Endovascular embolization is applicable for large and giant intracranial aneurysms: experience in one center with long-term angiographic follow-up

Exploring the latest findings on endovascular treatments for giant aneurysms: a review

Giant intracranial aneurysms represent a very challenging aspect of aneurysmal pathophysiology with very high mortality and morbidity if left untreated. Their variety in clinical presentation (subarachnoid hemorrhage, cranial nerve palsy, etc.) and pathological and imaging properties (location, anatomy, presence of collateral circulation) pose serious questions regarding the best treatment option. Admirable advances have been achieved in surgical techniques, while endovascular modalities with flow diversion techniques have become widely used. However, there is still lack of data regarding whether a single endovascular technique can be the universal treatment for such cases. In this review, we aim to summarize the current funds of knowledge concerning giant intracranial aneurysms and the role of endovascular management in their treatment.

Surgical Treatment of Large and Giant Anterior Cerebral Artery Aneurysms in the Endovascular Era: Analysis of Large Clinical Series

OBJECTIVE

Analysis of results of surgical treatment of 112 patients with large and giant anterior cerebral artery (ACA) aneurysms.

METHODS

This is the largest clinical series of large and giant ACA aneurysms ever reported. Retrospective analysis of medical charts, radiographic studies, and intraoperative videos was performed. Univariate and multivariate analysis of relations among 3 types of outcomes (complete aneurysm occlusion, ischemic complications, and clinical outcomes) and predicting factors was performed.

RESULTS

Most aneurysms were communicant (84.8%). Aneurysms of the A1 segment and distal segments (A2-A5) were encountered rarely. Complete aneurysm occlusion (class I) was shown in 95 cases (90.5%). In 4 patients, only exploration and wrapping were performed because of severe atherosclerosis and chronic intraluminal thrombi. Partial occlusion (class III) was shown in 2 patients, and neck residual (class II) in 4 patients. Cerebral ischemia developed in 29 patients postoperatively. Occlusion or injury of the A1 segment and anterior communicating artery perforators and recurrent branch of Heubner were the most common reason for ischemic complications. At follow-up, 97 patients (86.6%) had favorable outcomes. Ten patients (8.9%) had unfavorable outcomes because of postoperative complications.

CONCLUSIONS

Microsurgery provides effective and relatively safe occlusion of complex ACA aneurysms. Direct clipping can be applied in most cases independent of their precise location. In certain cases, alternative methods can be safely used. According to multivariate analysis, giant aneurysm size, aneurysm-related mass effect, involvement of large arterial branches in the aneurysm wall, and intraoperative complications were significant predicting factors for ischemic complications.

Analysis of Clinical Effects of Comprehensive Nursing Based on Enhanced Recovery after Surgery in Patients with Embolization for Intracranial Aneurysms

Objective. This research sets out to elucidate the clinical effect of comprehensive nursing based on the concept of enhanced recovery after surgery (ERAS) in patients with embolization for intracranial aneurysms (IAs). Methods. This study enrolled 119 patients with embolization for IAs in the Zhongnan Hospital of Wuhan University from January 2020 to January 2021 and divided them into two groups according to the perioperative care they received: a control group ( $n=39$ ) treated with routine perioperative nursing and an observation group ( $n=80$ ) treated with ERAS-based comprehensive nursing. Surgical indicators, neurological function (National Institute of Health Stroke Scale (NIHSS) score; Scandinavian Stroke Scale (SSS) score), anxiety and depression (Self-Rating Anxiety Scale (SAS) score; Self-Rating Depression Scale (SDS) score), incidence of adverse events, and patient satisfaction were compared. Results. The observation group had better surgical indicators and lower scores of NIHSS, SSS, SAS, and SDS than the control group, accompanied by a lower incidence of adverse events and higher patient satisfaction. Conclusions. ERAS-based comprehensive nursing can better promote patients’ neurological recovery after embolization for IAs, relieve unhealthy emotions (depression, anxiety, etc.), and reduce the occurrence of adverse reactions, facilitating patient discharge.

Current Strategies in the Treatment of Intracranial Large and Giant Aneurysms

INTRODUCTION

Very large and giant aneurysms are among the most challenging cerebrovascular pathologies in neurosurgery.

METHODS

The aim of this paper is to review the current literature on the management of very large and giant aneurysms and to describe representative cases illustrating possible treatment strategies.

RESULTS

In view of the poor natural history, active management using multiprofessional individualized approaches is required to achieve aneurysm occlusion, relief of mass effect, and obliteration of the embolic source. Both reconstructive (clipping, coiling, stent-assisted coiling, flow diversion [FD]) and deconstructive techniques (parent artery occlusion [PAO], PAO in conjunction with bypass surgery, and strategies of flow modification) are available to achieve definitive treatment with acceptable morbidity.

CONCLUSIONS

Patients harboring such lesions should be managed at high-volume cerebrovascular centers by multidisciplinary teams trained in all techniques of open and endovascular neurosurgery.

Flow-diverting device versus coil embolization for unruptured intracranial aneurysm: A meta-analysis

BACKGROUND

Both coil embolization (CE) and flow-diverting device (FDD) placement are widely used for treatment of intracranial aneurysms (IAs). The aim of this meta-analysis is to compare the relative clinical safety and efficacy of FDD and CE for the treatment of unruptured IAs.

METHODS

The PubMed, Embase, and Cochrane Library databases were searched for relevant studies from the date of inception through April 2020. The primary endpoint for this meta-analysis was the 6-month rate of complete occlusion, while secondary endpoints included rates of retreatment, complications, and parental arterial patency.

RESULTS

This meta-analysis includes 8 studies, which included 839 total patients that underwent FDD and 2734 that underwent CE. FDD group exhibited a significantly higher pooled 6-month complete occlusion rate (P = .02). The subgroup analysis demonstrated that FDD treatment was associated with significantly higher pooled 6-month complete occlusion rates in patients with large or giant IAs (P < .00001), whereas no differences in 6-month complete occlusion rates were observed between the FDD and CE groups of patients with non-large/giant IAs (P = .83). The pooled retreatment (P = .16) and complication (P = .15) rates were comparable between 2 groups. The CE group exhibited significantly higher pooled parent artery patency rate (P = .01). The funnel plots did not reveal any evidence of publication bias.

CONCLUSIONS

FDDs can be used to effectively and safely treat large and giant IAs, achieving higher rates of complete occlusion than CE treatment. For non-large/giant IAs, we observed comparable efficacy between FDD and CE treatments.

Endovascular management of large and giant intracranial aneurysms: Experience from a tertiary care neurosurgery institute in India

Objective

With the development of endovascular technique and devices, large and giant intracranial aneurysms are increasingly being managed by this less invasive method. Here we discuss our experience on managing such aneurysms via endovascular technique.

Methods

Retrospective data on 42 patients with large and giant intracranial aneurysms managed by endovascular techniques between September 2015 to December 2017 at our neurosurgery institute were included in this analysis.

Results

There were a total 42 patients with 9 giant and 33 large aneurysms in this study. Eight aneurysms were treated by parent vessel occlusion, 22 aneurysms with coils and rest 12 aneurysms were treated with stent assisted coiling. Following the procedure, Raymond class I occlusion was accomplished in 31 (73.8%) patients while class Ⅱ in 9 (21.4%) and class Ⅲ in 2 (4.8%) patients. Overall morbidity and mortality were 9.5% and 14.3% respectively and favorable outcome was seen in 80.9% patients. Significant correlation was observed with clinical outcome and initial neurological status.

Conclusions

The study indicates that endovascular intervention is a safe and effective method in managing large and giant intracranial aneurysms with lesser morbidity and mortality.

Balloon-Assisted Coils Embolization for Ophthalmic Segment Aneurysms of the Internal Carotid Artery

Objective: To explore the role of balloon-assisted coils technique for ophthalmic segment aneurysms (OSAS).

Methods: Clinical data of 30 patients with OSAS were reviewed between December 2017 and December 2018. OSAS were defined as arising from the internal carotid artery (ICA), reaching from the distal dural ring to the origin of the posterior communicating artery. OSAS were classified into four types based on the angiographic findings. The balloon-assisted coils technique was used for the embolization of aneurysms. The duration of balloon inflation cycles, as well as difficulty and complications during the embolization procedure, were recorded. The immediate angiographic results were evaluated according to the Raymond scale. Clinical results were evaluated based on the MRS score. Follow-ups were performed at 18 months post-embolization by DSA or MRA at our institution.

Results: Thirty-two aneurysms in 30 patients were detected by digital subtraction angiography (DSA), which included 30 unruptured and two ruptured cases. The patients with ruptured aneurysms were grade II status according to the Hunt-Hess scale. Three cases were type A, nine cases were type B, 17 cases were type C, and three cases were type D. According to aneurysm size, there were 19 cases of small, 11 cases of medium, two cases of large aneurysm. Thirty-two aneurysms were successfully embolized in 30 patients by balloon-assisted coils technique. The ophthalmic artery could be protected by an engorged balloon in the procedure, especially for type A aneurysms. Considering that type D aneurysm arises from the side-wall of the artery and near to tortuous ICA siphon, the balloon catheter was inflated to stabilize the microcatheter allowing for overinflation when necessary. The average duration of balloon dilatation was 4 min, and the average time was 2.5 times. Raymond class was one in 28 aneurysms and two in four aneurysms according to the immediate post-embolization angiographic results. All the patients achieved good clinical effects, except for one patient who presented with brain ischemia resulting in dizziness and contralateral limb weakness for 10 h due to prolonged temporary clamping of the responsible ICA. The follow-up angiography results were satisfactory at 18 months post-embolization.

Conclusion: OSAS endovascular treatment with balloon-assisted coils has different advantages in a different classification. The technique is safe, effective, and relatively inexpensive, especially for small and medium OSAS.

Assessment of the embolization effect of temperature-sensitive p(N-isopropylacrylamide-co-butyl methylacrylate) nanogels in the rabbit renal artery by CT perfusion and confirmed by macroscopic examination

Transcatheter embolization is an important treatment method in clinical therapy, and vascular embolization material plays a key role in embolization. The temperature-sensitive p(N-isopropylacrylamide-co-butyl methylacrylate) (PIB) nanogel is a novel embolic agent. To evaluate the feasibility of the nanogel as a blood vessel embolization agent, we aimed to assess the effect of embolization with PIB nanogels in the rabbit renal artery by non-invasive computed tomography (CT) perfusion, macroscopic and histological examination. Ten healthy adult Japanese rabbits were used to implement RAE of PIB nanogels in their right kidneys. CT perfusion scans were performed pre- and post-treatment at various time-points (1, 4, 8, and 12 weeks). Two rabbits were euthanized and histologically examined at each time-point, and the remaining rabbits were euthanized at 12 weeks after embolization. The RAE efficacy of the nanogels was further confirmed by macroscopic and histological examination. The renal volume and renal blood flow (BF) of the right kidney were significantly decreased post-treatment compared with those pre-treatment (volume: pre, 9278 ± 1736 mm³; post 1 week, 5155 ± 979 mm³, P < 0.0001; post 4 weeks, 3952 ± 846 mm³, P < 0.0001; post 8 weeks, 3226 ± 556 mm³, P < 0.0001; post 12 weeks, 2064 ± 507 mm³, P < 0.0001. BF: pre, 530.81 ± 51.50 ml/min/100 ml; post 1 week, 0 ml/min/100 ml, P < 0.0001; post 4 weeks, 0 ml/min/100 ml, P < 0.0001; post 8 weeks, 0 ml/min/100 ml, P < 0.0001; post 12 weeks, 0 ml/min/100 ml, P < 0.0001). No revascularization or collateral circulation was observed on histological examination during this period, and PIB nanogels were dispersed in all levels of the renal arteries. Twelve weeks after embolization, CT perfusion showed no BF in the right renal artery and renal tissue, a finding that was consistent with histological examination showing complete embolization of the right renal artery with a lack of formation of collateral vessels. The effect of embolization on PIB was adequate, with good dispersion and permanency, and could be evaluated by non-invasive and quantitative CT perfusion.

Evaluating the Tubridge™ flow diverter for large cavernous carotid artery aneurysms

Background

The Tubridge™ flow diverter (TFD) was recently developed in China; however, its safety and efficacy in treating large cavernous carotid artery aneurysms (LCCAs) are unclear. Our objective was to evaluate the safety and efficacy of the TFD in patients receiving TFDs to treat LCCAs (10–25 mm).

Methods

Between June 2013 and May 2014, seven patients with LCCAs were enrolled in our study, and all seven patients underwent TFD implantation combined with coils.

Results

Angiographic follow-up images were available for all seven patients at a median of 57.5 ± 16.7 (range, 6–69) months. Seven patients obtained favorable angiographic results defined as O’Kelly–Marotta Scale C and D. Clinical follow-up data were available for all seven patients at a median of 73.32 ± 3.6 (range, 66–78) months. No patients developed new neurological deficits. Six patients achieved a modified Rankin scale score of 0, and diplopia improved in the remaining patient.

Conclusions

The results were excellent for the aneurysms treated with TFDs in our patients with LCCAs. TFDs are feasible for the treatment of LCCAs, but a multicenter, controlled clinical trial is needed to evaluate the long-term safety and efficacy of the TFD to treat LCCAs.

Surgical Management of Giant Intracranial Aneurysms: Overall Results of a Large Series

OBJECTIVE

To review and discuss surgical treatment options for giant intracranial aneurysms (GIAs), focusing on indications, technical aspects, and results, along with some illustrative cases.

METHODS

We reviewed the data of 82 consecutive patients surgically managed between January 2000 and December 2019 for treatment of a GIA.

RESULTS

Male sex and hemorrhage at presentation were prevalent. The average follow-up was 81.2 ± 45 months. The anterior circulation was involved in 76.8% of GIAs. If the GIA showed a clear neck, minimal atherosclerosis, or intrasaccular thrombosis, and ≤2 branches arising from the neck, it was reconstructed. This procedure was possible in 78% of cases. The technique also involved temporary clipping, remodeling, and thrombectomy, as well as fragmentation techniques. Angioarchitectural features other than these techniques underwent bypass and aneurysm trapping. Most bypasses were extracranial to intracranial and high flow. Flow capacity, collateral circulation, and availability of the donor vessel mainly affected the choice of the type of bypass. Overall, successful exclusion of the GIA was 91.4%. The need for retreatment and complication rate were 3.6% and 19.5%, respectively. A good overall outcome (modified Rankin Scale score 0-3) was achieved in 84.2% of patients, and mortality was 10%.

CONCLUSIONS

Microneurosurgical techniques still maintain a significant role for most GIAs, with a high durability and acceptable rate of morbidity and mortality. Clip reconstruction is the first-line surgical treatment option, whereas bypass is indicated in cases of planned or unplanned sacrifice of the parent artery to prevent long-term ischemic complications.

Additional Embolization for Intra-aneurysmal Blood Flow Resumption after Stent-assisted Embolization of Cerebral Aneurysms

Objective

Stent-assisted aneurysmal embolization (SAAE) is an effective treatment for aneurysms with a low risk of recurrence. In rare cases, retreatment is necessary due to recanalization of blood flow into the aneurysm. However, only a few studies have reported on retreatment. We examined the efficacy and complications of stent-assisted aneurysm embolization for large or wide-neck aneurysms at our hospital.

Methods

Between July 2010 and June 2018, 293 patients underwent stent-assisted aneurysm embolization at our hospital. Among them, 12 (2 women, 10 men, mean age: 62 years) needed retreatment. We evaluated the initial treatment of these 12 patients, and the methods and results of their retreatment.

Results

Six of the 12 retreated patients were treated using the simple technique. It was possible to treat nine patients (75%) without placing new stents, but three needed additional stents. We were able to guide the microcatheter into the aneurysm using the trans-cell technique even with two overlapping stents. We achieved complete embolism in seven patients (58%), and remnants were observed in the neck in five (42%) patients. No complications were associated with our surgery. We were able to perform follow-up for 10 patients and there was no recurrence.

Conclusion

Embolization should be considered in recurrent cases after the initial stent-assisted coil embolization. We achieved good results and reduced the recurrence rate by selecting the appropriate treatment in each case.

Comparison of Safety and Effectiveness of Endovascular Treatments for Unruptured Intracranial Large or Giant Aneurysms in Internal Carotid Artery

PURPOSE

To analyze and compare safety and efficacy of different endovascular treatment modalities for unruptured intracranial large or giant aneurysms.

METHODS

We retrospectively reviewed 126 consecutive patients with 128 large (15-24 mm) or giant (≥25 mm) aneurysms that were treated with different endovascular procedures between January 2014 and February 2017. We compared clinical and angiographic outcomes and occurrence of technical events among 3 treatment modalities.

RESULTS

Complete occlusion at last follow-up was achieved in 65.6%, 90.5%, and 72.0% of aneurysms in stent-assisted coiling, parent artery occlusion, and Pipeline embolization device (PED) groups (P = 0.119). Complete occlusion rate at 6-month follow-up (odds ratio = 1.81, P = 0.396) and at last angiographic follow-up (odds ratio = 3.64, P = 0.123), was not superior with parent artery occlusion compared with PED. Retreatment rate was significantly different among all groups (P < 0.001); the rate was highest in the stent-assisted coiling group (21.9%). Rates of hemorrhagic events and ischemic events were not significantly different among groups (P = 0.581). Mass effect exacerbation was more frequently seen in the stent-assisted coiling group (24.4% vs. 7.7% and 3.3%, P = 0.004). Major complication rate was higher in the parent artery occlusion group compared with the PED group, but the difference was not statistically significant (19.2% vs. 16.4%, odds ratio = 1.21, P = 0.763). Rate of technical events was significantly different in the 3 groups (P = 0.0437), and technical events occurred more often in the PED group (18.0%).

CONCLUSIONS

For large and giant aneurysms located in the internal carotid artery, outcome for endovascular treatment remains poor, even with the introduction of PED.

Endovascular Treatment of Very Large and Giant Intracranial Aneurysms: Comparison between Reconstructive and Deconstructive Techniques-A Meta-Analysis

BACKGROUND

The safety and efficacy of reconstructive and deconstructive endovascular treatments of very large/giant intracranial aneurysms are not completely clear.

PURPOSE

Our aim was to compare treatment-related outcomes between these 2 techniques.

DATA SOURCES

A systematic search of 3 data bases was performed for studies published from 1990 to 2017.

STUDY SELECTION

We selected series of reconstructive and deconstructive treatments with >10 patients.

DATA ANALYSIS

Random-effects meta-analysis was used to analyze occlusion rates, complications, and neurologic outcomes.

DATA SYNTHESIS

Thirty-nine studies evaluating 894 very large/giant aneurysms were included. Long-term occlusion of unruptured aneurysms was 71% and 93% after reconstructive and deconstructive treatments, respectively (P = .003). Among unruptured aneurysms, complications were lower after parent artery occlusion (16% versus 30%, P = .05), whereas among ruptured lesions, complications were lower after reconstructive techniques (34% versus 38%). Parent artery occlusion in the posterior circulation had higher complications compared with in the anterior circulation (36% versus 15%, P = .001). Overall, coiling yielded lower complication and occlusion rates compared with flow diverters and stent-assisted coiling. Complication rates of flow diversion were lower in the anterior circulation (17% versus 41%, P < .01). Among unruptured lesions, early aneurysm rupture (within 30 days) was slightly higher after reconstructive treatment (5% versus 0%, P = .08) and after flow diversion alone compared with flow diversion plus coiling (7% versus 0%).

LIMITATIONS

Limitations were selection and publication biases.

CONCLUSIONS

Parent artery occlusion allowed high rates of occlusion with an acceptable rate of complications for unruptured, anterior circulation aneurysms. Coiling should be preferred for posterior circulation and ruptured lesions, whereas flow diversion is relatively safe and effective for unruptured anterior circulation aneurysms.

Comparison of the flow diverter and stent-assisted coiling in large and giant aneurysms: safety and efficacy based on a propensity score-matched analysis

OBJECTIVES

The flow diverter (FD) is a device aimed at reconstructing the parent artery and occluding an aneurysm. We performed a propensity score-matched analysis to compare safety and efficacy between the FD and stent-assisted coiling.

METHODS

A database review was conducted to identify patients with large and giant unruptured aneurysms (aneurysms located in the ACA, MCA, or PCA were excluded) treated with the FD or stent-assisted coiling. A propensity score, representing the probability of using the FD, was generated for each aneurysm using the relevant patient and aneurysmal variables. Angiographic results, complications, and clinical outcomes were compared.

RESULTS

Forty-five aneurysms treated with the FD (FD alone: 32; FD+Coils: 13) and 45 treated with stent-assisted coiling were matched. The rate of complete occlusion was significantly (P = 0.0002) higher in the FD cohort than the conventional stent cohort at the 6-month follow-up. The FD cohort achieved greater improvement (P < 0.0001) and a lower rate of recurrence (P = 0.0001). The rate of periprocedural complications was similar, as was the proportion of patients who attained mRS ≤ 2 at discharge and at the 6-month follow-up.

CONCLUSIONS

Our findings provide reliable evidence demonstrating that the FD may be a preferred treatment option for large and giant unruptured aneurysms.

KEY POINTS

• Flow Diverter provided a higher complete occlusion rate at 6-month follow-up. • Flow Diverter achieved more progress occlusion and less recurrence. • Compared with the conventional stents, procedure-related morbidity of Flow Diverter was similar. • Flow Diverter is a preferred treatment for large and giant unruptured aneurysms.

Endovascular coiling vs. surgical clipping for unruptured intracranial aneurysm: A meta-analysis

BACKGROUND

With increasing use of high-resolution imaging of brain, unruptured aneurysms are more and more frequently detected. With the advances in treatment techniques, an increasing number of aneurysms are now occluded using endovascular coiling instead of conventional surgical clipping. However, the better modality for unruptured intracranial aneurysm has been poorly understood.

OBJECTIVE

The objective of this meta-analysis was to compare the outcomes between endovascular coiling and surgical clipping among patients with unruptured intracranial aneurysms.

METHODS

PubMed, Embase, Web of Science, CENTRAL, and SIGLE were electronically searched from January 1, 1990 to March 13, 2012 with no language restriction for randomized or nonrandomized clinical controlled trials. Article screening and data extraction were conducted in duplicate. Results were statistically pooled through Review Manager 5 and StatsDirect 2.7.9.

RESULTS

Seven studies met our inclusion criteria. The pooled risk ratios (coiling vs. clipping) were 0.59 (95% CI = 0.23-1.54) for death; 0.37 (95% CI = 0.10-1.41) for bleeding; 0.78 (95% CI = 0.38-1.58) for cerebral ischemia; 0.87 (95% CI = 0.70-1.08) for occlusion of aneurysm; 0.53 (95% CI = 0.18-1.52) for independence in daily activities. The pooled rates of death, bleeding, ischemia, occlusion of aneurysm, and mRS no less than 3 were 1% (95% CI = 0-2%), 2% (95% CI = 0-5%), 8% (95% CI = 4-13%), 82% (95% CI = 64-95%), and 5% (95% CI = 1-10%) for endovascular coiling, respectively, and 1% (95% CI = 0-2%), 6% (95% CI = 3-10%), 9% (95% CI = 5-15%), 95% (95% CI = 90-98%), and 8% (95% CI = 3-14%) for surgical clipping, respectively. We failed to evaluate quality of life and cognitive outcome due to insufficient data. Both meta-regression and sensitivity analysis showed consistent results. Furthermore, Begg's test and Egger's test failed to detect publication bias.

CONCLUSION

We suggest that endovascular coiling and surgical clipping bear similar risk ratios of death, bleeding, cerebral ischemia, occlusion of aneurysm, and independence in daily activities and encourage further studies on quality of life and cognitive outcome. However, albeit the results in this meta-analysis are robust, due to great clinical heterogeneity and low quality of studies, the results in this meta-analysis should be interpreted with caution.