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.

A 5-Year Follow-Up after Endovascular Treatment of 402 Intracranial Aneurysms-A Single-Centre Experience

The aim of our study was to evaluate the early and long-term clinical and morphological outcomes of the endovascular treatment of ruptured and non-ruptured intracranial aneurysms in a cohort of patients from a single centre. We retrospectively analysed the treatment outcomes of 402 endovascularly treated intracranial aneurysms with an average follow-up of 5.5 years. All included patients were treated with endovascular techniques (coil, stent or both). We analysed patient demographics, risk factors for an aneurysm rupture, aneurysm characteristics, and clinical and angiographic complications and outcomes. We analysed and compared the data from the two groups, ruptured aneurysms (RAs) and unruptured aneurysms (UAs), separately. Out of the 318 patients included, a good early clinical outcome was achieved in 78.5% of RAs and in 95.3% of UAs. No complications occurred in 87.71% of patients with UAs and in 80.45% with RAs. The periprocedural rupture rate for UAs and RAs was 0.8% and 2.2%, respectively. The rate of thromboembolic events was 4.8 and 8% for UAs and RAs, respectively. A retreatment due to the recanalisation was required in 9.21% of patients with UAs and in 16.66% of patients with RAs. The results from our centre showed an overall favourable clinical outcome with acceptable periprocedural complications for both RAs and UR aneurysms and proved the endovascular method as safe and effective in the treatment of intracranial aneurysms.

Optimizing resources: financial evaluation of flow diverters versus stent assisted coiling in large and giant cerebral aneurysm management in Brazil public health system

BACKGROUND

Cerebral aneurysms, especially large and giant aneurysms, pose challenges in neurointerventional surgery. Treatment choices involve clinical presentation, aneurysm details, and global resource variations. Neurointerventional methods, while innovative, may be cost restrictive in certain regions. In public healthcare, cost is crucial, notably in countries like Brazil. This study examines the device specific cost estimation of flow diverters (FD) and traditional stent assisted coiling (SAC) for large and giant cerebral aneurysms, providing insights into optimizing neurosurgical interventions within the Brazilian public health system's unique challenges.

METHODS

A comprehensive retrospective analysis was conducted at our medical center of cases of large and giant aneurysms treated between 2013 and 2023. Determination of the estimated number of coils for aneurysms previously treated with FDs at our center was made, with the cost of each case, and the difference between both treatments was calculated.

RESULTS

We investigated the profiles of 77 patients: 40 had large aneurysms (51.9%) and 37 had giant aneurysms (48.1%). Large aneurysms had a mean cost difference of US$274 (standard deviation (SD) $2071), underscoring the device specific cost estimation of FDs over SAC in their treatment. For giant aneurysms, the mean cost difference increased to $6396 (SD $2694), indicating FDs as the more economically sound choice.

CONCLUSION

Our study indicated that, for the treatment of giant aneurysms and some large aneurysms, the FD intervention was more economical than SAC.

A Giant Stent for Giant Cerebral Aneurysms-The Accero®-Rex-Stent

OBJECTIVE

Until now, giant intracranial aneurysms (GIAs) have in many cases been a vascular disease that was difficult or impossible to treat, not least due to the lack of availability of a large-format stent. In this multicentre study, we report on the first five clinical applications of the Accero®-Rex-Stents (Acandis, Pforzheim, Germany) in the successful treatment of fusiform cerebral giant aneurysms.

MATERIAL AND METHODS

The Accero®-Rex-Stents are self-expanding, braided, fully radiopaque Nitinol stents designed for aneurysm treatment. The stent is available in three different sizes (diameter 7-10 mm, length 30-60 mm) and intended for endovascular implantation in vessels with diameters of 5.5-10 mm.

RESULTS

Five patients (all male, age 54.4 ± 8.1 years) with large fusiform aneurysms of the posterior circulation were treated endovascularly using the Accero®-Rex-Stents. There were no technical complications. One major ischemic complication occurred. A significant remodeling and reduction in the size of the stent-covered aneurysms was already seen in the short-term post-interventional course.

CONCLUSIONS

The Accero®-Rex-Stents were successfully and safely implanted in all five patients with fusiform giant aneurysms, showing technical feasibility with promising initial results and significant aneurysm size reduction in already available follow-up imaging.

KEY POINT

With the Accero-Rex-Stents, a new device is available that offers another treatment option for rare cerebral fusiform giant aneurysms with very large parent vessels.

The Management of Intracranial Aneurysms: Current Trends and Future Directions

Intracranial aneurysms represent a major global health burden. Rupture of an intracranial aneurysm is a catastrophic event. Without access to treatment, the fatality rate is 50% in the first 30 days. Over the last three decades, treatment approaches for intracranial aneurysms have changed dramatically. There have been improvements in the medical management of aneurysmal subarachnoid haemorrhage, and there has been an evolution of treatment strategies. Endovascular therapy is now the mainstay of the treatment of ruptured intracranial aneurysms based on robust randomised controlled trial data. There is now an expansion of treatment indications for unruptured intracranial aneurysms to prevent rupture with both microsurgical clipping and endovascular treatment. Both microsurgical and endovascular treatment modalities have evolved, in particular with the introduction of innovative endovascular treatment options including flow diversion and intra-saccular flow disruption. These novel therapies allow clinicians to treat more complex and previously untreatable aneurysms. We aim to review the evolution of treatment strategies for intracranial aneurysms over time, and discuss emerging technologies that could further improve treatment safety and functional outcomes for patients with an intracranial aneurysm.

Giant anterior communicating artery aneurysm with intrasellar extension

Introduction

Aneurysms extending into the sella are uncommon with only a few cases reported till date. Most of these arise from either the supraclinoidal or infraclinoidal segments of the internal carotid artery.

Research question

Can Anterior communication artery aneurysm present with hypopituitarism due to compression of pituitary gland?

Materials & methods

Case report and literature review.

Results

We discuss this rare presentation in a middle-aged patient its surgical management and the follow-up course with a review of available literature.

Discussion & conclusion

Anterior communicating artery aneurysms extending into the sella are extremely uncommon with only 4 cases reported in literature. They are usually giant aneurysms which are partially thrombosed with presenting with predominantly with mass effect in this case visual impairment and hypofunction of the pituitary.

Enhance Safety in Aneurysm Surgery: Strategies for Prevention of Intraoperative Vascular Complications

Complications during surgery for intracranial aneurysms can be devastating. Notorious pitfalls include premature rupture, parent vessel occlusion, local cerebral injury and brain contusion, and incomplete neck obliteration. These unfavorable intraoperative events can result in major neurological deficits with permanent morbidity and even mortality. Herein, the author highlights the relevant surgical strategies used in his daily practice of aneurysm surgery (e.g., aneurysm clipping with adenosine-induced temporary cardiac arrest), application of which may help prevent vascular complications and enhance surgical safety through reduction of the associated risks, thus allowing improvement of postoperative outcomes. Overall, all described methods and techniques should be considered as small pieces in the complex puzzle of prevention of vascular complications during aneurysm surgery.

Treatment of giant intracranial aneurysms: long-term outcomes in surgical versus endovascular management

Aneurysms with a major diameter > 25 mm are defined as giant intracranial aneurysms (GIAs). Different clinical, pathological, and radiological factors were revealed as playing a role in choosing the best strategy between surgical and endovascular approaches. Despite the improvement of both techniques, the efficacy and safety of these different management are still debated. We evaluated the differences in clinical and radiological outcomes of GIAs treated with surgical and endovascular techniques in a large retrospective mono-centric study. We compared aneurysm location, clinical, morphological features, treatment outcome, and complications on the ground of treatment technique. The final cohort consisted of 162 patients. All the patients were assigned on the ground of the type of eligible treatment: surgical (118 patients) and endovascular procedure (44 patients). The different treatment strategies were made through a multidisciplinary selection whereas clinical parameters, location, and morphologic features of the aneurysm were considered. The surgical group manifested a greater reduction in performance levels and neurological status in the post-operative phases than the endovascular group (p < 0.01) with a higher incidence of complications (p = 0.012) in contrast to a lower recurrence rate (p > 0.01). There is no significant difference in post-operative mortality and survival between surgical and endovascular groups. The surgical group manifested a higher incidence of complications after treatment. The endovascular group has a better post-operative outcome, but a higher risk of recurrence and the necessity of further treatment.

Risk factors and outcomes of postoperative stroke in surgical treatment for giant intracranial aneurysms

Background

Giant intracranial aneurysms (GIAs) are challenges for surgical treatment. Risk factors of postoperative stroke remain unclear. This study aims to investigate the predictors of postoperative stroke in GIAs and the impact of stroke on outcomes.

Methods

We performed a retrospective medical record review of patients with GIAs who received microsurgery at our institution between 2011 and 2018. Multivariate logistic regression analyses were carried out to identify risk factors for postoperative stroke. The clinical and angiographic outcomes were compared between patients with and without stroke.

Results

A total of 97 patients were included in this study. Surgical modalities included direct aneurysm neck clipping in 85 patients (87.7%), trapping with the bypass in 8 (8.2%), proximal artery ligation in 1 (1%), and bypass alone in 3 (3.1%). Postoperative stroke was found in 26 patients (26.8%). Independent factors that affect postoperative stroke were recurrent aneurysm (OR, 10.982; 95% CI, 1.976–61.045; P = 0.006) and size ≥ 3.5 cm (OR, 3.420; 95% CI, 1.133–10.327; P = 0.029). Combined perioperative mortality and morbidity was 26.8%. Follow-up was achieved from 89 patients (91.8%), with a mean follow-up period of 39 months (range 19 to 94 months). Good outcomes were observed in 75 patients (84.3%) and poor outcomes were observed in 14 patients (15.7%).

Conclusions

Postoperative stroke was significantly associated with clinical outcome. Favorable outcomes can be achieved in most patients with GIAs after appropriate microsurgical modality. Recurrent aneurysm and size ≥ 3.5 cm are risk factors of postoperative stroke.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41016-022-00297-x.

Giant Vertebrobasilar Aneurysm: The Rule of Decompressive Craniectomy Previous to Endovascular Treatment

Giant vertebral-basilar aneurysms are rare and represent 1% of intracranial aneurysms. Natural history and treatment are associated with severe clinical manifestations, such as ischemia, mass effect, hydrocephalus, and subarachnoid hemorrhage, leading to high mortality and morbidity. In this case, a 51-year-old male with no relevant medical history presented to the emergency department with severe pulsatile right temporo-occipital headache, radiating to the territory of the maxillary branch of the trigeminal nerve. Investigation revealed a giant unruptured vertebrobasilar aneurysm partially thrombosed. As treatment strategy, a suboccipital craniectomy was initially performed, and a week later, as a second stage, the patient underwent a stent placement from the V3 segment of the vertebral artery to the distal segment of the basilar trunk. Very few cases of this entity have been reported, and the endovascular treatment of this type of aneurysm is complex, with a high risk of mortality or morbidity, caused by thrombosis or by the inflammatory response secondary to the treatment, with compression of the brainstem. Decompressive craniectomy prior to endovascular treatment may play an important role in preventing life-threatening complications.

The changing landscape of cerebral revascularization surgery: A United Kingdom experience

Objective

We describe the chronological trends in cerebral revascularization surgery through a single-surgeon experience; and we review whether in the context of giant and fusiform cerebral aneurysms, flow-diverting stents have impacted on the use of cerebral revascularization surgery.

Methods

We review our single institution prospectively collected database of cerebral revascularization procedures between 2006 and 2018. Comparing this to our database of flow-diverting endovascular stent procedures, we compare the treatment of fusiform and giant aneurysms. We describe patient demographics, procedural incidence, complications, and outcomes.

Results

Between 2006 and 2018, 50 cerebral revascularization procedures were performed. The incidence of cerebral revascularization surgery is declining. In the context of giant/fusiform aneurysm treatment, the decline in cerebral revascularization is accompanied by a rise in the use of flow-diverting endovascular stents. Thirty cerebral revascularizations were performed for moyamoya disease and 11 for giant/fusiform aneurysm. Four (14%) direct bypass grafts occluded without neurological sequela. Other morbidity included hydrocephalus (2%), transient ischemic attacks (2%), and ischemic stroke (2%). There was one procedure-related mortality (2%). Flow-diverting stents were inserted for seven fusiform and seven giant aneurysms. Comparing the treatment of giant/fusiform aneurysms, there was no significant difference in morbidity and mortality between cerebral revascularization and flow-diverting endovascular stents.

Conclusion

We conclude that with the decline in the incidence of cerebral revascularization surgery, there is a need for centralization of services to allow high standards and outcomes to be maintained.

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.

Progressive volume reduction and long-term aneurysmal collapse following flow diversion treatment of giant and symptomatic cerebral aneurysms

Background

The primary goal of conventional endovascular and microvascular approaches is the clinical and radiological resolution of the symptomatic aneurysm-induced mass effect. This study assessed the volume changes and mass effect reduction due to sac shrinkage after treatment with flow diverter stents (FD) for unruptured cerebral aneurysms.

Methods

We analyzed retrospectively 36 symptomatic aneurysms that were larger or equal to 25 mm in diameter in patients treated at our center from January 2016 to April 2022. Radiological and clinical outcomes were analyzed, including aneurysmal volume changes and resolution of aneurysm-related symptoms.

Results

At 6 months, 25 aneurysms decreased in size, 2 remained unchanged, and 9 aneurysms demonstrated a post-treatment dimensional increase. At 12 months, 30 aneurysms showed a progressive radiological volume reduction. Either no change or negligible shrinkage was observed in the remaining six aneurysms. At 24 months, 32 aneurysms showed aneurysmal shrinkage by a mean 47% volume loss with respect to baseline. At the last follow-up, all 13 patients who had presented with third cranial nerve palsy showed improvements. Complete reversal of the pretreatment edematous changes was confirmed in all cases. The overall post-treatment complication rate was 8.3%, as 3 patients experienced non-fatal delayed rupture of their aneurysm. There was no mortality in this study.

Conclusion

Flow diversion could effectively induce progressive aneurysmal shrinkage and resolution of the mass effect associated with giant symptomatic cerebral aneurysms.

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.

Remarkable shrinkage of a thrombosed giant aneurysm by stent-assisted jam-packed coil embolization

Background:

Large and giant aneurysms are known to involve intra-aneurysmal thrombosis and present a poor prognosis because of compression of the surrounding brain tissue with enlargement of the aneurysm. These aneurysms are difficult to cure by endovascular treatment due to involvement of the vasa vasorum in their pathology. We report this technical note to describe stent-assisted jam-packed coil embolization for the treatment of a giant thrombosed aneurysm.

Case Description:

A 62-year-old man presented with right homonymous hemianopsia, and magnetic resonance imaging (MRI) showed a giant thrombosed aneurysm with poor wall contrast enhancement, which indicates little involvement of the vasa vasorum, at the terminal part of the left internal carotid artery. To block blood flow into the aneurysmal dome, stent-assisted “jam-packed” coil embolization was performed. For this, a braided stent was shortened to enhance metal coverage ratio and tight aneurysmal coil packing was performed using a hydrogel coil. Our technique resulted in complete obliteration of the aneurysm, and MRI performed 1 year later showed remarkable shrinkage of the aneurysm dome.

Conclusion:

Stent-assisted jam-packed coil embolization technique might be effective in shrinking the dome of giant thrombosed aneurysms with poor wall contrast enhancement.

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.

Unruptured Giant Intracranial Aneurysms: Risk Factors for Mortality and Long-Term Outcome

This study aims to investigate the long-term outcomes of unruptured giant intracranial aneurysms (GIAs) with different treatment modalities and to analyze the factors affecting prognosis. We performed a retrospective medical record review of patients with unruptured GIAs treated at our institution from 2011 to 2018. Prognosis was compared to the best medical treatment without intervention (conservative treatment, CT) and surgical (ST) or endovascular (ET) treatment. Risk factors for mortality were investigated. A total of 276 patients were included in this study. Patients received CT in 16.3%, ST in 30.1%, and ET in 53.6% of cases. After an average 7-year follow-up, the rupture rate after CT was 22.2%, accounting for an annual rupture rate of 7.3%. The postoperative complication rate was 30.1% and 8.1% after ST and ET, respectively. The recurrence rate after ET was 10.1%, compared with ST which was 1.2%. The follow-up mortality in unruptured GIAs was 26.7% after CT, 7.2% after ST, and 5.4% after ET. Older age (50~59, HR 5.877; 60~69, HR 8.565), size ≥ 40 mm (HR 3.916), and posterior circulation location (HR 6.411) were associated with increased mortality. ET significantly decreased mortality (HR 0.191). Unruptured GIAs warrant treatment if feasible due to the high rupture rate and mortality of the natural history. Older age, posterior circulation location, and larger size are risk factors for poor prognosis. Both ST and ET showed a lower mortality rate than CT. ST showed less likely recurrence compared to ET, while ET had a lower complication rate than ST.

Endovascular Treatment of Giant Intracranial Aneurysms

Objective

Giant intracranial aneurysms (GIAs) are associated with a high risk of rupture and have a high mortality rate when they rupture (65-100%). The traditional microsurgical approach to secure these lesions is challenging, and as such endovascular embolization has been increasingly selected as a treatment option.

Methods

We performed a retrospective analysis of consecutive patients with ruptured and unruptured GIAs at three medical centers from October 2008 to April 2016. Clinical follow-up and digital subtraction angiography were conducted at six months post-treatment. Chi-square analysis was used to determine differences in outcomes between anterior and posterior circulation aneurysms and if a pipeline embolization device (PED) provided favorable outcomes in unruptured GIAs.

Results

A total of 45 consecutive patients (mean/median age = 57/59; range: 16-82 years) were included. The mean/median aneurysm size was 29.9/28.3 mm (range: 25-50 mm). Eight (18%) patients presented with aneurysmal subarachnoid hemorrhage and 37 (82%) with unruptured GIAs. Twenty-eight (62%) were treated with a PED: 11 (24.4%) with one PED, 1 (2.2%) with PED + coils, 11 (24.4%) with more than one PED, and 5 (13.5%) with multiple PED + coils. The overall mortality rate was 3/45 (6.7%). No deaths were procedure-related. Five (11.1%) patients experienced ischemic stroke but only 2 had a 90-day modified Rankin Scale (mRS) score of ≥3. Of 33 patients available for six-month angiography, Raymond scale (RS) scores were 1, 2, and 3 for 23/45 (70%), 7/45 (20.9%), and 3/45 (9.1%), respectively. Chi-square test demonstrated that overall, anterior circulation GIAs had better clinical (mRS score) and radiographic (RS score) outcomes than posterior GIAs. PED alone provided similar clinical mRS outcomes but had a higher rate of complete occlusion at six months compared with PED + coils and coils alone in unruptured GIAs (p < 0.05).

Conclusions

Endovascular embolization using PED or PED + coils appears to be a moderately safe and effective treatment option for patients with GIAs.

Advances in endovascular aneurysm management: flow modulation techniques with braided mesh devices

Flow diverters and flow disruption technology, alongside nuanced endovascular techniques, have ushered in a new era of treating cerebral aneurysms. Here, we provide an overview of the latest flow modulation devices and highlight their clinical applications and outcomes.

Giant intracranial aneurysms: natural history and 1-year case fatality after endovascular or surgical treatment

OBJECTIVE

Clinical evidence on giant intracranial aneurysms (GIAs), intracranial aneurysms with a diameter of at least 25 mm, is limited. The authors aimed to investigate the natural history, case fatality, and treatment outcomes of ruptured and unruptured GIAs.

METHODS

In this international observational registry study, patients with a ruptured or unruptured GIA received conservative management (CM), surgical management (SM), or endovascular management (EM). The authors investigated rupture rates and case fatality.

RESULTS

The retrospective cohort comprised 219 patients with GIAs (21.9% ruptured GIAs and 78.1% unruptured GIAs) whose index hospitalization occurred between January 2006 and November 2016. The index hospitalization in the prospective cohort (362 patients with GIAs [17.1% ruptured and 82.9% unruptured]) occurred between December 2008 and February 2017. In the retrospective cohort, the risk ratio for death at a mean follow-up of 4.8 years (SD 2.2 years) after CM, compared with EM and SM, was 1.63 (95% CI 1.23-2.16) in ruptured GIAs and 3.96 (95% CI 2.57-6.11) in unruptured GIAs. In the prospective cohort, the 1-year case fatality in ruptured GIAs/unruptured GIAs was 100%/22.0% during CM, 36.0%/3.0% after SM, and 39.0%/12.0% after EM. Corresponding 1-year rupture rates in unruptured GIAs were 25.0% during CM, 1.2% after SM, and 2.5% after EM. In unruptured GIAs, the HR for death within the 1st year in patients with posterior circulation GIAs was 6.7 (95% CI 1.5-30.4, p < 0.01), with patients with a GIA at the supraclinoid internal carotid artery as reference. Different sizes of unruptured GIAs were not associated with 1-year case fatality.

CONCLUSIONS

Rupture rates for unruptured GIAs were high, and the natural history and treatment outcomes for ruptured GIAs were poor. Patients undergoing SM or EM showed lower case fatality and rupture rates than those undergoing CM. This difference in outcome may in part be influenced by patients in the CM group having been found poor candidates for SM or EM.Clinical trial registration no.: NCT02066493 (clinicaltrials.gov).

Clinical implications and radiographic characteristics of the relation between giant intracranial aneurysms of the posterior circulation and the brainstem

BACKGROUND

Giant intracranial aneurysms of the posterior circulation (GPCirA) are rare entities compressing the brainstem and adjacent structures. Previous evidence has shown that the amount of brainstem shift away from the cranial base is not associated with neurological deficits. This raises the question whether other factors may be associated with neurological deficits.

METHODS

All data were extracted from the Giant Intracranial Aneurysm Registry, an international multicenter prospective study on giant intracranial aneurysms. We grouped GPCirA according to the mass effect on the brainstem (lateral versus medial). Brainstem compression was evaluated with two indices: (a) brainstem compression ratio (BCR) or diameter of the compressed brainstem to the assumed normal diameter of the brainstem and (b) aneurysm to brainstem ratio (ABR) or diameter of the aneurysm to the diameter of the compressed brainstem. We examined associations between neurological deficits and GPCirA characteristics using binary regression analysis.

RESULTS

Twenty-eight GPCirA were included. Twenty GPCirA showed medial (71.4%) and 8 lateral compression of the brainstem (28.6%). Baseline characteristics did not differ between the groups for patient age, aneurysm diameter, aneurysm volume, modified Rankin Scale (mRS), motor deficit (MD), or cranial nerve deficits (CND). Mean BCR was 53.0 in the medial and 54.0 in the lateral group (p = 0.92). The mean ABR was 2.9 in the medial and 2.3 in the lateral group (p = 0.96). In the entire cohort, neither BCR nor ABR nor GPCirA volumes were associated with the occurrence of CND or MD. In contrast, disability (mRS) was significantly associated with ABR (OR 1.94 (95% CI 1.01-3.70; p = 0.045) and GPCirA volumes (OR 1.21 (95% CI 1.01-1.44); p = 0.035), but not with BCR.

CONCLUSION

In this cohort of patients with GPCirA, neither the degree of lateral projection nor the amount of brainstem compression predicted neurological deficits. Disability was associated only with aneurysm volume. When designing treatment strategies for GPCirA, aneurysm laterality or the amount of brainstem compression should be viewed as less relevant while the high risk of rupture of such giant lesions should be emphasized.

TRIAL REGISTRATION

The registry is listed at clinicaltrials.gov under the registration no. NCT02066493.

Microsurgical outcome of unruptured giant intracranial aneurysms: A single-center experience

Microsurgical treatment of unruptured giant intracranial aneurysms (GIAs) is challenging. Although previous studies regarded clipping as the first option to repair GIAs, quite a number of GIAs are not clippable. We conducted this study to evaluate the postoperative complications and long-term outcome of patients with unruptured GIAs treated by different microsurgical modalities. We retrospectively reviewed 505 consecutive patients with unruptured intracranial aneurysms (UIAs) who were surgically treated in our department from 2012 to 2015. Patients with UIAs of which diameter ≥2.5 cm were studied. We reported the characteristics of patients and GIAs. Postoperative major complications were observed, and patient functional status were assessed with the modified Rankin Scale (mRS) at discharge and at the last follow-up. Twenty-one patients with unruptured GIAs were analysed, of whom 12 patients were treated by clipping, whereas 9 patients with unclippable aneurysms were treated by trapping or parent vessel occlusion. Fourteen aneurysms were saccular, and 7 were fusiform or serpentine. The mean aneurysm size was 3.7 ± 1.5 cm. After surgery, major complications were observed in 13 of the 21 (61.9%) patients. One (4.8%) patient died during hospital. After a mean 5.2-year follow-up, 9 (75.0%) patients treated by clipping and 7 (77.8%) treated by non-clipping experienced a good outcome (mRS ≤2). We found no significant difference in both postoperative complications and long-term outcome between clipping and non-clipping group. Favorable prognosis can be obtained in most patients with unruptured GIAs treated by appropriate microsurgical modality.

Morphological parameters as factors of 12-month neurological worsening in surgical treatment of patients with unruptured saccular intracranial aneurysms: importance of size ratio

OBJECTIVE

It is well known that larger aneurysm size is a risk factor for poor outcome after surgical treatment of unruptured saccular intracranial aneurysms (USIAs). However, the authors have occasionally observed poor outcome in the surgical treatment of small USIAs and hypothesized that size ratio has a negative impact on outcome. The aim of this paper was to investigate the influence of size ratio on outcome in the surgical treatment of USIAs.

METHODS

Prospectively collected clinical and radiological data of 683 consecutive patients harboring 683 surgically treated USIAs were evaluated. Dome-to-neck ratio was defined as the ratio of the maximum width of the aneurysm to the average neck diameter. The aspect ratio was defined as the ratio of the maximum perpendicular height of the aneurysm to the average neck diameter of the aneurysm. The size ratio was calculated by dividing the maximum aneurysm diameter (height or width, mm) by the average parent artery diameter (mm). Neurological worsening was defined as an increase in modified Rankin Scale score of 1 or more points at 12 months. Clinical and radiological variables were compared between patients with and without neurological worsening.

RESULTS

The median patient age was 64 years (IQR 56-71 years), and 528 (77%) patients were female. The median maximum size, dome-to-neck ratio, aspect ratio, and size ratio were 4.7 mm (IQR 3.6-6.7 mm), 1.2 (IQR 1.0-1.4), 1.0 (IQR 0.76-1.3), and 1.9 (IQR 1.4-2.8), respectively. The size ratio was significantly correlated with maximum size (r = 0.83, p < 0.0001), dome-to-neck ratio (r = 0.69, p < 0.0001), and aspect ratio (r = 0.74, p < 0.0001). Multivariate logistic regression analysis showed that the specific USIA location (paraclinoid segment of the internal carotid artery: OR 6.2, 95% CI 2.6-15, p < 0.0001; and basilar artery: OR 8.4, 95% CI 2.8-25, p < 0.0001), size ratio (OR 1.3, 95% CI 1.1-1.6, p = 0.021), and postoperative ischemic lesion (OR 9.4, 95% CI 4.4-19, p < 0.0001) were associated with neurological worsening (n = 52, 7.6%), and other characteristics showed no significant differences.

CONCLUSIONS

The present study showed that size ratio, and not other morphological parameters, was a risk factor for 12-month neurological worsening in surgically treated patients with USIAs. The size ratio should be further studied in a large, prospective observational cohort to predict neurological worsening in the surgical treatment of USIAs.

Safety and Efficacy of Surgical Treatment of Intracranial Aneurysms: The Experience of a Single Brazilian Center

BACKGROUND

The use of microsurgery for aneurysm clipping has decreased considerably in recent years. This study was conducted to demonstrate the safety and effectiveness of surgical treatment of intracranial aneurysms even in less-developed countries.

METHODS

This study was a retrospective review of the medical records of 320 patients with 416 aneurysms treated with microsurgical clipping at a single neurosurgical center in Brazil between 2008 and 2016. We evaluated postoperative outcomes using the modified Rankin Scale (mRS) at the time of hospital discharge, treatment efficacy by digital subtraction angiography (DSA) performed postoperatively, and mortality.

RESULTS

The 320 patients with aneurysms included 228 patients with ruptured aneurysms and 92 with unruptured aneurysms. Overall, 81 (26.3%) had a poor outcome (mRS score >2), and the other 227 (73.4%) had a good outcome. The presence of a ruptured aneurysm was a statistically significant factor for poor outcome (P < 0.001) and mortality (P < 0.015). Giant and large aneurysms were also associated with poor outcome (P = 0.004). When analyzed separately, unruptured aneurysms with poor outcome were only associated with aneurysm size. Among the patients with ruptured aneurysms, those with Hunt and Hess (HH) grade >2 on hospital admission had unfavorable outcomes (P < 0.0001). Among the patients who underwent postoperative DSA, 207 (89.8%) had complete aneurysm occlusion and 24 (10.2%) had residual aneurysms, with reoperation required in 8 cases.

CONCLUSIONS

Microsurgical treatment of intracranial aneurysms is an effective and safe method.

Microsurgical Treatment for Complex Basilar Artery Aneurysms with Long-Term Follow-Up in a Series of 35 Cases

BACKGROUND

There has been a massive shift in the balance toward endovascular therapy for basilar artery (BA) aneurysms in the modern era.

METHODS

We retrospectively reviewed clinical and radiologic data from patients with BA aneurysms who were treated in a single medical center during a 10-year period from August 2006 to May 2016.

RESULTS

Thirty-five consecutive patients with 46 aneurysms during the 10-year period were included. The rate of complete aneurysm occlusion in 35 cases using a 1-stage operation was 58.8% (20/34). The graft patency rates of 13 bypass surgeries were 84.6% (11/13) within 1 week and 69.2% (9/13) at 3 months after surgery. The cut flow index for all bypass cases was 0.79. The overall survival was 94% at discharge (2 patients died). The 3-month outcome was favorable (modified Rankin Scale score 0-2) for 27 patients (77.1%) and poor (modified Rankin Scale score 3-5) for 5 patients (14.2%), and 3 patients died (8.6%). The survival for patients with BA apex aneurysms was higher than the survival observed for patients with BA trunk/vertebrobasilar junction aneurysms.

CONCLUSIONS

Microsurgical treatments for BA aneurysms can be effective, with good patient outcomes in the early stage after operation. Patients with wide-necked, fusiform, or dolichoectatic aneurysms seem to exclude the aneurysm, preventing unnecessary retreatments with bypass techniques. The potential for a poor prognosis of patients with BA trunk/vertebrobasilar junction aneurysms was higher than that for patients with basilar apex aneurysms who presented with unfavorable subsequent events.

A novel technology to model pressure-induced cellular injuries in the brain

BACKGROUND

Elevated intracranial pressure (ICP) accompanying a number of neurological emergencies is poorly understood, and lacks a model to determine cellular pathophysiology. This limits our ability to identify cellular and molecular biomarkers associated with the pathological progression from physiologic to pathologic ICP.

NEW METHOD

We developed an ex vivo model of pressure-induced brain injury, which combines 3D neural cell cultures and a newly developed Pressure Controlled Cell Culture Incubator (PC³I). Human astrocytes and neurons maintained in 3D peptide-conjugated alginate hydrogels were subjected to pressures that mimic both physiologic and pathologic levels of ICP for up to 48h to evaluate the earliest impacts of isolated pressure on cellular viability and quantify early indicators of pressure-induced cellular injury.

RESULTS

Compared to control cell cultures grown under physiologic pressure, sustained pathologic pressure exposure increased the release of intracellular ATP in a cell-specific manner. Eighteen hours of sustained pressure resulted in increased ATP release from neurons but not astrocytes.

COMPARISON WITH EXISTING METHODS

Cell culture incubators maintain cultures at normal atmospheric pressure. Based on multiple literature searches, we are not aware of any other cell culture incubator systems that modify the pressure at which primary CNS cells are maintained.

CONCLUSION

This model simulates the clinical features of elevated ICP encountered in patients with hydrocephalus, and provides a first estimate of the pathological signaling encountered during the earliest perid of progression in neonatal hydrocephalus. This model should provide a means to better understand the pathological biomarkers associated with the earliest stages of elevated ICP.

Giant Intracranial Aneurysms: Surgical Treatment and Analysis of Risk Factors

OBJECTIVE

To study clinical outcome of giant intracranial aneurysms (diameter ≥25 mm) treated with different surgical modalities and to analyze factors affecting prognosis.

METHODS

A retrospective analysis was performed of 204 consecutive patients with giant intracranial aneurysms who underwent surgical treatment in our department from 1995 to 2008. Clinical outcome was evaluated with the Glasgow Outcome Scale.

RESULTS

Surgical modalities included direct aneurysm neck clipping in 102 patients (50.0%), parent artery reconstruction in 51 patients (25.0%), proximal artery ligation in 23 patients (11.3%; 4 patients combined with revascularization), trapping in 26 patients (12.7%), and wrapping in 2 patients (1.0%). Follow-up data were available for 181 patients (88.7%), with a mean follow-up period of 62 months (range, 12-164 months). A good outcome (Glasgow Outcome Scale score 5) was observed in 114 patients (63.0%), and a poor outcome (Glasgow Outcome Scale score 1-4) was observed in 67 patients (37.0%). Independent factors that affected prognosis were age and location of aneurysm. Older age (≥50 years) and location of aneurysm in posterior circulation were associated with poor outcome. In 85 patients with preoperative subarachnoid hemorrhage, patients with a higher Hunt and Hess grade (≥3) had a worse outcome compared with patients with a low Hunt and Hess grade (1 or 2). Surgical modalities and other factors were not significantly associated with clinical outcome.

CONCLUSIONS

Giant intracranial aneurysms are effectively treated with craniotomy and surgical treatment. Older age, aneurysm location in posterior circulation, and higher Hunt and Hess grade are risk factors affecting prognosis.

Posterior Fossa Craniectomy with Endovascular Therapy of Giant Fusiform Basilar Artery Aneurysms: A New Approach to Consider?

BACKGROUND

The prognosis of unruptured giant basilar artery (BA) aneurysms is very poor. No treatment has shown efficacy in survival. This pilot case-control study examines the overall survival (OS) benefit of combined surgical and endovascular management of giant BA aneurysms.

METHODS

Combined treatment including posterior fossa craniectomy followed by endovascular treatment was performed in 3 patients with giant BA aneurysms. OS of the 3 patients was compared with a control group of 6 patients (ratio 1:2) treated with the endovascular procedure only.

RESULTS

The mean survival time was 32.6 months in the craniectomy group (SD 9.01, 95% confidence interval [14.9, 50.3]) and 3.5 months in the control group (SD = 2.08, 95% confidence interval [0.001, 7.6]; Mantel-Cox test P < 0.04). At mean follow-up of 36.5 months (SD 10.2), 2 of 3 patients had a favorable outcome with a Glasgow Outcome Scale score of 5. Univariate analysis determined that women had a statistically higher OS than men (33.7 months vs. 3.058 months for men; log-rank test P = 0.011). A similar outcome was obtained in the presence of a circulating posterior communicating artery (P = 0.03) and in the presence of an endovascular right vertebral artery occlusion (P = 0.022).

CONCLUSIONS

Our study suggests that preventive posterior fossa craniectomy increases significantly OS of patients with giant BA aneurysms.

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.