A single center comparison of coiling versus stent assisted coiling in 90 consecutive paraophthalmic region aneurysms

Stent-assistant versus non-stent-assistant coiling for ruptured and unruptured intracranial aneurysms: A meta-analysis and systematic review

Background

Several different endovascular and non-invasive treatment methods are suggested for the various types of intracranial aneurysms including simple, balloon-assisted, and stent-assisted coiling (SAC). Previous studies investigated the safety and efficacy of SAC versus non-stent-assisted coiling (non-SAC) but the results were controversial. We aim to perform a systematic review and meta-analysis to compare the efficacy and safety of SAC with non-SAC technique in stratifying by the ruptured and unruptured aneurysms.

Methods

PubMed, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched in April 2022 for studies investigated the efficacy and safety of SAC versus non-SAC.

Results

Overall, 26 studies entered into our qualitative and quantitative synthesis. We found that there was overall lower recurrence rate in SAC versus non-SAC significant (RR: 0.43, 95%CI: 0.33, 0.53). Furthermore, the comparisons were significant in unruptured (RR: 0.63, 95%CI: 0.40, 0.86), ruptured (RR: 0.29, 95%CI), and combination aneurysms (RR: 0.42, 95%CI: 0.30, 0.54). Also, we found higher risk of intraprocedural rupture for SAC versus non-SAC in unruptured aneurysms (RR: 1.40, 95%CI: 1.31, 1.50). Investigating hemorrhagic events risk showed that there was significant difference in ruptured (RR: 1.73, 95%CI: 1.12, 2.34) and combination aneurysms (RR: 0.60, 95%CI: 0.37, 0.82). There was no significant difference in immediate occlusion rate, complete occlusion, and risk of ischemic events in our analysis.

Conclusion

Overall, our findings demonstrated that SAC may have higher efficacy in term of recurrence rate, but also may have a higher risk of complications in the treatment of intracranial aneurysms. As there are several factors affecting the outcomes and safety of these interventions, further RCTs controlled for multiple factors are required better guide the neurointerventionists choose the best strategy.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

TRIAL REGISTRATION NUMBER

NCT02340585.

Stent-assisted coiling of intracranial carotid ophthalmic segment aneurysm segment aneurysms: Long-term follow-up from a single center

Background

To evaluate the efficacy of stent-assisted coiling (SAC) for the treatment of carotid ophthalmic segment aneurysm segment aneurysms (OSAs) of the internal carotid artery (ICA) through detailed long-term follow-up of a large patient cohort.

Methods

We retrospectively analyzed 88 consecutive patients with OSAs between January 2009 and January 2020 ​at our center. Angiographic results were evaluated using the modified Raymond grading system and clinical outcomes were evaluated using the mRS scale. The primary endpoints were major aneurysm recurrence and poor clinical outcomes for at least 18 months of follow-up. The patients were asked to attend clinical follow-up assessments and possibly undergo DSA or MR via telephone.

Results

We enrolled 88 patients with 99 OSAs treated with coiling, of whom 76 were treated with SAC. The coiling procedures were successful in all 88 patients. Overall, complications occurred in 8 patients (9.1%). No procedure-related mortality was observed. 67 (76.1%) experienced immediate aneurysm occlusion at the end of the procedure. Long-term angiographic follow-up (18 months) was available in 45/88 aneurysms (51%) (average 18.7 ​± ​5.2 months). Four patients continued their follow-up for 5 years after initial aneurysm treatment. After a clinical follow-up time of 28.7 months (range, 12-51 months), 85 patients (95.5%) achieved favorable clinical outcomes (mRS scores of 0-2).

Conclusions

This study indicates that SAC treatment is a safe and effective therapeutic alternative for ruptured and unruptured OSAs. The procedural risks are low with relatively long-term effectiveness.

Packing density and the angiographic results of coil embolization of intracranial aneurysms: A systematic review and meta-analysis

BACKGROUND

Endovascular coil embolization (ECE) for intracranial aneurysms has been proven as an effective minimally invasive treatment. However, the aneurysm recanalization after coiling is a serious complication of this technique. Among all the proposed factors associated with recanalization, the impact of packing density (PD) is still controversial.

OBJECTIVE

To clarify the role of PD in the aneurysm recanalization following ECE, via conducting a systematic review and meta-analysis.

METHODS

A systematic literature search was conducted using PubMed, Scopus, Embase, and Web of Science databases, until November 28, 2022, by adhering to the Preferred Reporting Items for Systematic Review and Meta-Analyses statement guidelines. Considering the eligibility criteria, all the studies reporting the outcomes of interest were included. Data elements of interest were extracted and analyzed using R software version 4.2.1.

RESULTS

The pooled analysis of the 17 eligible papers revealed a 29% higher PD of the nonrecanalized aneurysms (ROM = 1.29, 95% confidence interval [CI] = 1.18-1.40, p < 0.001), even after removing outlier studies to reduce heterogeneity. However, the pooled estimates from multivariable regression models within nine included studies showed no significant effect of PD on recanalization odds when incorporated into a multivariable model with other predictors (odds ratio [OR] = 0.93, 95% CI = 0.84-1.02, p = 0.126), even after removing outlier studies.

CONCLUSION

The current literature does not support PD as a significant predictor of aneurysm treatment outcomes, especially with adjusting for other variables. This finding necessitates further prospective multicenter studies with a larger sample size to overcome the current methodological shortcomings.

Aspiration versus stent retriever for posterior circulation stroke: A meta-analysis

AIMS

New thrombectomy strategies have emerged recently. Differences between posterior circulation stroke management via aspiration and stent retriever remain to be evaluated. We compared the safety and efficacy of aspiration and stent retriever in treating posterior circulation stroke.

METHODS

Three databases (PubMed, Embase, and Cochrane Library) were systematically searched for studies comparing aspiration and stent retriever in patients with posterior circulation stroke. The modified Newcastle-Ottawa scale was used to assess the risk of bias. A random-effects model was used.

RESULTS

Fifteen cohort studies with 1451 patients were included. Pooled results showed a significant difference in total complication (odds ratio [OR] 0.48, 95% confidence interval [CI] [0.30, 0.76], p = 0.002). successful recanalization (1.85, [1.30, 2.64], p = 0.0006), favorable outcome (1.30, [1.02, 1.67], p = 0.04), procedure duration (-22.10, [-43.32, -0.88], p = 0.04), complete recanalization (4.96, [1.06, 23.16], p = 0.009), and first-pass effect (2.59, [1.55, 4.32], p = 0.0003) between the aspiration and stent retriever groups, and in favor of aspiration. There was no significant difference in the outcomes of rescue therapy (1.42, [0.66, 3.05], p = 0.37) between the two groups.

CONCLUSION

Patients with posterior circulation stroke receiving treatment with aspiration achieved better recanalization, first-pass effect, and shorter procedure time. Aspiration may be more secure than a stent retriever.

Endovascular treatment of aneurysms of the paraophthalmic segment of the internal carotid artery: Current status

The paraophthalmic segment of the internal carotid artery (ICA) originates from the distal border of the cavernous ICA and terminates at the posterior communicating artery. Aneurysms arising from the paraophthalmic segment represent ~5–10% of intradural aneurysms. Due to the advent of endovascular treatment (EVT) techniques, specifically flow-diverting stents (FDSs), EVT has become a good option for these aneurysms. A literature review on EVT for paraophthalmic segment aneurysms is necessary. In this review, we discuss the anatomy of the paraophthalmic segment, classification of the paraophthalmic segment aneurysms, EVT principle and techniques, and prognosis and complications. EVT techniques for paraophthalmic segment aneurysms include coil embolization, FDSs, covered stents, and Woven EndoBridge devices. Currently, coiling embolization remains the best choice for ruptured paraophthalmic segment aneurysms, especially to avoid long-term antiplatelet therapy for young patients. Due to the excessive use of antiplatelet therapy, unruptured paraophthalmic segment aneurysms that are easy to coil should not be treated with FDS. FDS is appropriate for uncoilable or failed aneurysms. Other devices cannot act as the primary choice but can be useful auxiliary tools. Both coiling embolization and FDS deployment can result in a good prognosis for paraophthalmic segment aneurysms. The overall complication rate is low. Therefore, EVT offers promising treatments for paraophthalmic segment aneurysms. In addition, surgical clipping continues to be a good choice for paraophthalmic segment aneurysms in the endovascular era.

Rabbit Elastase Aneurysm Model Mimics the Recurrence Rate of Human Intracranial Aneurysms following Platinum Coil Embolization

BACKGROUND AND PURPOSE

Intracranial aneurysms treated with coils have been associated with incomplete occlusion, particularly in large or wide-neck aneurysms. This study aimed to validate the accuracy of the rabbit elastase model in predicting aneurysm recurrence in humans treated with platinum coils.

MATERIALS AND METHODS

Elastase-induced saccular aneurysms were induced in rabbits and embolized with conventional platinum coils. The recurrence rates of aneurysms were retrospectively analyzed. Morphologic characteristics of aneurysms, angiographic outcomes, and histologic healing were evaluated.

RESULTS

A total of 28 (15.3%) of 183 aneurysms recurred. The aneurysm recurrence rate observed in this study (15.3%) is similar to those reported in multiple analyses of aneurysm recurrence rates in humans (7%-27%). The rate of recurrence was higher in aneurysms treated without balloon assistance (19/66, 28.8%) compared with those treated with balloon assistance (9/117, 7.7%). Aneurysms treated with balloon-assisted coiling had a lower recurrence rate (OR = 0.17; 95% CI, 0.05-0.47; P = .001) and higher occlusion rate (OR = 6.88; 95% CI, 2.58-20.37; P < .001) compared with those treated without balloon-assisted coiling. In this rabbit elastase-induced aneurysm model, packing density and aneurysm volume were weak predictors of aneurysm recurrence; however, the packing density was a good predictor of the occlusion rate (OR = 1.05; 95% CI, 1.02-1.10; P = .008).

CONCLUSIONS

The rabbit elastase aneurysm model may mimic aneurysm recurrence rates observed in humans after platinum coil embolization. Moreover, balloon assistance and high packing densities were significant predictors of aneurysm recurrence and occlusion.

EFFECTS OF THE ANEURYSM TREATMENT METHOD ON COIL PACKING DENSITY AND ITS RELATIONSHIP WITH THE OSTIUM AREA

PURPOSE

To test the following hypotheses: (1) balloon or stent assistance increases coil packing density (CPD) in the endovascular treatment of intracranial aneurysms and (2) CPD is related to the ostium area and volume of the aneurysm.

MATERIALS AND METHODS

This retrospective study included 60 ruptured and unruptured (54 and 6, respectively) aneurysms treated between August 2017 and December 2019 in the authors' institution with simple coiling (n=18), balloon-assisted coiling (n=7), or stent-assisted coiling (n=35). Aneurysm volume and ostium area measurements were obtained using commercial software from three-dimensional digital subtraction angiography images. Coil sizes were retrieved from patient files, and coil volume measurements were obtained using https://www.angiocalc.com/. Analysis of covariance, multivariable covariance analysis, and Pearson's correlation analyses were performed.

RESULTS

The median values for the aneurysm volume, coil volume, CPD, and ostium area were 63.4 (range 5.5-1771.4) mm³, 23.13 (2.03-296.95) mm³, 33.29% (13.41%-81.02%), and 10.7 (2.7-49.9) mm², respectively. Multivariate analysis showed that the CPD values were not significantly different among the treatment groups, although the ostium area differed significantly between the simple and stent-assisted coiling groups (P<.05). Pearson's correlations showed that similar to aneurysm volume, the ostium area was negatively correlated with CPD (r=-0.321, P<.05).

CONCLUSION

In cerebral aneurysms treated with balloon- or stent-assisted coiling, the CPD value does not differ from that in aneurysms treated with simple coiling.

Risk Factors for Recanalization after Coil Embolization

The aim of our study was to identify risk factors for recanalization 6 months after coil embolization using clinical data followed by computational fluid dynamics (CFD) analysis. Methods: Firstly, clinical data of 184 patients treated with coil embolization were analyzed retrospectively. Secondly, aneurysm models for high/low recanalization risk were generated based on ROC curves and their cut-off points. Afterward, CFD was utilized to validate the results. Results: In multivariable analysis, aneurysm filling during the first embolization was an independent risk factor whilst packing density was a protective factor of recanalization after 6 months in patients with aSAH. For patients with unruptured aneurysms, packing density was found to be a protective factor whilst the aneurysm neck size was an independent risk factor. Complex flow pattern and multiple vortices were associated with aneurysm shape and were characteristic of the high recanalization risk group. Conclusions: Statistical analysis suggested that there are various factors influencing recanalization risk. Once certain values of morphometric parameters are exceeded, a complex flow with numerous vortices occurs. This phenomenon was revealed due to CFD investigations that validated our statistical research. Thus, the complex flow pattern itself can be treated as a relevant recanalization predictor.

Evaluation of Surgical Clipping and Endovascular Coiling on Oculomotor Nerve Palsy Caused by Internal Carotid Artery Aneurysm

Objectives: Internal carotid artery (ICA) aneurysm often leads to oculomotor nerve palsy (ONP) that impairs eye movement. Currently, microsurgical clipping and endovascular coiling are the two major options to treat ONP. The purpose of the current study is to compare the clinical outcomes of the two methods in patients with ONP caused by ICA aneurysm. Patients and Methods: In the present study, we assessed the prognostic factors and recovery outcomes of a total of 90 ICA aneurysm-induced ONP patients, where 50 of them were treated with microsurgical clipping and 40 of them were treated with endovascular coiling. Within the endovascular coiling group, 20 of the patients were treated with balloon-assisted coiling and the other 20 were treated with stent-assisted coiling. Results: Overall, we achieved a 59% (53 out of 90) full recovery rate. Both surgical clipping and endovascular coiling treatment methods achieved similar recovery outcomes in the tested patients. However, within the endovascular coiling group, balloon-assisted coiling treatment demonstrated a significantly higher full recovery rate (17 out of 20) compared to stent-assisted coiling treatment (eight out of 20). Conclusion: In general, no significant difference was identified between the surgical and coiling treatments, and both procedures were considered as beneficial for ICA aneurysm-induced ONP.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Investigating the parameters that affect the radiation exposure and establishing typical values based on procedure complexity for cerebral angiography and brain aneurysm embolization

PURPOSE

The purpose of this study is to investigate the parameters that affect the radiation exposure and to establish typical values (TV) based on procedure complexity for cerebral angiography (CA) and brain aneurysm embolization (BAE).

METHODS

Clinical parameters and exposure data were retrospectively reviewed for 348 examinations performed between March 2016 and December 2019 at a single specialized neuroradiology center. TV were derived as the median value of the distribution of exposure parameters such as total air kerma area product (P_KA,T), air kerma at the patient entrance reference point, fluoroscopy time, and number of frames. A statistical analysis was conducted to investigate the exposure variability with patient's gender, number of treated vessels during CA and patient gender, aneurysm location and dimension, and treatment strategies during BAE.

RESULTS

Patient gender was associated with a significant increase in the exposure level for both CA and BAE. For CA, TV were in term of P_KA,T of 52 Gycm² for male vs. 28 Gycm² for female patients. For BAE, these were 113 Gycm² for male vs. 75 Gycm² for female patients. Exposure levels increased significantly with the number of treated vessels in CA. TV were 20 Gycm² for one vessel vs. 77 Gycm² for 5-6 vessels CA. For BAE, aneurysm location was also a key factor that affects the patient exposure. TV were 55 Gycm² for aneurysms grouped in location 1 vs. 105 Gycm² for those grouped in location 2.

CONCLUSION

Male gender, number of treated vessels, and aneurysm location are key parameters affecting patient exposure during CA and BAE procedures.

Advances in endovascular aneurysm management: coiling and adjunctive devices

Endovascular coil embolisation continues to evolve and remains a valid modality in managing ruptured and unruptured cerebral aneurysms. Technological advances in coil properties, adjunctive devices and interventional techniques continue to improve long-term aneurysm occlusion rates. This review elaborates on the latest advances in next-generation endovascular coils and adjunctive coiling techniques for treating cerebral aneurysms.

Comparison of stent-assisted and no-stent coil embolization for safety and effectiveness in the treatment of ruptured intracranial aneurysms

OBJECTIVE

The safety of the stent-assisted coil embolization (SAC) technique for acutely ruptured aneurysms has not been established yet. SAC is believed to be associated with a high risk of thromboembolic and hemorrhagic complications in acute subarachnoid hemorrhage (SAH). The aim of this study was to evaluate the safety and efficacy of the SAC technique in the setting of acutely ruptured aneurysm.

METHODS

A total of 102 patients who received endovascular treatment for acute SAH between January 2011 and December 2017 were enrolled. The SAC technique was performed in 38 of these patients, whereas the no-stent coil embolization (NSC) technique was performed in 64. The safety and efficacy of the SAC technique in acute SAH was evaluated as compared with the NSC technique by retrospective analysis of radiological and clinical outcomes.

RESULTS

There were no significant differences in clinical or angiographic outcomes between the SAC and NSC techniques in patients with acute SAH. The rate of ventriculostomy-related hemorrhagic complications was higher in the SAC group than that in the NSC group (63.6% vs 12.5%; OR 12.25, 95% CI 1.78-83.94, p = 0.01). However, all these complications were asymptomatic and so small that they were only able to be diagnosed with imaging.

CONCLUSIONS

Ruptured wide-necked aneurysms could be effectively and safely treated with the SAC technique, which showed clinical and angiographic outcomes similar to those of the NSC technique. Hence, the SAC technique with dual-antiplatelet drugs may be a viable option even in acute SAH.

Predictors for ophthalmic segment aneurysms recanalization after coiling and flow diverter embolization in 6- and 12-month follow-up

Carotid-ophthalmic aneurysms are indication for endovascular treatment. Coil embolization is associated with a high recanalization rate and thus usage of flow diverter (FD) could constitute the treatment of choice. Although implementation of FD is very effective, it carries a significant risk of complications. The goal of our study was to find a radiological recanalization marker in order to facilitate decision process which would result in fewer treatment-related complications and in this way, to personalize endovascular therapy. We made a retrospective analysis of seventy-five patients with saccular carotid-ophthalmic aneurysms treated endovascularly. Morphometric measurements were performed in CTA 3D aneurysm models. The aneurysm size and volume were measured on the base of digital subtraction angiography (DSA) images. The treatment effectiveness was determined visually using the modified Raymond Roy classification after embolization and on the 6- and 12-month follow-up DSA. Statistica 13.1 software was used. Multivariate analyses showed that the aneurysm neck size (OR 2.51; 95%CI: 1.20-5.26), aspect ratio (OR 2.60; 95%CI: 1.27-5.21) and neck to parent artery ratio (OR 2.68; 95%CI: 1.26-5.70) were risk factors for carotid-ophthalmic aneurysms recanalization after 6 months. Of those factors, aneurysm neck size remained the only significant risk factor for carotid-ophthalmic aneurysms recanalization after 12 months (OR 5.23, 95%CI: 1.71-15.93). Various factors seem to influence recanalization. Preoperatively, if the above-mentioned predictors of recanalization are present, coiling is burdened with a high recanalization rate. In those cases, FD embolization should be considered.

Single-center experience with the new-generation Derivo embolization device for ruptured and unruptured intracranial aneurysms

BACKGROUND

The aim of this study is to evaluate safety and efficacy of the new-generation Derivo embolization device in complex ruptured (RIA) and unruptured (UIA) intracranial aneurysms.

METHODS

Retrospective analysis of 32 patients with complex RIAs and UIAs treated with Derivo at our hospital from November 2015 to December 2018. Clinical safety was defined as absence of death, transient attack, absence of minor and major stroke, and Derivo associated hemorrhage. Treatment efficacy was assessed angiographically (DSA) immediately after treatment and at 6-month follow-up according to the O'Kelly-Marotta (OKM) Grading Scale (from A=total filling to D=no filling; prolongation of stasis 1=arterial to 3=venous phase).

RESULTS

Thirty-two patients with 39 aneurysms were treated with 42 Derivos. In five aneurysms, additional coiling was performed. Deployment was technically successful in all cases. Two patients developed a procedure related minor stroke (one transient). In one patient bleeding due to an inflammatory aneurysmatic wall process occurred 20 days after retreatment and in one patient a stroke due to in-stent thrombosis occurred when dual platelet inhibition (PI) was switched to permanent single PI 12 month after FD treatment. No treatment related deaths were observed. Initial DSA revealed three OKM D, six OKM C, five OKM B, and 25 OKM A. Six-month follow-up for DSA and clinical evaluation was available in 20/32 patients (62.5%), 26 of 39 aneurysms (66.7%) and revealed 73.1% complete and 3.8% subtotal occlusion (OKM D: 19 of 26, OKM C3: one of 26).

CONCLUSIONS

Treatment of complex RIAs and UIAs with the new-generation Derivo appeared to be safe and effective in this single-center case series for ruptured and unruptured intracranial aneurysms. Immediate DSA revealed a significant flow modulation; and 6-month follow-up showed a high occlusion rate.

Stent assisted coiling versus non-stent assisted coiling for the management of ruptured intracranial aneurysms: a meta-analysis and systematic review

PURPOSE

To compare the safety and efficiency of stent assisted coiling (SAC) with non-SAC for the management of ruptured intracranial aneurysms.

METHODS

A meta-analysis that compared SAC with coiling alone and balloon assisted coiling was conducted by database searching. The primary outcomes of this study were immediate occlusion and progressive thrombosis rate, overall perioperative complication rate, and angiographic recurrence. Secondary outcomes included mortality at discharge, hemorrhagic and ischemic complications, and favorable clinical outcome at discharge and at follow-up.

RESULTS

Eight retrospective cohort studies with 1408 ruptured intracranial aneurysms (SAC=499; non-SAC=909) were included. The SAC group tended to show a lower immediate complete occlusion rate than the non-SAC group (54.3% vs 64.2%; RR 0.90; 95% CI 0.83 to 0.99; I²=17.4%) and achieved a significantly higher progressive complete rate at follow-up (73.4% vs 61.0%; RR 1.30; 95% CI 1.16 to 1.46; I²=40.5%) and a lower recurrence rate (4.8% vs 16.6%; RR 0.28; 95% CI 0.16 to 0.50; I²=0.0%). With respect to safety concerns, overall perioperative complications in the SAC group were significantly higher (20.2% vs 13.1%; RR 1.70; 95% CI 1.36 to 2.11; I²=0.0%). However, no significant difference was found for mortality rate at discharge (6.3% vs 6.2%; RR 1.29; 95% CI 0.86 to 1.94; I²=0.0%), or favorable clinical outcome rate at discharge (73.4% vs 74.2%; RR 0.95; 95% CI 0.88 to 1.02; I²=12.1%) and at follow-up (85.6% vs 87.9%; RR 0.98; 95% CI 0.93 to 1.02; I²=0.0%; P=0.338).

CONCLUSIONS

SAC has a lower recurrence rate than non-SAC. Nevertheless, further validation by well designed prospective studies is warranted for determining whether stents improve angiographic outcome without an increased complication rate or unfavorable clinical outcome.

WEB embolization versus stent-assisted coiling: comparison of complication rates and angiographic outcomes

Background

Intrasaccular flow disruption represents a new paradigm in endovascular treatment of wide-necked bifurcation aneurysms.

Objective

To perform a matched case–control study comparing complications and angiographic outcome using the Woven Endobridge (WEB) device and stent-assisted coiling (SAC).

Methods

Sixty-six patients treated with the WEB at three German tertiary care centers were included and matched with 66 patients treated with SAC based on aneurysm location and unruptured/ruptured aneurysm status. Parameters were retrospectively analysed and compared between the treatment groups using inverse probability of treatment weighting (IPTW) with propensity scores.

Results

Procedural complication rates were 12.1% in the WEB group and 21.2% in the SAC group, which was statistically significant after IPTW adjustment (OR=2.2, 95% CI 1.08 to 4.4, p=0.03). Favourable outcome (modified Rankin scale score ≤2) was achieved by 57/66 (86.4%) in the WEB group and 57/66 (86.4%) in the SAC group (p=1.0). At mid-term follow-up, a similar number of aneurysms achieved adequate occlusion (complete occlusion or neck remnant) in the WEB group (93.9%) and in the SAC group (93.9%, p=1.0). Re-treatment was performed in 10.6% after WEB embolization and 12.1% after SAC (p=1.0).

Conclusions

The WEB provides similar mid-term aneurysm occlusion rates to those of SAC, with no additional morbidity and potentially lower complication rates. Long-term outcome analysis will provide a definite conclusion on the use of WEB for intracranial aneurysms.

Pipeline Embolization for Salvage Treatment of Previously Stented Residual and Recurrent Cerebral Aneurysms

Introduction

This study assessed the safety and effectiveness of the Pipeline embolization device (PED) for persistent and recurrent aneurysms previously treated with either a vascular reconstruction device (VRD) or a flow diverter (FD).

Methods

A prospective, IRB-approved database was analyzed for patients treated with PED for aneurysms previously treated with a stent.

Results

Twenty procedures were performed on 18 patients, 11 with prior FD, 7 with VRD, and 2 previously treated with both. Overall, 15 aneurysms were saccular (75%), and size was 13.5 ± 7.6 mm. Location was internal carotid artery (ICA) in 14 cases (70%) and posterior circulation in 6 cases (30%). Average prior treatments were 1.7. Previously FD cases were re-treated at an average of 18.1 months from most recent treatment. Each case used 1 device, 82% with distal coverage and 82% with proximal coverage of prior stent. Balloon remodeling was performed in 3 cases (27%) and no in-stent thrombosis was observed. Previously VRD stent-coiled cases were re-treated at an average of 87.5 months. These cases used on average 1.9 devices, 89% with distal and 100% proximal coverage. Adjunctive coiling was performed in 1 case (11%), balloon remodeling in 5 cases (56%), and 2 cases (28%) developed thrombosis that resolved with abciximab. Re-VRD cases were longer (59.1 vs. 33.7 min, p = 0.02) than re-FD. Angiographic follow-up was available for 16 cases (80%). In re-FD, occlusion was complete in 56% and partial progressive in 33% at 17.1 months digital subtraction angiography. In re-VRD, occlusion was complete in 57% and partial progressive in 27% at 8.1 months. Two complications occurred (10%), including one asymptomatic cervical ICA occlusion and one stent occlusion with associated mortality (5%). Clinical follow-up was 17.8 months on average (range 0.5-51.9).

Conclusions

Salvage flow diversion for previously stented aneurysms is technically challenging but offers good prospects of aneurysm obliteration with acceptable complication rates.

Single-stage flow diversion with adjunctive coiling for cerebral aneurysm: outcomes and technical considerations in 72 cases

Background

Adjunctive coiling may improve occlusion outcomes when combined in a single stage with cerebral aneurysm flow diversion. This technique has not been well described.

Objective

To present a series of aneurysm patients treated by single-stage flow diversion with adjunctive coiling, describing technical considerations and outcomes.

Methods

This was a retrospective cohort study using an IRB-approved database of procedures performed at a single institution. Treatment selection was based on large aneurysm size, morphological irregularity, branch vessel location, and wide neck.

Results

A total of 72 Pipeline with adjunctive coiling (PAC) procedures were performed on 69 patients. Average aneurysm size was 11.0 mm and 86% were wide-necked. Three progressively complex techniques were performed approximately equally: 27 sequential (38%), 23 jailed single-intermediate (32%), and 22 bifemoral jailed microcatheter (31%) cases. Aneurysm dome (P=0.0223) and neck size (P=0.001) increased with procedural complexity and there was a trend toward increased procedure length, radiation exposure, and stent thrombosis. A ‘light’ coil pack was used with an average packing density of 14% that did not vary by technique. Of the three major complications (4.2%), none were observed with the sequential approach (0%), one with the jailed single-intermediate (4.3%), and two with bifemoral cases (9.1%) (P=0.116). Complete occlusion was achieved in 85% of PAC cases at 6 months and 96% at 12-month follow-up angiography.

Conclusions

There are multiple approaches to flow diversion with adjunctive coiling, each with technical challenges, suitable to different types of aneurysms. Flow diversion with coiling can expedite and improve occlusion outcomes without a significant increase in morbidity.

Complications of endovascular treatment for intracranial aneurysms: Management and prevention

Endovascular coiling for intracranial aneurysms has become an accepted treatment with good clinical results and provides adequate protection against rebleeding and rupture of aneurysms. However, despite the experience, preparation, or skill of the physician, complications during endovascular treatment still occur. The main complications of endovascular coiling are: procedural aneurysmal perforations by the microcatheter, micro-guidewire, or coil, and thromboembolic events. Such situations are unexpected, complex, and can have devastating consequences. In this article, we present a comprehensive review of the two most common complications, aneurysmal perforation and thromboembolism during endovascular coiling, and how we can prevent or overcome these complications to achieve a satisfactory outcome. In addition, as the flow diverter has been become an important tool for management of large, wide necked, and other anatomically challenging aneurysms, we also describe complications stemming from the use of the tool, which remains a novel treatment option for complex aneurysms.

Simple Coiling versus Stent-Assisted Coiling of Paraclinoid Aneurysms: Radiological Outcome in a Single Center Study

Objective

Paraclinoid aneurysms are a group of aneurysms arising at the distal internal carotid artery. Due to a high incidence of small, wide-necked aneurysms in this zone, it is often challenging to achieve complete occlusion when solely using detachable coils, thus stent placement is often required. In the present study, we aimed to investigate the effect of stent placement in endovascular treatment of paraclinoid aneurysms.

Methods

Data of 98 paraclinoid aneurysms treated by endovascular approach in our center from August 2005 to June 2016 were retrospectively reviewed. They were divided into two groups: simple coiling and stent-assisted coiling. Differences in the recurrence and progressive occlusion between the two groups were mainly analyzed. The recurrence was defined as more than one grade worsening according to Raymond-Roy Classification or major recanalization that is large enough to permit retreatment in the follow-up study compared to the immediate post-operative results.

Results

Complete occlusion was achieved immediately after endovascular treatment in eight out of 37 patients (21.6%) in the stent-assisted group and 18 out of 61 (29.5%) in the simple coiling group. In the follow-up imaging studies, the recurrence rate was lower in the stent-assisted group (one out of 37, 2.7%) compared to the simple coiling group (13 out of 61, 21.3%) (p=0.011). Multivariate logistic regression model showed lower recurrence rate in the stent-assisted group than the simple coiling group (odds ratio [OR] 0.051, 95% confidence interval [CI] 0.005-0.527). Furthermore there was also a significant difference in the rate of progressive occlusion between the stent-assisted group (16 out of 29 patients, 55.2%) and the simple coiling group (10 out of 43 patients, 23.3%) (p=0.006). The stent-assisted group also exhibited a higher rate of progressive occlusion than the simple coiling group in the multivariate logistic regression model (OR 3.208, 95% CI 1.106-9.302).

Conclusion

Use of stents results in good prognosis not only by reducing the recurrence rate but also by increasing the rate of progressive occlusion in wide-necked paraclinoid aneurysms. Stent-assisted coil embolization can be an important treatment strategy for paraclinoid aneurysms when considering the superiority of long term outcome.

Packing Density Necessary to Reach a High Complete Occlusion Rate in Circumferential Unruptured Intracranial Aneurysms Treated with Stent-Assisted Coil Embolization

BACKGROUND AND PURPOSE

This study is a homogeneous series of circumferential unruptured intracranial aneurysms with large necks treated with stent-assisted coil embolization. Our purpose was to demonstrate which value of packing density is required to produce a durable occlusion.

MATERIALS AND METHODS

We retrospectively evaluated all patients with unruptured intracranial aneurysms who were treated with stent-assisted coil embolization having late angiographic control between 2004 and 2014, in a single large cerebrovascular referral center. To calculate the packing density, aneurysm volume, and coil volume, we used an on-line system.

RESULTS

In 49 circumferential unruptured intracranial aneurysms treated with stent-assisted coil embolization, 38.7% (n = 19) had complete occlusion in the immediate control. Of those with incomplete occlusion, 80% (n = 24) progressed to complete occlusion in the late angiographic follow-up. At late angiographic control, 87.7% (n = 43) of aneurysms were completely occluded. All aneurysms with a packing density of ≥19% were completely occluded. Packing density was the only statistically significant predictor of complete occlusion. None of the aneurysms with complete occlusion at immediate control or at late angiographic control had recurrence.

CONCLUSIONS

In circumferential aneurysms treated with stent-assisted coil embolization, packing density is the main predictor of complete occlusion. In this type of aneurysm, a packing density of ≥19% was enough to reach complete occlusion; knowing this is important to avoid higher packing densities that have more risk.

Haemodynamic analysis for recanalisation of intracranial aneurysms after endovascular treatment: an observational registry study in China

INTRODUCTION

Recanalisation of intracranial aneurysms following endovascular treatment is a major issue. Many factors, including aneurysm morphology, the method of treatment, and haemodynamics, are considered to be associated with recanalisation. However, the underlying haemodynamic mechanisms are not completely understood.

METHODS AND ANALYSIS

This is a prospective, observational, registry study for patients with intracranial aneurysms who are treated endovascularly. It will enrol 200 eligible patients. Data on morphological, haemodynamic, and treatment factors will be collected prospectively. The advanced virtual stenting technique and porous media method will be used in haemodynamic simulations. The clinical and angiographic outcomes at 6 months will be measured and analysed. This observational study will determine the haemodynamic factors that affect the recanalisation of aneurysms.

ETHICS AND DISSEMINATION

Both the study protocol and written informed consent were reviewed and approved by the Institutional Review Board of Beijing Tiantan Hospital (KY2016-023-01). The results of study will be disseminated in professional printed media.

TRIAL REGISTRATION NUMBER

NCT02812108; Pre-results.

Cerebral aneurysm treatment: modern neurovascular techniques

Endovascular treatment of cerebral aneurysm continues to evolve with the development of new technologies. This review provides an overview of the recent major innovations in the neurointerventional space in recent years.

Surgical clipping is still a good choice for the treatment of paraclinoid aneurysms

Paraclinoid aneurysms are lesions located adjacent to the clinoid and ophthalmic segments of the internal carotid artery. In recent years, flow diverter stents have been introduced as a better endovascular technique for treatment of these aneurysms.

METHOD

From 2009 to 2014, a total of 43 paraclinoid aneurysms in 43 patients were surgically clipped. We retrospectively reviewed the records of these patients to analyze clinical outcomes.

RESULTS

Twenty-six aneurysms (60.5%) were ophthalmic artery aneurysms, while 17 were superior hypophyseal artery aneurysms (39.5%). The extradural approach to the clinoid process was used to clip these aneurysms. One hundred percent of aneurysms were clipped (complete exclusion in 100% on follow-up angiography). The length of follow-up ranged from 1 to 60 months (mean, 29.82 months).

CONCLUSION

Surgical clipping continues to be a good option for the treatment of paraclinoid aneurysms.

Comparison Between Balloon-Assisted and Stent-Assisted Technique for Treatment of Unruptured Internal Carotid Artery Aneurysms

Purpose

To compare clinical and angiographic outcomes between balloon-assisted (BAC) and stent-assisted coiling for internal carotid artery unruptured aneurysms (ICA-UA).

Materials and Methods

A total of 227 ICA-UA in 190 patients were treated with BAC (120 patients, 141 ICA-UA) or SAC (70 patients, 86 ICA-UA. We compared characteristics of patients and ICA-UA, and clinical and angiographic outcomes between groups.

Results

Aneurysm size and neck diameter were greater for SAC than in BAC, but aneurysm volume and coil packing density were not different between groups. Immediate angiographic occlusion grade was better for BAC than for SAC. Periprocedural thromboembolic events were more frequent during SAC (11.6%) than BAC (2.4%) per aneurysm, but hemorrhagic events were the opposite (2.4% for BAC and none for SAC per aneurysm) (p < 0.05). At discharge, treatment-related morbi-mortality rates were 1.6% for BAC and 1.4% per patient for SAC. At clinical follow-up (BAC, 118 patients [98.3%] for a mean of 48.4 months; SAC, 69 patients [98.6%], for a mean of 37.4 months), 1 additional treatment-related infarction occurred during SAC, resulting in a modified Rankin scale score of 4. Thus, overall treatment-related morbi-mortality rates were 1.7% in BAC and 2.9% in SAC. At imaging follow-up (BAC, 135 aneurysms [95.7%] for 28.3 months; SAC, 81 aneurysms [94.1%] for 23.9 months), BAC and SAC showed stable or improved occlusion in 94.1% and 95.0%, minor recurrence in 4.4% and 2.5%, and major recurrence in 1.5% and 2.5%, respectively.

Conclusion

Both BAC and SAC were safe and effective techniques for ICA-UA. There were no differences in morbi-mortality and recurrence rates between groups.

Effect of hemodynamics on outcome of subtotally occluded paraclinoid aneurysms after stent-assisted coil embolization

BACKGROUND

Endovascular treatment of paraclinoid aneurysms is preferred in clinical practice. Flow alterations caused by stents and coils may affect treatment outcome.

OBJECTIVE

To assess hemodynamic changes following stent-assisted coil embolization (SACE) in subtotally embolized paraclinoid aneurysms with residual necks that were predisposed to recanalization.

METHODS

We studied 27 paraclinoid aneurysms (seven recanalized and 20 stable) treated with coils and Enterprise stents. Computational fluid dynamic simulations were performed on patient-specific aneurysm geometries using virtual stenting and porous media technology.

RESULTS

After stent placement in 27 cases, aneurysm flow velocity decreased significantly, the reduction gradually increasing from the neck plane (11.9%), to the residual neck (12.3%), to the aneurysm dome (16.3%). Subsequent coil embolization was performed after stent placement and the hemodynamic factors decreased further and significantly at all aneurysm regions except the neck plane. In a comparison of recanalized and stable cases, univariate analysis showed no significant differences in any parameter before treatment. After stent-assisted coiling, only the reduction in area-averaged velocity at the neck plane differed significantly between recanalized (8.1%) and stable cases (20.5%) (p=0.016).

CONCLUSIONS

Aneurysm flow velocity can be significantly decreased by stent placement and coil embolization. However, hemodynamics at the aneurysm neck plane is less sensitive to coils. Significant reduction in flow velocity at the neck plane may be an important factor in preventing recanalization of paraclinoid aneurysms after subtotal SACE.

The expanding realm of endovascular neurosurgery: flow diversion for cerebral aneurysm management

The worldwide prevalence of intracranial aneurysms is estimated to be between 5% and 10%, with some demographic variance. Subarachnoid hemorrhage secondary to ruptured intracranial aneurysm results in devastating neurological outcomes, leaving the majority of victims dead or disabled. Surgical clipping of intracranial aneurysms remained the definitive mode of treatment until Guglielmi detachable coils were introduced in the 1990s. This revolutionary innovation led to the recognition of neurointervention/neuroendovascular surgery as a bona fide option for intracranial aneurysms. Constant evolution of endovascular devices and techniques supported by several prospective randomized trials has catapulted the endovascular treatment of intracranial aneurysms to its current status as the preferred treatment modality for most ruptured and unruptured intracranial aneurysms. We are slowly transitioning from the era of coils to the era of flow diverters. Flow-diversion technology and techniques have revolutionized the treatment of wide-necked, giant, and fusiform aneurysms, where the results of microsurgery or conventional neuroendovascular strategies have traditionally been dismal. Although the Pipeline Embolization Device (ev3-Covidien, Irvine, CA) is the only flow-diversion device approved by the Food and Drug Administration for use in the United States, others are commercially available in Europe and South America, including the Silk (Balt Extrusion, Montmorency, France), Flow-Redirection Endoluminal Device (FRED; MicroVention, Tustin, CA), Surpass (Stryker, Kalamazoo, MI), and p64 (Phenox, Bochum, Germany). Improvements in technology and operator experience and the encouraging results of clinical trials have led to broader acceptance for the use of these devices in cerebral aneurysm management. Continued innovation and refinement of endovascular devices and techniques will inevitably improve technical success rates, reduce procedure-related complications, and broaden the endovascular therapeutic spectrum for varied aneurysm morphology.

Comparison of Stent-Assisted Coiling vs Coiling Alone in 563 Intracranial Aneurysms: Safety and Efficacy at a High-Volume Center

BACKGROUND

Stent-assisted coiling has been used in both unruptured and ruptured aneurysms, but the safety and efficacy still remain controversial.

OBJECTIVE

To compare the safety and efficacy of stent-assisted coiling with coiling alone for intracranial aneurysms.

METHODS

We retrospectively reviewed 512 patients treated by endovascular coiling or stent-assisted coiling over a 1-year period. The patients' clinical and imaging information was recorded. Procedure-related complication rates, recurrence rates, and clinical outcomes were analyzed in both the total aneurysms and the subgroups of ruptured and unruptured aneurysms.

RESULTS

A total of 243 patients were treated by coiling alone and 269 patients were treated by stent-assisted coiling. Procedure-related complications occurred in 6.2% of patients in the coiling-alone group compared with 6.3% in the stent-assisted coiling group. The procedural permanent morbidity and mortality rates were 1.6% (4/243) and 1.2% (3/243), respectively, in the coiling-alone group and 1.1% (3/269) and 1.5% (4/269), respectively, in the stent-assisted coiling group. A significantly lower recurrence rate was found in the stent-assisted coiling group compared with the coiling-alone group (5.2% vs 16.5%, P = .002). In a comparison of subgroups of ruptured and unruptured aneurysms, the procedural complications rates were comparable in the 2 groups, with a lower recurrence rate in the stent-assisted coiling group. Multivariate analysis showed that larger aneurysm size and higher Hunt and Hess grade were predictors of procedural morbidity; larger aneurysm size, ruptured aneurysm, anterior circulation aneurysms, initial incomplete occlusion, and lack of stent assistance were predictors of recurrence.

CONCLUSION

Compared with coiling alone, stent-assisted coiling may achieve lower recurrence rates, with comparable procedure-related complications and clinical outcomes in both ruptured and unruptured aneurysms.

Comparison between Solitaire™ AB and Enterprise stent-assisted coiling for intracranial aneurysms

The aim of the present study was to analyze the feasibility, rate of procedure-related complications and midterm angiographic follow-up outcomes using the Enterprise (EP) and Solitaire™ AB (ST) stents in the stent-assisted coiling of intracranial aneurysms. In total, 81 patients with 90 aneurysms were included in the study, with the aim to treat 43 aneurysms with the EP stent (47.8%) and 47 aneurysms with the ST stent (52.2%). The 90 aneurysms were successfully stented and subsequently coiled; however, in four patients undergoing treatment with the EP stent, the stent was not navigable; thus, treatment with the ST stent was employed (EP, n=39, 43.3%; ST, n=51, 56.7%). Of the 90 aneurysms, 44 cases were ruptured aneurysms, with 74 located in the anterior circulation and 16 located in the posterior circulation. The stenting success rate of the ST stent was significantly higher compared with the EP stent. However, no statistically significant differences were observed with regard to the packing density, complete occlusion, progressive occlusion, recurrence rate, procedure-related complications, in-stent stenosis and stent migration rates between the two groups. In conclusion, the two common medical devices used for intracranial aneurysms are relatively safe and effective for the treatment of intracranial aneurysms. However, due to the higher stenting success rate of the ST stent, this medical devise was demonstrated to be more flexible and feasible compared with the EP stent.

Angiographic results of wide-necked intracranial aneurysms treated with coil embolization : a single center experience

Objective

Endovascular treatment of wide-necked intracranial aneurysms is a challenge and the durability and the safety of these treated aneurysms remain unknown. The aim of this study was to evaluate the clinical and long-term angiographic results of wide-necked intracranial aneurysms treated with coil embolization.

Methods

Between January 2002 and December 2012, 53 wide-necked aneurysms treated with coil embolization were selected. Forty were female, and 13 were male. Twenty eight (52.8%) were ruptured aneurysms, and 25 (47.2%) were unruptured aneurysms. The patents' medical and radiological records were reviewed retrospectively.

Results

Of the 53 aneurysms, coiling alone was employed in 45 (84.9%) and stent-assisted coiling was done in 8 (15.1%). The initial angiographic results revealed Raymond class 1 (complete occlusion) in 30 (56.6%) cases, Raymond class 2 (residual neck) in 18 (34.0%) cases, and Raymond class 3 (residual sac) in 5 (9.4%) cases. The mean angiographic follow-up period was 37.9 months (12-120 months). At the last angiographies, Raymond class 1 was seen in 26 (49.1%) cases, Raymond class 2 in 16 (30.2%), and Raymond class 3 in 11 (20.8%). Angiographic recurrence occurred in 22 (41.5%) patients, with minor recurrence in 7 (13.2%) cases and major recurrence in 15 (28.3%). Retreatment was performed in 8 cases (15.1%). A suboptimal result on the initial angiography was a significant predictor of recurrence in this study (p=0.03).

Conclusion

The predictor of recurrence in wide-necked aneurysms is a suboptimal result on the initial angiography. Long-term angiographic follow-up is recommended in wide-necked aneurysms.

Radiation dose analysis of large and giant internal carotid artery aneurysm treatment with the pipeline embolization device versus traditional coiling techniques

BACKGROUND

Flow diversion is an effective and increasingly accepted method for endovascular treatment of cerebral aneurysms. Additionally, the public has heightened concerns regarding radiation exposure from medical procedures. This study analyzes radiation dose and fluoroscopy time during treatment of large and giant proximal internal carotid artery (ICA) aneurysms with the pipeline embolization device (PED) versus traditional coiling techniques.

METHODS

Radiation dose, fluoroscopy time, and contrast dye administration were retrospectively analyzed in 55 patients undergoing endovascular treatment of aneurysms ≥ 10 mm from petrous to superior hypophyseal ICA segments. Patients were treated by either PED (37 patients) or traditional coiling techniques (18 patients). Aortic arch type and proximal ICA tortuosity were also assessed as markers of access difficulty.

RESULTS

Average radiation dose with PED treatment was 2840 ± 213 mGy and 4010 ± 708 mGy with traditional coiling techniques (p=0.048; 29% decrease with PED). Mean fluoroscopy time for PED was 56.1 ± 5.0 min and 85.9 ± 11.9 min for coiling cases (p=0.0087; 35% decrease with PED). These benefits existed despite more difficult arch anatomy and a trend towards greater proximal vessel tortuosity in PED cases. Contrast dye amounts were also reduced by 37.5% in PED cases (75 ± 6 mL) versus coiling cases (120 ± 13 mL, p=0.0008).

CONCLUSIONS

Treatment of large and giant proximal ICA aneurysms using PED requires less radiation, less fluoroscopy time, and less contrast administration than standard coiling techniques. This further demonstrates the benefits of flow diversion for treatment of these aneurysms.

Paraclinoid aneurysms: is there a new endovascular standard?

OBJECTIVES

Paraclinoid aneurysms are challenging lesions to treat with traditional surgical and conventional endovascular techniques despite modern improvements in technique and technology. Flow diversion emerged recently as a promising new therapy that overcomes limitations related to the wide-neck and fusiform morphology, and importantly addresses the underlying diseased parent artery from which the aneurysm arises.

METHODS

We reviewed the current literature regarding the safety and efficacy of flow diversion therapy for treatment of paraclinoid aneurysms.

RESULTS

Early results suggest excellent ability for flow diversion to remodel the diseased parent artery and achieve durable complete angiographic occlusion of the aneurysm with acceptable rates of peri-procedural risk.

DISCUSSION

Flow diversion therapy can achieve durable and high rates of obliteration that surpass traditional methods of management for paraclinoid aneurysms. However, caution is warranted when considering this treatment modality due to several concerning and often-unpredictable complications associated with this technology.

Stent-assisted coiling versus coiling in treatment of intracranial aneurysm: a systematic review and meta-analysis

Background and Purpose

Stent-assisted coiling was initially invented for wide-neck aneurysms, but is now used for smaller berry aneurysms. The aim of this study was to compare the safety and efficiency of stent-assisted coiling with conventional coiling in treatment of intracranial aneurysms.

Methods

A meta-analysis of studies that compared stent-assisted coiling with coiling only was conducted by searching English literatures via Pubmed, Medline and Cochrane Library databases without restricting the publication year. The primary outcomes in this study were immediate occlusion, progressive thrombosis rate, all-complication rate and angiographic recurrence. The secondary outcomes examined were packing density, mortality, permanent complication and thromboembolic complication rate.

Results

Ten retrospective cohort studies were included. There is currently only one unfinished randomized study. Although the stent-assisted coiling group tended to show a lower initial occlusion rate than that of the coiling-only group (57.6% versus 68.7%; OR, 0.66; 95% CI, 0.30–1.44; P = 0.30), it achieved a significantly higher progressive thrombosis rate during follow up compared to that of the coiling only group (37.5% versus 19.4%; OR, 2.75; 95% CI, 1.95–3.86; P<0.00001) and a significantly lower recurrence rate (16.2% versus 34.4%; OR, 0.35; 95% CI, 0.25–0.49; P<0.00001). With respect to safety concerns, the all-complication rate (17.6% versus 15.9%; OR, 1.12; 95% CI, 0.77–1.62; P = 0.56), mortality rate (9.1% versus 2.6%; OR, 2.31; 95% CI, 0.68–7.82; P = 0.18), permanent complication rate (5.6% versus 3.9%; OR, 1.52; 95% CI, 0.96–2.41; P = 0.08) and thromboembolic complication rate (4.2% versus 4.9%; OR, 0.99; 95% CI, 0.41–2.38; P = 0.97) did not show significant difference between the two groups.

Conclusions

Stent-assisted coiling has a lower recurrence rate than conventional coiling. Analysis of complication events did not show any significant difference between the two methods. Despite the findings reported herein, further validation by well-designed prospective studies is needed.

Various techniques of stent-assisted coil embolization of wide-necked or fusiform artherosclerotic and dissecting unruptured vertebrobasilar artery aneurysms for reducing recanalization: mid-term results

BACKGROUND

Coil embolization of wide-necked or fusiform vertebrobasilar aneurysms is challenging and tends to involve frequent recanalization.

PURPOSE

The aim of our study was to evaluate complications and mid-term outcomes of complex vertebrobasilar artery aneurysms after stent-assisted coiling with various techniques.

METHODS

We retrospectively evaluated 28 cases of unruptured vertebrobasilar aneurysm treated by stent-assisted coiling.

RESULTS

Forty-four of the 45 stents placed in 28 patients were deployed at the desired location (97.8 %). Single stent-assisted coiling was performed in 14 aneurysms, a stent-within-a-stent (SWS) technique was used in 12 aneurysms, and Y-stent-assisted coiling was employed in four basilar tip aneurysms. Two basilar tip aneurysms treated by single stent-assisted coiling recurred and were retreated by SWS and Y-stent-assisted coiling. Complete embolization was achieved in 19 aneurysms (67.8 %), and remnant neck persisted in eight aneurysms (28.6 %) and remnant aneurysm was noted in one aneurysm (3.6 %). Permanent neurologic deficit (Modified Rankin Scale 1 and 4) was noted in two patients (7.1 %). Angiographic follow-up (mean follow-up period: 20.8 months) was performed in 20 patients. Major recanalization occurred in two basilar tip aneurysms (10 %) and minor compaction was noted in one superior cerebellar artery aneurysm. The remaining 17 aneurysms were stable or improved (85 %).

CONCLUSIONS

Complex vertebrobasilar aneurysm embolization with stent-assisted techniques was effective and feasible as a method for reducing recanalization during midterm angiographic follow-up. Large and wide-necked basilar tip aneurysms showed frequent major recanalization, and compact packing with single or Y-stent-assisted coiling is needed to prevent recanalization even if coiling will be done without stenting.

Stent-assisted coiling in endovascular treatment of 500 consecutive cerebral aneurysms with long-term follow-up

BACKGROUND AND PURPOSE

Stent-assisted coil embolization has become one of the most preferred techniques in the treatment of wide-neck intracranial aneurysms; however, long-term patency and safety of the self-expanding neurostents and their role in durability of the endovascular treatment has remained ambiguous. We sought to retrospectively examine the long-term results of self-expanding stent usage in conjunction with coil embolization in treatment of wide-neck cerebral aneurysms.

MATERIALS AND METHODS

We coiled 500 wide-neck cerebral aneurysms with different types of self-expanding neurostent assistance in 468 patients. Patient and aneurysm characteristics, pharmacologic therapy protocol, complications, and initial occlusion grades were analyzed. Patients underwent angiographic follow-up at 6 months to 7 years after treatment. DSA or MRA images of all patients were analyzed to assess the occlusion rate of aneurysms and patency of the parent artery.

RESULTS

Enterprise (n = 340), Solitaire (n = 98), Wingspan (n = 41), LEO (n = 16), and Neuroform (n = 5) stent systems were used in this series. Stent-related thromboembolic events occurred in 21 patients and intraoperative rupture occurred in 4 patients. Initially, complete occlusion was achieved in 42.2% of the aneurysms, and, according to the last follow-up data, the rate had progressed to 90.8%. Recanalization rate at 6 months was 8%, whereas the late recanalization rate was 2%.

CONCLUSIONS

The use of stents in endovascular treatment provides high rates of complete occlusion and low rates of recurrence at a long-term follow-up study.

Endoscopic endonasal transplanum approach to the paraclinoid internal carotid artery

Objective To investigate the relevance of an endoscopic transnasal approach to the surgical treatment of paraophthalmic aneurysms. Setting Binasal endoscopic transplanum surgery was performed. Participants Seven cadaver heads were studied. Main Outcome Measures (1) Dimensions of the endonasal corridor, including the operative field depth, lateral limits, and the transplanum craniotomy. (2) The degree of vascular exposure. (3) Surgical maneuverability and access for clip placements. Results The mean operative depth was 90 ± 4 mm. The lateral corridors were limited proximally by the alar rim openings (29 ± 4 mm) and distally by the distance between the opticocarotid recesses (19 ± 2 mm). The mean posteroanterior distance and width of the transplanum craniotomy were 19 ± 2 mm and 17 ± 3 mm, respectively. Vascular exposure was achieved in 100% of cases for the clinoidal internal carotid artery (ICA), ophthalmic artery, superior hypophyseal artery, and the proximal ophthalmic ICA. Surgical access and clip placement was achieved in 97.6% of cases for vessels located anterior to the pituitary stalk (odds ratio [OR] 73.8; 95% confidence interval [CI] 7.66 to 710.8; p = 0.00). Conclusion The endoscopic transnasal approach provides excellent visualization of the paraclinoid region vasculature and offers potential surgical alternative for paraclinoid aneurysms.

Use of stent-assisted coil embolization for the treatment of wide-necked aneurysms: A systematic review

Background:

The use of stent-assisted coiling (SAC) has been shown to be a treatment option for complex aneurysms. We reviewed systematically the immediate and mid-term angiographic results following treatment of wide-necked aneurysms with self-expanding stents and coils, as well as the peri- and postprocedural rate of complications.

Methods:

A computerized database search was conducted from 01/2000 to 04/2011 using appropriate indexed terms on Pubmed. Inclusion criteria were: (1) homogeneous populations of ≥10 patients with wide-necked aneurysms; (2) use of a self-expandable neurovascular stent and coils for aneurysm treatment; (3) immediate and follow-up angiographic results; and (4) periprocedural and delayed thrombotic complications.

Results:

Seventeen studies were included, containing retrospectively collected data on 656 patients/702 aneurysms. The target aneurysm was located on the anterior circulation in 78.4% of patients. The immediate rate of complete occlusion was 46.3%, (19.3-98.1%). The intra- and postprocedural rate of intrastent thrombosis or thromboembolic event was 4.6% and 4.3%, respectively. Complete occlusion was documented in 71.9% at last angiographic follow-up. The rate of recanalization was 13.2% of aneurysms (0-28.8%). Delayed in-stent stenosis occurred in 5.3% cases (0-20.6%).

Conclusion:

SAC has been considered a treatment option for selected wide-necked aneurysms in some institutions. The use of intracranial stents should take into consideration the risk of ischemic complications, recanalization, delayed in-stent stenosis; and the currently unknown lifetime risks for stenosis, vascular injury, device failure, and aneurysm recurrence related to intracranial stenting. There is an evident need for a prospective multicenter registry for all treated patients with SAC.

Incomplete stent apposition in Enterprise stent-mediated coiling of aneurysms: persistence over time and risk of delayed ischemic events

OBJECT

Incomplete stent apposition of the closed cell-design Enterprise stent following stent-mediated coil embolization of intracranial aneurysms has been associated with increased risk of periprocedural thromboembolic events. In this study, the authors seek to determine the natural history of incomplete stent apposition and evaluate the clinical implications of the phenomenon.

METHODS

Since January 2009, all patients receiving Enterprise stents in the treatment of intracranial aneurysms at the authors' institution have undergone serial 3-T MRI with incomplete stent apposition identified by the crescent sign on multiplanar reconstructions of MR angiograms. Magnetic resonance images and MR angiograms obtained at 3, 9, and 18 months after stent-assisted coil embolization were analyzed along with admission and follow-up clinical medical records. These records were evaluated for any radiographic and clinical, transient or permanent ischemic neurological events.

RESULTS

Fifty patients receiving Enterprise stents were eligible for inclusion and analysis in the study. Incomplete stent apposition was identified in postoperative imaging studies in 22 (44%) of 50 patients, with 19 (86%) of 22 crescent signs persisting and 3 (14%) of 22 crescent signs resolving on subsequent serial imaging. Delayed ischemic events occurred in 8 (16%) of 50 cases, and all cases involved patients with incomplete stent apposition. The events were transient ischemic attacks (TIAs) in 5 cases, asymptomatic radiographic strokes in 2 cases, and symptomatic strokes and TIAs in the final case. There were no delayed ischemic events in patients who did not have incomplete stent apposition. Only 1 of the delayed ischemic events (2%) was permanent and symptomatic. The postoperative presence of a crescent sign and persistence of the crescent sign were both significantly associated with delayed ischemic events (p < 0.001 and p = 0.002, respectively).

CONCLUSIONS

Incomplete stent apposition is a temporally persistent phenomenon, which resolves spontaneously in only a small minority of cases and appears to be a risk factor for delayed ischemic events. Although further follow-up is needed, these results suggest that longer duration of antiplatelet therapy and clinical follow-up may be warranted in cases of recognized incomplete stent apposition.

Safety and efficacy of endovascular treatment of basilar tip aneurysms by coiling with and without stent assistance: a review of 235 cases

BACKGROUND

Endovascular therapy is now the preferred treatment option for basilar tip aneurysms (BTAs).

OBJECTIVE

To compare the safety and efficacy of common endovascular techniques in the treatment of BTAs.

METHODS

A retrospective review was conducted of 235 patients with BTAs treated with endovascular means in our institution between 2004 and 2011. Categorization was based on the presence and type of stent assistance (none, single, and Y stenting). The rates of perioperative complications, recanalization, rehemorrhage, and retreatment were analyzed.

RESULTS

A total of 147 patients were treated with coil embolization and 88 patients with stent-assisted coiling (72 single stents, 16 Y stents). Thromboembolic complications occurred in 6.8% of patients in both groups. There was no associated mortality. Angiographic follow-up (mean, 23.5 months) was available in 172 patients (77.1%). Stented patients had significantly lower recanalization (17.2% vs 38.9%; P=.003) and retreatment (7.8% vs 27.8%; P=.002) rates compared with nonstented patients. Four rehemorrhages (2.7%) occurred in the coiled group, whereas none were noted in the stented group (P=.3). In paired comparisons, lower recanalization (8.3% vs 19.2%; P=.21) and retreatment (0% vs 9.6%; P=.19) rates were seen in the Y-stent group compared with the single-stent group. Thromboembolic complications occurred in 6.9% and 6.2% of patients in the single-stent and Y-stent groups, respectively (P=.91). In multivariate analysis, larger aneurysms, nonstented aneurysms, incomplete initial occlusion, and subarachnoid hemorrhage were predictors of aneurysm recanalization.

CONCLUSION

Stent-assisted coiling has significantly lower recurrence, retreatment, and rehemorrhage rates than coiling alone for the treatment of BTAs. Y stenting has the highest efficacy with low complication rates.

The retreatment: indications, technique and results

Durability of endovascular treatment of intracranial aneurysms has always been an issue and a very strong point of criticism. Although studies on long-term results have made it clear that endovascular treatment safe and effective they, nonetheless showed retreatment after endovascular treatment is nearly 5-10 times more frequent than surgical clipping. Risk factors predisposing high probability of retreatment are aneurysm with dissecting nature, incomplete coiling, sac size larger than 10mm and localization at the bifurcations such as basilar tip. The indications for retreatment after endovascular treatment are not clear yet, although certain morphologic criteria can be used. Retreatment appears not to negate the initial advantage of endovascular treatment over surgical treatment and can be performed very small morbi-mortality numbers.