Treatment of unruptured intracranial aneurysms: surgery, coiling, or nothing?

Quality of life in patients with unruptured intracranial aneurysms treated conservatively, before and after occlusion. A single center cohort study

Introduction

Rupture of intracranial aneurysms is the most frequent cause of subarachnoid hemorrhage and is associated with high morbidity. Recommendations for preventive treatment of unruptured aneurysms (UIAs) remain controversial due to inconsistent data on their natural history and the risks associated with treatment. The awareness of being diagnosed with one or more UIAs can provoke feelings of anxiety and psychosocial distress. Therefore, the impact of management on a patients' health perception and quality of life (QoL) is an essential factor to be considered in the treatment decision-making process.

Objective

The aim of this study was to assess and compare QoL in patients diagnosed with one or more UIAs depending on their treatment as well as their pre- or postoperative status.

Material and methods

Demographic and clinical data as well as results of the 15D quality of life (15D QoL) questionnaire of 189 patients were prospectively collected and retrospectively analyzed. Patients were categorized into different subgroups, depending on their treatment modalities (conservative, microsurgery or endovascular treatment) and their pre- or postoperative status at the time of completion of the questionnaire. Statistical analysis was performed to compare the different subgroups.

Results

Conservatively treated patients had similar mean 15D QoL scores as preoperative patients. Despite an initial postoperative QoL reduction and a trend towards recovery and even an improvement of QoL in the long term after UIA occlusion, neither clinically relevant nor statistically significant differences between preoperative and postoperative mean 15D QoL scores were observed.

Conclusions

Health-related QoL does not significantly change after treatment of UIAs when compared to the preoperative period. Further studies are needed to confirm long-term postoperative quality of life changes as well as treatment-related influencing factors on patients' quality of life.

Clinical Factors Contributing to Cognitive Function in the Acute Stage after Treatment of Intracranial Aneurysms: A Cross-Sectional Study

Background: The factors affecting cognitive function after treatment of subarachnoid haemorrhage (SAH) can be categorised into aneurysmal factors, procedural factors, and complications. The aim of this study was to investigate which of these factors has greater influence on the cognitive function. Methods: We retrospectively identified 14 patients with unruptured intracranial aneurysms (UIAs) and 34 patients with SAH with mild symptoms at disease onset (Hunt and Hess grade: >3). All patients underwent neuropsychological tests within 35 days of discharge from hospitalisation for treatment. The relationship between the clinical factors and each neuropsychological test score was evaluated using multiple linear regression analysis after controlling for age and years of education. Results: Patients with UIA showed greater cognitive impairment in visual memory and the frontal/executive domains. Hypertension was associated with cognitive impairment. Patients with SAH showed greater cognitive impairment in the visuospatial, verbal memory, and frontal/executive domains. The dome-to-neck ratio, aneurysms located in the posterior circulation, microsurgical clipping, procedure time, anaesthesia duration, and complications were associated with cognitive impairment. Conclusions: Underlying diseases, procedural factors, and complications contributed to cognitive impairment after treatment of intracranial aneurysms. Since the effect of each factor on each cognitive domain was slightly different, a more in-depth study of these effects is needed.

Quality of life scores in patients with unruptured cerebral aneurysm: Prospective cohort study

BACKGROUND

Living with the diagnosis of an unruptured cerebral aneurysm can understandably cause distress to a patient. The goal of preventive treatment is to increase the number of years with good quality of life (QoL).

OBJECTIVE

This study aimed to measure the effect of unruptured intracranial aneurysm treatment on change in QoL scores measured by the SF36 and EQ-5D-5L.

METHODS

We prospectively collected SF36 and EQ-5D-5L survey data for patients with unruptured intracranial aneurysms at two time-points over 1 year between 2 treatment groups: observation and intervention (microsurgical and endovascular). Multivariable linear regression was used to examine treatment group differences in the mean change in scores from baseline to 1 year when adjusted for covariates.

RESULTS

92 patients were included in the observation group and 68 patients were included in the intervention group, for a total of 160 patients. The intervention group had lower SF36 total scores at baseline (p = 0.001). With multivariate linear regression models, the effect of treatment on mean change in SF36 total score from baseline to 1 year was not statistically significant (p = 0.4); similarly, there was no difference in mean change in EQ-5D-5L.

CONCLUSION

In this large prospective study, preventive aneurysm treatment was not associated with a significant change in QoL score at 1 year compared to observation as measured by the SF36 and EQ-5D-5L. Further studies are needed to explore the lower QoL scores in patients seeking treatment and its impact on management decision making.

Comparison of Clinical Outcomes of Intracranial Aneurysms: Procedural Rupture versus Spontaneous Rupture

BACKGROUND AND PURPOSE

Procedural rupture of an intracranial aneurysm is a devastating complication in endovascular treatment. The purpose of this study was to evaluate the clinical outcomes of patients with procedural rupture of unruptured saccular intracranial aneurysms compared with those with spontaneously ruptured aneurysms.

MATERIALS AND METHODS

A retrospective review was performed for 1340 patients with 1595 unruptured saccular intracranial aneurysms that underwent endovascular coil embolization between February 2010 and December 2014. The clinical outcomes of patients with procedural rupture of unruptured saccular intracranial aneurysms were compared with those of 198 patients presenting with spontaneously ruptured aneurysms.

RESULTS

In this series, procedural rupture developed in 19 patients (1.4% per patient and 1.2% per aneurysm), and the morbidity related to procedural rupture was 26.3% (95% confidence interval, 8.5%-61.4%) with no mortality. Hunt and Hess scale grades and hospitalization days of patients with procedural rupture were equivalent to those of patients presenting with spontaneous aneurysm rupture. Subsequent treatment procedures after hemorrhage (including lumbar drainage, extraventricular drainage, decompressive craniectomy, and permanent shunt) showed no difference between the 2 groups. The hemorrhage volumes were smaller in the procedural-rupture group (P = .03), and the endovascular vasospasm therapies tended to be more frequently required in the spontaneous aneurysm-rupture group (P = .08). At postictus 6 months, the proportion of modified Rankin Scale scores of ≥2 were lower in the procedural-rupture group (5.3% versus 26.8%, P = .049). In multivariate analysis, spontaneous aneurysm rupture was a significant risk factor for worse clinical outcome (OR = 14.9; 95% CI, 1.2-193.1; P = .039).

CONCLUSIONS

This study showed better clinical outcomes in the procedural-rupture group. Even though there is a potential chance of aneurysm rupture during treatment, the clinical outcomes after procedural bleeds seem to be more favorable than those of spontaneous rupture.

Influence of smoking on aneurysm recurrence after endovascular treatment of cerebrovascular aneurysms

OBJECTIVE Smoking is a known risk factor for aneurysm development and aneurysmal subarachnoid hemorrhage, as well as subsequent vasospasm in both untreated individuals and patients who have undergone surgical clipping of cerebrovascular aneurysms. However, there is a lack of data in the current scientific literature about the long-term effects that smoking has on the integrity of endovascular repairs of cerebral aneurysms. This study was designed to determine if any smoking history increased the risk of poorer outcomes and/or aneurysm recurrence in patients who have had endovascular repair of cerebral aneurysms. METHODS The authors retrospectively analyzed the medical records of patients admitted to the University of Michigan Health System from January 1999 to December 2011 with coiled aneurysms and angiography, CT angiography, or MR angiography follow-up. Patients were identified and organized based on many criteria including age, sex, smoking history, aneurysm recurrence, aneurysm location, and Hunt and Hess grade. Analysis was targeted to the patient population with a history of smoking. Bivariate chi-square tests were used to analyze the association between a positive smoking history and documented aneurysm recurrence and were adjusted for potential confounders by fitting multivariate logistic regression models of recurrence. RESULTS A total of 247 patients who had undergone endovascular treatment of 296 documented cerebral aneurysms were included in this study. The recurrence rate among all patients treated with endovascular repair was 24.3%, and the average time to the most recent follow-up imaging studies was 1.62 years. Smokers accounted for 232 aneurysms and were followed up for an average of 1.57 years, with a recurrence rate of 26.3%. Never smokers accounted for the remaining 64 aneurysms and were followed up for an average of 1.82 years, with a recurrence rate of 17.2%. Multivariate analysis revealed that, after controlling for potential confounders, a history of smoking-whether current or former-was associated with a significantly increased risk of aneurysm recurrence. The odds ratios for aneurysm recurrence for current and former smokers were 2.739 (95% CI 1.127-7.095, p = 0.0308) and 2.698 (95% CI 1.078-7.212, p = 0.0395), respectively, compared with never smokers. CONCLUSIONS A positive smoking history is associated with a significantly increased risk of aneurysm recurrence in patients who have undergone endovascular repair of a cerebral aneurysm, compared with the risk in patients who have never smoked.

Cerebral Aneurysm Clipping Surgery Simulation Using Patient-Specific 3D Printing and Silicone Casting

BACKGROUND

Neurosurgery simulator development is growing as practitioners recognize the need for improved instructional and rehearsal platforms to improve procedural skills and patient care. In addition, changes in practice patterns have decreased the volume of specific cases, such as aneurysm clippings, which reduces the opportunity for operating room experience.

OBJECTIVE

The authors developed a hands-on, dimensionally accurate model for aneurysm clipping using patient-derived anatomic data and three-dimensional (3D) printing. Design of the model focused on reproducibility as well as adaptability to new patient geometry.

METHODS

A modular, reproducible, and patient-derived medical simulacrum was developed for medical learners to practice aneurysmal clipping procedures. Various forms of 3D printing were used to develop a geometrically accurate cranium and vascular tree featuring 9 patient-derived aneurysms. 3D printing in conjunction with elastomeric casting was leveraged to achieve a patient-derived brain model with tactile properties not yet available from commercial 3D printing technology. An educational pilot study was performed to gauge simulation efficacy.

RESULTS

Through the novel manufacturing process, a patient-derived simulacrum was developed for neurovascular surgical simulation. A follow-up qualitative study suggests potential to enhance current educational programs; assessments support the efficacy of the simulacrum.

CONCLUSIONS

The proposed aneurysm clipping simulator has the potential to improve learning experiences in surgical environment. 3D printing and elastomeric casting can produce patient-derived models for a dynamic learning environment that add value to surgical training and preparation.

Prediction model for 3-year rupture risk of unruptured cerebral aneurysms in Japanese patients

OBJECTIVE

To build a prediction model that estimates the 3-year rupture risk of unruptured saccular cerebral aneurysms.

METHODS

Survival analysis was done using each aneurysm as the unit for analysis. Derivation data were from the Unruptured Cerebral Aneurysm Study (UCAS) in Japan. It consists of patients with unruptured cerebral aneurysms enrolled between 2000 and 2004 at neurosurgical departments at tertiary care hospitals in Japan. The model was presented as a scoring system, and aneurysms were classified into 4 risk grades by predicted 3-year rupture risk: I, < 1%; II, 1 to 3%; III, 3 to 9%, and IV, >9%. The discrimination property and calibration plot of the model were evaluated with external validation data. They were a combination of 3 Japanese cohort studies: UCAS II, the Small Unruptured Intracranial Aneurysm Verification study, and the study at Jikei University School of Medicine.

RESULTS

The derivation data include 6,606 unruptured cerebral aneurysms in 5,651 patients. During the 11,482 aneurysm-year follow-up period, 107 ruptures were observed. The predictors chosen for the scoring system were patient age, sex, and hypertension, along with aneurysm size, location, and the presence of a daughter sac. The 3-year risk of rupture ranged from <1% to >15% depending on the individual characteristics of patients and aneurysms. External validation indicated good discrimination and calibration properties.

INTERPRETATION

A simple scoring system that only needs easily available patient and aneurysmal information was constructed. This can be used in clinical decision making regarding management of unruptured cerebral aneurysms.

3D contrast enhancement-MR angiography for imaging of unruptured cerebral aneurysms: a hospital-based prevalence study

Background and Purpose

Contrast enhanced MRA (CE-MRA) can help to overcome the limitations of other techniques to clearly display the details of cerebral aneurysms at 1.5-T MR system. We investigated the prevalence of unruptured cerebral aneurysms (UCAs) using three dimensional (3D) CE-MRA in a tertiary comprehensive hospital in China.

Materials and Methods

The cases were prospectively recorded at our hospital between February 2009 and October 2010. 3D CE-MRA, interpreted by 2 observers blinded to the participants’ information, was used to identify the location and size of UCAs and to estimate the overall, age-specific, and sex-specific prevalence.

Results

Of the 3993 patients (men: women = 2159∶1834), 408 UCAs were found in 350 patients (men: women = 151∶199). The prevalence was 8.8% overall (95% CI, 8.0–10.0%), with 7.0% for men (CI, 6.0–8.0%) and 10.9% for women (CI, 9.0–12.0%). The overall prevalence of UCAs was higher in women than in men (P<0.001) and increased with age both in men and women. Prevalence peaked at age group 75–80 years. Forty-two patients (11.7%) had multiple aneurysms, including 10 (2.9%) male patients and 32 (9.1%) female patients. The most common site of aneurysm was the carotid siphon, and most lesions (71.3%) had a maximum diameter of 3−5 mm.

Conclusion

This hospital-based prevalence study suggested a high prevalence (8.8%) of UCAs and most lesions (71.3%) had a maximum diameter of 3–5 mm observed by 3D CE-MRA. Because the rupture of small cerebral aneurysms was not uncommon, an appropriate follow-up care strategy must be formulated.

The nose knows: an unusual presentation of a cerebral aneurysm

BACKGROUND

Cerebral aneurysms most commonly present with subarachnoid hemorrhage (SAH), a catastrophic event. However, 11-15% of unruptured aneurysms are symptomatic, with presentations including seizures, unilateral cranial nerve deficits, visual loss, headache, and ischemia. Of patients presenting with seizures, the semiology described includes speech arrest, "feelings of dread," localized pins and needles, and tonic clonic episodes. We report the case of a patient who presented to the emergency department (ED) with complex partial seizures secondary to a cerebral aneurysm.

CASE REPORT

A 54-year-old woman presented to the ED after an episode where she had noticed a "bad smell" and sensations of nausea and dizziness. This was the third episode she had experienced in 2 weeks, and other than migraine, she had no significant medical or family history. Physical examination was normal, but a computed tomography (CT) scan of the brain revealed a 15-mm aneurysm of the right middle cerebral artery. The patient was subsequently transferred for urgent neurosurgical intervention. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: The emergency physician should strongly consider the use of head CT in the evaluation of adults presenting with a first unprovoked seizure, as rarely they can be caused by urgent pathologies including cerebral aneurysms. If a patient is found to have a possible symptomatic unruptured aneurysm, they should be referred for urgent neurosurgical consultation, as these lesions have an increased risk of rupture.

Cognitive function, depression, anxiety and quality of life in Chinese patients with untreated unruptured intracranial aneurysms

Detected unruptured intracranial aneurysms (UIA) are becoming more common with the increased utilization of CT angiography, MR angiography and digital subtraction angiography. A proportion of patients with UIA remain untreated. We investigated to assess cognitive function, depression, anxiety and quality of life (QoL) in Chinese patients with untreated UIA. Thirty one Chinese patients with untreated UIA and 25 healthy controls were identified and matched for variables including age, sex, and living area. Cognitive function was evaluated with the Montreal Cognitive Assessment (MoCA). Depression, anxiety and QoL were screened with the Self-Rating Depression Scale, Self-Rating Anxiety Scale, and Short Form-36, respectively. Non-parametric tests were used for comparisons between groups. No patient had cognitive dysfunction at 1 month or 1 year after detection of UIA. However, a significant decrease of overall MoCA subscores was found in 30 (97%) of 31 patients 5 years after UIA discovery, suggestive of mild cognitive impairment. A significant decrease in depression and anxiety was found in patients over time. QoL in patients was reduced most prominently in psychosocial function and social activities 1 year after detection of UIA, but these improved to within normal limits at the end of the follow-up period. For Chinese patients with untreated UIA, depression, anxiety and reduced QoL may be short-term complications. Mild cognitive impairment may be a long-term complication.

Recent update of guidelines for neurointerventional procedures

Treatment guidelines of the neurointerventional procedures are continuously updated. However, these guidelines differ between countries and even medical societies within the same country because of the differing interests and patient groups. The differences between guidelines are confusing to many neurointerventionalists. Recently "Clinical Research Center for Stroke" in Korea updated "Clinical Practice Guidelines for Stroke" for the patients in Korea. So we introduce those guidelines and compare several recent guidelines of international medical societies for neurointerventionalists.

Estimated low risk of rupture of small-sized unruptured intracranial aneurysms (UIAs) in relation to intracranial aneurysms in patients with subarachnoid haemorrhage

OBJECTIVE

International guidelines for the management of unruptured intracranial aneurysms (UIAs) recommend observation in aneurysms <10 mm due to the estimated low risk of rupture. The aim of our study was analyse the data of recently treated patients with ruptured cerebral aneurysms with the special focus on size and configuration in view of the frequency scale in a daily routine setting.

METHODS

We reviewed the data of all patients with aneurysmal subarachnoid haemorrhage (SAH) during the last 24 months at our institution. Configuration and size of the aneurysms were measured. Clinical data were collected using the following classifications for analysis: Hunt and Hess (H&H), modified Rankin Scale (mRS) and Fisher classification.

RESULTS

Data of 135 patients with aneurysmal SAH (98 women, 37 men; ratio 2.6:1) were analysed. Analysis showed that 19 aneurysms (14 %) were >10 mm (mean size, 19.2 mm) and 116 aneurysms (85.9 %) <10 mm (mean size, 6.2 mm). In total, 112 were categorised as berry-like configured aneurysms (n = 113 <10 mm, n = 3 >10 mm), 18 as multi-lobar (n = 16 <10 mm, n = 2 >10 mm) and 5 as fusiform (n = 4 <10 mm, n = 1, >10 mm).

CONCLUSION

Since the results of our study showed that the majority of the aneurysms are <10 mm (mean, 6.2 mm), it is justified to challenge the recommendations of the international guidelines in a daily routine setting. We believe that the published data are not convincing enough to play a guidance role in daily routine. Due to improving surgical and endovascular techniques with satisfying results and the high number of ruptured small aneurysms, we believe a change in attitude in management of small-sized aneurysms is needed. Further diagnostic models are needed to determine the risk of rupture of intracranial aneurysms properly to obtain adequate treatment for UIAs.

Predictors of thromboembolism during coil embolization in patients with unruptured intracranial aneurysm

OBJECTIVES

To identify the incidence of thromboembolic complications based on magnetic resonance imaging (MRI) and to explore the potential risk factors for thromboembolism (TE) during the periprocedural period of elective coil embolization for unruptured intracranial aneurysms.

METHODS

We retrospectively reviewed all aneurysm cases treated with coil insertion between January 2008 and March 2011. Two hundred eighty-two coiling procedures for unruptured aneurysms were included in this study. The patients' demographic characteristics were documented and records reviewed for abnormalities in diffusion-weighted imaging (DWI) seen on post-procedure MRI, intraoperative thrombus formation, and clinical signs of stroke.

RESULTS

Overall, there were 87 (30.9 %) procedure-related complications in 282 aneurysms treated: 2 (0.7 %) procedural ruptures, 5 (1.8 %) symptomatic infarctions, and 80 (28.3 %) asymptomatic infarctions. Thromboembolic events during the procedure were observed more often in the the hyperlipidemia group (32/71 aneurysms, 45.1 %) than in the normal lipid profile group (39/196 aneurysms, 25.6 %; p = 0.002; chi-squre test). The coiling technique and size of the aneurysm were also associated with TE (p < 0.001 and p = 0.004).

CONCLUSION

Hyperlipidemia seems to be associated with a significant increase in the rate of thromboembolic events. In preventive procedures, modifiable risk factors should be managed to reduce complications. Although permanent deficits are rare, the high rate of thromboembolic events suggests that improvements in the technique, such as the addition of antiplatelet agents and the development of new embolic materials, are necessary.

Pipeline™ embolization device for the treatment of complex intracranial aneurysms: a NICE Medical Technology Guidance

As part of its Medical Technologies Evaluation Programme, the National Institute of Health and Clinical Excellence (NICE) invited the manufacturer, Covidien, to provide clinical and economic evidence for the evaluation of the Pipeline™ embolization device (PED) for the treatment of complex intracranial aneurysms. Cedar; a consortium between Cardiff and Vale University Health Board and Cardiff University, was commissioned to act as an External Assessment Centre (EAC) for NICE to independently critique the manufacturers' submissions. This article gives an overview of the evidence provided, the findings of the EAC and the final guidance published by NICE. The scope issued by NICE considered PED as the intervention in a patient population with complex unruptured intracranial aneurysms (IAs), specifically large/giant, wide-necked and fusiform aneurysms. The comparator treatments identified were stent-assisted coiling, parent vessel occlusion, neurosurgical techniques and conservative management. The manufacturer claimed that PED fulfils a currently unmet clinical need in the treatment of large or giant, wide-necked or fusiform IAs. Thirteen studies were identified by the manufacturer as being relevant to the decision problem, with two of these included for data extraction. The EAC identified 16 studies as relevant, three of which had been published after the manufacturer's search. Data extraction was carried out on these studies as, although many were low level research comprising of case reports and case series, they provided useful, pertinent safety and outcome data. No relevant economic studies of the device were identified; therefore, a new economic model was designed by the manufacturer. The base-case scenario provided recognized the costs of PED to be higher than the costs for endovascular parent vessel occlusion, neurosurgical parent vessel occlusion, neurosurgical clipping and conservative management. However, PED was found to be cost saving compared with stent-assisted coiling, with a saving of £13,110 per patient. Analysis of the clinical data suggested that treatment with PED has high rates of clinical success with high rates of aneurysm occlusion and acceptable adverse events for the patient population. Economic evidence suggested that the costs in the base-case for PED may have been underestimated, meaning that PED would only become cost saving in patients who would otherwise require treatment with 32 coils or more. NICE Medical Technologies Guidance MTG10, issued in May 2012, recommends the adoption of PED in selected patients within the UK National Health Service (NHS).

Prevalence of asymptomatic incidental aneurysms: a review of 2,685 computed tomographic angiograms

OBJECTIVE

Intracranial aneurysms are a public health issue with a potential for rupturing, causing significant morbidity/mortality. The prevalence of unruptured intracranial aneurysms, including those that are asymptomatic, varies widely, as it has been determined through autopsy studies as well as conventional angiography. However, computed tomography angiography, a less invasive procedure, has replaced the use of conventional angiography in the recent decades. The objective of the present study is to determine the prevalence of incidental aneurysms.

METHODS

The present study reviews all computed tomography angiography cases within the past decade at a single institution.

RESULTS

Of 2195 cases included in the study, 39 (1.8%) were found to have asymptomatic unruptured aneurysms.

CONCLUSIONS

The numbers of asymptomatic incidental aneurysms have increased.

"Sit back, observe, and wait." Or is there a pharmacologic preventive treatment for cerebral aneurysms?

Intracranial aneurysms (IA) are a relatively frequent vascular abnormality. The prevailing opinion is that cerebral aneurysmal disease is related to hemodynamic and genetic factors, associated with structural weakness in the arterial wall which was acquired by a specific, often unknown, event. Possibly the trigger moment of aneurysm formation may depend on the dynamic arterial growth, which is closely related to aging/atherosclerosis. In most individuals, an endovascular/microsurgical approach is possible in order to obliterate the IA. However, in a number of patients with an unruptured IA (UIA), the neurosurgeon's decision is to just "sit back, observe, and wait", based on the favorable natural history of some of the UIAs. Furthermore, some individuals need to be kept under close observation since they have a higher chance of developing IA, especially those with at least two affected first-degree relatives with an IA, subjects with polycystic kidney disease, and patients who have undergone an aneurysm intervention. In these examples prophylactic strategies should be adopted, if it is at all possible. The main question is deciding the best option of clinical treatment for these cases, when surgical approach is contraindicated, or for those subjects who are more prone to develop an IA. In the present article, we hypothetically suggest a pharmacologic form of treatment with statins, beta-adrenergic blocker agents, and/or angiotensin-converting-enzyme inhibitor/angiotensin II receptor blockers to inhibit or slow down IA formation, taking into consideration some pathophysiological aspects related to aneurysmal development, such as: hemodynamic stress, arterial wall inflammation, nitric oxide formation, and atheromatous disease.

The natural history and treatment options for unruptured intracranial aneurysms

Recent advances in angiographic technique have raised our awareness of the presence of unruptured intracranial aneurysms (UIAs). However, the appropriate management for these lesions remains controversial. To optimize patient outcomes, the physician must weigh aneurysmal rupture risk associated with observation against the complication risks associated with intervention. In the case that treatment is chosen, the two available options are surgical clipping and endovascular coiling. Our paper summarizes the current body of literature in regards to the natural history of UIAs, the evolution of the lesion if it progresses uninterrupted, as well as the safety and efficacy of both treatment options. The risks and benefits of treatment and conservative management need to be evaluated on an individual basis and are greatly effected by both patient-specific and aneurysm-specific factors, which are presented in this paper. Ultimately, this body of data has led to multiple sets of treatment guidelines, which we have summated and presented in this paper.

[Intracerebral aneurysm--treatment options, informed consent, and legal aspects]

All medical subspecialties and, in particular, high-tech field neurosurgery are subject to continuous change in therapeutic concepts due to novel treatment options emerging through research and evolution in the field. Hence, the question arises if the patient's informed consent needs to be adjusted in the face of multiple therapeutic options with different configurations of risk/benefit relationships. In this paper we discuss different therapeutic scenarios with regard to ruptured intracerebral aneurysms (RIA) and unruptured intracerebral aneurysms (UIA), and we advise the medical doctor involved in the process. Indeed, experienced neurosurgeons and endovascular interventionalists are very familiar with the management of these scenarios; likewise, interns, residents, and otherwise affiliated physicians may be faced with these situations. In general, asymptomatic and mentally capacitated patients as well as legal guardians of minor patients and of mentally incapacitated patients with incidental aneurysms and more than one therapeutic option need to be accurately informed about the advantages and disadvantages of the treatment options available to them. In case of emergency or when treating a mentally disabled patient who is incapable of making a sound judgment and has no legal guardian, the attending doctor will have to choose the best possible treatment option.

Extended follow-up of unruptured intracranial aneurysms detected by presymptomatic screening in patients with autosomal dominant polycystic kidney disease

BACKGROUND AND OBJECTIVES

Autosomal dominant polycystic kidney disease (ADPKD) patients have an increased risk for intracranial aneurysms (IAs). The importance of screening for unruptured IAs (UIAs) depends on their risks for growth and rupture.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

ADPKD patients with UIAs found by presymptomatic screening with magnetic resonance angiography (MRA) during 1989 to 2009 were followed initially at 6 months and annually, and less frequently after demonstration of stability.

RESULTS

Forty-five saccular aneurysms were detected in 38 patients from 36 families. Most were small (median diameter 3.5 mm) and in the anterior circulation (84%). Median age at diagnosis was 49 years. During cumulative imaging follow-up of 243 years, one de novo UIA was detected and increased in size from 2 to 4.4 mm over 144 months and two UIAs grew from 4.5 to 5.9 mm and 4.7 to 6.2 mm after 69 and 184 months, respectively. Seven patients did not have imaging follow-up. No change was detected in the remaining 28 patients. During cumulative clinical follow-up of 316 years, no aneurysm ruptured. Five patients died from unrelated causes and two were lost to follow-up after 8 and 120 months. Three patients underwent surgical clipping.

CONCLUSIONS

Most UIAs detected by presymptomatic screening in ADPKD patients are small and in the anterior circulation. Growth and rupture risks are not higher than those of UIAs in the general population. These data support very selective screening for UIAs in ADPKD patients, and widespread screening is not indicated.

The role of the renin—angiotensin system in the pathogenesis of intracranial aneurysms

Introduction: Recent work has begun to elucidate the pathogenesis of intracranial aneurysms (IA) and has shown that many genes are involved in the risk for this condition. There has also been increasing research interest in the renin—angiotensin system (RAS) in the brain and its involvement in a range of cardiovascular and neurological disorders. The possibility that the RAS is implicated in the pathogenesis of IA merits further investigation. The aim of this article is to review the literature on the pathogenesis of IA and the pathophysiological significance of the brain RAS, and to identify directions for research into their association.

Methods and results : A survey of the literature in these fields shows that although factors contributing to systemic hypertension predispose to IA, a large number of genes involved in endothelial cell adhesion, smooth muscle activity, extracellular matrix dynamics and the inflammatory and immune responses are also implicated. The brain RAS has a significant role in regulating blood pressure and in maintaining cerebrovascular autoregulation, but angiotensin II receptors are also involved in the maintenance of endothelial cell and vascular smooth muscle function and in the inflammatory response in the brain.

Conclusions: There is strong, albeit largely circumstantial, evidence in the literature for a relationship between the brain RAS and the formation of IA. Research on the association between polymorphisms in RAS-related genes and the incidence of unruptured and ruptured IA is indicated.

Current progress in patient-specific modeling

We present a survey of recent advancements in the emerging field of patient-specific modeling (PSM). Researchers in this field are currently simulating a wide variety of tissue and organ dynamics to address challenges in various clinical domains. The majority of this research employs three-dimensional, image-based modeling techniques. Recent PSM publications mostly represent feasibility or preliminary validation studies on modeling technologies, and these systems will require further clinical validation and usability testing before they can become a standard of care. We anticipate that with further testing and research, PSM-derived technologies will eventually become valuable, versatile clinical tools.

In vitro evaluation of MR imaging issues at 3T for aneurysm clips made from MP35N: Findings and information applied to 155 additional aneurysm clips

BACKGROUND AND PURPOSE

Aneurysm clips need to be tested at 3T to characterize MR imaging concerns, including magnetic field interactions, MR imaging-related heating, and artifacts. Therefore, we evaluated these risks for aneurysm clips.

MATERIALS AND METHODS

Three different MP35N aneurysm clips (Codman Slim-Line Aneurysm Clip, straight, blade length 25-mm; Codman Slim-Line Aneurysm Clip Graft, 5-mm diameter x 5-mm width; Codman Slim-Line Aneurysm Clip, reinforcing 30 degrees angle, 6-mm x 18-mm) that represented the largest mass for 155 additional clips made from MP35N were tested. The clips were evaluated at 3T for magnetic field interactions, heating, and artifacts. We studied MR imaging-related heating, placing the clip in a gelled-saline-filled phantom with MR imaging performed by using a transmit/receive radio-frequency body coil at a whole-body average SAR of 3 W/kg for 15 minutes. Artifacts were characterized by using T1-SE and GRE pulse sequences.

RESULTS

Each aneurysm clip showed relatively minor magnetic field interactions, which would not cause movement in situ. Heating was not excessive (highest temperature change, <1.8 degrees C). Artifacts may create problems if the area of interest is in the same area or close to the aneurysm clip.

CONCLUSIONS

The results of this investigation demonstrated that it would be acceptable (ie, "MR conditional" using current terminology) for patients with these aneurysm clips to undergo MR imaging at < or =3T. Notably, on the basis of the sizes of the clips that underwent testing, these findings pertain to 155 additional aneurysm clips made from the same material.

Autosomal dominant polycystic kidney disease: the last 3 years

Autosomal dominant polycystic kidney disease is the most prevalent, potentially lethal monogenic disorder. It has large inter- and intra-familial variability explained to a large extent by its genetic heterogeneity and modifier genes. An increased understanding of its underlying genetic, molecular, and cellular mechanisms and a better appreciation of its progression and systemic manifestations have laid out the foundation for the development of clinical trials and potentially effective therapies. The purpose of this review is to update the core of knowledge in this area with recent publications that have appeared during 2006-2009.