Epidemiology, genetic, natural history and clinical presentation of giant cerebral aneurysms

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.

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.

Flow Diverter Stenting for Symptomatic Intracranial Internal Carotid Artery Aneurysms: Clinical Outcomes and Factors for Symptom Improvement

Flow diverter (FD) stenting is expected to improve cranial nerve symptoms caused by aneurysms via the theoretical reduction of the mass effect by promoting spontaneous thrombosis through the flow diversion effect. However, the factors involved in symptom improvement after treatment remain unclear. This study was performed to identify factors for symptom improvement after FD stenting and the symptom improvement rate of each impaired cranial nerve. We retrospectively evaluated 33 patients who underwent FD stenting for symptomatic internal carotid artery aneurysms at our institution from January 2016 to June 2021. Twenty-three (69.7%) patients had resolved or improved symptoms after 1 year of treatment. The optic nerve was affected in 12 patients; the oculomotor nerve, in 16; the trigeminal nerve, in 2; and the abducens nerve, in 13. There was no statistically significant difference in the symptom improvement rate of each impaired cranial nerve. The patients were classified into the improved and nonimproved groups based on their symptoms after 1 year of treatment, and the factors related to the symptoms were analyzed. The time from onset to treatment was significantly shorter in the improved group than in the nonimproved group (197.1 and 800 days, respectively; p = 0.023). There were no significant differences in age, aneurysm diameter, adjunctive coil embolization, partial thrombosis, change in mass diameter on magnetic resonance imaging, or aneurysm occlusion rate on angiography between the two groups. These results suggest that early treatment after the onset of aneurysm-induced cranial neuropathies increases the likelihood of symptom improvement.

The "pipe-anchor" technique: A method for intra-aneurysmal loop reduction using a partially unsheathed pipeline stent

PURPOSE

Large aneurysms often present a challenge for endovascular navigation, as they may require utilization of "around-the-world" technique for distal access. In this study, we describe the use of a pipeline stent to stabilize the microcatheter allowing gradual unsheathing and straightening of the microcatheter within the aneurysm enabling stent deployment.

METHODS

A pipeline stent is partially deployed distal to the aneurysm, after using intra-aneurysmal loop ("around-the-world") to cross the aneurysm. Partially unsheathed, using its radial force and vessel wall friction to establish an anchoring point, the microcatheter is stabilized and pulled with the stent locked to gradually to allow loop reduction and microsystem straightening, allowing unsheathing as the microsystem is aligned with the inflow and outflow vessel.

RESULTS

Two patients harboring cavernous segment aneurysms (measuring 18 × 12 mm and 21 × 24 mm) were treated by 3.75 × 25 mm and 4.25 × 25 mm pipeline devices, respectively, using this technique, deployed through a Phenom 0.027" microcatheter. Patients did well clinically with no thromboembolic complications, as follow-up imaging demonstrated good wall apposition and appreciable contrast stagnation.

CONCLUSION

Anchoring for loop reduction was previously described using a non-flow diverter stents or balloon requiring additional devices and exchange maneuvers to deploy a pipeline. The "pipe anchor" technique describes the use of a partially deployed flow diverter system as an anchor. This report suggests that pipeline radial force, albeit low, is sufficient. We believe that this method is worthy of consideration in select cases as a first choice and can be valuable tool in the armamentarium of the endovascular neurosurgeon.

Giant aneurysm arising from a cortical middle cerebral artery branch presenting as an extra-axial tumour: a case report

The size and anatomical complexity make giant intracranial aneurysms challenging surgical lesions. There is limited literature available for those arising from distal branches. The cases that have been reported in the literature have all presented with symptoms from a rupture leading to an intracranial haemorrhage. In this case report, the authors present a case of a giant aneurysm arising from a cortical branch of the middle cerebral artery presenting as an extra-axial tumour. A 76-year-old gentleman presented with a 2-day history of subjective left arm numbness. Imaging revealed a large conical right-sided parietal lesion. Intraoperatively, it was found that the lesion was being supplied by a single vascular pedicle. Histology was consistent with an aneurysm. In this case, that patient did not have any evidence of a rupture unlike all reported cases of cortical giant aneurysms. This case highlights the myriad location and presentation of giant intracranial aneurysms.

Microsurgical Treatment of a Giant Intracavernous Carotid Artery Aneurysm in a Pediatric Patient: Case Report and Literature Review

Intracranial aneurysms in children account for 4%-5% of all cases, with 20% being considered giant (>25 mm). The main sites of occurrence are the internal carotid artery (ICA) and the middle cerebral artery (MCA). Rupture and secondary subarachnoid hemorrhage occur in approximately 55%-72.5% of cases, with a 10%-23% mortality rate. We report the case of a previously healthy nine-year-old girl who developed sudden, severe right retroocular pain and a holocranial headache as a mode of onset. Besides, the patient presented with double vision, and her relatives sought medical attention. Paresis of the right III, IV, and VI cranial nerves was found at physical examination. An MRI and digital subtraction angiography showed the presence of a giant aneurysm in the cavernous portion of the ICA with a mass effect. The patient was treated surgically through a high-flow bypass using a radial artery graft and trapping of the aneurysm. She had an uneventful postoperative course and was discharged three days after the operation to continue follow-up at the outpatient clinic. The therapeutic options were: a) an endovascular approach using flow diverters or stenting and coiling; or b) surgical treatment with proximal closure of the ICA if the patient had good collateral circulation or trapping the aneurysm combined with a high-flow bypass if the collateral circulation was not good or absent. After discussion, we decided on the surgical option. Even when the surgery was successful in this case, there is no consensus about the best way to treat it; the selection should be based on the center´s experience when confronting this rare entity.

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 Aneurysm Management

The treatment of giant aneurysms has always been a challenge in the field of neurovascular disease. Giant aneurysms are larger in size and are associated with thrombosis development and the calcification of the aneurysmal wall and neck, which often interfere with direct clipping. Most giant aneurysms have a wide neck with an incomplete thrombus, making complete embolization almost impossible. Giant aneurysms of different sites have entirely different hemodynamic characteristics. Moreover, aneurysms at the same site may exhibit very different hemodynamics among different individuals. Therefore, careful assessment of each case is required before and during treatment to develop and carry out an individualized treatment plan.

Symptomatic Cavernous Internal Carotid Artery Aneurysm Complicated by Simultaneous Rapid Growth of the Intra-aneurysmal and Parent Artery Thromboses

Cavernous internal carotid artery (ICA) aneurysm complicated by simultaneous and spontaneous formation of thromboses in the aneurysm and the parent artery is a rare clinical condition. Although the majority of patients have good outcomes, some patients experience severe ischemic stroke. Here, we report a case of symptomatic large cavernous ICA aneurysm complicated by rapid growth of an intra-aneurysmal thrombosis with simultaneous parent artery thrombosis. A 68-year-old female presented with sudden-onset diplopia, right ptosis, right conjunctival hyperemia, and paresthesia of the right face. Magnetic resonance imaging (MRI) and digital subtract angiography (DSA) revealed the presence of a large partially thrombosed aneurysm in the cavernous portion of the right ICA. We planned endovascular embolization using a flow-diverting (FD) stent. Dual-antiplatelet therapy (DAPT) with aspirin and clopidogrel was started 2 weeks prior to treatment. Although the neurological state was stable, DSA conducted on the day of the endovascular treatment showed rapid growth of an intra-aneurysmal thrombosis and de novo thrombosis in the parent artery. Direct aspiration was performed via a distal support catheter with proximal blood flow arrest using a balloon-guide catheter, and the FD stent was successfully deployed. The patient’s symptoms improved postoperatively and DSA obtained 12 months after the procedure confirmed complete occlusion of the aneurysm. Although the exact mechanism of simultaneous thrombosis formation of the aneurysm and its parent artery remains unclear, it is important to recognize that rapid growth of the thrombosis increases the risk of ischemic stroke.

Partial Clipping Occlusion Including Rupture Point Is an Effective Strategy for Ruptured Giant Fusiform Basilar Artery Aneurysm: A Technical Case Report

Treatment of fusiform basilar artery aneurysms is still challenging today. The authors present a case of a patient with a ruptured giant fusiform basilar artery aneurysm successfully treated by clipping occlusion of the rupture point. A 62-year-old man suddenly fell into a coma due to subarachnoid hemorrhage (SAH) with a ruptured giant fusiform basilar artery aneurysm with a bleb on the right shoulder. We considered treating the lesion with stent-assisted coil embolization because of the aneurysm's shape, but we had to give up because stents were off-label in the acute phase SAH in our country. Instead, we successfully performed clipping surgery to partially occlude the aneurysm, including the rupture point via the anterior transpetrosal approach. His postoperative course was uneventful, without rerupture of the aneurysm, and his conscious level tended to improve. The postoperative imaging studies showed no complications and disappearance of the rupture point of the aneurysm. Although direct surgery for the giant fusiform basilar artery aneurysms is one of the challenging operations, it is an essential and highly effective treatment as a last resort for complex aneurysms if other treatments are not available.

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 Reversal" and Cure in a Case of Giant Intracranial Aneurysm: A Case Report

We describe the case of an 11-year-old girl having a giant anterior circulation aneurysm. The ipsilateral internal carotid artery was entirely blocked and the aneurysm was supplied by posterior circulation. Following a high-flow bypass that connected the external carotid artery to the middle cerebral artery, the giant aneurysm thrombosed spontaneously. We discuss several relatively rare and unique features of the case.

Brain ischemia due to direct vascular compression associate with rapid enlargement of unruptured middle cerebral artery aneurysm: A case report

Background

Acute cerebral infarction is a rare complication resulting from an unruptured cerebral aneurysm (UCA). There is presently no consensus on the optimal strategy for the management of UCAs with cerebral infarctions.

Case Description

A 53-year-old man presented with transient dysarthria and left hemiparesis. Magnetic resonance imaging (MRI) demonstrated the presence of a 7 mm UCA originating from the middle cerebral artery bifurcation, and diffusion-weighted imaging showed no evidence of cerebral infarction. One month later, his transient left hemiparesis recurred, and the patient was admitted to our hospital. Computed tomography angiography showed enlargement of the aneurysm. His left hemiparesis worsened 3 days later. MRI showed cerebral infarction in the area of perforating arteries and further enlargement of the aneurysm with surrounding parenchymal edema. Therefore, the rupture risk was considered to be rarely high and dome clipping was performed immediately. Postoperatively, his neurological status improved without any recurrent brain ischemia.

Conclusion

We report a rare case of a rapidly enlarging aneurysm that presented with cerebral infarction. This is the first report describing aneurysmal sac enlargement that can lead to perforating artery obstruction and brain ischemia. The case illustrates the importance of performing close follow-up examinations to confirm findings that suggest a high rupture risk.

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.

A rare case of a completely thrombosed bilobed giant intracranial aneurysm of the anterior cerebral artery with spontaneous parent vessel thrombosis: case report

Background

A huge spherical intracranial mass can sometimes be misdiagnosed, due to the lack of typical radiographic features. Thrombosed giant intracranial aneurysms (GIAs) are an uncommon but still a possible differential diagnosis that must be kept in mind to guarantee the best surgical approach and resection of the lesion. We describe an extremely rare case of a huge bifrontal mass mimicking a cystic echinococcosis, in which the surgery unveiled a completely thrombosed GIA of the left anterior cerebral artery (ACA).

Case presentation

A 61-year-old patient complained about intermittent weakness of the right leg, mild holocephalic headache, beginning cognitive deficits and lethargy. Magnetic resonance imaging (MRI) showed a huge partially calcified and bilobed frontal mass with peripheral edema. Based on a time-resolved angiography with interleaved Stochastic trajectories MRI (TWIST-MRI), a vascular origin of the lesion was considered unlikely. Therefore, the surgery was performed under the suspicion of a cystic echinococcosis but revealed a bilobed GIA of the left ACA with a parent vessel thrombosis. Although only a limited left frontal craniotomy was performed, a proximal control of the parent vessel could be ensured, and the aneurysm was successfully clipped. The patient showed postoperatively no new neurological deficits.

Conclusions

Completely thrombosed GIAs with parent vessel thrombosis are rare lesions that might be misdiagnosed if typical radiographic features are missing. Thus, in case of an intracranial spherical mass with signs of intralesional hemorrhage and mural calcifications, presence of a completely thrombosed GIA should be considered as a possible differential diagnosis.

Variation of Mass Effect After Using a Flow Diverter With Adjunctive Coil Embolization for Symptomatic Unruptured Large and Giant Intracranial Aneurysms

Background: Mass effect associated with large or giant aneurysms is an intractable problem for traditional endovascular treatments. Preventing recurrence of aneurysms requires dense coiling, which may aggravate the mass effect. However, the flow diverter (FD) is a new device that avoids the need for dense coiling. This study was performed to investigate whether use of FDs with adjunctive coil embolization can relieve the aneurysmal mass effect and to explore the factors that affect the variation of compressional symptoms.

Methods: We retrospectively evaluated patients with compressional symptoms caused by unruptured aneurysms who underwent endovascular treatment with an FD with adjunctive coil embolization at our center from January 2015 to December 2017. Imaging follow-up included digital subtraction angiography (DSA) ranging from 11 to 14 months and magnetic resonance imaging (MRI) ranging from 24 to 30 months; the former was used to evaluate the intracavitary volume, and the latter was used to measure the variation of the mass effect. Follow-up physical examinations were performed to observe variations of symptoms.

Results: In total, 22 patients with 22 aneurysms were treated by an FD combined with coil embolization. All 22 patients underwent the last clinical follow-up. Regarding compressional symptoms, 12 (54.54%) patients showed improvement, 6 (27.27%) were fully recovered, and 6 (27.27%) showed improvement but with incomplete cranial palsy. However, five (22.72%) patients showed no change, four (18.18%) showed worsening symptoms compared with their preoperative state, and one (4.55%) died of delayed rupture. Seventeen of the 22 patients underwent MRI. Of these 17 patients, the aneurysm shrank in 13 (76.47%) and no significant change occurred in 4 (23.53%). In the multivariate analysis, a short duration from symptom occurrence to treatment (p = 0.03) and younger patient age (p = 0.038) were statistically significant factors benefiting symptom improvement, and shrinkage of the aneurysm was associated with favorable clinical outcomes (p = 0.006).

Conclusions: Use of the FD with adjunctive loose coil embolization might help to alleviate the compressional symptoms caused by intracranial aneurysms. Shrinkage of the aneurysm, a short duration of symptoms, and younger patient age might contribute to favorable outcomes of mass effect-related symptoms.

Prognostic significance of factor XIIIA promoter methylation status in aneurysmal subarachnoid haemorrhage (aSAH)

BACKGROUND

Aneurysmal subarachnoid hemorrhage is a life- threatening condition with high rate of disability and mortality. Apolipoprotein E (APOE) and Factor XIIIA (F13A) genes are involved in the pathogenetic mechanism of aneurysmal subarachnoid haemorrhage (aSAH). We evaluated the association of promoter methylation status of APOE and F13A gene and risk of aSAH.

METHODS

For evaluating the effect of hypermethylation in the promoter region of these genes with risk of aSAH, we conducted a case -control study with 50 aSAH patients and 50 healthy control. The methylation pattern was analysed using methylation specific PCR. The risk factors associated with poor outcome after aSAH was also analysed in this study. The outcome was assessed using Glasgow outcome score (GOS) after 3 months from the initial bleed.

RESULTS

The frequency of APOE and F13A methylation pattern showed insignificant association with risk of aSAH in this study. Gender stratification analysis suggests that F13A promoter methylation status was significantly associated with the risk of aSAH in male gender. Age, aneurysm located at the anterior communicating artery and diabetes mellitus showed significant association with poor outcome after aSAH.

CONCLUSION

There was no significant association with APOE promoter methylation with the risk as well as outcome of patients after aSAH. F13A promoter methylation status was significantly associated with risk of aSAH in male gender, with no significant association with outcome after aSAH.

The 25th anniversary of the retrograde suction decompression technique (Dallas technique) for the surgical management of paraclinoid aneurysms: historical background, systematic review, and pooled analysis of the literature

OBJECTIVE

Paraclinoid internal carotid artery (ICA) aneurysms frequently require temporary occlusion to facilitate safe clipping. Brisk retrograde flow through the ophthalmic artery and cavernous ICA branches make simple trapping inadequate to soften the aneurysm. The retrograde suction decompression (RSD), or Dallas RSD, technique was described in 1990 in an attempt to overcome some of those treatment limitations. A frequent criticism of the RSD technique is an allegedly high risk of cervical ICA dissection. An endovascular modification was introduced in 1991 (endovascular RSD) but no studies have compared the 2 RSD variations.

METHODS

The authors performed a systematic review of MEDLINE/PubMed and Web of Science and identified all studies from 1990-2016 in which either Dallas RSD or endovascular RSD was used for treatment of paraclinoid aneurysms. A pooled analysis of the data was completed to identify important demographic and treatment-specific variables. The primary outcome measure was defined as successful aneurysm obliteration. Secondary outcome variables were divided into overall and RSD-specific morbidity and mortality rates.

RESULTS

Twenty-six RSD studies met the inclusion criteria (525 patients, 78.9% female). The mean patient age was 53.5 years. Most aneurysms were unruptured (56.6%) and giant (49%). The most common presentations were subarachnoid hemorrhage (43.6%) and vision changes (25.3%). The aneurysm obliteration rate was 95%. The mean temporary occlusion time was 12.7 minutes. Transient or permanent morbidity was seen in 19.9% of the patients. The RSD-specific complication rate was low (1.3%). The overall mortality rate was 4.2%, with 2 deaths (0.4%) attributable to the RSD technique itself. Good or fair outcome were reported in 90.7% of the patients.Aneurysm obliteration rates were similar in the 2 subgroups (Dallas RSD 94.3%, endovascular RSD 96.3%, p = 0.33). Despite a higher frequency of complex (giant or ruptured) aneurysms, Dallas RSD was associated with lower RSD-related morbidity (0.6% vs 2.9%, p = 0.03), compared with the endovascular RSD subgroup. There was a trend toward higher mortality in the endovascular RSD subgroup (6.4% vs 3.1%, p = 0.08). The proportion of patients with poor neurological outcome at last follow-up was significantly higher in the endovascular RSD group (15.4% vs 7.2%, p < 0.01).

CONCLUSIONS

The treatment of paraclinoid ICA aneurysms using the RSD technique is associated with high aneurysm obliteration rates, good long-term neurological outcome, and low RSD-related morbidity and mortality. Review of the RSD literature showed no evidence of a higher complication rate associated with the Dallas technique compared with similar endovascular methods. On a subgroup analysis of Dallas RSD and endovascular RSD, both groups achieved similar obliteration rates, but a lower RSD-related morbidity was seen in the Dallas technique subgroup. Twenty-five years after its initial publication, RSD remains a useful neurosurgical technique for the management of large and giant paraclinoid aneurysms.

Arterial Spin Labeling Imaging of a Giant Aneurysm Leading to Subarachnoid Hemorrhage following Cerebral Infarction

An 83-year-old Japanese man was admitted with dysarthria and right hemiparesis. He had had a large intracranial aneurysm on the left internal carotid artery 5 years before admission and had been followed up under conservative treatment. On admission, diffusion-weighted imaging revealed a hyperintense signal on the left anterior choroidal artery territory. Time-of-flight magnetic resonance angiography demonstrated poor visibility of the middle and anterior cerebral arteries and the inferior giant aneurysm, suggesting distal emboli from aneurysm thrombosis or a reduction of blood outflow due to aneurysm thrombosis. Arterial spin labeling (ASL) signal increased in the giant aneurysm, suggesting blood stagnation within the aneurysmal sac, and decreased in the left hemisphere. We diagnosed cerebral infarction due to aneurysm thrombosis, and started antithrombotic therapy. On day 2, he suddenly died of subarachnoid hemorrhage due to rupturing of the giant aneurysm. When thrombosis occurs in a giant aneurysm, increasing ASL signal within the aneurysm and decreasing ASL signal with poor visibility on magnetic resonance angiography in the same arterial territory may indicate the danger of impending rupture of the giant aneurysm.

Current Treatment Strategies for Intracranial Aneurysms: An Overview

Intracranial aneurysm is a leading cause of stroke. Its treatment has evolved over the past 2 decades. This review summarizes the treatment strategies for intracranial aneurysms from 3 different perspectives: open surgery approach, transluminal treatment approach, and new technologies being used or trialed. We introduce most of the available treatment techniques in detail, including contralateral clipping, wrapping and clipping, double catheters assisting coiling and waffle-cone technique, and so on. Data from major trials such as Analysis of Treatment by Endovascular approach of Non-ruptured Aneurysms (ATENA), Internal Subarachnoid Trial (ISAT), Clinical and Anatomical Results in the Treatment of Ruptured Intracranial Aneurysms (CLARITY), and Barrow Ruptured Aneurysm Trial (BRAT) as well as information from other clinical reports and local experience are reviewed to suggest a clinical pathway for treating different types of intracranial aneurysms. It will be a valuable supplement to the current existing guidelines. We hope it could help assisting real-time decision-making in clinical practices and also encourage advancements in managing the disease.

Flow Diverters in the Treatment of Pediatric Cerebrovascular Diseases

BACKGROUND AND PURPOSE

There is very limited data concerning utilization of flow diverters in children. Our aim is to report results for the treatment of complex intracranial aneurysms and carotid cavernous fistulas by using flow diverters in children.

MATERIALS AND METHODS

Retrospective review of children (17 years of age or younger) treated with flow diverters between May 2011 and July 2014 was performed. Clinical and laboratory data and angiographic findings were extracted. Seven patients (6 males, 1 female; mean age, 12.7 years; range, 3-16 years) were included. Two presented with posttraumatic fistulas. The remaining patients presented with traumatic aneurysms of the cavernous carotid artery or fusiform aneurysms of the distal vertebral artery, M1, or A2 segments. All patients were premedicated with clopidogrel (75 mg daily for patients with body weights of >45 kg, 37.5 mg daily for 1 small child with a body weight of <45 kg) and aspirin (300 mg daily for ≥45 kg, 100 mg daily for smaller children).

RESULTS

VerifyNow and Multiplate Analyzer values were higher than expected. No clinical complications were noted. Imaging performed at 7-52 months after the procedure (mean/median, 22.3/14 months) revealed occlusions of all aneurysms and fistulas. One patient had an asymptomatic occlusion of the parent artery; otherwise, no hemodynamically significant parent artery restenosis was observed. There were no clinically significant neurologic events during follow-up.

CONCLUSIONS

Although flow-diverter placement appears to be safe and effective on midterm follow-up in children, longer follow-up is critical. The current sizes of flow diverter devices and delivery systems cover the pediatric size range, obviating developing flow diverters specific to children.