Comparing health-related quality of life in modified Rankin Scale grades: 15D results from 323 patients with brain arteriovenous malformation and population controls

Background

We wanted to understand how patients with different modified Rankin Scale (mRS) grades differ regarding their health-related quality of life (HRQoL) and how this affects the interpretation and dichotomization of the grade.

Methods

In 2016, all adult patients in our brain arteriovenous malformation (AVM) database (n = 432) were asked to fill in mailed letters including a questionnaire about self-sufficiency and lifestyle and the 15D HRQoL questionnaire. The follow-up mRS was defined in 2016 using the electronic patient registry and the questionnaire data. The 15D profiles of each mRS grade were compared to those of the general population and to each other, using ANCOVA with age and sex standardization.

Results

Patients in mRS 0 (mean 15D score = 0.954 ± 0.060) had significantly better HRQoL than the general population (mean = 0.927 ± 0.028), p < 0.0001, whereas patients in mRS 1–4 had worse HRQoL than the general population, p < 0.0001. Patients in mRS 1 (mean = 0.844 ± 0.100) and mRS 2 (mean = 0.838 ± 0.107) had a similar HRQoL. In the recently published AVM research, the most commonly used cut points for mRS dichotomization were between mRS 1 and 2 and between mRS 2 and 3.

Conclusions

Using 15D, we were able to find significant differences in the HRQoL between mRS 0 and mRS 1 AVM patients, against the recent findings on stroke patients using EQ-5D in their analyses. Although the dichotomization cut point is commonly set between mRS 1 and 2, patients in these grades had a similar HRQoL and a decreased ability to continue their premorbid lifestyle, in contrast to patients in mRS 0.

Characteristics and Long-Term Outcome of 127 Children With Cerebral Arteriovenous Malformations

BACKGROUND

Population-based long-term data on pediatric patients with cerebral arteriovenous malformations (AVMs) are limited.

OBJECTIVE

To clarify the characteristics and long-term outcome of pediatric patients with AVM.

METHODS

A retrospective analysis was performed on 805 consecutive brain AVM patients admitted to a single center between 1942 and 2014. The patients were defined as children if they were under 18 yr at admission. Children were compared to an adult cohort. Changing patterns of presentation were also analyzed by decades of admission.

RESULTS

The patients comprised 127 children with a mean age of 12 yr. The mean follow-up time was 21 yr (range 0-62). Children presented more often with intracerebral hemorrhage (ICH) but less often with epilepsy than adults. Basal ganglia, cerebellar, and posterior paracallosal AVMs were more common in pediatric than in adult patients. Frontal and temporal AVMs, in contrast, were more common in adult than in pediatric patients. As the number of incidentally and epilepsy-diagnosed AVMs increased, ICH rates dropped in both cohorts. In total, 22 (82%) pediatric and 108 (39%) adult deaths were assessed as AVM related. After multivariate analysis, small AVM size and surgical treatment correlated with a favorable long-term outcome.

CONCLUSION

Hemorrhagic presentation was more common in children than in adults. This was also reflected as lower prevalence of epileptic presentation in the pediatric cohort. Lobar and cortical AVM locations were less frequent, whereas deep and cerebellar AVMs were more common in children. Hemorrhagic presentation correlated negatively with incidentally and epilepsy-diagnosed AVMs. In children, AVM was a major cause of death, but in adults, other factors contributed more commonly to mortality.

Long-term health-related quality of life in 262 patients with brain arteriovenous malformation

OBJECTIVE

To discover the health-related quality of life (HRQOL) of patients with treated arteriovenous malformation (AVM), we used the self-applicable HRQOL instrument, the 15D, and analyzed the scores in both in the whole study population and specified cohorts.

METHODS

The 15D questionnaires were mailed to adult patients with AVM alive in 2016 (n = 432) in our database. Patients with completely eradicated AVM (n = 262) were included in a subsequent analysis. The results were compared with those of the general population standardized for age and sex. Subgroup analyses were conducted for epilepsy, number of bleeding episodes, location of the lesion, modified Rankin Scale score, and Spetzler-Ponce classification (SPC) using independent-samples t test or analysis of covariance. Tobit regression was used to explain the variance in the 15D score.

RESULTS

Patients had impaired HRQOL compared to the reference population (p < 0.0001). Deep location, multiple bleeding episodes, and refractory epilepsy were associated with impaired HRQOL. Patients in SPC A and B had similar posttreatment 15D scores, whereas those in class C had an impaired HRQOL. Significant explanatory variables in the regression model were age, sex, number of bleeding episodes, refractory epilepsy, and SPC.

CONCLUSIONS

With careful patient selection, patients in SPC B can reach as favorable HRQOL as those in SPC A provided the operation is successful. Multiple bleeding episodes should be prevented with effective treatment aiming at complete AVM obliteration. The postoperative treatment of patients with AVM should focus on preventing depressive symptoms, anxiety, and epileptic seizures. We encourage other research groups to use HRQOL instruments to fully understand the consequences of neurologic and neurosurgical diseases on patients' HRQOL.

Local Hemodynamic Conditions Associated with Focal Changes in the Intracranial Aneurysm Wall

BACKGROUND AND PURPOSE

Aneurysm hemodynamics has been associated with wall histology and inflammation. We investigated associations between local hemodynamics and focal wall changes visible intraoperatively.

MATERIALS AND METHODS

Computational fluid dynamics models were constructed from 3D images of 65 aneurysms treated surgically. Aneurysm regions with different visual appearances were identified in intraoperative videos: 1) "atherosclerotic" (yellow), 2) "hyperplastic" (white), 3) "thin" (red), 4) rupture site, and 5) "normal" (similar to parent artery), They were marked on 3D reconstructions. Regional hemodynamics was characterized by the following: wall shear stress, oscillatory shear index, relative residence time, wall shear stress gradient and divergence, gradient oscillatory number, and dynamic pressure; these were compared using the Mann-Whitney test.

RESULTS

Hyperplastic regions had lower average wall shear stress (P = .005) and pressure (P = .009) than normal regions. Flow conditions in atherosclerotic and hyperplastic regions were similar but had higher average relative residence time (P = .03) and oscillatory shear index (P = .04) than thin regions. Hyperplastic regions also had a higher average gradient oscillatory number (P = .002) than thin regions. Thin regions had lower average relative residence time (P < .001), oscillatory shear index (P = .006), and gradient oscillatory number (P < .001) than normal regions, and higher average wall shear stress (P = .006) and pressure (P = .009) than hyperplastic regions. Thin regions tended to be aligned with the flow stream, while atherosclerotic and hyperplastic regions tended to be aligned with recirculation zones.

CONCLUSIONS

Local hemodynamics is associated with visible focal wall changes. Slow swirling flow with low and oscillatory wall shear stress was associated with atherosclerotic and hyperplastic changes. High flow conditions prevalent in regions near the flow impingement site characterized by higher and less oscillatory wall shear stress were associated with local "thinning" of the wall.

Riskier-than-expected occlusive treatment of ruptured posterior communicating artery aneurysms: treatment and outcome of 620 consecutive patients

OBJECTIVE: Occlusive treatment of posterior communicating artery (PCoA) aneurysms has been seen as a fairly uncomplicated procedure. The objective here was to determine the radiological and clinical outcome of patients after PCoA aneurysm rupture and treatment and to evaluate the risk factors for impaired outcome. METHODS: In a retrospective clinical follow-up study, data were collected from 620 consecutive patients who had been treated for ruptured PCoA aneurysms at a single center between 1980 and 2014. The follow-up was a minimum of 1 year after treatment or until death. RESULTS: Of the 620 patients, 83% were treated with microsurgical clipping, 8% with endovascular coiling, 2% with the two procedures combined, 1% with indirect surgical methods, and 6% with conservative methods. The most common procedural complications were treatment-related brain infarctions (15%). The occurrence of artery occlusions (10% microsurgical, 8% endovascular) was higher than expected. Most patients made a good recovery at 1 year after aneurysmal subarachnoid hemorrhage (modified Rankin Scale [mRS] score 0-2: 386 patients [62%]). A fairly small proportion of patients were left severely disabled (mRS score 4-5: 27 patients [4%]). Among all patients, 20% died during the 1st year. Independent risk factors for an unfavorable outcome, according to the multivariable analysis, were poor preoperative clinical condition, intracerebral or subdural hematoma due to aneurysm rupture, age over 65 years, artery occlusion on postoperative angiography, occlusive treatment-related ischemia, delayed cerebral vasospasm, and hydrocephalus requiring a shunt. CONCLUSIONS: Even though most patients made a good recovery after PCoA aneurysm rupture and treatment during the 1st year, the occlusive treatment-related complications were higher than expected and caused morbidity even among initially good-grade patients. Occlusive treatment of ruptured PCoA aneurysms seems to be a high-risk procedure, even in a high-volume neurovascular center.

Arteriovenous Malformations of the Posterior Fossa: Focus on Surgically Treated Patients Presenting with Hemorrhage

BACKGROUND

Arteriovenous malformations (AVMs) of the posterior fossa are demanding lesions that often present with rupture. Studies including outcome analyses in surgically operated patients with ruptured infratentorial AVMs are scarce. Certain anatomic and demographic features have shown associations with postoperative outcomes.

METHODS

Eighty-six patients with infratentorial AVM were collected from our AVM database. Fifty-four patients were admitted from 1990 onward, and their demographic, lesion, and treatment characteristics were analyzed. The cohort was further refined to 38 consecutive patients with surgically treated ruptured infratentorial AVM admitted to our center between 1990 and 2014, and statistical analyses of factors influencing outcomes were conducted.

RESULTS

Twenty-seven patients (69%) had a favorable outcome at early follow-up and 24 (67%) had a favorable outcome at final follow-up. Factors associated with poor outcome in early recovery on univariate analyses were deep venous drainage of the lesion (odds ratio [OR], 5.3; P = 0.037) and high Hunt & Hess score (P = 0.003). In the multivariate model, independent predictors for poor outcome were deep venous drainage (OR, 14.5; P = 0.010) and older age at admission (OR, 1.06; P = 0.028). The sole independent predictor for poor outcome at last follow-up was deep venous drainage (OR, 5.00; P = 0.046). The total follow-up time was 370 person-years.

CONCLUSIONS

AVMs of the posterior fossa usually present with rupture and thus require prompt clinical treatment. The majority of surgically treated patients recover favorably. Our data show that venous drainage patterns have the greatest influence on the patient's postoperative condition. Other influencing factors include the severity of hemorrhage and patient age at admission.

Anatomic Features of Paraclinoid Aneurysms: Computed Tomography Angiography Study of 144 Aneurysms in 136 Consecutive Patients

BACKGROUND

Paraclinoid aneurysms are among the most challenging aneurysms to treat. Computed tomography (CT) angiography helps in evaluating the radiological characteristics of these aneurysms next to bony structures.

OBJECTIVE

To present the CT angiography characteristics of paraclinoid aneurysms in order to better understand such pathology.

METHODS

The study examined CT angiography-based anatomical characteristics obtained retrospectively from 136 patients with 144 paraclinoid aneurysms selected from single-defined catchment populations in Finland. We examined the diameters of the parent artery (internal carotid artery), the location of the aneurysm, its dimensions (width, height, neck), and aneurysm wall irregularity.

RESULTS

We analyzed 144 paraclinoid aneurysms in 136 patients admitted to the hospital during 2000-2014. Multivariable analysis reveals that rupture aneurysms have the following radiological features: aneurysm larger than 5 mm in diameter (P = .006), irregular wall (P = .046), superior location, larger aspect ratio (P = .039), and neck wider than parent artery (P < .001).

CONCLUSION

Smaller diameter of the internal carotid artery and superior location, as well as a large and irregular aneurysm wall, are radiological characteristics of ruptured paraclinoid aneurysms, which CT angiography can measure easily.

Simple Lateral Suboccipital Approach and Modification for Vertebral Artery Aneurysms: A Study of 52 Cases Over 10 Years

INTRODUCTION

Complex skull base approaches are frequently used to treat intracranial vertebral artery (VA) and proximal posterior inferior cerebellar artery (PICA) aneurysms. These complex procedures are associated with higher risk of neurovascular injury. Hence, a less-invasive surgical approach is needed to improve the efficacy and safety of treatment.

METHODS

A retrospective analysis was conducted on clinical and radiologic data from surgeries in which simple lateral suboccipital and "lateral-enough" approaches were used to clip VA aneurysms in the Department of Neurosurgery at Helsinki University Central Hospital from 2000 to 2009.

RESULTS

Fifty-two VA or PICA aneurysms were treated using the simple lateral suboccipital approach. Sixteen patients (31%) presented with an unruptured aneurysm, 21 patients (40%) with World Federation of Neurosurgical Societies (WFNS) grade 1-3, and 15 patients (29%) with World Federation of Neurosurgical Societies grade 4-5. The aneurysms were saccular in 48 cases (92%), dissecting in 3 cases (6%), and fusiform in 1 case (2%). The most common aneurysm location was the VA-PICA junction (81%). The mean final modified Rankin Scale score was 2, and in unruptured cases, all patients had favorable clinical outcomes. The main causes of unfavorable outcome were poor preoperative clinical grade (P = 0.002), preoperative intraventricular hemorrhage (P = 0.008), postoperative hydrocephalus (P = 0.003), brain infarction (P = 0.005), and postoperative pneumonia (P < 0.001).

CONCLUSIONS

We describe a 10-year experience using a simple lateral suboccipital approach and its modification by the senior author (J.H.) to treat VA and proximal PICA aneurysms. Unfavorable outcome was related to the poor preoperative clinical grade, preoperative intraventricular hemorrhage, and postoperative pneumonia.

CTA analysis and assessment of morphological factors related to rupture in 413 posterior communicating artery aneurysms

Posterior communicating artery (PcomA) aneurysms are frequently encountered, but there are few publications on their morphology. A growing number of aneurysms are incidental findings, which makes evaluation of rupture risk important. Our goal was to identify morphological features and anatomical variants associated with PComA aneurysms and to assess parameters related to rupture. We studied CT angiographies of 391 consecutive patients treated between 2000 and 2014 at a single institution. We determined clinically important morphological parameters and performed univariate and multivariate analysis. There were a total of 413 PComA aneurysms: 258 (62%) were ruptured and 155 (38%) unruptured. Ruptured PComA aneurysms had the potential to cause severe bleeding with IVH and/or temporal ICH (n = 170, 66% of ruptured). The main types of PComA origin were classified as follows: (1) separate (32%), (2) side by side (21%) and (3) a joint neck with the aneurysm (6%). After the multivariate logistic regression, the morphological parameters related to PComA aneurysm rupture were an irregular aneurysm dome, neck diameter, and aspect ratio >1.5. The most marked morphological features of the PComA aneurysms were: saccular nature (99%), infero-posterior dome orientation (42%), infrequency of large or giant aneurysms (4%), narrow neck compared to the aneurysm size, PComA originating directly from the aneurysm neck or the dome (28%), and fetal or dominant PComA on the side of the aneurysm (35%). There were location-related parameters that were more strongly associated with PComA aneurysm rupture than aneurysm size: an irregular aneurysm dome, larger diameter of the aneurysm neck and aspect ratio >1.5.

Natural History of Ruptured but Untreated Intracranial Aneurysms

Background and Purpose—

Knowledge on a natural history of untreated ruptured intracranial aneurysms is based on a small historical cohort from 1960s. We calculated mortality rates for patients with untreated ruptured intracranial aneurysms using a more recent and relatively large hospital cohort.

Methods—

Patients admitted to the study hospital between 1968 and 2007 with saccular but untreated ruptured intracranial aneurysms were identified from the hospital aneurysm registry of 6850 patients. The study cohort included only patients who were followed up until death and for whom the date of symptom onset and the date of hospital admission were available.

Results—

For 510 patients identified, the median survival time from symptom onset to death was 20 days. The 1-year mortality rate was 65%, but varied substantially by admission delays and clinical status on admission, being lowest (13%) for patients admitted later than a month after symptom onset and highest (89%) for poor-grade patients. The 1-year mortality rate was 75% for good-grade patients admitted within a week.

Conclusions—

Mortality rates for patients with untreated ruptured intracranial aneurysms are even worse than presented in the historical study. When discussing with subarachnoid hemorrhage patients and their relatives about treatment options, the presented natural history figures are of use.

Size and location of ruptured intracranial aneurysms: consecutive series of 1993 hospital-admitted patients

OBJECTIVE Large consecutive series on the size and location of ruptured intracranial aneurysms (RIAs) are limited, and therefore it has been difficult to estimate population-wide effects of size-based treatment strategies of unruptured intracranial aneurysms. The authors' aim was to define the size and location of RIAs in patients diagnosed with subarachnoid hemorrhage due to aneurysm rupture in a high-volume academic center. METHODS Consecutive patients admitted to a large nonprofit academic hospital with saccular RIAs between 1995 and 2009 were identified, and the size, location, and multiplicity of RIAs were defined and reported by patient sex. RESULTS In the study cohort of 1993 patients (61% women) with saccular RIAs, the 4 most common locations of RIAs were the middle cerebral (32%), anterior communicating (32%), posterior communicating (14%), and pericallosal arteries (5%). However, proportional distribution of RIAs varied considerably by sex; for example, RIAs of the anterior communicating artery were more frequently found in men than in women. Anterior circulation RIAs accounted for 90% of all RIAs, and 30% of the patients had multiple intracranial aneurysms. The median size (measured as maximum diameter) of all RIAs was 7 mm (range 1-43 mm), but the size varied considerably by location. For example, RIAs of the ophthalmic artery had a median size of 11 mm, whereas the median size of RIAs of the pericallosal artery was 6 mm. Of all RIAs, 68% were smaller than 10 mm in maximum diameter. CONCLUSIONS In this large consecutive series of RIAs, 83% of all RIAs were found in 4 anterior circulation locations. The majority of RIAs were small, but the size and location varied considerably by sex. The presented data may be of help in defining effective prevention strategies.

Early Moderate Hyperoxemia Does Not Predict Outcome After Aneurysmal Subarachnoid Hemorrhage

BACKGROUND

Targeting hyperoxemia is common practice in neurocritical care settings, but the safety of hyperoxemia has been questioned.

OBJECTIVE

To investigate the independent effect of hyperoxemia on outcome in patients with aneurysmal subarachnoid hemorrhage (SAH).

METHODS

We included 432 patients with aneurysmal SAH on mechanical ventilation for at least 24 hours after intensive care unit (ICU) admission. Arterial blood gas levels were calculated as time-weighted averages (TWAs) of all blood gas measurements during the first 24 hours in the ICU. Patients were categorized into 3 TWA-PaO2 bands (low, <97.5 mm Hg; intermediate, 97.5-150 mm Hg; high, ≥150 mm Hg). Outcome measures were unfavorable outcome at 3 months (Glasgow Outcome Scale score 1-3) and mortality. Multivariate logistic regression analysis was used to assess the independent effect of oxygen on outcome.

RESULTS

Overall, 28% of patients died, and a total of 53% had an unfavorable outcome at 3 months. Patients with an unfavorable outcome had significantly higher TWA-PaO2 levels compared with patients with a favorable outcome (137 mm Hg vs 118 mm Hg, P < .001). Multivariate analysis demonstrated no significant association between TWA-PaO2 bands and unfavorable outcome (with intermediate PaO2 as a reference, odds ratio [OR] for low PaO2 1.05, 95% confidence interval [CI]: 0.52-2.12, P = .89; OR for high PaO2: 1.09, 95% CI: 0.61-1.97, P = .77) or mortality (with intermediate PaO2 as reference, the OR for low PaO2 was 0.67 (95% CI: 0.30-1.46, P = .31), and the OR for high PaO2 was 0.73 (95% CI: 0.38-1.40, P = .34).

CONCLUSION

Early moderate hyperoxemia may not increase or decrease the risk of a poor outcome in mechanically ventilated aneurysmal SAH patients.

Incidence of subarachnoid hemorrhage is decreasing together with decreasing smoking rates

OBJECTIVE

To determine the nationwide incidence of subarachnoid hemorrhage (SAH) and report nationwide changes in smoking rates between 1998 and 2012 in Finland.

METHODS

In this register-based study, we utilized the nationwide Causes of Death Register and Hospital Discharge Register in identifying SAH events between 1998 and 2012. Population statistics in Finland, which were obtained through a database of Statistics Finland, were used to calculate crude annual incidence rates of SAH. For the direct age standardization of crude incidence rates, we used the European Standard Population (ESP) 2013. Data on changes in nationwide smoking rates between 1998 and 2012 were extracted from a database of the National Institute for Health and Welfare.

RESULTS

For the total of 79,083,579 cumulative person-years, we identified 6,885 people with SAH. Sudden deaths from SAH away from hospitals or in emergency rooms accounted for 1,771 (26%) of the events. Crude nationwide annual incidence rates varied between 6.2 and 10.0 per 100,000 persons, and increased by age particularly in women. Among 70- to 75-year-old women, the incidence of SAH was highest (22.5 per 100,000 persons). The 3-year average of ESP standardized incidence decreased 24% from 11.7 in 1998-2000 to 8.9 per 100,000 persons in 2010-2012. Daily smoking decreased 30% between 1998 and 2012.

CONCLUSIONS

The incidence of SAH seems to be decreasing. This tendency may be coupled with changes in smoking rates. The incidence of SAH in Finland is similar to other Nordic countries.

Shared Genetic Risk Factors of Intracranial, Abdominal, and Thoracic Aneurysms

Background

Intracranial aneurysms (IAs), abdominal aortic aneurysms (AAAs), and thoracic aortic aneurysms (TAAs) all have a familial predisposition. Given that aneurysm types are known to co‐occur, we hypothesized that there may be shared genetic risk factors for IAs, AAAs, and TAAs.

Methods and Results

We performed a mega‐analysis of 1000 Genomes Project‐imputed genome‐wide association study (GWAS) data of 4 previously published aneurysm cohorts: 2 IA cohorts (in total 1516 cases, 4305 controls), 1 AAA cohort (818 cases, 3004 controls), and 1 TAA cohort (760 cases, 2212 controls), and observed associations of 4 known IA, AAA, and/or TAA risk loci (9p21, 18q11, 15q21, and 2q33) with consistent effect directions in all 4 cohorts. We calculated polygenic scores based on IA‐, AAA‐, and TAA‐associated SNPs and tested these scores for association to case‐control status in the other aneurysm cohorts; this revealed no shared polygenic effects. Similarly, linkage disequilibrium–score regression analyses did not show significant correlations between any pair of aneurysm subtypes. Last, we evaluated the evidence for 14 previously published aneurysm risk single‐nucleotide polymorphisms through collaboration in extended aneurysm cohorts, with a total of 6548 cases and 16 843 controls (IA) and 4391 cases and 37 904 controls (AAA), and found nominally significant associations for IA risk locus 18q11 near RBBP8 to AAA (odds ratio [OR]=1.11; P=4.1×10⁻⁵) and for TAA risk locus 15q21 near FBN1 to AAA (OR=1.07; P=1.1×10⁻³).

Conclusions

Although there was no evidence for polygenic overlap between IAs, AAAs, and TAAs, we found nominally significant effects of two established risk loci for IAs and TAAs in AAAs. These two loci will require further replication.

The orbitozygomatic stich: A technical modification of the lateral supraorbital approach

Background:

The lateral supraorbital approach (LSO) provides access to a variety of pathologies including anterior and some posterior circulation aneurysms, sellar and suprasellar lesions, and anterior fossa tumors. Technical modifications of LSO improve the surgical exposure of the skull base.

Methods:

We retrospectively analyzed 73 consecutive patients treated by the senior author (Juha A. Hernesniemi), at the Department of Neurosurgery, Helsinki University Hospital in Helsinki, Finland from May 2013 to October 2013. This study cohort underwent a modified LSO to access anterior circulation aneurysms, sellar and suprasellar tumors, and anterior fossa tumors. The studied population comprised 30 men and 43 women, with a mean age at treatment of 54 years (9–83 years).

Results:

LSO was successfully used to access anterior circulation aneurysms in 59 (81%) patients, 10 (14%) patients with anterior cranial fossa tumors, and 4 (5%) patients with suprasellar tumors. The skull base drilling provided a mean of 6.8 mm (1.7–22 mm) in increased exposure.

Conclusion:

LSO provides adequate access to vascular and neoplastic lesions of the anterior cranial fossa, by drilling approximately 6.8 mm (1.7–22 mm) of the lateral orbital wall and sphenoid wing. This enhances surgical exposure and trajectory. An additional trick while performing an LSO is to place a single or multiple stiches (orbitozygomatic stich) at the base of the dura once opened, eliminating the dead space between the dura and anterior skull base.

De novo giant A2 aneurysm following anterior communicating artery occlusion

BACKGROUND

De novo intracranial aneurysms are reported to occur with varying incidence after intracranial aneurysm treatment. They are purported to be observed, however, with increased incidence after Hunterian ligation; particularly in cases of carotid artery occlusion for giant or complex aneurysms deemed unclippable.

CASE DESCRIPTION

We report a case of right-sided de novo giant A2 aneurysm 6 years after an anterior communicating artery (ACoA) aneurysm clipping. We believe this de novo aneurysm developed in part due to patient-specific risk factors but also a significant change in cerebral hemodynamics. The ACoA became occluded after surgery that likely altered the cerebral hemodynamics and contributed to the de novo aneurysm. We believe this to be the first reported case of a giant de novo aneurysm in this location. Following parent vessel occlusion (mostly of the carotid artery), there are no reports of any de novo aneurysms in the pericallosal arteries let alone a giant one. The patient had a dominant right A1 and the sudden increase in A2 blood flow likely resulted in increased wall shear stress, particularly in the medial wall of the A2 where the aneurysm occurred 2 mm distal to the A1-2 junction.

CONCLUSION

ACoA preservation is a key element of aneurysm surgery in this location. Suspected occlusion of this vessel may warrant closer radiographic follow-up in patients with other risk factors for aneurysm development.

Factors Determining Surgical Approaches to Basilar Bifurcation Aneurysms and Its Surgical Outcomes

BACKGROUND:

The basilar bifurcation aneurysm (BBA) is still considered to be one of the most challenging aneurysms for micro- and endovascular surgery. Classic surgical approaches, such as subtemporal, lateral supraorbital (LSO), and modified presigmoid, are still reliable and effective.

OBJECTIVE:

To analyze the clinical and radiological factors that affect the selection of these classic surgical approaches and their outcomes.

METHODS:

A retrospective analysis was conducted on the clinical and radiological data from computed tomographic angiography of BBA that have been clipped in the Department of Neurosurgery of Helsinki University Central Hospital between 2004 and 2014. Statistical analyses were performed using parametric and nonparametric tests where values were considered significant below P = .05.

RESULTS:

One hundred four patients with BBA underwent surgical clipping in our department between 2004 and 2014. Eight patients were excluded from the study because of incomplete preoperative radiological evaluations, leaving 96 patients for further analysis. Multiple aneurysm clipping, mean basilar bifurcation angle, and aneurysm neck distance from posterior clinoid process were shown to be factors that determine the surgical approach. Unfavorable outcome is strongly associated with poor Hunt-Hess grade on admission, distance from aneurysm neck (the posterior clinoid process), thrombosis, and dome size.

CONCLUSION:

Microsurgery for BBA clipping can be performed safely with simple surgical approaches: subtemporal and LSO. There are several factors determining the approach selected. Poor patient outcome in BBA was highly associated with poor preoperative clinical grade and large size of aneurysm dome.

Contralateral Approach to Bilateral Middle Cerebral Artery Aneurysms: Comparative Study, Angiographic Analysis, and Surgical Results

BACKGROUND

Bilateral aneurysms located between the 2 middle cerebral artery (MCA) bifurcations may be approachable through a single unilateral approach.

OBJECTIVE

To identify anatomic parameters based on imaging that would favor a contralateral approach.

METHODS

From January 1998 to December 2013, we retrospectively identified 173 patients with bilateral intracranial aneurysms. Fifty-one patients had bilateral MCA aneurysms. A total of 38 patients underwent a single craniotomy with a contralateral microsurgical approach (group 1 or contralateral group) and 13 patients underwent bilateral craniotomies (group 2 or bilateral group). For both groups, we analyzed aneurysm characteristics, morphology, size, projections, and distance to the contralateral corridor, as well as surgical time, outcome, and postoperative complications.

RESULTS

All aneurysms approached contralaterally were unruptured and without wall calcifications. Of the contralaterally approached aneurysms, 97% were smaller than 14 mm. The median length of the contralateral A1 was 13.2 mm (range: 6-19.8 mm) and the median length of the contralateral M1 was 14.2 mm (range: 4.6-21 mm). The contralateral group had a good postoperative outcome (modified Rankin Scale 0-3) in 80% of ruptured cases and 86% of unruptured cases. The median surgical time was 120 minutes (range: 75-255 minutes), 43% shorter than the bilateral group.

CONCLUSION

The contralateral approach for bilateral MCA aneurysms in selected patients is feasible in experienced hands, with acceptable morbidity and mortality. The contralateral approach requires a meticulous preoperative analysis of the characteristics of the aneurysms to be clipped and of the anatomic constraints of the microsurgical operative corridor.

ABBREVIATIONS

A1, anterior cerebral artery proximal segmentbMCA, bilateral middle cerebral arteryCTA, computed tomographic angiographyHH, Hunt-Hess scaleIA, intracranial aneurysmsICA, internal carotid arteryICAbif, internal carotid artery bifurcationMCA, middle cerebral arteryM1, middle cerebral artery proximal segmentmRS, modified Rankin ScaleSAH, subarachnoid hemorrhage.

Surgical Clipping of Very Small Unruptured Intracranial Aneurysms

BACKGROUND:

Treatment of very small unruptured intracranial aneurysms (VSUIAs, defined as ⩽3 mm) can be indicated in selected circumstances. The feasibility and outcomes of endovascular therapy for VSUIAs have been recently published; however, the efficacy and complication rate of surgical clipping has not been reported in any large series to date.

OBJECTIVE:

We conducted a multicenter study to examine surgical outcomes for VSUIAs.

METHODS:

All consecutive patients undergoing surgery for a VSUIA in 4 neurosurgical centers between October 2001 and December 2012 were retrospectively analyzed.

RESULTS:

In the study, 183 patients (128 women, mean age 51.3 years) were treated with 190 procedures for a total of 228 aneurysms. Most were anterior circulation aneurysms (n = 215). The majority were directly clipped (n = 222, 97.4%), with coagulation or wrapping in the remainder. After 1 reoperation for incomplete clipping, postoperative imaging of 225 aneurysms confirmed complete occlusion in 221 (98.2%), 1 neck remnant (0.44%), and 3 partial occlusions (1.3%). Mortality was 0%. Early postoperative neurological deficit developed in 12 patients (6.6%); posterior circulation location was a significant risk factor for early neurological deficit (P &lt; .001). Middle cerebral artery aneurysms had the lowest rate of postoperative deficits at 1.5% (P = .023). After the initial 30-day perioperative period, all deficits related to treatment of posterior circulation aneurysms recovered; overall neurological morbidity decreased to 2.7% with no mortality.

CONCLUSION:

VSUIA clipping is highly effective and is associated with a low morbidity rate. For VSUIAs selected for treatment, our data support surgical clipping as the modality of choice.

Long-Term Excess Mortality After Aneurysmal Subarachnoid Hemorrhage

Background and Purpose—

There is high case-fatality rate and loss of productive life-years related to aneurysmal subarachnoid hemorrhage (aSAH) but data on long-term survival of patients with aSAH are scarce. We aim to evaluate long-term excess mortality and related risk factors after an aSAH event.

Methods—

Survivors (n=3078) of aSAH who had survived for ≥1 year were reviewed for this retrospective follow-up study, which was conducted in the Department of Neurosurgery in Helsinki between 1980 and 2007. Follow-up started 1 year after the aSAH and continued until death or the end of 2012 (48 918 patient-years). Mortality and relative survival ratios were derived using a matched general population.

Results—

Survivors of aSAH after 20 years showed 17% excess mortality compared with the general population. Even young patients and patients with good recovery showed excess mortality. The highest excess mortality was among patients with multiple aneurysms, old age, poor preoperative clinical condition, conservative aneurysm treatment, and unfavorable clinical outcome at 1 year.

Conclusions—

Even after initially favorable recovery from an aSAH, survivors experience excess mortality in the long run in comparison to a matched general population. Cardiovascular disease at younger age and cerebrovascular events were overrepresented as causes of death, which indicates the importance of treatment of vascular risk factors. Young patients and patients with multiple aneurysms who are recovering from an aSAH should be followed-up and treated most actively.

Lateral supraorbital approach to ipsilateral PCA-P1 and ICA-PCoA aneurysms

Background:

Aneurysms of the posterior cerebral artery (PCA) are rare and often associated with anterior circulation aneurysms. The lateral supraorbital approach allows for a very fast and safe approach to the ipsilateral lesions Circle of Willis. A technical note on the successful clip occlusion of two aneurysms in the anterior and posterior Circle of Willis via this less invasive approach has not been published before. The objective of this technical note is to describe the simultaneous microsurgical clip occlusion of an ipsilateral PCA-P1 and an internal carotid artery - posterior communicating artery (ICA-PCoA) aneurysm via the lateral supraorbital approach.

Case Description:

The authors present a technical report of successful clip occlusions of ipsilateral located PCA-P1 and ICA-PCoA aneurysms. A 59-year-old female patient was diagnosed with a PCA-P1 and an ipsilateral ICA-PCoA aneurysm by computed tomography angiography (CTA) after an ischemic stroke secondary to a contralateral ICA dissection. The patient underwent microsurgical clipping after a lateral supraorbital craniotomy. The intraoperative indocyanine green (ICG) videoangiography and the postoperative CTA showed a complete occlusion of both aneurysms; the parent vessels (ICA and PCA) were patent. The patient presents postoperative no new neurologic deficit.

Conclusion:

The lateral supraorbital approach is suitable for the simultaneous microsurgical treatment of proximal anterior circulation and ipsilateral proximal PCA aneurysms. Compared to endovascular treatment, direct visual control of brainstem perforators is possible.

Transfusion Frequency of Red Blood Cells, Fresh Frozen Plasma, and Platelets During Ruptured Cerebral Aneurysm Surgery

BACKGROUND

The use of blood products after subarachnoid hemorrhage (SAH) is common, but not without controversy. The optimal hemoglobin level in patients with SAH is unknown, and data on perioperative need for red blood cell (RBC), fresh frozen plasma (FFP), or platelet transfusions are limited. We studied perioperative administration of RBCs, FFP, and platelets and the impact of red blood cell transfusions (RBCTs) on outcome in patients undergoing surgery for ruptured a cerebral arterial aneurysm.

METHODS

A retrospective analysis was performed of 488 patients with aneurysmal SAH during the years 2006-2009 at Helsinki University Central Hospital. Patients who received RBC, FFP, or platelet concentrates perioperatively were compared with a cohort of patients from the Helsinki database of aneurysmal SAH who did not receive transfusions. A multiple regression model was created to identify factors related to transfusion and outcome.

RESULTS

RBC, FFP, or platelet concentrates were given in 7.6% (37 of 488), 3.1% (15 of 488), and 1.2% (6 of 488) of patients intraoperatively and in 3.5% (17 of 486), 1.6% (8 of 488), and 0.9% (4 of 488) of patients postoperatively. Of 37 intraoperative RBCTs, 26 were related to intraoperative rupture of the aneurysm. Intraoperative RBCTs were associated with lower preoperative hemoglobin concentration, higher World Federation of Neurosurgical Societies classification, and intraoperative rupture of an aneurysm. In multivariate analysis, intraoperative RBCT (odds ratio = 5.13, 95% confidence interval = 1.53-17.15), worse World Federation of Neurosurgical Societies classification and Fisher grade (odds ratio = 1.97, confidence interval = 1.64-2.36 and odds ratio = 1.89, confidence interval = 1.23-2.92, respectively), and increasing age (odds ratio = 1.07, confidence interval = 1.04-1.10) independently increased the risk of poor neurologic outcome at 3 months.

CONCLUSIONS

Transfusion frequencies of RBCs, FFP, and platelets were relatively low. Intraoperative RBCT was strongly related to intraoperative rupture of the aneurysm in patients with poor-grade SAH. The observed association between poor outcome and RBCT in patients with SAH warrants further study.

Intracranial Vertebral Artery Aneurysms: Clinical Features and Outcome of 190 Patients

BACKGROUND

Vertebral artery (VA) aneurysms comprise approximately one-third of posterior circulation aneurysms. They are morphologically variable, and located critically close to the cranial nerves and the brainstem. We aim to represent the characteristics of these aneurysms and their treatment, and to analyze the outcome.

METHODS

We reviewed retrospectively 9709 patients with intracranial aneurysms. Of these, we included 190 with aneurysms at the VA or VA-posterior inferior cerebellar artery junction. These patients were treated in the Department of Neurosurgery, Helsinki, Finland, between 1934 and 2011.

RESULTS

The 190 patients had 193 VA aneurysms, among which 131 (68%) were ruptured. The VA aneurysm caused a mass effect in 7 and ischemia in 2 patients. Compared to 4387 patients with a ruptured aneurysm in other locations, those with a VA aneurysm were older, their aneurysms were more often fusiform, and more often caused intraventricular hemorrhages. Among surgically treated aneurysms, clipping was the treatment in 91 (88%) saccular and 11 (50%) fusiform aneurysms. Treatment was endovascular in 13 (9%), and multimodal in 6 (4%) aneurysms. Within a year after aneurysm diagnosis, 53 (28%) patients died. Among the survivors, 104 (93%) returned to an independent or to their previous state of life; only 2 (2%) were unable to return home.

CONCLUSIONS

Microsurgery is a feasible treatment for VA aneurysms, although cranial nerve deficits are more common than in endovascular surgery. Despite the challenge of an often severe hemorrhage, of challenging morphology, and risk for laryngeal palsy, most patients surviving the initial stage return to normalcy.

Contralateral Approach to Internal Carotid Artery Ophthalmic Segment Aneurysms: Angiographic Analysis and Surgical Results for 30 Patients

BACKGROUND

Contralateral aneurysm clipping can be applied to bilateral intracranial aneurysms of the anterior circulation and to selected aneurysms on the medial wall of the internal carotid artery (ICA).

OBJECTIVE

To identify anatomic and radiological parameters that would favor a contralateral microsurgical approach to ICA-ophthalmic segment (ICA-opht) aneurysms.

METHODS

For the period January 1957 to December 2012, we retrospectively analyzed 268 patients with ICA-opht aneurysms treated in our institution. Of these patients, 30 underwent a contralateral approach; 15 patients (50%) had multiple intracranial aneurysms, and 15 patients had a single aneurysm on the contralateral side of the craniotomy.

RESULTS

Thirty saccular aneurysms located on the contralateral ICA were treated. Six aneurysms (20%) were present in patients with a subarachnoid hemorrhage due to associated aneurysms, whereas 24 aneurysms (80%) had no history of bleeding. Contralateral aneurysms were smaller than 14 mm and showed no wall irregularities, calcifications, or secondary pouches. Projections of the aneurysms were superomedial (n = 23, 77%), medial (n = 4, 13%), and superior (n = 3, 10%). The median prechiasmatic distance was 5.7 mm (range, 3.4-8.7 mm), the median interoptic distance was 10.5 mm (range, 7.6-15.9 mm), and the median distance between both ICAs was 14.7 mm (range, 10.4-21.4 mm).

CONCLUSION

The contralateral approach for ICA-opht aneurysms remains a treatment option for intracranial aneurysms. Its feasibility depends on specific anatomic parameters related to the aneurysm itself and to the prechiasmatic distance, interoptic distance, and relationship of the ICA with the anterior clinoid process.

Risk factors for all-cause death after diagnosis of unruptured intracranial aneurysms

OBJECTIVES

We investigated all-cause mortality and risk factors of death of patients with unruptured intracranial aneurysms (UIAs) in a long-term follow-up study.

METHODS

A total of 142 patients with 181 UIAs diagnosed between 1956 and 1978 when UIAs were not treated were included in this study. Patients were followed until death or until 2011 to 2012. Mortality rates and risk factors were studied with Kaplan-Meier survival analysis and the Cox proportional hazards regression models.

RESULTS

During 3,530 person-years, 113 (80%) had died, giving an average annual mortality of 3.2%. Of them, 19 (17%) died of aneurysm rupture from the index UIA, 6 (5%) of other aneurysm-related causes, and 2 (2%) of unspecified subarachnoid hemorrhage. The remaining 86 died of causes unrelated to intracranial aneurysms. The cumulative death rate was 20% (95% confidence interval 14%-27%) at 10 years and 60% (52%-68%) at 30 years. Independent risk factors for subsequent death were patient age (adjusted hazard ratio 1.09 per year, 95% confidence interval 1.05-1.12, p < 0.001), male sex (2.81, 1.59-4.96, p < 0.001), heavy alcohol use (4.22, 2.22-8.02, p < 0.001), and cigarette smoking (1.72, 0.97-3.07, p = 0.064). History of hypertension, family history of subarachnoid hemorrhage, and diameter of UIA predicted death only in univariable analysis.

CONCLUSIONS

In patients of working age with a UIA, alcohol consumption and cigarette smoking are modifiable risk factors for untimely death through several causes and should be taken into account when treatment is considered.

Genome-wide association study of intracranial aneurysm identifies a new association on chromosome 7

BACKGROUND AND PURPOSE

Common variants have been identified using genome-wide association studies which contribute to intracranial aneurysms (IA) susceptibility. However, it is clear that the variants identified to date do not account for the estimated genetic contribution to disease risk.

METHODS

Initial analysis was performed in a discovery sample of 2617 IA cases and 2548 controls of white ancestry. Novel chromosomal regions meeting genome-wide significance were further tested for association in 2 independent replication samples: Dutch (717 cases; 3004 controls) and Finnish (799 cases; 2317 controls). A meta-analysis was performed to combine the results from the 3 studies for key chromosomal regions of interest.

RESULTS

Genome-wide evidence of association was detected in the discovery sample on chromosome 9 (CDKN2BAS; rs10733376: P<1.0×10(-11)), in a gene previously associated with IA. A novel region on chromosome 7, near HDAC9, was associated with IA (rs10230207; P=4.14×10(-8)). This association replicated in the Dutch sample (P=0.01) but failed to show association in the Finnish sample (P=0.25). Meta-analysis results of the 3 cohorts reached statistical significant (P=9.91×10(-10)).

CONCLUSIONS

We detected a novel region associated with IA susceptibility that was replicated in an independent Dutch sample. This region on chromosome 7 has been previously associated with ischemic stroke and the large vessel stroke occlusive subtype (including HDAC9), suggesting a possible genetic link between this stroke subtype and IA.

Double-clip technique for the microneurosurgical management of very small (< 3 mm) intracranial aneurysms

BACKGROUND

The treatment of very small (≤ 3 mm) aneurysms is technically challenging. Mini-clips used for clipping these small aneurysms have a smaller closing force compared with standard clips.

OBJECTIVE

To describe the double-clip technique for very small aneurysms.

METHODS

The double-clip technique, a parallel duplication clipping technique of booster clipping, is used by the senior author for clipping very small aneurysms with morphology suitable for the application of 2 clips. The aneurysm is clipped after application of temporary clip(s), administration of adenosine, or both. An initial mini-clip is applied, leaving a small residual neck sufficient for application of the second mini-clip. A second mini-clip of the same size and shape is applied on the residual neck parallel to the initial clip. The initially applied mini-clip, which is in close contact with the second clip, supports the second clip and prevents its slippage. This technique was retrospectively reviewed over a 13-year period (1997-2009). There were 3246 patients with 4757 aneurysms treated in the same period.

RESULTS

The outcomes of 39 patients with 40 very small aneurysms clipped with the double-clip technique were analyzed. None of the patients had technique-related complications. Postoperative angiograms revealed complete aneurysm occlusion of 39 aneurysms and a small residual neck in 1 aneurysm. No parent artery obstruction was observed in the postoperative angiogram.

CONCLUSION

The double-clip technique is a safe and effective variation of booster clipping in the treatment of very small aneurysms with suitable morphology.

Lifelong Rupture Risk of Intracranial Aneurysms Depends on Risk Factors

Background and Purpose—

Our aim was to define for the first time the lifelong natural course of unruptured intracranial aneurysms (UIAs) and identify high-risk and low-risk patients for the rupture.

Methods—

One hundred and eighteen patients (61 women) with UIAs were diagnosed between 1956 and 1978 and followed up until death or subarachnoid hemorrhage (SAH). The median age at the diagnosis was 43.5 years (range, 22.6–60.7 years). The median size of the UIA at the diagnosis was 4 mm (range, 2–25 mm). Analyzed risk factors for a rupture included sex, age, cigarette smoking, systolic blood pressure values, diagnosed hypertension, UIA size, and number of UIAs.

Results—

Thirty four (29%) out of 118 people had SAH during the lifelong follow-up. The median age at SAH was 51.3 years (range, 30.1–71.8 years). The annual rupture rate per patient was 1.6%. Female sex, current smoking, and aneurysm size of ≥7 mm in diameter were risk factors for a lifetime SAH. Depending on the risk factor burden, the lifetime risk of an aneurysmal SAH varied from 0% to 100%, and the annual rupture rate from 0% to 6.5%. Of the 96 patients with small (<7 mm) UIAs, 24 (25%) had an aneurysmal SAH during the follow-up.

Conclusions—

Almost 30% of all UIAs in people of working age ruptured during a lifelong follow-up. The risk varied substantially on the basis of risk factor burden. Because even small UIAs ruptured, treatment decisions of UIAs should perhaps be based on the risk factor status.

Anatomic risk factors for middle cerebral artery aneurysm rupture: computed tomography angiography study of 1009 consecutive patients

BACKGROUND

The middle cerebral artery (MCA) is the most frequent location for unruptured intracranial aneurysms. Controversy remains as to which unruptured MCA aneurysms should be treated prophylactically.

OBJECTIVE

To identify independent topographical and morphological variables that could predict increased rupture risk of MCA aneurysms.

METHODS

A retrospective analysis of computed tomography angiography data of 1009 consecutive patients with 1309 MCA aneurysms, referred between 2000 and 2009 to Helsinki University Hospital, was carried out. Morphological and topographical parameters examined for MCA aneurysms comprised aneurysm wall regularity, size, neck width, aspect ratio, bottleneck factor, height-width ratio, location along the MCA, side, distance from the internal carotid artery bifurcation, and dome projection in axial and coronal computed tomography angiography views. Univariate and multivariate logistic regression analyses were performed to determine independent risk factors for rupture.

RESULTS

Of the 1309 MCA aneurysms, 69% were unruptured and 31% were ruptured. Most unruptured MCA aneurysms were smaller than 7 mm (78%), with a smooth wall (80%) and a height-width ratio of 1 (47%) and were located at the main bifurcation (57%). Ruptured MCA aneurysms, mostly 7 to 14 mm in size (55%), had an irregular wall (78%) and a height-width ratio greater than 1 (72%) and were located at the main bifurcation (77%). Thirty-eight percent of MCA bifurcation aneurysms, 74% of large aneurysms, 64% of aneurysms with an irregular wall, and 49% of aneurysms with a height-width ratio greater than 1 were ruptured.

CONCLUSION

Location at the main MCA bifurcation, wall irregularity, and less spherical geometry were independently associated with rupture of MCA aneurysms with a correlation with aneurysm size. artery.

Genetic risk load according to the site of intracranial aneurysms

OBJECTIVE

We investigated whether risk alleles of single nucleotide polymorphisms associated with intracranial aneurysm (IA) are enriched in patients with familial IA, IA located at the middle cerebral artery (MCA), or IA rupture at a younger age.

METHODS

In this case-only study, we calculated genetic risk scores (GRS) for 973 Dutch and 718 Finnish patients with IA by summing effect size-weighted risk allele counts of 7 single nucleotide polymorphisms associated with IAs previously identified through genome-wide association studies. We tested the GRS for association with presence of familial IA or IA at the MCA using logistic regression, and with age at time of IA rupture using linear regression. We also calculated odds ratios with 95% confidence intervals for the proportion of patients with each characteristic in the highest compared with the lowest GRS tertile.

RESULTS

GRS were higher in IA at the MCA in the Dutch (p = 2.5 × 10(-4)), Finnish (p = 0.039), and combined cohort (p = 4.9 × 10(-5)). GRS were not associated with familial IA in the Dutch (p = 0.34), Finnish (p = 0.45), and combined cohort (p = 0.98), or with age at time of IA rupture in the Dutch (p = 0.28), Finnish (p = 0.86), and combined cohort (p = 0.45). In the combined cohort, odds ratios were 0.89 (0.67-1.20) for familial IA, 1.03 (0.79-1.34) for lower age, and 1.54 (1.20-1.98) for MCA aneurysms.

CONCLUSIONS

Our findings suggest that genetic risk factors have a larger role in the development of IA at the MCA than at other sites, and that genetic heterogeneity should be considered in future genetic studies.

Characteristics of Posterior Cerebral Artery Aneurysms

BACKGROUND:

Posterior cerebral artery (PCA) aneurysms are rare lesions. Because of their low incidence, the individual or institutional experience is usually limited.

OBJECTIVE:

To identify specific anatomic features related to PCA aneurysms based on the analyses of pretreatment angiograms.

METHODS:

We performed a detailed angiographic study of 81 patients with a diagnosis of 93 PCA aneurysms. Fifty-three patients underwent computed tomography angiography, 49 underwent digital subtraction angiography, and 6 underwent magnetic resonance angiography. Between 1980 and 2012, a total of 120 patients with 136 PCA aneurysms and 11 352 patients with 16 444 intracranial aneurysms were treated at our institutions.

RESULTS:

There were 29 ruptured and 64 unruptured PCA aneurysms. The distribution of the aneurysms along the PCA segments was P1 (n = 39; 9 ruptured), P1/P2 junction (n = 25; 9 ruptured), P2 (n = 21; 5 ruptured), and P3 (n = 8; 6 ruptured). The median aneurysm size was 7 mm for the ruptured and 4 mm for the unruptured aneurysms. Saccular aneurysms (n = 69, 74%) had a typical projection for each location: P1 segment, upward (67%); P1/P2 junction, anterior/upward (80%); P2 segment, lateral (67%); and P3 segment, posterior (50%). Multiple aneurysms were seen in 43 patients. PCA aneurysms related to arteriovenous malformations were observed in 10 patients.

CONCLUSION:

PCA aneurysms are infrequent lesions, often associated with multiple aneurysms and arteriovenous malformations and are fusiform in shape. Most ruptured PCA aneurysms are smaller than 10 mm and usually distally located. At each PCA segment, saccular PCA aneurysms have a typical dome orientation.

Bypass surgery for complex middle cerebral artery aneurysms: impact of the exact location in the MCA tree

Object

The object of this study was to describe the authors' institutional experience in the treatment of complex middle cerebral artery (MCA) aneurysms necessitating bypass and vessel sacrifice.

Methods

Cases in which patients with MCA aneurysms were treated with a combination of bypass and parent artery sacrifice were reviewed retrospectively.

Results

The authors identified 24 patients (mean age 46 years) who were treated with bypass and parent artery sacrifice. The aneurysms were located in the M1 segment in 7 patients, MCA bifurcation in 8, and more distally in 9. The mean aneurysm diameter was 30 mm (range 7–60 mm, median 26 mm). There were 8 saccular and 16 fusiform aneurysms.

Twenty-one extracranial-intracranial and 4 intracranial-intracranial bypasses were performed. Partial or total trapping (only) of the parent artery was performed in 17 cases, trapping with resection of aneurysm in 3, and aneurysm clipping with sacrifice of an M2 branch in 4.

The mean follow-up period was 27 months. The aneurysm obliteration rate was 100%. No recanalization of the aneurysms was detected during follow-up.

There was 1 perioperative death (4% mortality rate) and 6 cerebrovascular accidents, causing permanent morbidity in 5 patients. The median modified Rankin Scale score of patients with an M1 aneurysm increased from 0 preoperatively to 2 at latest follow-up, while the score was unchanged in other patients. Most of the permanent deficits were associated with M1 aneurysms. Twenty-one patients (88%) had good outcome as defined by a Glasgow Outcome Scale score of 4 or 5.

Conclusions

Bypass in combination with parent vessel occlusion is a useful technique with acceptable frequencies of morbidity and mortality for complex MCA aneurysms when conventional surgical or endovascular techniques are not feasible. The location of the aneurysm should be considered when planning the type of bypass and the site of vessel occlusion. Flow alteration by partial trapping may be preferable to total trapping for the M1 aneurysms.

High risk population isolate reveals low frequency variants predisposing to intracranial aneurysms

3% of the population develops saccular intracranial aneurysms (sIAs), a complex trait, with a sporadic and a familial form. Subarachnoid hemorrhage from sIA (sIA-SAH) is a devastating form of stroke. Certain rare genetic variants are enriched in the Finns, a population isolate with a small founder population and bottleneck events. As the sIA-SAH incidence in Finland is >2× increased, such variants may associate with sIA in the Finnish population. We tested 9.4 million variants for association in 760 Finnish sIA patients (enriched for familial sIA), and in 2,513 matched controls with case-control status and with the number of sIAs. The most promising loci (p<5E-6) were replicated in 858 Finnish sIA patients and 4,048 controls. The frequencies and effect sizes of the replicated variants were compared to a continental European population using 717 Dutch cases and 3,004 controls. We discovered four new high-risk loci with low frequency lead variants. Three were associated with the case-control status: 2q23.3 (MAF 2.1%, OR 1.89, p 1.42×10-9); 5q31.3 (MAF 2.7%, OR 1.66, p 3.17×10-8); 6q24.2 (MAF 2.6%, OR 1.87, p 1.87×10-11) and one with the number of sIAs: 7p22.1 (MAF 3.3%, RR 1.59, p 6.08×-9). Two of the associations (5q31.3, 6q24.2) replicated in the Dutch sample. The 7p22.1 locus was strongly differentiated; the lead variant was more frequent in Finland (4.6%) than in the Netherlands (0.3%). Additionally, we replicated a previously inconclusive locus on 2q33.1 in all samples tested (OR 1.27, p 1.87×10-12). The five loci explain 2.1% of the sIA heritability in Finland, and may relate to, but not explain, the increased incidence of sIA-SAH in Finland. This study illustrates the utility of population isolates, familial enrichment, dense genotype imputation and alternate phenotyping in search for variants associated with complex diseases.

Anatomy and morphology of giant aneurysms--angiographic study of 125 consecutive cases

BACKGROUND

Giant intracranial aneurysms are rare and heterogeneous lesions with complex vascular anatomy. The aim of this retrospective study was to provide a comprehensive description of the anatomical features of giant aneurysms.

METHODS

We identified 125 patients with 129 giant aneurysms (≥ 25 mm) who were treated between 1987 and 2007 at the Department of Neurosurgery of Helsinki University Central Hospital (HUCH). All the imaging studies and medical records were reviewed for relevant information.

RESULTS

The distribution of the giant aneurysms among regions was as follows: internal carotid artery (ICA) 39%, middle cerebral artery (MCA) 32%, vertebrobasilar and posterior cerebral artery (VB-PCA) region 25%, and anterior cerebral artery (ACA) including the anterior communicating artery 5%. The cavernous ICA segment (n = 21, 16%) and the MCA bifurcation (n = 25, 19%) were the most frequent specific locations. Half (n = 11) of all fusiform aneurysms were found in the VB-PCA region. As many as 41 % of the giant MCA aneurysms were ruptured. Major anatomic variations were found in three (2%) and multiple giant aneurysms in three (2%) patients. Wall calcification was noted in 24% and intraluminal thrombosis in 33% of ruptured giant aneurysms (n = 42).

CONCLUSIONS

The majority of giant aneurysms are located in the ICA and MCA regions, while the ACA region is an exceptional site. The MCA region is the most common site for ruptured giant aneurysms. Associated anatomic variations and the multiplicity of giant aneurysms are a rare finding.

Focused opening of the sylvian fissure for microsurgical management of MCA aneurysms

BACKGROUND

A wide sylvian opening, with either a proximal or distal start, has been standard for microsurgical management of middle cerebral artery (MCA) aneurysms. However, extensive sylvian dissection is potentially associated with increased incidence of iatrogenic injury to the brain and neurovascular structures. The aim of the present study was to describe the technique of focused opening of the sylvian fissure for microsurgical management of MCA aneurysms with additional tips on handling difficulties which may be encountered with this technique.

METHOD

A 3D image-based anatomic orientation, clipping field-focused surgical planning, slack brain, and high magnification are the basic requirements for this approach. A 10-15 mm sylvian opening is placed so that it allows safe access and a good surgical view of the MCA aneurysm clipping field. Under proximal control of the MCA, the aneurysm neck can be dissected and clipped effectively and safely, in this small surgical field.

RESULTS

The presented technique has been developed and refined by the senior author during the surgery of 1,097 aneurysms over the last 13 years. It has proved to be safe, and effective for clipping of both ruptured and unruptured MCA aneurysms. Its greatest advantages are a shorter operative time and less brain and vessel manipulation compared to more extensive approaches.

CONCLUSION

The focused sylvian opening is a less-invasive alternative to the classical wide sylvian opening for the microsurgical management of most MCA aneurysms.

Prospective flutemetamol positron emission tomography and histopathology in normal pressure hydrocephalus

BACKGOUND/OBJECTIVE: To determine the level of association between uptake of the amyloid positron emission tomography (PET) imaging agent [(18)F]flutemetamol and the level of amyloid-β measured by immunohistochemical and histochemical staining in a frontal cortical region biopsy site.

METHODS

Seventeen patients with probable normal pressure hydrocephalus (NPH) underwent prospective [(18)F]flutemetamol PET and subsequent frontal cortical brain biopsy during ventriculoperitoneal shunting. Tissue amyloid-β was evaluated using the monoclonal antibody 4G8, thioflavin S and Bielschowsky silver stain.

RESULTS

Four of the 17 patients (23.5%) had amyloid-β pathology based on the overall pathology read and also showed increased [(18)F]flutemetamol uptake. [(18)F]Flutemetamol standardized uptake values from the biopsy site were significantly associated with biopsy specimen amyloid-β levels (Pearson's r = 0.67; p = 0.006). There was also good correlation between the biopsy specimen amyloid-β level and uptake of [(18)F]flutemetamol in the region contralateral to the biopsy site (r = 0.67; p = 0.006), as well as with composite cortical [(18)F]flutemetamol uptake (r = 0.65; p = 0.008). The blinded visual read showed a high level of agreement between all readers (κ = 0.88). Two of 3 readers were in full agreement on all images; 1 reader disagreed on 1 of the 17 NPH cases. Blinded visual assessments of PET images by 1 reader were associated with 100% sensitivity to the overall pathology read, and assessments by the 2 others were associated with 75% sensitivity (overall sensitivity by majority read was 75%); specificity of all readers was 100%.

CONCLUSIONS

[(18)F]Flutemetamol detects brain amyloid-β in vivo and shows promise as a valuable tool to study and possibly facilitate diagnosis of Alzheimer's disease both in patients with suspected NPH and among the wider population.

De Novo and Recurrent Aneurysms in Pediatric Patients With Cerebral Aneurysms

Background and Purpose—

Long-term angiographic follow-up studies on pediatric aneurysm patients are scarce.

Methods—

We gathered long-term clinical and angiographic follow-up data on all pediatric aneurysm patients (≤18 years at diagnosis) treated at the Department of Neurosurgery, Helsinki University Central Hospital, between 1937 and 2009.

Results—

Fifty-nine patients with cerebral aneurysms in childhood had long-term clinical and radiological follow-up (median, 34 years; range, 4–56 years). Twenty-four patients (41%) were diagnosed with altogether 25 de novo and 11 recurrent aneurysms, with 9 (25%) of the aneurysms being symptomatic. New subarachnoid hemorrhage occurred in 7 patients; 4 of these patients died. Eight patients (33%) had multiple new aneurysms. The annual rate of hemorrhage was 0.4%, and the annual rate for the development of de novo or recurrent aneurysm was 1.9%. There were no de novo aneurysms in 7 patients with previously unruptured aneurysms. However, 1 recurrent aneurysm was diagnosed. Current and previous smoking (risk ratio, 2.44; 95% confidence interval, 1.07–5.55) was the only statistically significant risk factor for de novo and recurrent aneurysm formation in patients with previous subarachnoid hemorrhage, whereas hypertension, sex, or age at onset had no statistically significant effect. Smoking was also a statistically significant risk factor for new subarachnoid hemorrhage.

Conclusions—

Patients with ruptured intracranial aneurysms in childhood have a high risk for new aneurysms and new subarachnoid hemorrhage, especially if they start to smoke as adults. Life-long angiographic follow-up is mandatory.

A New, More Accurate Classification of Middle Cerebral Artery Aneurysms

BACKGROUND:

Classification of middle cerebral artery (MCA) aneurysms is sometimes difficult because the identification of the main MCA bifurcation, the key for accurate classification of MCA aneurysms, is inconsistent and somewhat subjective.

OBJECTIVE:

To use the meeting point of the M1 and M2 trunks as an objective, generally accepted, and angiographically evident hallmark for identification of MCA bifurcation and more accurate classification of MCA aneurysms.

METHODS:

We reviewed the computed tomographic angiography data of 1009 consecutive patients with 1309 MCA aneurysms. The M2 trunks were followed proximally until their meeting with the M1 trunk at the main MCA bifurcation. The aneurysms were classified according to their relative location: proximal, at, or distal to the MCA bifurcation. The M1 aneurysms were further subgrouped into M1 early cortical branch aneurysms and M1 lenticulostriate artery aneurysms, extending the classic 3-group classification of MCA aneurysms into a 4-group classification.

RESULTS:

The main MCA bifurcation was the most common location for MCA aneurysms, harboring 829 aneurysms (63%). The 406 M1 aneurysms comprised 242 M1 early cortical branch aneurysms (60%) and 164 M1 lenticulostriate artery aneurysms (40%). We found 106 MCA aneurysms (8%) at the origin of large early frontal branches simulating M2 trunks liable to be misclassified as MCA bifurcation aneurysms. Even though 51% of the 407 ruptured MCA aneurysms were associated with an intracerebral hematoma, this did not affect the classification.

CONCLUSION:

Studying MCA angioarchitecture and applying the 4-group classification of MCA aneurysms is practical and facilitates the accurate classification of MCA aneurysms, helping to improve surgical outcome.

Long-term excess mortality in pediatric patients with cerebral aneurysms

BACKGROUND AND PURPOSE

Knowledge of the long-term excess mortality in pediatric aneurysm patients is lacking. The aim of this study was to assess the long-term excess mortality of 102 pediatric patients with cerebral aneurysm treated at the department of neurosurgery at Helsinki University Central Hospital between 1937 and 2009.

METHODS

Patients were followed from diagnosis until death or the end of the year 2010. Relative survival ratio provided the measure of excess mortality in these patients compared with mortality of the general Finnish population matched by age, sex, and calendar time.

RESULTS

A majority of the patients (n=89) presented with subarachnoid hemorrhage. Aneurysms (n=118) were treated operatively (n=79), endovascularly (n=1), or conservatively (n=36). The mean follow-up time was 26.8 years (range, 0-55.6 years). By the end of follow-up, 34 of the 102 patients had died; 26 of these deaths (76%) were aneurysm-related. There was overall excess mortality of 10% (cumulative relative survival ratio, 0.90; 95% CI, 0.80-0.96) and 19% (cumulative relative survival ratio, 0.81; 95% CI, 0.66-0.91) at 20 and 40 years after the diagnosis among the 1-year subarachnoid hemorrhage survivors, respectively. The excess mortality was particularly high in boys. There was no long-term excess mortality among patients with unruptured aneurysms. Aneurysm-related deaths included rebleedings from open or partially occluded aneurysms, epileptic seizures, de novo and recurrent aneurysms, or sequelae of subarachnoid hemorrhage.

CONCLUSIONS

There is long-term excess mortality in pediatric patients with aneurysm even decades after successful treatment of a ruptured aneurysm, especially among boys. The excess mortality is mainly aneurysm-related.