The many faces of intracranial arterial dissections

Bifurcation dissecting aneurysm: tips and tricks to differentiate from saccular aneurysm

Bifurcations are a common site for saccular aneurysms, but rarely can be a site for dissecting aneurysms. Identification of these aneurysms is extremely important because the management plan depends on it. We describe a rare case of a ruptured dissecting aneurysm at the right ICA bifurcation in a pre-teen child which posed a diagnostic dilemma but ultimately was successfully managed with flow diversion.

Comparative meta-analysis of endovascular strategies for intracranial dissecting aneurysms: Flow diverters versus stents with or without coiling

BACKGROUND

Intracranial dissecting aneurysms present a challenging subset linked to considerable morbidity and mortality, necessitating effective therapeutic strategies to prevent complications. Traditional treatments face technical limitations, while emerging endovascular modalities like stent-assisted coiling, multiple stenting, and flow-diverting devices (FDDs) offer promise in reducing periprocedural risks and enhancing patient outcomes. The aim of this study is to compare the safety and efficacy outcomes of endovascular treatment for intracranial dissecting aneurysms using FDDs versus stents (with or without coiling).

METHODS

A systematic review and meta-analysis were conducted following established guidelines. The search included PubMed, Scopus, Web of Science, and Embase databases up to July 30, 2023. Eligible studies reporting outcomes of interest in both FDD and stent-treated groups were included, and the data was extracted and analyzed using STATA software.

RESULTS

Six studies were analyzed, involving 131 patients in the FDD group and 199 patients in the stent group. The pooled rates for favorable functional outcomes (86.8% vs. 86%), mortality (3.9% vs. 6%), adequate occlusion (79.7% vs. 86.3%), aneurysm recurrence (1.3% vs. 13.3%), in-stent stenosis/thrombosis (7% vs. 6.9%), ischemic events/infarctions (6.7% vs. 7.8%), retreatment (7% vs. 8.6%), and technical success (100% vs. 98.7%) were comparable in individuals treated with FDDs and stents (p > 0.05 in all cases). Additionally, complete occlusion rates were not significantly different between FDD (62.7%) and stent-treated patients (75.2%) (p = 0.06). However, after excluding one study in a leave-one-out analysis of the random effects meta-analysis, a significant difference in the pooled rates of this outcome was observed between the FDD (59.2%) and stent (75.2%) groups (p = 0.034).

CONCLUSION

FDDs present a promising approach for the treatment of intracranial dissecting aneurysms, yielding outcomes that are roughly comparable to stent-based methods. However, the absence of randomized trials and data limitations highlight the need for further research to enhance treatment strategies.

Atherosclerosis-Like Spontaneous Middle Cerebral Artery Dissection

The standard of care for treating acute large vessel occlusion is endovascular therapy. The most frequent cause of occlusion is either embolic occlusion or in situ thrombotic occlusion. However, occlusion resulting from intracranial dissection is extremely rare, especially in the middle cerebral artery. Prior to a thrombectomy or endovascular therapy, understanding and interpreting the angiographic findings is crucial for planning the appropriate treatment and preventing complications.

Intimal Hemorrhage of Basilar Artery Induced by Severe Vasospasm Following Subarachnoid Hemorrhage: The Experimental Analysis

BACKGROUND

 Cerebral vasospasm, a serious complication of subarachnoid hemorrhage (SAH), has been extensively studied for its neurochemical and pathophysiologic mechanisms. However, the contribution of inner elastic membrane dissection and subintimal hemorrhage to basilar artery occlusion remains underexplored. This study investigates inner elastic membrane-related changes in the basilar artery after SAH.

METHODS

 Twenty-four hybrid rabbits were divided into control, sham, and SAH groups, with SAH induced by autologous blood injection. After 2 weeks, basilar artery changes, vasospasm indexes (VSIs), and dissections were evaluated.

RESULTS

 The SAH group showed significantly higher VSI, with vascular wall thickening, luminal narrowing, convoluted smooth muscle cells, intimal elastic membrane disruption, endothelial cell desquamation, and apoptosis. Some SAH animals exhibited subintimal hemorrhage, inner elastic membrane dissection, and ruptures. Basilar arteries with subintimal hemorrhage had notably higher VSI.

CONCLUSIONS

 These findings highlight the role of subintimal hemorrhage and inner elastic membrane dissection in basilar artery occlusion post-SAH, offering valuable insights into vasospasm pathophysiology.

Spontaneous intracranial vertebral artery dissections presenting with subarachnoid hemorrhage

BACKGROUND

Vertebral artery dissection (VAD) is an infrequent source of subarachnoid hemorrhage (SAH), with a high mortality rate, primarily due to the risk of rebleeding both before and after medical intervention. This paper provides a comprehensive analysis of the anatomy, pathophysiology, clinical presentation, treatment strategies, and outcomes of intracranial vertebral artery dissections that result in subarachnoid hemorrhage.

METHODS

Comprehensive five-year literature review (2018-2022) and a retrospective analysis of patient records from our institution between 2016 and 2022. We included studies with a minimum of 5 patients.

RESULTS

The study incorporated ten series from the literature and 22 cases from CHUM. Key anatomical factors increasing the risk of VAD include the vertebral artery's origin from the aortic arch, asymmetry of the vertebral artery, and its tortuosity. Patients may display specific collagen and genetic abnormalities. The occurrence of VAD appears to be more prevalent in men. Those with a ruptured intracranial VAD typically show prodromal symptoms and present with severe SAH. Rebleeding within the first 24 h is frequent. While standard imaging methods are usually adequate for VAD diagnosis, they may not provide detailed information about the perforator anatomy. Treatment approaches include both deconstructive and reconstructive methods.

CONCLUSION

Ruptured VAD is a critical, life-threatening condition. Many patients have a poor neurological status at presentation, and rebleeding prior to treatment is a significant concern. Deconstructive techniques are most effective in preventing rebleeding, whereas the efficacy of reconstructive techniques needs more investigation.

Neuroendovascular Surgery Applications in Craniocervical Trauma

Cerebrovascular injuries resulting from blunt or penetrating trauma to the head and neck often lead to local hemorrhage and stroke. These injuries present with a wide range of manifestations, including carotid or vertebral artery dissection, pseudoaneurysm, occlusion, transection, arteriovenous fistula, carotid-cavernous fistula, epistaxis, venous sinus thrombosis, and subdural hematoma. A selective review of the literature from 1989 to 2023 was conducted to explore various neuroendovascular surgical techniques for craniocervical trauma. A PubMed search was performed using these terms: endovascular, trauma, dissection, blunt cerebrovascular injury, pseudoaneurysm, occlusion, transection, vasospasm, carotid-cavernous fistula, arteriovenous fistula, epistaxis, cerebral venous sinus thrombosis, subdural hematoma, and middle meningeal artery embolization. An increasing array of neuroendovascular procedures are currently available to treat these traumatic injuries. Coils, liquid embolics (onyx or n-butyl cyanoacrylate), and polyvinyl alcohol particles can be used to embolize lesions, while stents, mechanical thrombectomy employing stent-retrievers or aspiration catheters, and balloon occlusion tests and super selective angiography offer additional treatment options based on the specific case. Neuroendovascular techniques prove valuable when surgical options are limited, although comparative data with surgical techniques in trauma cases is limited. Further research is needed to assess the efficacy and outcomes associated with these interventions.

Incidental vascular findings on brain magnetic resonance angiography

Given the ever-increasing utilization of magnetic resonance angiography, incidental vascular findings are increasingly discovered on exams performed for unconnected indications. Some incidental lesions represent pathology and require further intervention and surveillance, such as aneurysm, certain vascular malformations, and arterial stenoses or occlusions. Others are benign or represent normal anatomic variation, and may warrant description, but not further work-up. This review describes the most commonly encountered incidental findings on magnetic resonance angiography, their prevalence, clinical implications, and any available management recommendations.

Intramural Hematoma in Vertebrobasilar Dolichoectasia-Related Stroke: A Retrospective Analysis of Six Consecutive Patients

BACKGROUND

The pathophysiology underlying vertebrobasilar dolichoectasia (VBD) is largely unknown. However, a few reports have demonstrated that acute intramural hematoma (IMH) in VBD is associated with stroke. We aimed to investigate the clinical and radiological features of IMH in VBD and the role of IMH in predicting rupture and patient outcomes.

METHODS

We retrospectively reviewed the medical records of patients treated in 2 stroke centers between January 2012 and December 2021. Patients presenting with VBD and stroke were eligible for study inclusion. We excluded patients with stroke caused by arterial dissection or artery-to-artery embolism. IMH was defined as a crescent-shaped area of high signal density in the vessel wall on axial computed tomography in the absence of an intimal flap, double lumen, and pearl-and-string sign.

RESULTS

Six patients were analyzed. All presented with symptoms of brainstem/cerebellar infarction without headache. Interobserver agreement for the presence or absence of IMH was excellent (100%). IMH was detected in 5 patients. The positive predictive value of IMH for rupture was 80% (95% confidence interval, 28%-99.5%). The median time from symptom onset to rupture was 2.5 days (range, 1.5-4). Median computed tomography values were significantly higher within the IMH than those in the lumen of the basilar artery (70 vs. 44.5 Hounsfield units; P = 0.008). The modified Rankin scale score on day 30 after onset was 5 in 1 patient and 6 in the remaining 5.

CONCLUSIONS

IMH in patients with VBD presenting with brainstem/cerebellar infarction should be regarded as a sign associated with a high risk of rupture.

Outcomes of reconstructive endovascular treatment of vertebrobasilar dissecting aneurysms with intramural hematoma

Background

Vertebrobasilar dissecting aneurysms (VBDAs) with an intramural hematoma (IMH) usually cause symptoms because of mass effect and grow in size over time. Clinical outcomes are generally poor.

Objective

This study aimed to examine outcomes of reconstructive endovascular treatment (EVT) in patients with VBDAs with IMH. Safety and effectiveness were compared between flow diverters (FDs) and conventional stents.

Methods

We retrospectively analyzed the clinical and radiological data of 36 VBDAs with IMH in 36 patients who underwent EVT with either FDs or conventional stents from January 2012 to December 2020 at our institution.

Results

Among the 36 study patients, 20 were treated with FDs and 16 with conventional stents. Incidence of procedure-related complications did not significantly differ between the two stents. IMH growth occurred after EVT in a significantly higher proportion of conventional stent group aneurysms (zero vs. 31.3% [5/16]; p = 0.012). Among the five aneurysms with IMHs that grew, all recurred. Change in IMH size after EVT was significantly lower in the FD group (−2.7 vs. +8.1%, p = 0.036). However, after the recurrent aneurysms were removed from the conventional stent group, change in IMH size did not significantly differ between the two groups (−2.7 vs. +1.0%, p = 0.332). The proportion of patients who experienced an improvement in mRS score after EVT was significantly higher in the FD group (60 vs. 25%, p = 0.036).

Conclusion

IMHs in VBDAs stop growing after successful reconstructive EVT. Although both FD and conventional stent treatment are effective, FD treatment may be superior based on clinical outcomes and effect on IMH size.

Efficacy of Magnetic Resonance Contrast-Enhanced Vessel Wall Imaging as an Ancillary Examination for Subarachnoid Hemorrhage With Bleeding Points Difficult to Determine on Conventional Vascular Imaging: A Report of Three Cases

Here, we have demonstrated the efficacy of magnetic resonance contrast-enhanced vessel wall imaging (CE-VWI) as an ancillary examination for subarachnoid hemorrhage with bleeding points difficult to confirm by conventional vascular imaging. Case 1 had a ruptured small aneurysm with a size of 1.8 × 1.1 mm at the origin of left anterior choroidal artery. CE-VWI showed enhancement of the apex of the aneurysm. Surgical clipping was performed by a mini-clip. In Case 2, a ruptured small aneurysm, 2.1 × 1.9 mm, was detected at right middle cerebral artery bifurcation. CE-VWI showed enhancement of the aneurysmal wall. Endovascular coil embolization was performed. In Case 3, irregular dilatation of left internal carotid artery (ICA) was detected. CE-VWI demonstrated enhancement of the dilatation wall. The lesion was deemed to be a dissection of the ICA or a blood blister-like aneurysm. Endovascular treatment using intracranial stent placement was performed, and the patient has had no rebleeding events for one and a half years. In all cases, conventional vascular imaging detected scanty morphological changes, and CE-VWI information provided reliable confirmation of the lesions as bleeding points.

Atypical intracranial aneurysms: spectrum of imaging findings in computed tomography and magnetic resonance imaging

We aim to describe demographics, clinical presentation, and spectrum of CT and MRI features suggestive of atypical intracranial aneurysms. The imaging protocols used for the diagnosis of intracranial aneurysms were thoroughly reviewed, including different CT and MRI protocols. We classified atypical aneurysms according to their location, size, clinical presentation, and specific imaging features. Dissecting aneurysms are one of the causes of stroke in young adults that may show intimal flap and double lumen. Traumatic intracranial aneurysms are a rare but serious complication of head injuries. Mycotic aneurysms are small and multiple at distal branch points with a high risk of rupture. Aneurysms with vasculitis are fusiform with a wide neck at a non-branch point that may be associated with vessel wall enhancement. Atherosclerotic aneurysms are usually large fusiform that affect large arteries. Oncotic aneurysms are relatively rare. They were reported to occur in patients with left atrial myxoma. Our study represented a wide spectrum of atypical intracranial aneurysms with their detailed diagnostic imaging findings on MRI and CT including newly introduced MRI sequences, which greatly influenced early diagnosis and timely management.

Deconstructive versus reconstructive endovascular approaches for intracranial dissecting aneurysms

Background

The annual incidence of the intracranial dissecting aneurysms is about 1 to 1.5 per 100,000. This is a well-known cause of stroke and subarachnoid hemorrhage in young and middle-aged patients (Santos-Franco et al. in Neurosurg Rev, 2008. https://doi.org/10.1007/s10143-008-0124-x). Various surgical and endovascular treatment methods have been proposed for intracranial dissecting aneurysms. All treatment methods aim to reduce the blood flow in the dissected region. Deconstructive techniques sacrifice the parent artery, whereas reconstructive techniques aim to maintain a parent artery (Stéphanie et al. in Lancet Neurol 14(6):640–654, 2015. https://doi.org/10.1016/S1474-4422(15)00009-5). Due to its dissecting nature, wall friability can make surgical clipping difficult and even risky. On the other hand, recanalization after coiling alone is almost certain. Therefore, deconstructive modalities of treatment like trapping or parent vessel occlusion, performed either surgically or endovascularly, have predominated for managing those lesions, usually with good results. Nevertheless, in absence of efficient collateral pathways, the deconstructive technique carries an ischemic risk. In situations in which parent artery preservation is mandatory, the use of stent-assisted techniques may be the most appropriate choice (de Barros Faria et al. in Am J Neuroradiol 32(11):2192–2195, 2011. https://doi.org/10.3174/ajnr.A2671). However, the usage of stent with recently ruptured aneurysms is always perplexing due to the necessity of dual antiplatelet administration. Hence the management of dissecting aneurysms remain challenging.

Results

Between January 2017 and July 2019, 19 patients presenting with intracranial dissecting aneurysms were referred to our department for endovascular treatment. Among the nineteen patients, 11 cases were treated by parent artery occlusion representing 57.9% of the cases, and 7 cases (36.8%) were treated by artery preserving technique, and only one case (5.3%) was treated by combination of parent artery occlusion and artery preserving technique. One week after the intervention 26.3% of patients had no disability (mRS = 0), 47.4% had no significant disability (mRS = 1), 15.8% had slight disability (mRS = 2) and 10.5% had moderate to severe disability (mRS = 3–4). After three months we found an overall improvement of the clinical outcome, as 57.9% of patients had no disability (mRS = 0), 26.3% had no significant disability (mRS = 1) and 15.8% had mild disability (mRS = 2). Finally, after six months reassessment with angiography showed that 89.5% of patients had stable aneurysmal occlusion, and 10.5% had recurrence of aneurysm.

Conclusions

Both endovascular approaches, whether parent artery occlusion or artery preserving technique showed favorable outcome which indicates the safety and efficacy of both approaches if selected properly according to the morphology of the aneurysm.

Safety and Efficacy of the FRED Jr Flow Re-Direction Endoluminal Device for Intracranial Aneurysms: Retrospective Multicenter Experience With Emphasis on Midterm Results

Background and Purpose: Flow diversion is increasingly used as an endovascular treatment for intracranial aneurysms. In this retrospective multicenter study, we analyzed the safety and efficacy of the treatment of intracranial, unruptured, or previously treated but recanalized aneurysms using Flow Re-Direction Endoluminal Device (FRED) Jr with emphasis on midterm results.

Materials and Methods: Clinical and radiological records of 150 patients harboring 159 aneurysms treated with FRED Jr at six centers between October 2014 and February 2020 were reviewed and consecutively included. Clinical outcome was measured by using the modified Rankin Scale (mRS). Anatomical results were assessed according to the O'Kelly-Marotta (OKM) scale and the Cekirge-Saatci Classification (CSC) scale.

Results: The overall complication rate was 24/159 (16%). Thrombotic-ischemic events occurred in 18/159 treatments (11%). These resulted in long-term neurological sequelae in two patients (1%) with worsening from pre-treatment mRS 0–2 and mRS 4 after treatment. Complete or near-complete occlusion of the treated aneurysm according to the OKM scale was reached in 54% (85/158) at 6-month, in 68% (90/133) at 1-year, and in 83% (77/93) at 2-year follow-up, respectively. The rates of narrowing or occlusion of a vessel branch originating from the treated aneurysm according to the CSC scale were 11% (12/108) at 6-month, 20% (17/87) at 1-year, and 23% (13/57) at 2-year follow-up, respectively, with all cases being asymptomatic.

Conclusions: In this retrospective multicenter study, FRED Jr was safe and effective in the midterm occlusion of cerebral aneurysms. Most importantly, it was associated with a high rate of good clinical outcome.

Spontaneous Intracranial Artery Dissection causing Subarachnoid Hemorrhage: Importance of Short-Term Surveillance

Hemorrhagic intracranial artery dissections are unstable lesions, with a high propensity for rebleeding (up to 40%) in the acute period. Imaging plays an important role in the diagnosis and management of intracranial artery dissections. In this paper, we describe 2 cases in which the dissected intracranial artery underwent rapid morphological change within 3 days or less, highlighting the importance of short-term follow-up imaging in patients with these hemorrhagic lesions.

Endovascular Treatment Using a Small Amount of Contrast Medium in a Patient with a Posterior Communicating Artery Ruptured Dissecting Aneurysm and Chronic Kidney Disease: A Case Report

Objective

We report a rare case of a patient with a ruptured posterior communicating artery (P-com A) dissecting aneurysm and chronic kidney disease (CKD) treated by endovascular embolization using a small amount of contrast medium.

Case Presentation

An 88-year-old female patient had sudden onset of headache and vomit due to subarachnoid hemorrhage. MRI revealed a ruptured dissecting aneurysm of the right P-com A. The patient had CKD of severity grade 4. Endovascular treatment was performed using only 10 mL of diluted contrast medium with injection through a microcatheter. The postoperative course was uneventful, and no deterioration of renal function occurred.

Conclusion

With minimal amount of contrast medium, endovascular treatment could be safely and effectively performed for patients with P-com A dissecting aneurysms and severe CKD.

Current Clinical Applications of Intracranial Vessel Wall MR Imaging

Intracranial vessel wall MR imaging (VWI) is increasingly being used as a valuable adjunct to conventional angiographic imaging techniques. This article will provide an updated review on intracranial VWI protocols and image interpretation. We review VWI technical considerations, describe common VWI imaging features of different intracranial vasculopathies and show illustrative cases. We review the role of VWI for differentiating among steno-occlusive vasculopathies, such as intracranial atherosclerotic plaque, dissections and Moyamoya disease. We also highlight how VWI may be used for the diagnostic work-up and surveillance of patients with vasculitis of the central nervous system and cerebral aneurysms.

Diagnosis and treatment of pure arterial malformation: Three case reports and literature review

RATIONALE

The incidence of pure arterial malformations is relatively low, and few cases have been reported. Only 2 cases with pure arterial malformation have been reported to receive surgery or endovascular treatment.

PATIENT CONCERNS

We report 3 cases and review the relevant literatures. The head examinations of the patients suggested the presence of high-density shadows in front of the pons and midbrain, the dilation of the supraclinoid segment of the right internal carotid artery, and moyamoya in the left brain with an aneurysm-like expansion located on the left posterior communicating artery respectively. After admission, head digital subtraction angiography (DSA) was performed.

DIAGNOSES

Digital subtraction angiography (DSA) for these 3 patients showed that the left posterior communicating artery, the supraclinoid segment of the right internal carotid artery, and the left posterior communicating artery appeared dilated, tortuous, and spirally elongated. In addition, the lesions in the latter 2 patients were accompanied with local aneurysmal changes.

INTERVENTIONS

Two patients were given conservative treatment, and another patient was given endovascular treatment. A head DSA was reviewed 6 months after therapy.

OUTCOMES

The prognosis status of the 3 patients was good. Two patients in the conservative treatment group showed no changes in the lesions on head DSA examination. The DSA examination of the third patient indicated that the vascular remodeling of the diseased vessels was good, the blood vessels were unobstructed, and the aneurysms had disappeared.

LESSONS

Pure arterial malformations mostly occur in young women and may involve any blood vessels in the brain. It can be accompanied with local aneurysms and calcification. The patients are often given conservative treatment but need to be reviewed regularly. However, it is beneficial to give endovascular treatment to the patients with local aneurysms.

Neuroanatomy of the middle cerebral artery: implications for thrombectomy

Our perspective on anatomy frequently depends on how this anatomy is utilized in clinical practice, and by which methods knowledge is acquired. The thrombectomy revolution, of which the middle cerebral artery (MCA) is the most common target, is an example of a clinical paradigm shift with a unique perspective on cerebrovascular anatomy. This article reviews important features of MCA anatomy in the context of thrombectomy. Recognizing that variation, frequently explained by evolutionary concepts, is the rule when it comes to branching pattern, vessel morphology, territory, or collateral potential is key to successful thrombectomy strategy.

Pure arterial malformations

OBJECTIVE

Over the last half century, there have been isolated case reports of purely arterial malformations. In this study, the authors report a consecutive series of patients with pure arterial malformations, emphasizing the clinical and radiological features of these lesions.

METHODS

Pure arterial malformations were defined as dilated, overlapping, and tortuous arteries with a coil-like appearance and/or a mass of arterial loops without any associated venous component. Demographic characteristics of the patients, cardiovascular risk factors, presentation, radiological characteristics, and follow-up data were collected. Primary outcomes were new neurological symptoms including disability, stroke, and hemorrhage.

RESULTS

Twelve patients meeting the criteria were identified. Ten patients were female (83.3%) and 2 were male (16.6%). Their mean age at diagnosis was 26.2 ± 11.6 years. The most common imaging indication was headache (7 patients [58.3%]). In 3 cases the pure arterial malformation involved the anterior cerebral arteries (25.0%); in 4 cases the posterior communicating artery/posterior cerebral artery (33.3%); in 2 cases the middle cerebral artery (16.6%); and in 1 case each, the superior cerebellar artery, basilar artery/anterior inferior cerebellar artery, and posterior inferior cerebellar artery. The mean maximum diameter of the malformations was 7.2 ± 5.0 mm (range 3–16 mm). Four lesions had focal aneurysms associated with the pure arterial malformation, and 5 were partially calcified. In no cases was there associated intracranial hemorrhage or infarction. One patient underwent treatment for the pure arterial malformation. All 12 patients had follow-up (mean 29 months, median 19 months), and there were no cases of disability, stroke, or hemorrhage.

CONCLUSIONS

Pure arterial malformations are rare lesions that are often detected incidentally and probably have a benign natural history. These lesions can affect any of the intracranial arteries and are likely best managed conservatively.

Treatment outcomes in cerebral artery dissection and literature review

Methods Patients with cerebral artery dissections were reviewed in a hospital setting from 2008 to 2015. Clinical presentations, lesion locations, treatment modalities, functional outcomes, and mortality were reviewed. Parent artery occlusion was the first choice for surgery or endovascular treatment of a hemorrhagic dissecting cerebral artery. Endovascular or surgical reconstructive treatment was indicated in patients whose parent artery could not be occluded. Favorable functional outcomes were determined using modified Rankin Scale (mRS) scores of 0-2. Results In total, 61 patients with cerebral artery dissections were admitted to the hospital. Seven (11.5%) had traumatic dissections. All traumatic dissections were located in the internal carotid arteries. Overall favorable outcome rate was about 57% (4/7). Spontaneous cerebral artery dissections were found in 54 patients. No difference in favorable outcomes was observed between parent vessel occlusion and selective occlusion with parent vessel preservation (or vessel reconstruction) (70% and 63%, respectively, p = 1.000). Patients who presented with spontaneous dissection without intracranial hemorrhage had more favorable outcomes than those with intracranial hemorrhage (79% and 52%, respectively, p = 0.045). The mortality rate of patients with spontaneous dissection was 7.4%. Conclusions Most of the traumatic dissections were located on the internal carotid arteries and spontaneous dissections were commonly located on vertebral arteries. Nonhemorrhagic spontaneous cerebral dissections had better functional outcomes after treatment. Endovascular and surgical management were effective treatments by parent vessel occlusion or reconstructions.

Intracranial Vessel Wall Imaging with Magnetic Resonance Imaging: Current Techniques and Applications

Vessel wall magnetic resonance imaging (VW-MRI) is a modern imaging technique with expanding applications in the characterization of intracranial vessel wall pathology. VW-MRI provides added diagnostic capacity compared with conventional luminal imaging methods. This review explores the principles of VW-MRI and typical imaging features of various vessel wall pathologies, such as atherosclerosis, dissection, and vasculitis. Radiologists should be familiar with this important imaging technique, given its increasing use and future relevance to everyday practice.

Ruptured dissecting aneurysm in communicating internal carotid artery segments treated using a stent-assisted endovascular technique

Hemorrhagic intracranial dissecting aneurysms are known to have a poor natural history and an increased tendency to rebleed. The communicating segment of the internal carotid artery (ICA) is an infrequent site of dissection that is difficult to manage using deconstructive endovascular treatment because of the need to preserve important vascular branches. We report two cases of ruptured dissecting aneurysms that occurred in communicating segments of the ICA and treated using a reconstructive endovascular technique involving stent-assisted coiling. Case 1 was a 59-year-old woman who was diagnosed with subarachnoid hemorrhage (SAH). Digital subtraction angiography (DSA) indicated a ruptured dissecting aneurysm that arose from the left communicating segment of the ICA. Stent-assisted coiling was performed and followed by a second overlapping stent technique. No deterioration was observed on DSA after one week of follow-up or on magnetic resonance angiography (MRA) after four months of follow-up. The patient was discharged without neurological complications (Glasgow Outcome Scale 5). Case 2 was a 34-year-old man who was admitted with a diagnosis of SAH. DSA revealed a suspected lesion of a ruptured dissecting aneurysm of the left communicating segment of the ICA. Stent-assisted coiling was performed, and partial occlusion was achieved. No deterioration was observed on DSA after two weeks of follow-up or on MRA after six months of follow-up. The patient was discharged without neurological complications (Glasgow Outcome Scale 5). These cases suggest that using stent-assisted coiling could be a feasible modality for treating ruptured ICA dissecting aneurysms in the communicating segment.

Quantitative Analysis of Intracranial Vertebrobasilar Dissecting Aneurysm with Intramural Hematoma After Endovascular Treatment Using 3-T High-Resolution Magnetic Resonance Imaging

OBJECTIVE

Quantitative measurements of intracranial vessel walls are reliable in 3-T high-resolution magnetic resonance imaging (HR-MRI). However, few reports have assessed the arterial wall after endovascular treatment (EVT) by 3-T HR-MRI. This study aimed to quantitatively analyze vessel walls in vertebrobasilar artery dissecting aneurysms after EVT.

METHODS

From May 2012 to December 2015, a total of 21 patients with 21 intracranial vertebrobasilar dissecting aneurysms (VBDAs) were enrolled in this consecutive study. All the VBDAs were characterized by intramural hematomas (IMHs ≥5 mm) and treated with reconstructive EVT. Images of preoperative and follow-up 3-T HR-MRI were used to evaluate the arterial wall. The relative signal intensity (RSI) of IMHs was quantified on T1-weighted imaging (T1WI) and magnetization-prepared rapid acquisition gradient-echo (MPRAGE).

RESULTS

Angiographic follow-up was performed for a mean of 9.19 ± 3.22 months. According to angiographic results at follow-up, 21 patients were divided into 2 groups (progressive group, n = 6; stable group, n = 15). In the progressive group, RSI of IMHs was significantly increased on MPRAGE of follow-up 3-T HR-MRI compared with that before treatment (P < 0.05), and the difference was not significant on T1WI. However, in the stable group, RSI of IMHs was significantly reduced after treatment (P < 0.05).

CONCLUSIONS

Persistent high signal intensity of IMHs in VBDAs after reconstructive EVT may be associated with the progression of VBDAs. It may also indicate an unsteady state of the aneurysm, which suggests that reconstruction of the parent artery is not satisfactory.

Ruptured intracranial vertebral artery dissecting aneurysms: An evaluation of prognostic factors of treatment outcome

Objective Intracranial spontaneous vertebral artery dissecting aneurysms commonly occur in the third to fifth decades of life, and are mostly associated with hypertension. Patients present with intracranial haemorrhage or thromboembolic events. Patients who present with intracranial haemorrhage carry about a 70% risk of recurrent bleeding. Patients with a posterior-inferior cerebellar artery (PICA) or ipsilateral dominant vertebral artery involve selecting which parent vessel could not be sacrificed. Recent reconstructive techniques such as stent-assisted coiling embolisation and flow-diverting stents are effective treatments of choice. Methods Seventeen patients presented subarachnoid haemorrhage and nine patients with other symptoms. Sacrificing the parent vertebral artery was the first choice for surgical or endovascular methods. Endovascular reconstructive treatment by stent-assisted coiling embolisation was indicated in dissecting vertebral artery aneurysms with ipsilateral dominant vertebral artery or PICA involvement. Clinical outcomes were determined using the modified Rankin Score (mRS) at 90 days, with favourable outcomes defined as 0 to 2. Results Of the patients presenting with ruptured aneurysms, 11 (61.1%) had a good clinical outcome, with a mRS of 0-2. Favourable Hunt and Hess grading (65%), mild to moderate GCS (65%) and total occlusion of aneurysms after treatment (65%) were significantly good prognostic factors in patients with ruptured vertebral artery dissecting aneurysms. Conclusion Endovascular parent vessel sacrifice could be the first choice to treat a ruptured vertebral artery dissecting aneurysm. Stent-assisted coiling to preserve the patency of the parent artery and its branches is a promising treatment for vertebral artery dissections.

Intracranial vessel wall imaging for evaluation of steno-occlusive diseases and intracranial aneurysms

Cerebrovascular diseases have traditionally been classified, diagnosed and managed based on their luminal characteristics. However, over the past several years, several advancements in MRI techniques have ushered in high-resolution vessel wall imaging (HR-VWI), enabling evaluation of intracranial vessel wall pathology. These advancements now allow us to differentiate diseases which have a common angiographic appearance but vastly different natural histories (i.e. moyamoya versus atherosclerosis, reversible cerebral vasoconstriction syndrome versus vasculitis, stable versus unstable intracranial aneurysms). In this review, we detail the anatomical, histopathological and imaging characteristics of various intracranial steno-occlusive diseases and types of intracranial aneurysms and describe the role that HR-VWI can play in diagnosis, risk stratification and treatment.

Spontaneous and Unruptured Chronic Intracranial Artery Dissection : High-resolution Magnetic Resonance Imaging Findings

PURPOSE

The aim of this article is to present high-resolution magnetic resonance imaging (HR-MRI) findings of chronic stage spontaneous and unruptured intracranial artery dissection (ICAD).

MATERIAL AND METHODS

From March 2012 to April 2016 a total of 29 patients (15 male and14 female, age range 37-68 years) with chronic stage spontaneous and unruptured ICAD (vertebral artery 27, posterior inferior cerebellar artery 1 and middle cerebral artery 1) were retrospectively enrolled. Patients underwent HR-MRI more than 2 months (median interval 564 days, range 69-391 days) after symptom onset and were diagnosed at symptom onset or at the first imaging acquisition, which included luminal angiography and/or HR-MRI with clinical information. The HR-MRI findings were evaluated against those of luminal angiography on the basis of the lumen wall morphology, including thickening, contrast enhancement and residual dissection.

RESULTS

The HR-MRI findings were classified into complete normalization (normal lumen and wall with or without mild enhancement, n = 6), complete normalization with minimal wall changes (focal wall thickening with enhancement but normal luminal angiography, n = 8), incomplete normalization (focal wall thickening with enhancement with dilatation and stenosis on luminal angiography, n = 4), dissecting aneurysm (fusiform aneurysm with residual dissection findings, n = 8) and occlusion (small outer arterial diameter with diffuse contrast enhancement, n = 3).

CONCLUSION

The use of HR-MRI can demonstrate the distinguishing morphological features of chronic stage of spontaneous and unruptured ICAD as complete normalization, complete normalization with minimal wall changes, incomplete normalization, dissecting aneurysm and occlusion.

The insidious appearance of the dissecting aneurysm: Imaging findings and related pathophysiology. A report of two cases

Intracranial dissecting aneurysms have been frequently reported to present with fairly challenging and time-variable imaging findings that can be mostly explained by the pathological mechanisms that underline the dissection. We present two cases of spontaneous dissecting aneurysm of the supraclinoid ICA, both clinically presenting with SAH, but characterized by different progression of clinical symptoms and imaging. However, in both cases an outpouch and a mild fusiform dilation of the supraclinoid ICA was present in the initial CTA performed after the occurrence of symptoms. These findings were well depicted by the MPR reformats performed retrospectively. We postulate that this finding may represent the point of initial transmural dissection and we recommend that careful analysis of the CTA MRP reformatted images should be performed in order to detect this finding promptly.

High-resolution intracranial vessel wall imaging: imaging beyond the lumen

Accurate and timely diagnosis of intracranial vasculopathies is important due to significant risk of morbidity with delayed and/or incorrect diagnosis both from the disease process as well as inappropriate therapies. Conventional vascular imaging techniques for analysis of intracranial vascular disease provide limited information since they only identify changes to the vessel lumen. New advanced MR intracranial vessel wall imaging (IVW) techniques can allow direct characterisation of the vessel wall. These techniques can advance diagnostic accuracy and may potentially improve patient outcomes by better guided treatment decisions in comparison to previously available invasive and non-invasive techniques. While neuroradiological expertise is invaluable in accurate examination interpretation, clinician familiarity with the application and findings of the various vasculopathies on IVW can help guide diagnostic and therapeutic decision-making. This review article provides a brief overview of the technical aspects of IVW and discusses the IVW findings of various intracranial vasculopathies, differentiating characteristics and indications for when this technique can be beneficial in patient management.

State-of-art in surgical treatment of dissecting posterior circulation intracranial aneurysms

Vertebrobasilar (VB) intracranial dissecting aneurysms (IDAs) pose difficult therapeutic issues and are especially among the most difficult to manage surgically. There are, however, some cases where selective aneurysm obliteration by endovascular approach is impossible or is associated with an unacceptable risk of morbidity. This is particularly true when the aneurysm is dissecting, giant, or has a large neck. In such cases, surgical treatment may be the only alternative. Optimal management of these lesions is therefore challenging and treatment decisions have to be made on a case-by-case basis. Ideal treatment should be a complete surgical excision of the lesion; however, this procedure might only be possible after distal and proximal vessel wall occlusion which might not be tolerated by the patient depending on the location of the aneurysm. Therefore, formulation of recommendations concerning the surgical strategy remains still difficult due to inconsistency of surgical outcomes. The literature describing surgical strategy of VB IDAs is varying in quality and content, and many studies deal with only a few patients. In the presented review, the authors summarize the current knowledge on the incidence, pathogenesis, clinical presentation, and diagnostic procedures with special emphasis on surgical treatment of IDAs in posterior circulation.

Three Cases of Ruptured Basilar Artery Dissection: From Diagnosis to Endovascular Treatment

BACKGROUND

Ruptured basilar artery dissections are rare, and prognosis is often disastrous.

CASE DESCRIPTION

We report 3 recent cases of ruptured dissection from imaging diagnosis to endovascular treatment, presenting 3 different types of dissection and 3 different treatment approaches. These 3 patients presented major subarachnoid hemorrhage (Fisher grade 4): 2 of them were in a coma (World Federation of Neurosurgical Societies Grading System [WFNS] 5), and 1 patient presented with headache only (WFNS 1). Two of the 3 dissections presented a dilated pseudoaneurysm responsible for the bleeding (1 large and 1 small), and the remaining dissection was extensive. The dissection with the larger pseudoaneurysm was treated with coils, resulting in early recanalization requiring another endovascular treatment with coils and a flow diverter stent. The patient with the small pseudoaneurysm was treated with a flow diverter only. These 2 patients had a favorable outcome. The remaining patient with a large tear of the basilar artery had 3 overlapping stents, and fatal rebleeding occurred prematurely.

CONCLUSIONS

These 3 cases illustrate different patient management strategies. We discuss this challenging condition and the current position of endovascular therapeutic techniques.

Imaging Characteristics of Growing and Ruptured Vertebrobasilar Non-Saccular and Dolichoectatic Aneurysms

Background and Purpose—

Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms generally have a poor natural history. We performed a study examining the natural history of vertebrobasilar, nonsaccular, and dolichoectatic aneurysms receiving serial imaging and studied imaging characteristics associated with growth and rupture.

Methods—

We included all vertebrobasilar dolichoectatic, fusiform, and transitional aneurysms with serial imaging follow-up seen at our institution over a 15-year period. Two radiologists and a neurologist evaluated aneurysms for size, type, mural T1 signal, mural thrombus, daughter sac, mass effect, and tortuosity. Primary outcomes were aneurysm growth or rupture. Univariate analysis was performed with chi-squared tests for categorical variables and Student’s t test or analysis of variance for continuous variables. Multivariate logistic regression analysis was performed to identify variables independently associated with aneurysm growth or rupture.

Results—

One hundred and fifty-two patients with 542 patient-years (mean 3.6±3.5 years) of imaging follow-up were included. Aneurysms were fusiform in 45 cases (29.6%), dolichoectatic in 75 cases (49.3%), and transitional in 32 cases (21.1%). Thirty-five aneurysms (23.0%) grew (growth rate=6.5%/year). Eight aneurysms (5.3%) ruptured (rupture rate=1.5%/year). Variables associated with growth and rupture on univariate analysis were size >10 mm (57.6% versus 16.0%, P <0.0001), mural T1 signal (39.7% versus 16.3%, P =0.001), daughter sac (56.3% versus 21.3%), and mural thrombus (45.5% versus 13.4%, P <0.0001). 26.7% of fusiform aneurysms, 9.3% of dolichoectatic aneurysms, and 59.4% of transitional aneurysms grew or ruptured ( P <0.0001). The only variable independently associated with rupture was transitional morphology ( P =0.003).

Conclusions—

Vertebrobasilar, nonsaccular, and dolichoectatic aneurysms are associated with a poor natural history with high growth and rupture rates. Further research is needed to determine the best treatments for this disease.

Huge Intramural Hematoma in a Thrombosed Middle Cerebral Artery Aneurysm: A Case Report

We describe a case of a huge intramural hematoma in a thrombosed middle cerebral artery aneurysm. A 47-year-old female patient with liver cirrhosis and thrombocytopenia presented to the neurosurgical unit with a 5-day history of headache and cognitive dysfunction. Magnetic resonance imaging and computed tomography of the brain showed a thrombosed aneurysm located in the right middle cerebral artery with a posteriorly located huge intramural hematoma mimicking an intracerebral hematoma. Imaging studies and cerebrospinal fluid analysis showed no evidence of subarachnoid hemorrhage. Angiography showed a partially thrombosed aneurysm at the origin of the right anterior temporal artery and an incidental aneurysm at the bifurcation of the right middle cerebral artery. Both aneurysms were embolized by coiling. After embolization, the thrombosed aneurysmal sac and intramural hematoma had decreased in size 4 days later and almost completely disappeared 8 months later. This is the first reported case of a nondissecting, nonfusiform aneurysm with a huge intramural hematoma, unlike that of a dissecting aneurysm.

Clinical features and prognosis of intracranial artery dissection

BACKGROUND

Intracranial artery dissections (IADs) are an important cause of stroke or subarachnoid hemorrhage (SAH). Outcome of IAD in the anterior circulation or presentation without SAH is rarely investigated and might be different.

OBJECTIVE

To evaluate the clinical features and prognosis of patients with IAD, with special emphasis on the location (anterior vs posterior circulation) and clinical presentation (SAH or cerebral ischemia).

METHODS

Between January 1998 and May 2012, 60 patients with IAD were included in this single-center cohort study. Clinical features, functional outcome, mortality, and prognostic factors were evaluated. Unfavorable functional outcome was defined as a modified Rankin scale score of 3 to 6.

RESULTS

In 18 patients (30%), IAD was located in the anterior circulation. At a median follow-up of 6.4 months, 35.3% of patients with IAD in the anterior circulation had an unfavorable functional outcome vs 39.0% in patients with IAD in the posterior circulation (P = .79). Forty-two patients (70%) presented with SAH. Clinical presentation with SAH was not significantly associated with poor functional outcome (41.5% vs 29.4%, P = .39). Low Glasgow Coma Scale score on admission (odds ratio, 0.72, P = .003) and older age (odds ratio, 1.04, P = .04) were independent predictors of unfavorable functional outcome. Mortality rate was 13% and did not significantly differ with location or clinical presentation.

CONCLUSION

Low Glasgow Coma Scale score on admission and older age were independent predictors of unfavorable functional outcome. IAD presenting with SAH was not significantly associated with poor functional outcome.

Evolution of a chronic dissecting aneurysm on magnetic resonance imaging in a pediatric patient

Clinical and imaging manifestations of the so-called partially thrombosed aneurysm (PTA) are different from those of the classic intracranial saccular aneurysm. Given some of their peculiar imaging features, it had been hypothesized that some PTAs occur due to repeated intramural hemorrhages. The authors present a case of PTA that evolved from an acute dissecting aneurysm as shown by serial imaging. A previously healthy 5-year-old boy had a sudden onset of left hemiparesis. Initial MRI sequences showed a perforating vessel infarction in the right basal ganglia area secondary to an acute distal middle cerebral artery (MCA) dissection as demonstrated on conventional angiography. Conservative management with close observation of this dissection was chosen, and serial MRI studies revealed layering of blood of various ages within the wall of an aneurysmal outpouching of the MCA, thereby leading to the imaging appearance of a PTA. The findings in this case indicate that some PTAs may be caused by repeated or chronic dissections, with blood entering the wall through an endothelial defect. Understanding the pathological mechanism underlying the formation of these aneurysms will help inform appropriate treatment strategies.

Hyperhomocysteinemia and methylenetetrahydrofolate reductase polymorphism in cervical artery dissection: a meta-analysis

BACKGROUND

Cervical artery dissection (CAD) is a recognized cause of ischemic stroke. Hyperhomocysteinemia (HHcy), i.e. an elevated concentration of plasma homocysteine, is identified as an independent risk factor for stroke prevalence. However, an association between HHcy and CAD has so far remained unknown.

METHODS

A meta-analysis was performed to analyze the association between HHcy and CAD as well as the relevance of the C677T polymorphism of methylenetetrahydrofolate reductase (MTHFR), the key enzyme in homocysteine metabolism during CAD. We searched PubMed and Embase for studies reporting homocysteine concentrations or MTHFR genotype frequencies in CAD patients from 1990 to 2013. Outcomes were extracted from studies meeting the inclusion criteria and were subjected to a meta-analysis by the random-effect model. Heterogeneity was assessed by the I(2) test.

RESULTS

Eight case-control studies with 2,146 individuals fulfilled the required criteria and were included in the meta-analysis. HHcy was found to be significantly associated with CAD (pooled standardized mean difference: 0.96; 95% confidence interval, CI: 0.42-1.49; p < 0.01). We also found a significantly increased risk of CAD in individuals with the MTHFR C677T polymorphism by both the recessive model (TT vs. CT+CC; odds ratio, OR = 1.81; 95% CI: 1.22-2.67; p = 0.003) and the dominant model (TT+CT vs. CC; OR = 1.47; 95% CI: 1.08-1.99; p = 0.014).

CONCLUSION

Our data suggest positive correlations between HHcy and CAD and between the C677T polymorphism of MTHFR and CAD.

Traumatic dissection of the internal carotid artery: simultaneous infarct of optic nerve and brain

KEY CLINICAL MESSAGE

Traumatic intracranial internal carotid artery dissection is a rare but significant cause of stroke in patients in their forties, leading to high morbidity and mortality. Simultaneous ischemic stroke and optic nerve infarction can occur. Clinical suspicion of dissection is determining in the acute management.

Imaging investigation of intracranial arterial dissecting aneurysms by using 3 T high-resolution MRI and DSA: from the interventional neuroradiologists' view

OBJECTIVES

The purpose of this study was to investigate vessel wall imaging features combined with the luminal shapes of intracranial dissecting aneurysms (IDAs) by using 3 Tesla (3T) high-resolution magnetic resonance imaging (MRI) and digital subtraction angiography (DSA).

METHODS

Sixty-seven patients with 76 IDAs were consecutively enrolled in the study from December 2011 to May 2013. DSA was performed to diagnose an IDA and to categorize its angiography patterns into either aneurysmal dilation, steno-occlusive, combined, or unclassifiable. Images of 3T high-resolution MRI were used to evaluate arterial wall imaging features of each lesion. Chi-squared tests were used for statistical analyses.

RESULTS

Aneurysmal dilation (51 of 76, [67%]) was the most common angiography pattern of IDAs, followed by the combined pattern (20 of 76, [26%]). Seven percent (five of 76) of IDAs showed steno-occlusive (n = 3) and unclassifiable (n = 2) angiography patterns, in which intramural hematomas were detected in the arterial wall without luminal connection. Intimal flaps (32 of 76, [42%]), double-lumen sign (38 of 76, [50%]) and intramural hematomas (46 of 76, [61%]) were recognized as the characteristic features of dissection by high-resolution MRI. Intramural hematomas occurred more frequently in the combined patterns group (16 of 20, [80 %]) than in the aneurysmal dilation group (25 of 51, [49%]) (P = .017), while the occurrence of intimal flaps and double-lumen sign did not differ between angiographic patterns (P > .05).

CONCLUSIONS

3T high-resolution MRI combined with DSA offered clear visualization of vessel wall features and accurate assessment of the vessel lumen in IDAs. This combined approach would be highly useful for understanding the underlying pathological status of IDAs and in guiding treatment choices.

Flow-diversion panacea or poison?

Endovascular therapy is now the treatment of choice for intracranial aneurysms (IAs) for its efficacy and safety profile. The use of flow diversion (FD) has recently expanded to cover many types of IAs in various locations. Some institutions even attempt FD as first line treatment for unruptured IAs. The most widely used devices are the pipeline embolization device (PED), the SILK flow diverter (SFD), the flow redirection endoluminal device (FRED), and Surpass. Many questions were raised regarding the long-term complications, the optimal regimen of dual antiplatelet therapy, and the durability of treatment effect. We reviewed the literature to address these questions as well as other concerns on FD when treating IAs.

Controversy in the management of lenticulostriate artery dissecting aneurysm: a case report and review of the literature

BACKGROUND

Intracranial arterial dissection is an uncommon but well-recognized entity. Treatment remains variable, ranging from observation to intervention via the use of either surgical or endovascular techniques. Aneurysms along the lenticulostriate artery have been reported in only 41 patients. With the current case study we illustrate the effectiveness of observation in the context of a dissecting lenticulostriate aneurysm and discuss other approaches that have been used in the treatment of this particular entity.

CLINICAL SUMMARY

An accomplished mountain climber presented, after coitus, with acute headache, mild facial weakness, and forgetfulness. Vascular imaging studies revealed a right putaminal hemorrhage secondary to a 3-mm lenticulostriate artery dissecting aneurysm. Clinically, the patient did well, with marked improvement in presenting symptoms enabling his return to mountain climbing. Follow-up angiography showed spontaneous resolution of the arterial dissecting aneurysm. Among the 41 reported cases, 19 were idiopathic, 5 associated with hypertension, and 17 related to various conditions such as Moyamoya disease, arteriovenous malformation, systemic vasculitis, intraventricular tumor, or substance abuse. Of the 42 cases, including the present case, 28 were surgically or endovascularly managed and 12 observed. Only one of the reported cases, a 33-year-old man with Moyamoya disease, who was managed conservatively, died of rebleeding.

CONCLUSION

There is no common consensus in the literature on a single treatment strategy for a lenticulostriate artery aneurysm. The present case illustrates that observation and follow-up vascular imaging can be an important treatment strategy, allowing healing of the vessel wall and disappearance of the dissecting aneurysm.

Thunderclap headache: diagnostic considerations and neuroimaging features

Thunderclap headache (TCH) is an acute and severe headache that has maximum intensity at onset; TCH can be primary or secondary. Primary TCH is diagnosed when no underlying cause is discovered; however, imaging is crucial in distinguishing secondary causes, which are wide-ranging. The radiologist should be aware of the list of potential diagnoses. Subarachnoid haemorrhage (SAH) is the most common cause of secondary TCH. Aneurysmal SAH accounts for the majority of cases, although other causes should also be considered and these include perimesencephalic haemorrhage, arteriovenous malformations, and dural arteriovenous fistula as well as reversible cerebral vasoconstriction syndrome. Conditions that may present with TCH, with or without SAH include cervical artery dissection and cerebral venous sinus thrombosis. Ischaemic stroke, pituitary apoplexy, and posterior reversible leucoencephalopathy are other potential causes, whereas non-vascular causes include colloid cysts of the third ventricle and spontaneous intracranial hypotension. Imaging features are reviewed with reference to clues gleaned from initial imaging using computed tomography, as well as characteristics that should be sought using magnetic resonance imaging or angiographic imaging.

Long-term clinical and imaging follow-up of complex intracranial aneurysms treated by endovascular parent vessel occlusion

BACKGROUND AND PURPOSE

Flow-diverting stents are increasingly being used for the treatment of complex intracranial aneurysms, but the indications for their use in lieu of traditional endovascular PVO have yet to be precisely defined. The purpose of this study was to review the clinical and imaging outcomes of patients with intracranial aneurysms treated by PVO.

MATERIALS AND METHODS

A total of 28 patients with intracranial aneurysms, treated by PVO between July 1992 and December 2009, were reviewed. Aneurysms arising from peripheral arteries were excluded. Clinical and imaging data were retrospectively analyzed from a prospectively maintained data base.

RESULTS

There were 28 patients with 28 aneurysms treated by PVO. Aneurysms of the anterior circulation presenting with mass effect (n = 11) or discovered incidentally (n = 1), and dissecting-type VB aneurysms presenting with subarachnoid hemorrhage (n = 6) faired the best with high obliteration rates (83.3% and 83.6%, respectively) and no permanent major ischemic complications. In contrast, VB aneurysms presenting with mass effect (n = 7) demonstrated the lowest obliteration rate (57.1%), the highest rate of permanent major ischemic complications (28.6%), and a high mortality rate (28.6%).

CONCLUSIONS

PVO is a safe and effective treatment for complex intracranial aneurysms of the carotid artery and dissecting-type VB aneurysms presenting with SAH. In contrast, PVO for aneurysms of the VB circulation presenting with mass effect is less efficacious and associated with significant morbidity and mortality. It is hoped that flow diverters may represent a better treatment technique for these most difficult-to-treat lesions.

Investigation of the endovascularly treated and untreated unruptured vertebrobasilar artery aneurysms

BACKGROUND AND PURPOSE

The present study aimed to investigate the endovascular indication with close monitoring of both endovascularly treated and untreated unruptured vertebrobasilar aneurysms.

MATERIALS AND METHODS

In the past 2 years, 36 patients [7 women and 29 men with a mean age of 48.5 years (range, 13-75 years)] who had 40 unruptured vertebrobasilar artery aneurysms were reviewed. The decision of the endovascular treatment was not randomized. In both endovascularly untreated and treated patients, overall mortality and morbidity corresponding to Glasgow outcome scale (GOS) score III or worse was counted as unruptured aneurysm related event. The ratio of event free was compared between endovascularly treated and untreated patients using Log-rank test. In a univariate analysis, poor outcome was predicted by endovascularly untreated.

RESULTS

Thirty-six patients were followed with a mean period of 10.7 months (range, 0.7 months-21 months). In untreated cases, new neurological deficits caused by the aneurysm were noted in 2 cases. The annual deterioration rate of the untreated cases was 9.1%. In endovascularly treated cases, there was no mortality and morbidity. There was no SAH in all cases during follow-up period. When ratio of event free was compared, significant advantage of endovascular treatment was noted (X(2)=4.429, P=0.035).

CONCLUSIONS

The present results indicated that endovascular treatment has a benefit for the unruptured vertebrobasilar artery aneurysms.