Towards the mechanical characterisation of unruptured intracranial aneurysms: Numerical modelling of interactions between a deformation device and the aneurysm wall

Intracranial aneurysm is a critical pathology related to the arterial wall deterioration. This work is an essential aspect of a large scale project aimed at providing clinicians with a non-invasive patient-specific decision support tool regarding the rupture risk assessment. A machine learning algorithm links the aneurysm shape observed and a database of UIA clinical images associated with in vivo wall mechanical properties and rupture characterisation. The database constitution is derived from a device prototype coupled with medical imaging. It provides the mechanical characterisation of the aneurysm from the wall deformation obtained by inverse analysis based on the variation of luminal volume. Before performing in vivo tests of the device on small animals, a numerical model was built to quantify the device's impact on the aneurysm wall under natural blood flow conditions. As the clinician will never be able to precisely situate the device, several locations were considered. In preparation for the inverse analysis procedure, artery material laws of increasing complexity were studied (linear elastic, hyper elastic Fung-like). Considering all the device locations and material laws, the device induced relative displacements to the Systole peak (worst case scenario with the highest mechanical stimulus linked to the blood flow) ranging from 375 μm to 1.28 mm. The variation of luminal volume associated with the displacements was between 0.95 % and 4.3 % compared to the initial Systole volume of the aneurysm. Significant increase of the relative displacements and volume variations were found with the study of different cardiac cycle moments between the blood flow alone and the device application. For forthcoming animal model studies, Spectral Photon CT Counting, with a minimum spatial resolution of 250 μm, was selected as the clinical imaging technique. Based on this preliminary study, the displacements and associated volume variations (baseline for inverse analyse), should be observable and exploitable.

Diagnosis of Small Unruptured Intracranial Aneurysms : Comparison of 7 T versus 3 T MRI

PURPOSE

Differentiating normal anatomical variants such as an infundibulum or a vascular loop from true intracranial aneurysms is crucial for patient management. We hypothesize that high-resolution 7 T magnetic resonance imaging (MRI) improves the detection and characterization of normal anatomical variants that may otherwise be misdiagnosed as small unruptured aneurysms.

METHODS

This is a retrospective, single-center study. All patients were scanned on a clinically approved 7 T MRI scanner and on a 3 T scanner. Image analysis was performed independently by three neuroradiologists blinded to clinical information. The presence of an unruptured intracranial aneurysm (UIA) and level of diagnostic certainty were assessed and the interrater agreement was calculated. If an aneurysm was present, the anatomic location and shape were recorded and compared.

RESULTS

In total, 53 patients with equivocal cerebrovascular findings on 1.5 T or 3 T MRI referred for a 7T MRI examination were included. Aneurysms were suspected in 42 patients examined at 3 T and in 23 patients at 7 T (rate difference 36%, 95% confidence interval, CI, 19-53%, p-value < 0.001). Major disagreement between the field strengths was observed in the A1 segment of anterior cerebral artery/anterior communicating artery (A1/ACOM) complex. The interrater agreement among the readers on the presence of an aneurysm on 7 T MRI was higher than that for 3 T MRI (0.925, 95% CI 0.866-0.983 vs. 0.786, 95% CI 0.700-0.873).

CONCLUSION

Our analysis demonstrates a significantly higher interrater agreement and improved diagnostic certainty when small intracranial aneurysms are visualized on 7 T MRI compared to 3 T. In a selected patient cohort, clinical implementation of 7 T MRI may help to establish the definitive diagnosis and thus have a beneficial impact on patient management.

Irreversible postoperative cognitive impairment after unruptured intracranial aneurysm treatment in the elderly

PURPOSE

Postoperative cognitive dysfunction and recovery remain unclear in older patients undergoing interventional therapies for unruptured intracranial aneurysms (UIAs). This study aimed to compare changes in postoperative cognitive function between younger and older patients and to detect factors associated with non-recovery from postoperative cognitive dysfunction.

METHODS

This study reviewed 59 consecutive patients with UIAs who underwent interventional therapies, including microsurgical clipping or endovascular treatment, from 2021 to 2022. All patients were divided into the older (aged ≥ 70 years) and younger (aged < 70 years) groups. Mini-Mental State Examination (MMSE) and Frontal Assessment Battery (FAB) were performed within 2 months before interventions, at 1 week postoperatively (POW1), and 3-6 months postoperatively (POM3-6).

RESULTS

MMSE and FAB scores decreased more frequently in the older group than in the younger group at POW1 (older vs. younger: MMSE: 48% vs. 21%, p < 0.05; FAB: 56% vs. 18%, p < 0.01). In the older group, the FAB Z-score decreased in POW1 and recovered by POM3-6 (p < 0.01), while the MMSE Z-score continued to decrease (p = 0.04). Age and the preoperative MSME Z-score were significantly associated with non-recovery from decreased MMSE score at POM3-6 (recovery vs. non-recovery, age: 62 years old vs. 72 years old, p = 0.03, preoperative MMSE Z-score: 0.16 vs. - 0.90, p < 0.01).

CONCLUSIONS

This retrospective study found that older patients were more likely to have a postoperative cognitive decline after UIA treatment and implicated that global cognitive function tended to decline more than executive function in the long term. In addition, this study demonstrated that lower preoperative cognitive function was associated with inadequate postoperative cognitive recovery. The findings potentially contribute to the establishment of indications for treating UIAs in older patients.

Neutrophil-to-lymphocyte ratio associated with symptomatic saccular unruptured intracranial aneurysm

BACKGROUND AND PURPOSE

Whether symptomatic unruptured intracranial aneurysms (UIAs) lead to change in circulating inflammation remains unclear. This study aims to evaluate the role of hematological inflammatory indicators in predicting symptomatic UIA.

METHODS

Adult patients diagnosed with saccular intracranial aneurysm from March 2019 to September 2023 were recruited retrospectively. Clinical and laboratory data, including the white blood cells (WBC), neutral counts (NEUT), lymphocyte counts (LYM), and monocyte counts (MONO) of each patient, were collected. The neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) were calculated as NLR = NEUT/LYM, LMR = LYM/MONO, SII = PLT*NEUT/LYM. The hematological inflammatory indicators were compared in symptomatic saccular and asymptomatic UIA patients. Multivariable logistic regression analyses were performed to explore the factors predicting symptomatic UIA.

RESULTS

One hundred and fifty UIA patients with a mean age of 58.5 ± 12.4 were included, of which 68% were females. The NLR and LMR were significantly associated with symptomatic UIA, and the association remained in small UIAs (< 7 mm). The multiple logistic regression analysis showed that NLR was independently associated with symptomatic UIA. On ROC curve analysis, the optimal cutoff value of NLR to differentiate symptomatic from asymptomatic was 2.38. In addition, LMR was significantly associated with symptomatic UIA smaller than 7 mm.

CONCLUSION

There was a significant correlation between NLR and symptomatic UIA. The NLR was independently associated with symptomatic UIA.

Geometric versus Hemodynamic Indexes for Rupture-Destined Aneurysms: A Retrospective Cohort and a Repeated-Measures Study

INTRODUCTION

A proper stratification of intracranial aneurysms is critical in identifying rupture-destined aneurysms and unruptured intracranial aneurysms. We aimed to determine the utility of geometric and hemodynamic indexes in differentiating two types of aneurysms and to examine the characteristics of natural evolutionary changes of unruptured aneurysms.

METHODS

Rupture-destined aneurysm refers to an aneurysm that undergoes subsequent aneurysmal subarachnoid hemorrhage (SAH). On the other hand, an unruptured intracranial aneurysm is characterized by an aneurysm that does not experience rupture during serial time-of-flight magnetic resonance angiography (TOF-MRA). In addition to geometric indexes, signal intensity gradient (SIG), an in vivo approximated wall shear stress from TOF-MRA, was measured in aneurysms. The difference between the maximum and minimum values of SIG in an aneurysm compared to parent arterial values was designated as the delta-SIG ratio.

RESULTS

This study analyzed 20 rupture-destined aneurysms in 20 patients and 45 unruptured intracranial aneurysms in 41 patients with follow-up TOF-MRA. While geometric indexes did not show differences between the two groups, the delta-SIG ratio was higher in the rupture-destined aneurysms (1.5 ± 0.6 vs. 1.1 ± 0.3, p = 0.032). The delta-SIG ratio showed a higher area under the receiver operating characteristic curve for SAH than the size ratio (0.72 [95% CI, 0.58-0.87] vs. 0.56 [95% CI, 0.41-0.72], p = 0.033). The longitudinal re-examination of TOF-MRA in the unruptured intracranial aneurysms revealed evidence of aneurysmal growth, while concurrently exhibiting hemodynamic stability.

CONCLUSION

The delta-SIG ratio showed higher discriminatory results between the two groups compared to geometric indexes. Aneurysmal rupture risk should be assessed by considering both geometric and hemodynamic information. This study was registered on ClinicalTrials.gov (NCT05450939).

The impact of initial counselling for patients' decision-making and the accuracy of interdisciplinary neurovascular board evaluation in elective treatment of unruptured intracranial aneurysms - a German single-centre retrospective study

OBJECTIVE

Interdisciplinary-neurovascular-boards (INVB) are deemed to find the patient's optimum treatment-modality in elective unruptured intracranial aneurysm-repair (EUIAR). If INVB judges risk/success estimation similar for microsurgical/endovascular EUIAR, the choice for either modality is up to the informed patient. However, it is unknown if the patients' decision-making might be biased by the discipline of initial counselling prior to INVB and if INVB's equal risk/success estimation is finally accurate.

METHODS

We analysed all our patients with EUIAR after INVB-discussion between 2007 and 2017 and identified those patients where INVB-recommendation estimated similar risk/success rates for both treatment-modalities. We investigated the procedural/outcome parameters and determined if the mode of initial counselling prior to INVB influenced the patients' choice of EUIAR and if INVB's equal risk/success estimation was accurate.

RESULTS

Within altogether 572 patients with EUIAR during our study period, we identified 99 patients (agemean:58 yrs; m:f=1:2) in whom pre-treatment INVB-discussion estimated risk/success rates for both modalities of EUIAR to be similar. Prior to INVB-discussion, 80 of the 99 patients had been initially counselled in the neurosurgical discipline and 19 patients in the endovascular discipline. The final patients' decision rates for surgical vs. endovascular EUIAR (after secondary consultation of each patient in both disciplines after INVB-discussion) were 67% vs. 33% in the first and 58% vs. 42% in the latter group (no significant difference: p = 0.345). Uni- and multivariate analysis did not show any hints for a bias in patients' decision-making caused by the discipline of initial counselling prior to INVB/secondary bilateral consultations. Clinical and procedural outcome at last follow-up (median:18mos) did not differ between those 66 patients that eventually decided for microsurgical and those 33 patients that eventually decided for endovascular EUIAR, underlining the high accuracy of INVB's pre-treatment risk/success estimations.

CONCLUSION

Only in a small number of patients, INVB estimates both disciplines to be of equal value for EUIAR which proves to be highly accurate at long-term outcome measures. Initial contact to one or the other neurovascular discipline does not appear to play a significant role in the final patient's decision-making process.

Posterior reversible encephalopathy syndrome following uneventful clipping of an unruptured intracranial aneurysm: A case report

BACKGROUND

Posterior reversible encephalopathy syndrome (PRES) is characterized mainly by occipital and parietal lobe involvement, which can be reversible within a few days. Herein, we report a rare case of PRES that developed after craniotomy for an unruptured intracranial aneurysm (UIA).

CASE SUMMARY

A 59-year-old man underwent clipping surgery for the treatment of UIA arising from the left middle cerebral artery. Clipping surgery was performed uneventfully, and he regained consciousness quickly immediately after the surgery. At the 4th hour after surgery, he developed a disorder of consciousness and aphasia. Magnetic resonance imaging revealed cortical and subcortical T2/FLAIR hyperintensities in the parietal, occipital, and frontal lobes ipsilaterally, without restricted diffusion, consistent with unilateral PRES. With conservative treatment, his symptoms and radiological findings almost completely disappeared within weeks. In our case, the important causative factor of PRES was suspected to be a sudden increase in cerebral perfusion pressure associated with temporary M1 occlusion.

CONCLUSION

Our unique case highlights that, to our knowledge, this is the second report of PRES developing after craniotomy for the treatment of UIA. Surgeons must keep PRES in mind as one of the causes of perioperative neurological abnormality following clipping of an UIA.

Prevalence and risk factors of unruptured intracranial aneurysms in ischemic stroke patients - A global meta-analysis

Background

Unruptured intracranial aneurysms (UIAs) have an estimated global prevalence of 2.8% in the adult population; however, UIA was identified among more than 10% of ischemic stroke patients. Many epidemiological studies and reviews have pointed to the presence of UIA among patients with ischemic stroke; yet, the extent of this association is not fully known. We performed a systematic review and meta-analysis to determine the prevalence of UIA in patients admitted to hospitals with ischemic stroke and transient ischemic attack (TIA) at both global and continental levels and evaluate factors associated with UIA in this population.

Methods

We identified, in five databases, all studies describing UIA in ischemic stroke and TIA patients between January 1, 2000, and December 20, 2021. Included studies were of observational and experimental design.

Results

Our search yielded 3581 articles of which 23 were included, with a total of 25,420 patients. The pooled prevalence of UIA was 5% (95% confidence interval [CI] = 4-6%) with stratified results showing 6% (95% CI = 4-9%), 6% (95% CI = 5-7%), and 4% (95% CI = 2-5%) in North America, Asia, and Europe, respectively. Significant risk factors were large vessel occlusion (odds ratios [OR] = 1.22, 95% CI = 1.01-1.47) and hypertension (OR = 1.45, 95% CI = 1.24-1.69), while protective factors were male sex (OR = 0.60, 95% CI = 0.53-0.68) and diabetes (OR = 0.82, 95% CI = 0.72-0.95).

Conclusion

The prevalence of UIA is notably higher in ischemic stroke patients than the general population. Physicians should be aware of common risk factors in stroke and aneurysm formation for appropriate prevention.

A survey of the radiological follow-up of unruptured intracranial aneurysms in the United Kingdom

OBJECTIVE

Unruptured intracranial aneurysms (UIA) are common. For many the treatment risks outweigh their risk of subarachnoid haemorrhage and patients undergo surveillance imaging. There is little data to inform if and how to monitor UIAs resulting in widely varying practices. This study aimed to determine the current practice of unruptured UIA surveillance in the United Kingdom.

METHODS

A questionnaire was designed to address the themes of surveillance protocols for UIA including when surveillance is initiated, how frequently it is performed, and when it is terminated. Additionally, how aneurysm growth is managed and how clinically meaningful growth is defined were explored. The questionnaire was distributed to members of the British Neurovascular Group using probability-based cluster and non-probability purposive sampling methods.

RESULTS

Responses were received from 30 of the 30 (100.0%) adult neurosurgical units in the United Kingdom of which 27 (90.0%) routinely perform surveillance for aneurysm growth. Only four units had a unit policy. The mean patient age up to which a unit would initiate follow-up of a low-risk UIA was 65.4 ± 9.0 years. The time points at which imaging is performed varied widely. There was an even split between whether units use a fixed duration of follow-up or an age threshold for terminating surveillance. Forty percent of units will follow-up patients more than 5 years from diagnosis. The magnitude in the change in size that was felt to constitute growth ranged from 1 to 3mm. No units routinely used vessel wall imaging although 27 had access to 3T MRI capable of performing it.

CONCLUSIONS

There is marked heterogeneity in surveillance practices between units in the United Kingdom. This study will help units better understand their practice relative to their peers and provide a framework forplanning further research on aneurysm growth.

The incidence and prevalence of unruptured intracranial aneurysms in sickle cell disease patients: a systematic review

BACKGROUND

Unruptured Intracranial Aneurysms (UIAs) pose a significant risk of morbidity in the general population and much more so among sickle cell disease (SCD) patients. Meanwhile, the proportion of these patients with UIAs is not established just as the course and characteristics of the aneurysms are not well known.

AIM

To estimate the prevalence, incidence and characteristics of UIAs in SCD patients and compare same with the metrics and features in the general population.

METHODS

The Data repositories, Medline (PubMed), Embase and Web of science were systematically searched from January 1st, 1990, to July 31st, 2021. Publications that passed an inclusion test were reviewed for data on the incidence and prevalence of UIAs, aneurysm characteristics and outcomes in SCD patients extracted. Findings from the included studies were appraised, using the Methodological Index for Non-randomized studies score (MINORS). The results were descriptively analysed. Given the marked heterogeneity of retrieved data, results were reported as standardized values, including the mean weighted annual incidence rate.

RESULTS

105 SCD patients with 186 UIAs were identified in 10 retrospective studies. Mean age ranged from 10.5 to 40.18 across studies with adult (>18 years) predominance. The prevalence of UIAs in SCD was 4.1% (95%CI 3.6 and 4.6) incidence rate was 1290.3/100,000 patient-years (95% CI 1018.0-1562.6). Aneurysms tended to be small (60%), anterior (76.1%), multiple (45.7%), and managed conservatively (62%) with mostly good outcomes (95%). The average MINORS score was 9.4 ± 3.1 for non-comparative studies (n = 8) and 19.5 ± 0.7 for comparative studies (n = 2).

CONCLUSION

UIAs have a definite relationship with SCD, with higher incidence figures relative to the general population. Aneurysmal characteristics although largely similar, tend to be smaller in SCD patients. The low methodological quality of reviewed studies informs the need for well-designed prospective randomized controlled studies to better understand the mechanics of this relationship.

Rapid Change in Shape of Unruptured Intracranial Aneurysm with Acute Perforating Infarction

Acute ischemic stroke is a rare complication resulting from an unruptured intracranial aneurysm (UIA). Ischemic stroke adjacent to the aneurysms is considered the risk of rupture of aneurysms. However, there is presently no consensus on the optimal strategy for the management of UIAs with ischemic stroke. A 27-year-old woman presented with sudden onset left hemiparesis. Acute infarction of the right basal ganglia and an aneurysm of the right middle cerebral artery were discovered on brain imaging. Antiplatelet therapy was used to treat her. The diagnosis revealed ischemic stroke caused by a thrombosed aneurysm due to the change in the shape of the aneurysm on day 4. The UIA clipping procedure was performed on day 21 due to the risk of subarachnoid hemorrhage (SAH). The findings of the surgery and indocyanine green imaging revealed a partially thrombosed aneurysm and occlusion of a perforating artery. As is well known, enlargement of aneurysm size indicates increasing rupture risk. In the present case, after ischemic events developed, magnetic resonance angiography revealed enlargement of the aneurysm. The findings of the surgery revealed possible pathogenic mechanisms were perforating artery occlusion due to local extension of the luminal thrombus. Clinicians should be aware of the risk of ischemic stroke due to luminal thrombosis of the UIA and SAH and should consider urgent treatment of the UIA even immediately after ischemic stroke.

Recruitment in a pragmatic randomized trial on the management of unruptured intracranial aneurysms

OBJECTIVES

The Comprehensive Aneurysm Management (CAM) study is a pragmatic trial designed to manage UIA patients within a care research framework.

METHOD

CAM is an all-inclusive study. Management options are allocated according to an algorithm combining pre-randomization and clinical judgment. Eligible patients are offered 1:1 randomized allocation of intervention versus conservative management and 1:1 randomization allocation of surgical versus endovascular treatment. Ineligible patients are registered. The primary outcome is survival without dependency (mRS<3) at 10 years. All UIA patients at one center are reported.

RESULTS

Between February 2020 and July 2021, 403 UIA patients were recruited: 179 (44%) in one of the RCTs and 224 (56%) in one of the registries. Conservative management was recommended for 205/403 patients (51%); of 198 (49%) patients considered for curative treatment, 159 (80%) were randomly allocated conservative (n=81) or curative treatment (n=78). These patients were younger and had larger aneurysms than those in the observation registry (P = .004). In 39/198 patients (20%), conservative management was not considered reasonable (17 patients were recommended endovascular, 2 surgery, and 20 the RCT comparing endovascular with surgical treatment). In total, 70 patients were recruited in the RCT comparing surgery and endovascular treatment. After informed discussion at time of consent, 141/159 patients (89%) agreed with the randomly allocated management plan, while 11% crossed-over to the alternative management option.

CONCLUSION

CAM was successfully integrated into routine practice. Meaningful conclusions can be obtained if multiple centers actively participate in the trial.

Prevalence of unruptured intracranial aneurysms among first-degree relatives of Thai patients who had aneurysmal subarachnoid hemorrhage

Background:

The prevalence of familial unruptured intracranial aneurysm (UIA) in Thai population was unknown.

Methods:

Our study population comprised first-degree relatives of patients who were diagnosed with aneurysmal subarachnoid hemorrhage (aSAH) in two cerebrovascular neurosurgical centers from January 2018 to December 2018. The volunteers underwent three-dimensional time-of-flight magnetic resonance angiography for screening intracranial aneurysms (IA). Those who were reported positive or suspected of IA then underwent computed tomography angiography for confirmation.

Results:

We identified 12 patients who had 12 unruptured IAs (UIAs) from among 93 first-degree relatives. The prevalence of UIA among our study population was 12.9%. An estimated prevalence of UIA among Thai population was 9.05% (95% confidence interval [CI] 7.32–10.78). Of the 93 relatives, 84 had only one first-degree relative who suffered aSAH. Siblings posed a higher risk for UIA than offspring (16% vs. 9.5%), but the difference was not statistically significant (odds ratio 1.810, 95% CI 0.50–6.50, P = 0.274). The most common aneurysm location was the anterior cerebral artery territory (50%).

Conclusion:

The prevalence of familial UIA in a Thai population was relatively high. There was no significant between-group difference in the occurrence of UIA between the siblings and offspring of the aSAH patients.

Warning Signs in the Era of Unruptured Intracranial Aneurysms: Report on 2 Cases of Fatal Aneurysmal Hemorrhage

Introduction

The timing of treatment remains unresolved for patients with unruptured intracranial aneurysms (UIAs) and headaches, particularly when the pain is short term, localized, and related to the aneurysm site. We lack evidence to support the notion that when a headache accompanies an aneurysm, it elevates the risk of rupture.

Results

We describe 2 cases of fatal subarachnoid hemorrhage in patients with a history of headache and known aneurysms. Both of these patients had good indications for treatment: a young age and an aneurysm >7 mm, and both were qualified for elective surgery. However, both patients died of fatal aneurysm ruptures before the planned surgery.

Conclusion

These cases suggested that treatment should be started as soon as possible, when a UIA is diagnosed based on a short-term period of severe headaches or when a UIA is observed and then severe headaches appear. There is no straightforward guideline for treatment timing in these patients. However, in this era of UIAs, the significance of sentinel headaches should be reevaluated. Given the incidence of headaches in the general population and the very low risk of aneurysm rupture, there may be a tendency to neglect the role of headache as a possible warning sign.

Is physical activity a trigger factor for subarachnoid hemorrhage?

INTRODUCTION

Subarachnoid hemorrhage (SAH) is a serious pathology, associated with 43% mortality and significant disability. In the absence of relevant guidelines, some teams advocate that patients harboring an unruptured intracranial aneurysm (ICA) abstain from all sports activity, as a prophylactic precaution. The aim of the present study was to evaluate the impact of physical activity as a risk factor for SAH, through a review of the literature.

METHOD

A systematic literature review was performed for the period 2000 to 2020 in accordance with the PRISMA guidelines. Prospective and retrospective articles reporting more than 50 patients whose physical activity was associated with onset of SAH were included. The main end-point was prevalence of SAH occurring after physical activity. For comparison purposes, the prevalences of other circumstances were calculated to establish a range of frequency.

RESULTS

Physical activity appeared to be quite rarely associated with onset of SAH, with a prevalence of 3%, compared to 30% at rest, 7.3% in association with defecation and 4.5% in association with sexual activity. Age under 60 years, male gender (M/F ratio 1.38) and smoking (67.1%) were associated with onset of SAH during physical activity.

CONCLUSION

Physical activity appears to be a rare trigger factor for SAH. These results are in contrast to the idea that physical activity should, as a precaution, be avoided in patients with unruptured ICA. There is at present no scientific evidence of an association with aneurysmal SAH.

MISIAN (Minimally Invasive Surgery for Treatment of Unruptured Intracranial Aneurysms): A Prospective Randomized Single-Center Clinical Trial With Long-Term Follow-Up Comparing Different Minimally Invasive Surgery Techniques with Standard Open Surgery

BACKGROUND

Unruptured intracranial aneurysms (UIAs) are increasingly diagnosed but treatment is still controversial. Although the descriptions and use of minimally invasive surgery (MIS) have increased, comparative studies with standard approaches are rare.

OBJECTIVE

MISIAN (Minimally Invasive Surgery for Treatment of Unruptured Intracranial Aneurysms) is a prospective randomized single-center clinical trial with long-term follow-up comparing different MIS techniques with standard open surgery for treatment of UIAs.

METHODS

We randomly allocated a standard pterional approach (PtA) or MIS (1:2) to 111 patients with UIAs of the anterior circulation (mean dome diameter, 6.4 mm; range, 3-20 mm). Patients selected for MIS underwent a second randomization between a transeyelid approach (TelA) or nanopterional approach (NPtA) (1:1).

RESULTS

Forty-one patients were randomized to and treated with the PtA, 36 with the TelA, and 34 with the NPtA. Only patients treated with PtA had permanent facial nerve palsy (n = 4 [10%]; P = 0.032). MIS cosmetic results were considered better than those of PtA by independent observers (P < 0.001), and less temporal atrophy in the MIS group was also observed (P = 0.0034). The proportion of excellent results was higher in the TelA group than in the NPtA group (86% vs. 67.6%; P = 0.039). Patients undergoing MIS also reported consistently higher satisfaction and quality-of-life scores (P < 0.001).

CONCLUSIONS

MIS is superior to standard PtA for microsurgical clipping of small UIAs of the anterior circulation in terms of cosmetic, satisfaction, and quality-of-life outcomes. The TelA or NPtA for UIAs did not show significant outcome differences at 12-18 months.

Correlation of Inflow Velocity Ratio Detected by Phase Contrast Magnetic Resonance Angiography with the Bleb Color of Unruptured Intracranial Aneurysms

BACKGROUND

Intraoperative rupture is the most fatal and catastrophic complication of surgery for unruptured intracranial aneurysms (UIAs); thus, it is extremely useful to predict reddish and thin-walled regions of the UIA before surgery. Although several studies have reported a relationship between the hemodynamic characteristics and intracranial aneurysm wall thickness, a consistent opinion is lacking. We aimed to investigate the relationship between objectively and quantitatively evaluated bleb wall color and hemodynamic characteristics using phase-contrast magnetic resonance angiography (PC-MRA).

METHODS

Ten patients diagnosed with UIA who underwent surgical clipping and preoperative magnetic resonance imaging along with PC-MRA were included in this study. Bleb wall color was evaluated from an intraoperative video. Based on the Red (R), Green, and Blue values, bleb wall redness (modified R value; mR) was calculated and compared with the hemodynamic characteristics obtained from PC-MRA.

RESULTS

The wall redness distribution of 18 blebs in 11 UIAs in 10 patients was analyzed. Bleb/neck inflow velocity ratio (Vb/Va: r = 0.66, P = 0.003) strongly correlated with mR, whereas bleb/neck inflow rate ratio (r = 0.58, P = 0.012) correlated moderately. Multivariate regression analysis revealed that only Vb/Va (P = 0.017) significantly correlated with mR. There was no correlation between wall shear stress and mR.

CONCLUSIONS

The bleb redness of UIAs and Vb/Va, calculated using PC-MRA, showed a significantly greater correlation. Thus, it is possible to predict bleb thickness noninvasively before surgery. This will facilitate more detailed pre- and intraoperative strategies for clipping and coiling for safe surgery.

Giant Vertebrobasilar Fusiform Aneurysm Mass Effect Heralds Rapid in Situ Thrombosis and Ischemic Stroke in the Setting of Ulcerative Colitis

Here we describe a case of brainstem infarction secondary to rapid thrombus formation in a giant vertebrobasilar fusiform aneurysm (GVBFA) that was preceded clinically by several months of headaches and dizziness initially attributable to mass effect. Less than a month after initial identification of the aneurysm, a large partially-occluding thrombus formed leading to infarction of the brainstem. Interestingly, this patient also had ulcerative colitis, which has been associated with acquired hypercoagulability. Balancing risk versus benefit in the management of GVBFA to prevent morbidity and mortality is very challenging; thus more information is needed to better stratify treatment options for patients, particularly those that may have an accelerating clinical course or co-morbidities that increase clotting risk.

[Application of 3.0T Time-of-flight Magnetic Resonance Angiography with Sparse Undersampling and Iterative Reconstruction in the Diagnosis of Unruptured Intracranial Aneurysms]

OBJECTIVE

To evaluate the diagnostic value of 3.0T time-of-flight MR angiography with sparse undersampling and iterative reconstruction (TOFu-MRA) for unruptured intracranial aneurysms (UIAs) on the basis of using digital subtraction angiography (DSA) as the reference standard.

METHODS

A total of 65 patients with suspected UIAs were prospectively enrolled and all patients underwent TOFu-MRA and DSA. Relying on DSA as the reference standard, the sensitivity (SEN), specificity (SPE), positive predictive value (PPV) and negative predictive value (NPV) of using TOFu-MRA in UIA diagnosis were calculated, and the inter-observer agreement between two doctors was determined. Comparison of maximum intensity projection (MIP) and volume rendering (VR) image datasets was made to evaluate the agreement between DSA results and TOFu-MRA in the measurement of UIA morphological parameters, including the neck width (D neck), height (H) , and width (D width) of UIAs.

RESULTS

The study covered 55 UIAs from 46 patients. The SEN, SPE, PPV and NPV of the two doctors using TOFu-MRA in UIA diagnosis were as follows: (95.7%, 95.7%), (94.7%, 94.7%), (97.8%, 97.8%) and (90.0%, 90.0%), respectively for patient-based assessment; (96.4%, 94.5%), (94.7%, 94.7%), (98.1%, 98.1%) and (90.0%, 85.7%), respectively, for aneurysm-based assessment. There is a strong inter-observer agreement (Kappa=0.93 for patient-based assessment and 0.96 for aneurysm-based assessment) between the two doctors. Moreover, Bland-Altman analysis showed that more than 95% points fell within the limits of agreement (LoA), suggesting strong agreement between the two examination methods for the measurement of UIAs morphological parameters.

CONCLUSION

TOFu-MRA showed good diagnostic efficacy for UIAs and the results were in good agreement with those of DSA, the reference standard, for assessing UIA morphological parameter. TOFu-MRA can be used as a first choice for noninvasive diagnostic evaluation of UIAs.

Smoking habits and detection rate of unruptured intracranial aneurysms and incidence rate of subarachnoid haemorrhage in Norway between 2008 and 2015

Objective

The aim of this study was to investigate the detection rate of unruptured intracranial aneurysms (UIAs) and incidence of aneurysmal subarachnoid haemorrhage (SAH) in relation to the rapidly changing smoking rates in Norway between 2008 and 2015.

Methods

The registry-based study included all patients (≥ 16 years old) admitted to a hospital in Norway between 2008 and 2015 with a primary diagnosis of aneurysmal SAH or an outpatient diagnosis of UIAs. Age group–specific and total detection rate of UIAs and incidence rate of SAH over the years were calculated. Age group–specific data on smoking habits was retrieved from a national annual survey representative of the whole Norwegian population.

Results

The rate of daily smokers decreased by 48% between 2008 and 2015. The detection rate of UIAs decreased by 47% from 17.3 in 2008 to 9.3 per 100,000 persons in 2015, and the incidence of SAH decreased by 30% from 11.3 in 2008 to 7.9 per 100,000 persons in 2015. The average annual decline in prevalence of daily smoking, UIA detection rate, and SAH incidence was 6.9%, 6.7%, and 4.3% per year, respectively. Multinomial logistic regression analyses revealed that the correlation between the decline in estimated daily smoking rates and decline in detection rate of UIAs (hazard ratio 52.5 CI = (14.9,∞), p < 0.00001) and incidence of SAH (hazard ratio 11.8 CI=(5.6,32.5), p < 0.00001) are statistically significant. The association is particularly strong in young and middle-aged cohorts (< 66 years old).

Conclusion

It is likely that reducing cigarette smoking on a population-based level strongly reduces the rates of UIAs and SAH.

Impact of Neurovascular Comorbidities and Complications on Outcomes After Procedural Management of Intracranial Aneurysm: Part 1, Unruptured Intracranial Aneurysm

OBJECTIVE

This study investigates the relationship between neurovascular comorbidities and in-hospital complications in determining functional outcome, mortality, length of stay (LOS), and cost of stay.

METHODS

Patients were identified from the 2012-2015 National Inpatient Sample (NIS) using International Classification of Diseases, Ninth Revision codes for unruptured intracranial aneurysm (UIA) treatment in patients without subarachnoid hemorrhage. In-hospital complications were divided into medical complications, surgical complications, and seizures. Primary outcomes were functional outcome measured by modified Rankin Scale (mRS)-equivalent measure, in-hospital mortality, LOS, and cost. Multivariable logistic regression models were built for mRS-equivalent and in-hospital mortality. Multivariable linear regression models in log scale were built for LOS and cost.

RESULTS

A total of 7398 procedurally managed patients with UIA were included (median age, 58 years; 75% female; 66% white; 43% private insurance). Higher Neurovascular Comorbidities Index (NCI) was associated with seizure (odds ratio [OR], 1.11 if NCI = 1; OR, 2.49 if NCI = 7; P < 0.001), medical complication (OR, 1.21, NCI = 1; OR, 3.46, NCI = 7; P < 0.001), and surgical complication (OR, 1.25, NCI = 1; OR, 3.47, NCI = 7; P < 0.001). NCI remained significantly predictive of poor mRS-equivalent outcome (OR, 1.20, NCI = 1; OR, 5.79, NCI = 7; P < 0.001), in-hospital mortality (OR, 1.98, NCI = 1; OR, 10.9, NCI = 7; P < 0.001), LOS (coefficient dependent on multiple variables, P < 0.001), and cost (coefficient dependent on multiple variables, P < 0.001) after adjustment.

CONCLUSIONS

Neurovascular comorbidities are the primary driver of poor mRS-equivalent outcome, in-hospital mortality, higher LOS, and higher cost after procedural treatment of UIA. The conditional event of complication influences patients with fewer comorbidities more so than those with no comorbidities or high comorbidities. It is imperative to precisely account for these factors to optimize targeted resource allocation and increase the value of care for patients with UIA.

Clinical Interrogation of Mandatory Insertion of Central Venous Catheter for Clipping Surgery of Unruptured Intracranial Aneurysm: A Propensity Score Matched Study

BACKGROUND AND OBJECTIVE

Microsurgical clipping, along with endovascular treatment, has evolved in the treatment of unruptured intracranial aneurysms (UIA), and these developments have resulted in a reduction of the complication rate. We discuss the need for a central venous catheter (CVC) insertion as an anesthetic preparation for microsurgical clipping.

METHODS

Between January 2019 and September 2019, 722 patients with UIA were treated at our institution. We excluded patients with a history of endovascular treatment or bypass surgery, recurrent aneurysms after coil embolization, brain tumors, or subarachnoid hemorrhages. A total of 272 patients were enrolled. Eighty-four patients underwent CVC insertion, and 188 patients underwent clipping surgery without CVC insertion. Outcome-related factors were compared between the 2 groups. We performed propensity score matching of the 2 groups to increase comparability.

RESULTS

There were no significant differences in outcome, sex, aneurysm location, aneurysm multiplicity, aneurysm size, or comorbid disease between the 2 groups. The mean age at the time of surgery was higher in the non-CVC insertion group than in the CVC insertion group. There were no meaningful differences in primary outcomes, including premature rupture and intraoperative motor evoked potential/somatosensory evoked potential change, and secondary outcomes, including estimated blood loss, duration of intensive care unit stay, duration of hospitalization, and Glasgow Outcome Scale score at discharge.

CONCLUSIONS

CVC insertion for clipping surgery for UIA is not mandatory. Considering the possible complications associated with CVCs, we cautiously suggest aneurysm surgery with CVC insertion in patients with serious medical comorbidities, aneurysm sizes >10 mm, and difficult proximal parent artery control.

Remote cerebellar hemorrhage following surgical clipping of an unruptured cerebral aneurysm of the middle cerebral artery

An infrequent complication, remote cerebellar hemorrhage (RCH) may occur after supratentorial craniotomy at a reported incidence of 0.08-0.6%. Although RCH is mostly self limiting, early diagnosis and treatment are necessary as the condition may result in severe neurologic deficits or mortality. Because RCH is often asymptomatic, occurrence of it was occasionally recognized with brain computed tomography (CT) scans only. We experienced two contrasting cases of RCH in patients with unruptured cerebral aneurysms of the middle cerebral artery. These cases indicate that it should be mandatory to perform a brain CT scans immediately after surgery and on appropriate time to detect RCH. Awareness of this complication and close monitoring are essential for avoiding fatal neurological deficits or mortality.

Stent-assisted coil embolization of unruptured middle cerebral artery aneurysms using LVIS Jr. stents

Authors reported the anatomical and clinical results of the stent assisted coiling (SAC) of unruptured middle cerebral artery (MCA) aneurysms using Low-profile Visualized Intraluminal Support Junior (LVIS Jr.). Forty-seven MCA aneurysms in 46 patients were the subjects of this study. The mean aneurysm size, neck width were 4.5 ± 1.8 mm, 3.0 ± 1.0 mm, respectively. Immediate anatomical outcomes were class Ⅰ in 31 (65.0%), class Ⅱ in 5 (10.6%) and class III in 11 (23.4%) patients according to Raymond-Roy classification. The latest anatomical outcomes were class Ⅰ in 33 (86.8%), class Ⅱ in 2 (5.3%) and class III in 3 (7.9%) patients. The change of aneurysm obliteration status were unchanged in 27 (71.0%), improved in 9 (23.7%) and worsen in 2 (5.3%). There were no recurrence necessitating additional treatment. Two patients suffered from angiographically evident in-stent thrombosis, but their clinical outcomes remain good. The modified Rankin scale at discharge were 0 in 45 patients, 1 in 1 patient. No patient showed clinical worsening during the clinical follow-up period at outpatient clinic (mean, 27.4 months). SAC of unruptured MCA aneurysms using LVIS Jr. provide safe and durable effect with high complete obliteration rate recurrence rate.

Physician factors influencing endovascular treatment decisions in the management of unruptured intracranial aneurysms

PURPOSE

Deciding about whether an unruptured intracranial aneurysm (UIA) should be treated or not is challenging because robust data on rupture risks, endovascular treatment complication rates, and treatment success rates are limited. We aimed to investigate how neurointerventionalists conceptually approach endovascular treatment decision-making in UIAs.

METHODS

In a web-based international multidisciplinary case-based survey among neurointerventionalists, participants provided their demographics and UIA treatment-volumes, estimated 5-year rupture rates, endovascular treatment complication and success rates and gave their endovascular treatment decision for 15 pre-specified UIA case-scenarios. Differences in estimated 5-year rupture rates, endovascular treatment complication and success rates based on physician and hospital characteristics were evaluated with the Kruskal-Wallis test. Multivariable logistic regression analysis was used to derive adjusted effect size estimates for predictors of endovascular treatment decision.

RESULTS

Two hundred-thirty-three neurointerventionalists from 38 countries participated in the survey (median age 47 years [IQR: 41-55], 25/233 [10.7%] females). The ranges of estimates for 5-year rupture risks, endovascular treatment complication rates, and particularly endovascular treatment success rates were wide, especially for UIAs in the posterior circulation. Estimated 5-year rupture risks, endovascular treatment complication and success rates differed significantly based on personal and institutional endovascular UIA treatment volume, and all three estimates were significantly associated with physicians' endovascular treatment decision.

CONCLUSION

Although several predictors of endovascular treatment decision were identified, there seems to be a high degree of uncertainty when estimating rupture risks, treatment complications, and treatment success for endovascular UIA treatment. More data on the clinical course of UIAs with and without endovascular treatment is needed.

Comprehensive Aneurysm Management (CAM): An All-Inclusive Care Trial for Unruptured Intracranial Aneurysms

BACKGROUND

In the absence of randomized evidence, the optimal management of patients with unruptured intracranial aneurysms (UIA) remains uncertain.

METHODS

Comprehensive Aneurysm Management (CAM) is an all-inclusive care trial combined with a registry. Any patient with a UIA (no history of intracranial hemorrhage within the previous 30 days) can be recruited, and treatment allocation will follow an algorithm combining clinical judgment and randomization. Patients eligible for at least 2 management options will be randomly allocated 1:1 to conservative or curative treatment. Minimization will be used to balance risk factors, using aneurysm size (≥7 mm), location (anterior or posterior circulation), and age <60 years.

RESULTS

The CAM primary outcome is survival without neurologic dependency (modified Rankin Scale [mRS] score <3) at 10 years. Secondary outcome measures include the incidence of subarachnoid hemorrhage during follow-up and related morbidity and mortality; morbidity and mortality related to endovascular treatment or surgical treatment of the UIA at 1 year; overall morbidity and mortality at 1, 5, and 10 years; when relevant, duration of hospitalization; and, when relevant, discharge to a location other than home. The primary hypothesis for patients randomly allocated to at least 2 options, 1 of which is conservative management, is that active UIA treatment will reduce the 10-year combined neurologic morbidity and mortality (mRS score >2) from 24% to 16%. At least 961 patients recruited from at least 20 centers over 4 years will be needed for the randomized portion of the study.

CONCLUSIONS

Patients with unruptured intracranial aneurysms can be comprehensively managed within the context of an all-inclusive care trial.

The Clinical and Morphologic Features Related to Aneurysm Wall Enhancement and Enhancement Pattern in Patients with Anterior Circulation Aneurysms

BACKGROUND

Aneurysm wall enhancement (AWE) may predict rupture-prone intracranial aneurysms (IAs). However, the clinical and morphologic risk factors related to AWE have not been well described. Furthermore, the risk factors related to enhancement patterns have never been studied, especially in patients with anterior circulation aneurysms. Therefore, we aimed to investigate the risk factors related to wall enhancement and the enhancement patterns in anterior circulation unruptured aneurysms.

METHODS

One hundred patients (median age, 59 years; 68% female) with 113 anterior circulation unruptured aneurysms were included in this prospective study. Clinical and morphologic risk factors related to wall enhancement and circumferential enhancement were analyzed using univariate and multivariate analyses.

RESULTS

There were 33 symptomatic unruptured IAs (29.2%) and 50 IAs with AWE (44.2%) (partial [n = 16] and circumferential [n = 34]). Univariate analysis showed that symptomatic IAs and morphologic factors (irregular shape, size, width, dome depth, size ratio, aspect ratio, and bottleneck) correlated with wall enhancement. Furthermore, female sex, blood parameters (cholesterol and low-density lipoprotein), and morphologic factors (size and dome depth) correlated with wall enhancement patterns (P <0.05). Multivariate analysis showed that size was the most important factor in wall enhancement (P = 0.06; odds ratio, 3.758) and a trend for symptomatic IAs (P = 0.033; odds ratio, 2.426). Female sex was the most important factor in circumferential enhancement (P = 0.017; odds ratio, 7.276).

CONCLUSIONS

AWE was strongly associated with aneurysm size and was observed more frequently in symptomatic unruptured IAs. Sex hormones and atherosclerotic factors may be involved in circumferential enhancement. However, further studies should be performed to investigate the pathologic mechanisms for pattern of enhancement.

Long-term Outcomes After Intraprocedural Aneurysm Rupture During Coil Embolization of Unruptured Intracranial Aneurysms

BACKGROUND

The long-term outcomes of patients with intraprocedural aneurysm rupture (IPR) during endovascular coiling of unruptured intracranial aneurysms (UIAs) remain unclear. We investigated the long-term outcomes and predictors of neurological outcomes in patients who sustained IPR during coil embolization of UIAs.

METHODS

We retrospectively analyzed the medical record of 312 untreated UIAs in 284 patients who underwent endovascular coiling between April 2013 and July 2018.

RESULTS

The mean follow-up period for the entire cohort was 25.6 months. Twelve patients (3.8%) experienced IPR. The mean aneurysm size in the IPR cohort was significantly smaller than that in the no-IPR cohort (P = 0.045). The IPR cohort had a higher percentage of earlier subarachnoid hemorrhage from another aneurysm (P = 0.019), anterior communicating artery (AComA) aneurysm (P < 0.001), and basilar artery (BA) aneurysm (P = 0.022) than the no-IPR cohort. Neurologic deterioration was observed in 3 patients. The morbidity and mortality rates of the IPR cohort were 25% and 8.3%, respectively. Patients with IPR during coil embolization for AComA aneurysm did not develop neurological deterioration. Two of the 3 patients (66.7%) with a BA aneurysm had neurological deterioration. The proportion of patients with an mRS score of 0-2 at the last follow-up did not differ between the 2 cohorts (P = 0.608).

CONCLUSIONS

The proportion of functionally independent patients did not differ between patients with and without IPR. Patients with BA aneurysms who developed an IPR tended to exhibit more unfavorable clinical courses than patients with AcomA aneurysms.

External Validation of the ELAPSS Score for Prediction of Unruptured Intracranial Aneurysm Growth Risk

Background and Purpose

Prediction of intracranial aneurysm growth risk can assist physicians in planning of follow-up imaging of conservatively managed unruptured intracranial aneurysms. We therefore aimed to externally validate the ELAPSS (Earlier subarachnoid hemorrhage, aneurysm Location, Age, Population, aneurysm Size and Shape) score for prediction of the risk of unruptured intracranial aneurysm growth.

Methods

From 11 international cohorts of patients ≥18 years with ≥1 unruptured intracranial aneurysm and ≥6 months of radiological follow-up, we collected data on the predictors of the ELAPSS score, and calculated 3- and 5-year absolute growth risks according to the score. Model performance was assessed in terms of calibration (predicted versus observed risk) and discrimination (c-statistic).

Results

We included 1,072 patients with a total of 1,452 aneurysms. During 4,268 aneurysm-years of follow-up, 199 (14%) aneurysms enlarged. Calibration was comparable to that of the development cohort with the overall observed risks within the range of the expected risks. The c-statistic was 0.69 (95% confidence interval [CI], 0.64 to 0.73) at 3 years, compared to 0.72 (95% CI, 0.68 to 0.76) in the development cohort. At 5 years, the c-statistic was 0.68 (95% CI, 0.64 to 0.72), compared to 0.72 (95% CI, 0.68 to 0.75) in the development cohort.

Conclusions

The ELAPSS score showed accurate calibration for 3- and 5-year risks of aneurysm growth and modest discrimination in our external validation cohort. This indicates that the score is externally valid and could assist patients and physicians in predicting growth of unruptured intracranial aneurysms and plan follow-up imaging accordingly.

Rupture immediately after growth of unruptured intracranial aneurysms during follow-up

Background:

The annual rupture rate of small unruptured intracranial aneurysms (UIAs) <5 mm is generally low; further, small UIAs are often treated conservatively. While the growth of aneurysms during follow-up is associated with a high risk of rupture, the urgency for surgical treatment of asymptomatic enlarged UIAs remains controversial. We experienced two patients in whom UIAs ruptured shortly after asymptomatic growth during follow-up.

Case Description:

A 1-mm right middle cerebral artery aneurysm was incidentally found in a 63-year-old woman. Preventive surgery was planned because the aneurysm grew rapidly; however, the aneurysm ruptured preoperatively. A 68-year-old woman had a small (4 mm) aneurysm at the left internal carotid-posterior communicating artery. The aneurysm grew rapidly after many years. Several hours after magnetic resonance imaging was performed, she presented to the hospital with loss of consciousness, and a diagnosis of subarachnoid hemorrhage due to the ruptured aneurysm was made.

Conclusion:

UIAs that rapidly increase during follow-up may be regarded as impending ruptured aneurysms.

Vasospasm and delayed cerebral ischemia after uneventful clipping of an unruptured intracranial aneurysm - a case report

Background

Due to improvements in both the quality and availability of intracranial imaging as well as the evolution of surgical and endovascular techniques during the last decade, the number of treatments of unruptured intracranial aneurysms (UIA) has increased steadily. However, it is not generally known that vasospasm can arise after an uneventful clipping.

Case presentation

We present a case of a 69-year-old woman who suffered from vasospasm and delayed cerebral ischemia that occurred after an uneventful clipping of a UIA.

The aneurysm of the right middle cerebral artery was found incidentally via magnetic resonance imaging ordered after the patient complained of a short period of slight gait disturbances. To avoid a subarachnoid hemorrhage and consecutive complications like vasospasms, the patient elected microsurgical treatment. Clipping was managed by keyhole approach. Temporal clipping of the M1 was not necessary. After clip placement, appropriate flow in all distal segments was confirmed by indocyanine green video-angiography and micro-Doppler. The patient was discharged seven days after surgery without neurological deficits.

After 12 days, the patient developed at home a sudden drooping on the left side of the face. Upon admission to the emergency room, the patient was alert but slightly confused. Neurological examination revealed a left-sided hemiparesis and motor speech disorder. In contrast to the preoperative transfemoral catheter angiography, the subsequent right internal carotid angiogram showed clear signs of vasospasm along the M1 and M2 segments of the right middle cerebral artery.

Antithrombotic treatment with acetylsalicylic acid was begun. In accordance with guidelines for the treatment of subarachnoid hemorrhage and vasospasm, nimodipine was added. After 11 days the patient was discharged with no symptoms.

Conclusion

Cerebral vasospasm as a cause of ischemic stroke after uneventful surgery for a UIA seems to be a rare but possibly underestimated etiology that demands particular attention with respect to providing appropriate treatment. In future, it may be prudent to perform follow-up transcranial ultrasonography testing after the clipping of a UIA, especially considering the availability of potentially neuroprotective medications like nimodipine.

Vessel Wall Imaging Predicts the Presence of Atherosclerotic Lesions in Unruptured Intracranial Aneurysms

BACKGROUND

Recent studies have suggested that magnetic resonance vessel wall imaging (VWI) can visualize thickened intracranial aneurysm wall. We aimed to investigate correlations between VWI findings and intraoperative aneurysm wall features based on the hypothesis that VWI can visualize atherosclerotic changes in unruptured intracranial aneurysm (UIA) walls.

METHODS

A total of 36 microsurgically treated UIAs were retrospectively reviewed. All aneurysms underwent VWI before microsurgical clipping, and fusion images with time-of-flight magnetic resonance angiography were created to localize aneurysm wall enhancement (AWE) lesions. Intraoperatively, 2 neurosurgeons who were blinded to the VWI findings evaluated the aneurysm wall features, giving each aneurysm an atherosclerosis score on a 5-point scale (5: yellowish, 4: whitish, 3: normal, 2: slightly reddish, 1: reddish). We defined atherosclerotic lesions as those having average scores ≥4. We evaluated the rate of correspondence between AWE lesions and atherosclerotic lesions, and the factors associated with AWE.

RESULTS

Sixteen of the 36 UIAs (44%) were identified as AWE. The sensitivity, specificity, positive predictive value, and negative predictive value of correspondence between AWE lesions and atherosclerotic lesions were 79%, 94%, 94%, and 80%, respectively. The average atherosclerosis scores (4.2 ± 0.5 vs. 2.7 ± 0.9; P < 0.001) were significantly higher in aneurysms with AWE. Twelve of 16 UIAs with wall enhancement had wall thinning adjacent to the part with AWE.

CONCLUSIONS

AWE lesions corresponded with intraoperatively confirmed atherosclerotic lesions of UIAs. Detecting these lesions would be valuable in exploring UIAs with wall degeneration.

Advantages of Coil Embolization Performed Immediately After Diagnostic Cerebral Digital Subtraction Angiography in Unruptured Intracranial Aneurysms: Patients' Perspective

BACKGROUND

We are inevitably faced with the need to perform coil embolization immediately after diagnostic cerebral digital subtraction angiography (DSA) for economic reasons, patient convenience, fear of rupture, and other reasons. Here we report the advantages of coil embolization performed immediately after diagnostic cerebral DSA for unruptured intracranial aneurysms (UIAs) from the patients' perspective.

METHODS

Between January 2017 and October 2018, 145 patients were treated for UIAs with endovascular coil embolization at the Yeungnam University Medical Center. There were 87 patients in the group in which coil embolization was to be performed at least 1 week after diagnostic cerebral DSA (regular [R] group) and 58 patients in the group in which coil embolization was to be performed immediately after diagnostic cerebral DSA (immediate [I] group).

RESULTS

There were no statistically significant between group differences in any factor analyzed expect for medical expenses (out-of-pocket costs), 2,218,416 KRW (1963 USD) for the R group and 1,128,906 KRW (999 USD) for the I group (P < 0.001). There were no statistically significant differences in the rate of complications between the 2 groups, with 4 minor complications and 1 death in the R group and 3 minor complications and 1 death in the I group.

CONCLUSIONS

Our findings indicate that coil embolization performed immediately after diagnostic cerebral DSA can be a relatively safe alternative approach to treating patients with UIAs.

Influence of comorbidities on treatment of unruptured intracranial aneurysms in the elderly

Current evidence does not conclusively justify conservative management of unruptured intracranial aneurysms (UIA) in the elderly (age ≥ 65 years). To rationalise intervention, the authors investigated the role of age and comorbidity burden on treatment outcomes. A retrospective chart review for consecutive cases of UIAs treated in the elderly between 2007 and 2018 was performed. Preoperative Charlson Comorbidity Index (CCI) and Neurovascular Comorbidities Index (NCI) were calculated. Standard statistical methods with univariate and multiple logistic regression were used. A total of 123 patients (46 surgery, 77 endovascular) with 131 UIAs were treated. The mean age was 70.6 ± 4.1 years, and 90 patients were female (73.1%). The mean aneurysm size was 8.6 ± 5.0 mm, and the mean follow up period was 22.9 ± 21.3 months. The rates of poor outcome (mRS > 1) at discharge, 6 weeks and 6 months were 9.8%, 5.8% and 3.6%, respectively. There was no difference in outcomes between surgical and endovascular treatment. Correlation and regression analyses revealed that aneurysm size, higher preoperative comorbidity index (CCI > 4), and endovascular treatment with a stent or flow diverter (p = 0.009, 0.02, and 0.005, respectively) were associated with a poor outcome. When adjusted in a multivariate analysis, only high comorbidity burden (CCI > 4) predicted unfavourable outcome (p = 0.01). Elderly patients who undergo treatment for UIAs are at high risk of postoperative deterioration. Careful preoperative case selection based on comorbidity burden, rather than chronological age, would be useful for improved risk stratification.

A retrospective comparison of sac and lobe morphology between ruptured and unruptured intracranial aneurysms

There are few reliable morphologic indices to aid in the determination of an intracranial aneurysm's rupture risk. We sought to characterize morphological characteristics of aneurysm sacs and their lobes that are associated with ruptured status at time of initial evaluation with diagnostic angiography. These factors could be associated with an aneurysm's risk of rupturing. We retrospectively reviewed all aneurysms imaged with digital subtraction angiography (DSA) at a single institution over five years. Patients presenting with aneurysmal subarachnoid hemorrhage (aSAH) were assigned to the ruptured group, and those presenting without aSAH were assigned to the unruptured group. Angiograms were evaluated for the presence of various morphological parameters. Binary logistic regression was used to assess their associations between groups. A total of 331 aneurysms among 241 patients were included in the analysis. Posterior circulation, larger size ratio, and the presence of two or more lobes were associated with aneurysm rupture (p < 0.001 for each). Aneurysms containing a lobe with a greater height than width were observed more frequently in the ruptured group (OR 5.26, 95% CI 2.66-10.41). In the receiver operating characteristic (ROC) curves, mean diameter had an AUC of 0.72 and an optimum threshold of 2.85 mm. For size ratio, the AUC was 0.70 and the optimum threshold was 2.02. A larger SR was observed in ruptured aneurysms. The presence of multiple lobes and greater lobe height than width were associated with rupture status as well. These factors merit investigation in a prospective study.

Analysis for risk factors of 12-month neurological worsening in patients with surgically treated small-to-moderate size unruptured intracranial aneurysms

The risk associated with surgical treatment for small-to-moderate size unruptured intracranial aneurysms (SMUIAs, defined as <15 mm) has not been well characterized. Authors aimed to investigate risk factors for poor outcome in surgical treatment of SMUIAs. The data of prospectively collected 801 consecutive patients harboring 971 surgically treated SMUIAs was evaluated. Neurological worsening (NW) was defined as an increase in 1 or more modified Rankin Scale at 12-month. Clinical and radiological characteristics were compared. Neurological worsening was observed in 45 (4.6%). In multivariate analysis, only perforator territory infarction (PTI) on postoperative diffusion-weighted imaging (odds ratio (OR), 13; 95% confidence interval (CI), 4.9-32, p < 0.0001), and aneurysm locations (paraclinoid (OR, 6.9; 95% CI, 3.1-15, p < 0.0001), basilar artery (OR, 4.5; 95% CI, 1.5-14, p = 0.008), vertebral artery (OR, 11; 95% CI, 3.3-34, p < 0.0001)) were related to neurological worsening. Multivariate analysis showed that statin use (OR, 12; 95% CI, 3.8-39, p < 0.0001) and aneurysm locations (internal carotid artery-posterior communicating artery (OR, 3.9; 95% CI, 1.8-8.2, p < 0.0001) and basilar artery (OR, 6.3; 95% CI, 2.3-17, p = 0.008)), and aneurysm size >10 mm (OR, 5.3; 95% CI, 1.8-15, p = 0.003) were related to PTI. Although all SMUIAs should be carefully considered whether to be treated, those with statins, specific locations, and larger sizes should perhaps be more meticulously contemplated, and neurosurgeons should continue to avoid PTI.

Microsurgical Treatment of Unruptured Anterior Choroidal Artery Aneurysms: Incidence of and Risk Factors for Procedure-Related Complications

OBJECTIVE

To describe our experiences with microsurgical treatment of unruptured anterior choroidal artery (AchA) aneurysms, and to evaluate the incidence of and risk factors for procedure-related complications.

METHODS

The study included 110 patients treated between January 2012 and December 2016. All patients met the following criteria: 1) microsurgical treatment of an unruptured AchA aneurysm was performed; and 2) clinical and radiographic follow-up data were available, including findings from preoperative digital subtraction angiography. The incidence of and risk factors for procedure-related complications were retrospectively evaluated. The χ² test and Mann-Whitney U test were used in statistical analysis, and univariate analysis and multivariate logistic regression analysis were conducted.

RESULTS

Procedure-related complications occurred in 5 patients (4.5%), including symptomatic complications in 4 patients (3.6%) and asymptomatic complications in 1 patient (0.9%). Multivariate logistic regression analysis indicated that the angle between the vertical line to the cranial base and the axis of the communicating segment of the internal carotid artery (MiC angle) (odds ratio [OR], 1.66; 95% confidence interval [CI], 1.13-5.26; P = 0.038) and the angle between the projection line of the aneurysmal dome and the axis of the communicating segment of the internal carotid artery (DC angle) (OR, 3.82; 95% CI, 1.49-11.7; P = 0.014) were independent risk factors for procedure-related complications.

CONCLUSIONS

When microsurgical treatment of unruptured AchA aneurysms was performed, the procedure-related complication rate was 4.5%. Patients with AchA aneurysms with a smaller MiC angle and smaller DC angle may be at a higher risk of procedure-related complications when undergoing microsurgical treatment.

A local excitation magnetic resonance imaging method for intracranial unruptured aneurysm at the distal internal carotid artery

It is often difficult to diagnose an intracranial aneurysm at the distal internal carotid artery by conventional magnetic resonance imaging.

PURPOSE

We assessed the effectiveness of the local excitation technique, a new application for magnetic resonance imaging, to clarify the geometric structure of aneurysm and adjacent branches at the distal internal carotid artery.

STUDY DESIGN

Two independent evaluators diagnosed 10 cases of suspected aneurysms at the distal internal carotid artery by T2-weighted magnetic resonance imaging with application of local excitation, adding it to conventional time-of-flight-magnetic resonance angiography.

FINDINGS

We successfully distinguished the aneurysm from infundibular dilatation in five of 10 cases.

CONCLUSION

Our results suggested that addition of local excitation to conventional magnetic resonance angiography was effective to diagnose unruptured aneurysm at the distal internal carotid artery, to clarify the configuration of the prominent lesion or whether the location of the adjacent branch orifice on the parent vessel was symmetric or asymmetric.

Subdural Fluid Collection After the Clipping of Unruptured Intracranial Aneurysms: Its Clinical Course and Significance

OBJECTIVE

We evaluated the clinical course and significance of postoperative subdural fluid collection (SFC) and identified the patients who were at risk of developing postoperative chronic subdural hematoma (CSDH) after the clipping of unruptured intracranial aneurysms (UIAs).

METHODS

Between January 2012 and June 2014, we retrospectively reviewed 298 patients with UIAs treated by microsurgical clipping. Among them, 257 patients were enrolled in the present study. Subdural lesions (SDLs) were defined as SFC at 1-month follow-up computed tomography (CT) and a CSDH at any time within 1 month after the clipping of UIAs. We examined the volume changes, Hounsfield unit (HU) values, and the end results of SFC in serial CT scans.

RESULTS

The incidence of postoperative CSDH that needed burr hole surgery was 2.5%. Changes in SFC volume that occurred within 1 week of surgery were a risk factor for the occurrence of SDL at the 1-month follow-up CT (odds ratio 34.039; P < 0.001). The corrected average HU value of SCF (cut-off value: 11.9, with a sensitivity of 83.3% and specificity of 73.7%) on postoperative day 7 was an independent risk factor for development of a CSDH at the 1-month follow-up CT (odds ratio 19.261; P = 0.003).

CONCLUSIONS

SDLs seen during 1-month follow-up may be associated with the occurrence of increased SFC volume within a week after the clipping of UIAs. The corrected average HU value of the SFC on postoperative day 7 was the only risk factor for the development of CSDHs at 1-month follow-up CT.

Headache Outcomes After Coil Embolization in Patients with Unruptured Intracranial Aneurysms: Do They Get Better or Worse? A Prospective Analysis

BACKGROUND

To investigate the association between headache outcomes and coil embolization and to identify potential factors associated with different headache outcomes in patients with unruptured intracranial aneurysms (UIAs) after treatment with coil embolization.

METHODS

A prospective study of patients with planned coil embolization for UIAs was conducted. The changes in headache patterns, headache-related disability, and depression were assessed before coil embolization and at 3 days and 2 and 6 weeks after coil embolization. All variables were analyzed to identify factors associated with different headache outcomes.

RESULTS

Fifty-nine (72%) of 82 patients reported headaches before coil embolization. Of these, improvements in the severity of headaches were reported by 42 patients (71%). In addition to a significant reduction in headache severity, significant reductions in headache-related disability and depression scores also were observed. Demographic factors, aneurysmal characteristics, or procedural factors were not found to be significantly associated with improvement in the severity of headaches after coil embolization. In addition, the number of microemboli on diffusion-weighted imaging was not significantly associated with improvement of headaches after coil embolization. Twenty-three patients reported no headaches before coil embolization, and 3 (13%) patients reported new-onset headaches after coil embolization. All new-onset headaches were mild and dull in nature without combined symptoms in the temporal area.

CONCLUSIONS

Our study suggested that regardless of headache characteristics, the aneurysm size (even those <5 mm in diameter), technique used (stent-assisted or not stent-assisted), and coil embolization of UIAs resulted in headache improvement in most patients with pretreatment headaches.

Symptomatic and silent cerebral infarction following surgical clipping of unruptured intracranial aneurysms: incidence, risk factors, and clinical outcome

Cerebral infarction (CI) associated with clipping of unruptured intracranial aneurysms (UIAs) has not been completely studied. The role of individual and operative characteristics is not known, and the risk of silent CI has not been well described. To determine the incidence, risk factors, and clinical outcome of postoperative CI, we retrospectively analyzed 388 consecutive patients undergoing clipping of UIAs between January 2012 and December 2015. We reviewed the pre- and postoperative computed tomography (CT) images of each patient. Postoperative CI was defined as a new parenchymal hypodensity in the vascular territory of treated artery. Patient-specific, aneurysm-specific, and operative variables were analyzed as potential risk factors. Functional outcome at discharge was assessed with the modified Rankin Scale (mRS). Postoperative CI was found in 49 (12.6%) patients, 29 of whom manifested neurological deficits. The incidences of symptomatic stroke and silent CI were 7.5 and 5.2%, respectively. Multivariate analysis showed that larger aneurysm size and history of hypertension were significantly associated with CI. Disability (mRS > 2) rate was 42.9% among patients with CI, which was substantially higher than that among patients without (0.9%). In conclusion, the incidence of CI following clipping of UIAs was not low. Larger aneurysm size and history of hypertension were independent risk factors. Postoperative symptomatic stroke correlated with an extremely high risk of disability. Silent CI was seemingly nondisabling, but the possible cognitive consequence is pending.

[Concomitant unruptured intracranial aneurysms and ischemic cerebrovascular diseases: a surgical experience of 31 cases]

Objective: To summarize the clinic experience of preventing cerebral ischemic events during perioperative period in patients which concomitant unruptured intracranial aneurysms and ischemic cerebrovascular diseases. Methods: The clinical materials of 31 consecutive patients with concomitant unruptured intracranial aneurysms and ischemic cerebrovascular diseases from April 2010 to April 2014 were retrospectively reviewed.A total of 35 aneurysms were detected, and all of them were unruptured aneurysms.Among them, 17 cases were located on the ipsilateral side of artery stenosis or occlusion, and 18 cases were detected in the contralateral side. Minimal invasive surgical approaches such as small pterional approach and lateral sub-frontal approach were adopted.The better management of perioperative blood pressure was performed. Intraoperative electroencephalogram and somatosensory evoked potential monitoring, indocyanine green video angiography and/or microvascular Doppler ultrasonography were regularly used to guarantee the safety of the surgery. The follow-up by digital subtraction angiography or computed tomography angiography were made. Results: All of 35 aneurysms were clipped. Major infarction occurred in one patient with posterior communicating artery aneurysm concomitant with common cervical carotid artery stenosis.Large bone flap was resected and dural-matter were got enlarged to tolerate the edema period.Paralysis and aphasia accompanied at discharge.Minor infarction in posterior limb of internal capsule occurred in one patient.Twenty-nine patients were favorable with Glasgow Outcome Scale (GOS) score 5 at discharge, one patient with minor neurological defect (GOS 4), and one patient with severe neurological defect (GOS 3). The follow-up period was 6 to 40 months.Four patients were lost.The modified Rankin scale (MRS) of last follow-up were 0-1 in 25 patients, 2 in one patient and 3 in one patient.Third months after operation, 3 cases were performed carotid artery stenosis, 1 patients were performed carotid endarterectomy. Conclusion: Reinforcing the management of perioperative blood pressure, adjusting the perioperative blood coagulation function, and combine application of intraoperative monitoring technology can effectively prevent the occurrence of cerebral ischemia.

Risk Factors to Predict Neurologic Complications After Endovascular Treatment of Unruptured Paraclinoid Aneurysms

OBJECTIVE

Unruptured paraclinoid aneurysms are often asymptomatic, and endovascular coiling is the main treatment. However, endovascular treatment of these lesions still leads to neurologic complications. We aimed to identify predictors of neurologic complications in these lesions.

METHODS

We retrospectively analyzed patients with unruptured paraclinoid aneurysms who were treated with endovascular coiling between January 2014 and December 2015. A neurologic complication was defined as any transient or permanent increase in the modified Rankin Scale score after aneurysm embolization. Univariate and mulitivariate logistic regression analyses were performed to assess the risk factors of neurologic complications.

RESULTS

Of the 443 unruptured paraclinoid aneurysms that were included in this study, the incidence of neurologic complications was 5.2%. Neurologic complications were highly correlated with hypertension (odds ratio [OR], 3.147; 95% confidence interval [CI], 1.217-8.138; P = 0.018), cerebral ischemic comorbidities (OR, 3.396; 95% CI, 1.378-8.374; P = 0.008), and aneurysm size (OR, 7.714; 95% CI, 1.784-31.635; P < 0.001), and irregular shape (OR, 3.157; 95% CI, 1.239-8.043; P = 0.016) in the univariate analysis. Cerebral ischemic comorbidities (OR, 2.837, 95% CI, 1.070-7.523; P = 0.036) and aneurysm size as dichotomous variables (OR, 7.557; 95% CI, 2.975-19.198; P < 0.001) were strongly correlated with neurologic complications in the final adjusted multivariate logistic analysis.

CONCLUSIONS

Unruptured paraclinoid aneurysms after endovascular treatments had 5.2% of neurologic complications. Cerebral ischemic comorbidities and aneurysm size were predictors of neurologic complications.

Local Anesthesia for Endovascular Treatment of Unruptured Intracranial Aneurysms: Feasibility, Safety, and Periprocedural Complications

OBJECTIVE

The aim of the study is to report the feasibility, safety, and outcomes associated with endovascular treatment (EVT) of unruptured intracranial aneurysms (UIAs) under local anesthesia.

METHODS

Between March 2011 and December 2016, 184 consecutive patients with 198 UIAs were treated with coil embolization under local anesthesia at the author's center. The data about medical comorbidities according to American Society of Anesthesiologists grade, procedural details, and clinical and radiographic outcomes were reviewed.

RESULTS

A total of 388 procedures were performed under local anesthesia, and 198 procedures with UIA were included. The mean age was 63.8 ± 12.5 years, and 118 (59.6%) cases had a risk status of American Society of Anesthesiologists class III or IV. Of those 198 procedures, 196 procedures (99.0%) were completed successfully. The overall procedure-related event rate was 5% (10/198). The rates of morbidity and mortality were 0.5% (1 of 198) and 0% at 1 month, respectively. Among the 3 recurred cases (1.5%), two (1%) underwent EVT again. The mean intensive care unit stay was 0.99 ± 0.1 days, and the mean postoperative hospital stay was 3.6 ± 7.2 days.

CONCLUSIONS

Local anesthesia in the EVT of UIA is feasible and safe. It could be considered as an alternative for the patients with high risk of general anesthesia.

Antiplatelet drug resistance did not increase the thromboembolic events after stent-assisted coiling of unruptured intracranial aneurysm: a single center experience of 99 cases

We aimed to evaluate the correlation between aspirin or clopidogrel resistance and the risk of thromboembolic events (TEs). Between June 2011 and April 2015, we reviewed clinical and angiographic characteristics, and TEs in the patients undergoing stent-assisted coil embolization (SAC) of unruptured intracranial aneurysms (UIA) at our institution. We did not modify antiplatelet medication in patients with resistance. The relationships between antiplatelet resistance and the occurrence of acute symptomatic TEs, any diffusion-positive lesions, multiple diffusion-positive lesions, or delayed TEs were investigated. Ninety-nine endovascular treatments with stent-assisted technique were performed on 99 patients. The prevalence of aspirin resistance was 12% and clopidogrel resistance was 62.6%. Acute symptomatic TEs were demonstrated in 4 patients (4%). Diffusion-positive lesions were found in 82 patients [82.1%; 36 patients were group I (≤5) and 46 patients were group II (>5)]. Delayed TEs were demonstrated in 10 patients (10.1%). Neither aspirin resistance nor clopidogrel resistance was relevant to the development of acute symptomatic TEs, any diffusion-positive lesions, multiple diffusion-positive lesions, and delayed TEs (P _logistic = not available, 0.448, 0.362, and 0.829 for aspirin resistance and P _logistic = 0.607, 0.367, 0.278, and 0.245 for clopidogrel resistance). Without modification of antiplatelet medication, we demonstrated 4% of acute symptomatic TEs and 10% of delayed TEs. Aspirin or clopidogrel resistance did not show significant relationships with acute and delayed TEs in the SAC of UIA.

Small Unruptured Intracranial Aneurysm (≤5 mm) Associated with Epilepsy: Report of 2 Cases and Literature Review

BACKGROUND

Owing to the continuing improvements in imaging technology, an increasing number of epileptogenic small (≤5 mm) unruptured intracranial aneurysms (sUIAs) are being diagnosed. However, these sUIAs have not been systematically described and reviewed until now.

CASE DESCRIPTION AND LITERATURE REVIEW

We report 2 patients with sUIAs who initially presented with complex partial seizures. Scalp electroencephalography identified the seizure activity as arising from the mesial temporal/frontal areas, but conventional magnetic resonance imaging (MRI) was normal in both patients. The diagnosis of sUIA was achieved by cerebral angiography. One of the patients had idiopathic seizures and sustained a subarachnoid hemorrhage before the final diagnosis of sUIA. Both of the patients were treated by surgical clipping without resection of the adjacent discolored brain tissue, and the seizures were controlled after surgery. Furthermore, we thoroughly reviewed the relevant literature. We analyzed a total of 5 documented cases, including out 2 cases, and described the clinical characteristics, diagnosis, underlying mechanism, treatment, and prognosis of epileptogenic sUIA.

CONCLUSIONS

The seizures caused by sUIAs are most likely related to subclinical hemorrhages. Angiography may be helpful in identifying seizures associated with sUIA in patients with normal conventional MRI findings. For epileptogenic sUIA with normal preoperative MRI, clipping without damaging the surrounding brain tissue may be sufficient to resolve this complex issue.

Relationship between aneurysm wall enhancement and conventional risk factors in patients with unruptured intracranial aneurysms: A black-blood MRI study

BACKGROUND AND PURPOSE

Aneurysmal wall enhancement (AWE) has emerged as a new possible biomarker for depicting inflammation of the intracranial aneurysm (IA). However, the relationships of AWE with other risk factors are still unclear for unruptured IA. The purpose of this study was to investigate the association between AWE and other risk metrics.

METHODS

Forty-eight patients with unruptured saccular IAs diagnosed by digital subtraction angiography were recruited to undergo magnetic resonance (MR) black-blood imaging. AWE was evaluated using the pre- and post-contrast black-blood MR images. Univariate and multivariate logistic regression analysis was performed to investigate the association of AWE with other risk factors, including size, maximal neck width, parent vessel diameter, location, multiplicity, daughter sacs and other clinical factors. The prevalence of AWE in each ISUIA grade was reported and compared by Wilcoxon rank sum test.

RESULTS

In total, 61 aneurysms were detected in 48 patients. Aneurysm size was found to be an independent risk factor associated with AWE (OR 2.46 per mm increase, 95% CI 1.34-4.51; p = 0.004). Patient age was independently and inversely associated with AWE (OR 0.898 per year increase, 95% CI 0.812-0.994; p = 0.037). Higher prevalence of AWE was observed in larger aneurysms (12%, 71.4%, 100%, and 100% of ISUIA grade 1-4 IAs have AWE, respectively). Notably, 12% of small IAs (size <7 mm) exhibited AWE. The IAs with AWE had significant higher ISUIA grade than the IAs without (p < 0.001, Wilcoxon rank sum test).

CONCLUSIONS

The wall enhancement in contrast-enhanced black-blood MR images was independently associated with aneurysm size in unruptured IAs. However, some small unruptured aneurysms did exhibit wall enhancement, suggesting that AWE may provide additional aneurysm instability information to improve current size-based rupture risk evaluation metrics.

A 54-year-old man with 12 intracranial aneurysms and familial subarachnoid hemorrhage: case report

Unruptured intracranial aneurysms occur in 1-3 % of the general population, and the risk of rupture is generally considered to be low. However, patients with multiple aneurysms and familial predisposition carry a particular risk of subarachnoid hemorrhage (SAH). A 54-year-old hypertensive man underwent screening with a head CT angiography (CTA) because of his comorbidities. CTA revealed multiple bilateral aneurysms around the circle of Willis. At first surgery, seven aneurysms were clipped (BA, ACOM, ICA ×2, and MCA ×3), two of which were detected intraoperatively only. During the second surgery, another three aneurysms were surgically clipped (PCOM and MCA ×2), one of which was detected intraoperatively. Follow-up angiography revealed another two aneurysms. A PCOM aneurysm was treated by coil embolization and a VA aneurysm clipped surgically during a third admission. The patient made an uneventful recovery. However, 4 months after his second surgery, his daughter underwent surgical clipping of a right-sided ICA aneurysm. This case report highlights both the importance of screening of high risk patients with family history of SAH, as well as its limitations, as our patient developed two de novo aneurysms during 6-month follow-up and CTA preoperatively missed three small aneurysms.

Coma and Stroke Following Surgical Treatment of Unruptured Intracranial Aneurysm: An American College of Surgeons National Surgical Quality Improvement Program Study

OBJECTIVE

A large national surgical registry was used to establish national benchmarks and associated predictors of major neurologic complications (i.e., coma and stroke) after surgical clipping of unruptured intracranial aneurysms.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program data set between 2007 and 2013 was used for this retrospective cohort analysis. Demographic, comorbidity, and operative characteristics associated with the development of a major neurologic complication (i.e., coma or stroke) were elucidated using a backward selection stepwise logistic regression analysis. This model was subsequently used to fit a predictive score for major neurologic complications.

RESULTS

Inclusion criteria were met by 662 patients. Of these patients, 57 (8.61%) developed a major neurologic complication (i.e., coma or stroke) within the 30-day postoperative period. On multivariable analysis, operative time (log odds 0.004 per minute; 95% confidence interval [CI], 0.002-0.007), age (log odds 0.05 per year; 95% CI, 0.02-0.08), history of chronic obstructive pulmonary disease (log odds 1.26; 95% CI, 0.43-2.08), and diabetes (log odds 1.15; 95% CI, 0.38-1.91) were associated with an increased odds of major neurologic complications. When patients were categorized according to quartile of a predictive score generated from the multivariable analysis, rates of major neurologic complications were 1.8%, 4.3%, 6.7%, and 21.2%.

CONCLUSIONS

Using a large, national multi-institutional cohort, this study established representative national benchmarks and a predictive scoring system for major neurologic complications following operative management of unruptured intracranial aneurysms. The model may assist with risk stratification and tailoring of decision making in surgical candidates.

Major recanalization occurs more often in young patients after unruptured aneurysm coil embolization

BACKGROUND

The recanalization rate after coil embolization of unruptured aneurysms was compared between young and old age groups.

METHODS

From May 2003 to December 2010, 636 patients with 715 saccular unruptured intracranial aneurysms (UIA) underwent endovascular coiling and were followed for at least 6 months. For comparative analysis, patients were categorized into two groups according to age 40: 42 patients with 46 aneurysms who were 40 years or younger (young age group) and 594 patients with 669 aneurysms who were older than 40 years (old age group). Angiographic and clinical outcomes including recanalization rates were compared.

RESULTS

Angiographically, class 1 or 2 occlusion according to the Raymond-Roy Occlusion Classification system was achieved in 89.2 % of the patients (91.3 % in the young age group and 89.1 % in the old age group, p = 0.74). Procedure-related complication rate was 2.2 % and 3.4 % in the young and the old age group (p = 0.16), respectively. The mean follow-up duration was 30.51 ± 18.59 months. Major recanalization occurred in seven aneurysms (15.2 %) in the young age group and in 44 aneurysms (6.6 %) in the old age group (p = 0.03). Retreatment was performed in seven patients (15.2 %) in the young age group and in 35 patients (5.2 %) in the old age group (p = 0.01).

CONCLUSIONS

The present study showed that the technical feasibility and safety of endovascular coiling for UIA did not differ between the two age groups. However, the major recanalization rate was higher in the young age group.