary clip (odds ratio [OR]: 2.673, 95% confidence interval [CI]: 1.291-5.536), history of hypertension (OR: 2.176, 95% CI: 0.897-5.279), history of diabetes mellitus (OR: 2.530, 95% CI: 1.079-5.932), and current smoker (OR: 3.553, 95% CI: 1.288-9.802) were independent risk factors of PCI, whereas endoscopic assistance was an independent inverse risk factor (OR: 0.387, 95% CI: 0.182-0.823). Compared to the location of the unruptured intracranial aneurysms, internal carotid artery aneurysms showed a significant decrease in the incidence of PCI (5.8% vs. 22.9%, p = 0.019). In terms of clinical outcomes, PCI was a significant risk factor for longer admission duration, intensive care unit stay, and poor clinical outcomes. However, endoscopic assistance itself was not a significant risk factor for clinical outcomes on the 45-day modified Rankin Scale. In this study, we noted the clinical significance of endoscope-assisted clipping in preventing PCI. These findings could reduce the incidence of PCI and improve the understanding of its mechanisms of action. However, a larger and longer-term study is required to evaluate the benefits of endoscopy on clinical outcomes.

Necessity of Mandatory Postoperative Intensive Care Unit Management after Clipping Surgery for Unruptured Intracranial Aneurysms

OBJECTIVE

Many neurosurgeons routinely perform postoperative intensive care unit (ICU) management after clipping of unruptured intracranial aneurysms (UIAs). However, whether routine postoperative ICU care is necessary remains a clinical question. Therefore, we investigated which factors acted as risk factors that actually required ICU care after microsurgical clipping of unruptured aneurysms.

METHODS

We included a total of 532 patients who underwent clipping surgery for UIA between January 2020 and December 2020. The patients were divided into two groups: those who really required ICU care (41 patients, 7.7%) and those who did not (491 patients, 92.3%). A backward stepwise logistic regression model was used to identify factors that were independently associated with ICU care requirement.

RESULTS

The mean hospital stay duration and the operation time were significantly longer in the ICU requirement group than in the no ICU requirement group (9.9 ± 10.7 vs. 6.3 ± 3.7 days, p = 0.041), (259.9 ± 128.4 vs. 210.5 ± 46.1 min, p = 0.019). The transfusion rate was significantly higher (p = 0.024) in the ICU requirement group. Multivariable logistic regression analysis identified male sex (odds ratio [OR], 2.34; 95% confidence interval [CI], 1.15-4.76; p = 0.0195), operation time (OR, 1.01; 95% CI, 1.00-1.01; p = 0.0022), and transfusion (OR, 2.35; 95% CI, 1.00-5.51; p = 0.0500) as independent risk factors for requiring ICU care after clipping.

CONCLUSIONS

Postoperative ICU management may not be mandatory after clipping surgery for UIAs. Our results suggest that postoperative ICU management may be more required in the male sex, patients with longer operation times, and those who received a transfusion.

The impact of high-resolution cone-beam CT findings on decision-making for the treatment of unruptured middle cerebral artery aneurysms

Even with the advent of endovascular treatment for intracranial aneurysms, microsurgical clipping continues to play a significant role in the treatment of middle cerebral artery (MCA) aneurysms. Securing perforators around unruptured intracranial aneurysms (UIAs) is essential for minimizing procedural risks in each treatment option. Therefore, we herein investigated whether the findings of high-resolution cone-beam computed tomography (HR-CBCT) have an impact on decision-making for the treatment of MCA UIAs. Patients with MCA UIAs between October 2017 and September 2021 were consecutively recruited for this study. All patients underwent HR-CBCT and 3D-DSA before treatment. The imaging quality of both modalities to visualize the microvasculature around aneurysms was evaluated. Specific findings on the microvasculature surrounding aneurysms on HR-CBCT were investigated to facilitate microsurgical clipping. Fifty-two MCA UIAs were treated, including 43 by microsurgical clipping and 9 by endovascular approaches. The overall imaging quality of HR-CBCT was superior to that of 3D-DSA. Regarding microsurgical insights, sensitivity and specificity for the visualization of small vessels around aneurysms were 79 and 100%, respectively, using HR-CBCT, and 57 and 93%, respectively, using 3D-DSA. The presence of a low-density band between adhesive vessels and aneurysm sacs was indicative of successful and safe microsurgical dissection between these structures. HR-CBCT enabled visualization of the intracranial microvasculature around MCA UIAs at the submillimeter level in vivo. In cases in which the tight adhesion of the microvasculature to the aneurysm sac is indicated by HR-CBCT, an endovascular approach may be considered in order to avoid the risks associated with securing perforators.

Clinical features of ischemic complications after unruptured middle cerebral artery aneurysm clipping: patients and radiologically related factors

Postoperative ischemic complication results in neurological sequelae and longer hospitalization after unruptured middle cerebral artery (MCA) aneurysm clipping surgery. We evaluated the radiological and patient-related factors associated with ischemic complications after unruptured MCA aneurysm clipping surgery. Patient demographics, radiological findings, and intraoperative factors were compared between patients with and without postoperative ischemic complications. The clinical courses and outcomes of postoperative ischemic complications were compared according to the types of ischemic complication. Forty-two out of 2227 patients (1.9%) developed postoperative ischemic complications after MCA aneurysm clipping. Multivariate analysis revealed that diabetes mellitus (DM) was a patient-related factor. Intraarterial (IA) calcification of the distal internal carotid artery (ICA), preoperative M1 stenosis, and M1 aneurysm were radiological factors that increased the risk of postoperative ischemic complications. DM was significantly associated with divisional branch territory infarction (P = 0.04). The time to first presentation of ischemic complication was significantly longer in divisional branch territory infarction than perforator territory infarction (67.8 ± 75.9 h vs. 22 ± 20.7, P = 0.023). Twelve out of 42 patients with ischemic complications (28.6%) had unfavorable outcome (mRS > 3). Perforator territory infarction was significantly associated with an unfavorable outcome (mRS > 3, P = 0.019). IA calcification of the distal ICA, M1 stenosis and aneurysms, and DM were significantly associated with postoperative ischemic complications after unruptured MCA aneurysm clipping. Patients with DM should be closely monitored postoperatively to detect delayed occurrence of divisional branch infarction. Trial registration number: 2019-1002, Date of registration: January 1, 2005, "retrospectively registered".

Clinical and radiological outcomes in relation with the anatomical orientation of clipped middle cerebral artery bifurcation aneurysms

BACKGROUND

The middle cerebral artery (MCA) bifurcation represents the most frequent location for intracranial aneurysms. Often, the aneurysmal dome can hide the origin of perforating arteries from the M1 segment during the surgical clipping causing ischemic lesions and worse clinical outcome. The aim of this paper is to analyze the association between the orientation of the aneurysm sac and the clinical and radiological outcomes after surgical clipping.

METHODS

Data from 50 MCA bifurcation clipped aneurysms in 47 patients were collected retrospectively. Three different groups were identified according to the aneurysmal sac orientation: anterior-inferior, posterior and superior. A possible association between the aneurysmal sac projection and the outcome was searched through a univariable logistic regression analysis.

RESULTS

Statistical analysis showed significant correlation between the radiologic evidence of post-operative ischemia in the posterior group (p = 0.046, RR = 1.65) and an increased risk in the superior orientation group (p = 0.145, RR = 1.38). The anterior-inferior group was, instead, significantly associated with no evidence of radiologic ischemia (p = 0.0019, RR = 0.58).

CONCLUSION

The orientation of the aneurysmal dome and sac represents a fundamental feature to be considered during the surgical clipping of the MCA aneurysms. Indeed, its posterior and superior projection is associated with a higher incidence of radiologic ischemic lesions due to the origin of perforating arteries from M1 segment behind the aneurysmal sac. The anterior-inferior orientation, on the contrary, is associated with a lower risk.

Morphology parameters for rupture in middle cerebral artery mirror aneurysms

Objective

To identify the morphological parameters correlated with the rupture of middle cerebral artery (MCA) aneurysms.

Methods

We retrospectively analyzed the digital subtraction angiography (DSA) data of 48 patients with ruptured mirror MCA aneurysms. Morphological parameters included aneurysm with wall protrusion, maximum diameter (Dmax), height, neck width, aneurysm width, dome projection, parent artery average diameter (Dp), aspect ratio (AR), bottleneck factor (BNF), size ratio (SR), M1/M2 ratio, and height/width (H/W) ratio. These paired parameters were analyzed by conditional univariate and multivariate logistic regressions to screen out the independent risk factors. We established a score based on the independent risk factors. Receiver operating characteristics (ROC) were generated to estimate the prediction performance of the score in our large database of 763 aneurysms.

Results

In the univariate regressions, Dmax, height, aneurysm width, neck width, AR, BNF, H/W ratio, SR, anterior dome projection and aneurysm with wall protrusion were significant risk factors. Aneurysm width (OR 3.296, p=0.015), AR (OR 11.594, p=0.014) and anterior dome projection (OR 9.385, p=0.016) were independent risk factors in multivariate regression. The area under the curve (AUC) value of the score based on the three independent risk factors was 0.829.

Conclusion

Aneurysm width, AR and anterior dome projection were independent risks factors of rupture.

Flow-T stenting with the Silk Vista Baby and Baby Leo stents for bifurcation aneurysms - A novel endovascular technique

We present the first case using a novel flow diverter, the Silk Vista Baby (Balt, Montmorency, France), in combination with a low-profile braided stent, the Baby Leo (Balt, Montmorency, France), in a T configuration that we term Flow-T. We describe the technical characteristics of the case as well as the early follow-up results. We believe that this combination may provide an alternative to standard T-stenting and alternative to treat bifurcation aneurysms.

Predictors of Atherosclerotic Change in Unruptured Intracranial Aneurysms and Parent Arteries During Clipping

OBJECTIVES

To identify predictors of atherosclerotic change in aneurysms and parent arteries, and to retrospectively analyze outcomes from clipped aneurysms that showed atherosclerotic changes.

METHODS

Between May 2017 and April 2018, we collected a total of 151 clipping cases and reviewed records of operation videos to classify atherosclerosis by location (dome, neck of aneurysm, or parent artery). To identify predictors of atherosclerotic change in aneurysms, we analyzed baseline demographic characteristics, preoperative images, and Framingham Risk Scores (FRS). We also analyzed incomplete clipping cases according to atherosclerosis presence and location.

RESULT

This study cohort included 110 women (mean age, 59.3 ± 7.1 years) and 41 men (mean age, 55.9 ± 9.6 years). Atherosclerotic change was seen in 77 cases. FRS, diabetes mellitus, and aneurysm size were identified as independent risk factors for atherosclerotic change in multivariate logistic regression analysis. There were 11 incomplete clipping cases (7.2%). Among the 30 cases with atherosclerotic change in the neck were 10 cases of incomplete clipping (P < 0.001).

CONCLUSIONS

FRS, diabetes mellitus, and aneurysm size as predictors of atherosclerosis in patients undergoing aneurysm surgery can help guide surgical decisions and performance.

Stent-Assisted Coil Embolization of MCA Bifurcation Aneurysms at a Hypoplastic M1 Branch by Use of Hook Technique

BACKGROUND

We describe the Hook technique enabling coil embolization in unfavorable M1 bifurcation aneurysms and analyze the morphologic variations in M1 bifurcation to evaluate how often such aneurysms can be seen.

METHODS

Among 42 MCA aneurysms treated by stent-assisted coil embolization, aneurysms arising at the acute-angled hypoplastic M1 branch (n = 14) were treated by the Hook technique, in which a short stent was deployed only to protect the aneurysm neck after microcatheter selection of the hypoplastic M2, followed by subsequent coiling of the aneurysm. Outcome was evaluated, including Raymond classification, coil packing density, final modified Rankin Scale (mRS), and recurrence. Separately, 100 middle cerebral artery (MCA) bifurcation aneurysms were analyzed to assess the proportion of such unfavorable aneurysms.

RESULTS

Procedural success of the Hook technique was obtained in 13 of 14 patients (93%). A mean packing density of 30% was achieved. Magnetic resonance angiographic follow-up at a median 4 months (range, 1-26 months) showed complete occlusion in 11 patients and residual neck filling in 3 patients. There was no clinical event (mRS = 0) over a median 17 months (range, 2-26 months) of clinical follow-up. One patient had a thrombotic occlusion during the procedure, which was resolved after tirofiban infusion, without evidence of an infarct or deficit. Of the 100 MCA bifurcation aneurysms, aneurysm arising in asymmetric hypoplastic M2 division was the most common type (48%).

CONCLUSIONS

The Hook technique enabled stent-assisted coiling of M1 bifurcation aneurysm with extension along the asymmetric hypoplastic M2 division and also securing the M2 branch.

Keyhole strategy aiming at minimizing hospital stay for surgical clipping of unruptured middle cerebral artery aneurysms

OBJECTIVE

Aneurysms of the middle cerebral artery (MCA) are still most often treated by clipping through standard craniotomy, but a longer hospital stay is one of the main drawbacks of this treatment. The authors developed a pterional keyhole clipping strategy for unruptured MCA aneurysms with the intention of minimizing hospital stay. In this paper, they report on their experience with this approach and analyze the long-term neurological and radiological outcomes.

METHODS

A total of 160 relatively small unruptured MCA aneurysms (mean 6.4 mm) were clipped through the pterional keyhole approach (19-30 mm, mean 24.6 mm) in 149 patients (aged 34-79 years, mean 62 years). Neurological and cognitive function were examined by several scales, including the modified Rankin Scale (mRS) and Mini-Mental State Examination (MMSE). Patients' level of depression was assessed using the Beck Depression Inventory and Hamilton Depression Scale. The state of clipping was assessed at 1 year and then every few years after the operation.

RESULTS

The mean duration of postoperative hospitalization was 2.3 ± 3.4 days; in 31.3% of the cases, the patients were discharged on the day after the operation (overnight hospital stay) and in 93.2% within 3 days. Of the patients younger than 60 years, 40.4% required only an overnight stay. Complete aneurysm neck clipping was confirmed in 157 cases (98.1%). None of the completely clipped aneurysms showed any recurrence during the mean follow-up period of 5.0 years. The mean length of clinical follow-up was 5.4 years. After 2 (1.3%) of the surgical procedures, the patients showed persistent neurological deficits, defined as mRS score 1, but the overall operative morbidity based on the International Study of Unruptured Intracranial Aneurysms (ISUIA) definition (mRS score ≥ 2 or MMSE score < 24) was 0% at the last examination. Depression scores were significantly improved after surgery, and in 85.6% of the cases the patients were satisfied with their cosmetic results.

CONCLUSIONS

Pterional keyhole clipping is less invasive than clipping via standard craniotomy, minimizes hospital stay, and achieves durable treatment for relatively small unruptured MCA aneurysms.

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.

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.

Middle cerebral artery extension and the risk for aneurysmal disease

The intracranial artery aneurysm is an abnormal dilatation at the wall and the most serious complication is its rupture that is associated with high rates of neurological mortality and morbidity. Its most common location in arterial bifurcations suggests that the hemodynamic of blood flow plays a key role, but the effect of the length of the M1 segment of the middle cerebral artery is poorly explored. We analyzed biplanar brain angiograms to measure the extent of the M1 segment and its relationship to the presence of aneurysm at the bifurcation. Of 475 patients, a total of 682 bilateral measurements were analyzed. Women accounted for 58.7% and the mean age was 50.2 ± 15.5. Aneurysms were detected in 45 arteries, about the average length of the M1 artery; the right segment measure (2.98 ± 0.99 cm) was statistically lesser than the left (3.09 ± 1.38 cm). Applying the regression coefficient, arteries with aneurysm have an average length of 0.419 cm smaller than an artery without aneurysm, and this difference was statistically significant (p < 0.05). Though the wall shear stress component is a proven risk factor for the development of aneurysms in bifurcations, a smaller extension of the M1 segment may also be implicated in its development.

Minimally Invasive Transpalpebral ‘‘Eyelid’’ Approach to Unruptured Middle Cerebral Artery Aneurysms

BACKGROUND: Although recent technological advances have led to successful endovascular treatment, middle cerebral artery (MCA) aneurysms are still prone to surgery. Because minimally invasive options are limited and possess several functional and cosmetic drawbacks, a transpalpebral approach is proposed as a new alternative.

OBJECTIVES: To describe and assess surgical results of the minimally invasive transpalpebral approach in patients with MCA aneurysms.

METHODS: The data of 25 patients with unruptured MCA aneurysms from 2013 to 2016 were included in a cohort prospective database. We describe modifications of the approach and technique for MCA aneurysm clipping, in a step-by-step manner. The outcome was based on complications, procedural morbidity and mortality, and clinical and angiographic outcomes.

RESULTS: All procedures were successfully performed in a standardized way, and no major complications related to the new approach were observed. Twenty-two patients were discharged the day after surgery (88%). The majority of aneurysms were 5 to 6 mm in diameter (mean, 7 mm; range 4-21 mm). All patients underwent postoperative angiographic control, which showed no significant residual neck. A 3-mo follow-up was sufficient to show no visible scars with excellent cosmetic results. The mean duration of follow-up was 16 mo.

CONCLUSION: The transpalpebral approach comes as a minimally invasive, safe, definitive, and cosmetically adequate solution for MCA aneurysms at the present time.

Clinical and Anatomical Follow-up in Patients With Aneurysms Treated With the WEB Device: 1-Year Follow-up Report in the Cumulated Population of 2 Prospective, Multicenter Series (WEBCAST and French Observatory)

BACKGROUND

Flow disruption with WEB is an innovative endovascular approach for wide-neck bifurcation aneurysms. Initial series have shown a low complication rate with good efficacy.

OBJECTIVE

To report clinical and anatomical results of the WEB treatment in the cumulated population of WEBCAST (WEB Clinical Assessment of Intrasaccular Aneurysm) and French Observatory series.

METHODS

WEBCAST and French Observatory are single-arm, prospective, multicenter, Good Clinical Practice studies dedicated to the evaluation of WEB treatment. Ruptured and unruptured bifurcation aneurysms located in the basilar artery, middle cerebral artery, anterior communicating artery, and internal carotid artery terminus were included in both studies. Clinical data were independently evaluated. Postoperative, 6-month (in WEBCAST), and 1-year aneurysm occlusion was independently evaluated with a 3-grade scale: complete occlusion, neck remnant, and aneurysm remnant.

RESULTS

The cumulated population was 113 patients (74 female, 65.5%) 33 to 74 years of age with 114 aneurysms with a mean neck size of 5.6 mm. There was no mortality at 1 month, and morbidity was 2.7%. A statistically significant difference in the rate of occurrence of thromboembolic events was observed between the use of any antiplatelet agent and the use of no antiplatelet agent (P < .001). At 1 year, complete aneurysm occlusion was observed in 56.0%, neck remnant in 26.0%, and aneurysm remnant in 18.0%. Worsening of aneurysm occlusion between the procedure and 12 months was observed in 2.0% and between 6 months and 1 year in 7.1%.

CONCLUSION

The analysis in this large cumulated population of studies confirms favorable safety and efficacy of WEB treatment.

Comparison of the Efficacy and Safety of Endovascular Coiling Versus Microsurgical Clipping for Unruptured Middle Cerebral Artery Aneurysms: A Systematic Review and Meta-Analysis

OBJECTIVE

Middle cerebral artery aneurysms (MCAAs) are regularly treated by both microsurgical clipping and endovascular coiling. We performed a systematic meta-analysis to compare the safety and efficacy of these 2 methods.

METHODS

Literature was reviewed for all studies reporting angiographic occlusion and/or functional outcomes in adults with unruptured MCAA treated by endovascular coiling or microsurgical clipping. All studies in English that reported results for adults (≥18 years) with unruptured MCAAs, from 1990 to 2011 were considered for inclusion.

RESULTS

Twenty-six studies involving 2295 aneurysms treated with clipping or coiling for unruptured MCAAs were included for analysis. There were 1530 aneurysms that were treated with clipping and 765 aneurysms treated with coiling. Pooled analysis revealed failure of aneurysmal occlusion in 3.0% (95% confidence interval [CI] 1.2%-7.4%) of clipped cases. Pooled analysis of 15 studies (606 aneurysms) involving coiling and occlusion revealed lack of occlusion rates of 47.7% (95% CI 43.6%-51.8%) with the fixed-effects model and 48.2% (95% CI 39.0%-57.4%) with the random-effects model. Thirteen studies examined neurological outcomes after clipping and were pooled for analysis. Both fixed-effect and random-effect models revealed unfavorable outcomes in 2.1% (95% CI 1.3%-3.3%) of patients. There were 17 studies evaluating potential unfavorable neurological outcomes after coiling that were pooled for analysis. Fixed-effect and random-effect models revealed unfavorable outcomes in 6.5% (95% CI 4.5%-9.3%) and 4.9% (95% CI 3.0%-8.1%) of patients, respectively.

CONCLUSIONS

Based on this systematic review and meta-analysis of unruptured MCAAs, after careful consideration of patient, aneurysmal, and treatment center factors, we recommend surgical clipping for unruptured MCAA.