Unruptured Saccular Aneurysms Research Articles

Intracranial Aneurysms: Midterm Outcome of Pipeline Embolization Device—A Prospective Study in 143 Patients with 178 Aneurysms

To evaluate the midterm clinical and angiographic outcomes after pipeline embolization device (PED) placement for treatment of intracranial aneurysms. This prospective nonrandomized multicenter study was approved by the review boards of all involved centers; informed consent was obtained. Patients (143 patients, 178 aneurysms) with unruptured saccular or fusiform aneurysms or recurrent aneurysms after previous treatment were included and observed angiographically for up to 18 months and clinically for up to 3 years. Study endpoints included complete aneurysm occlusion; neurologic complications within 30 days and up to 3 years; clinical outcome of cranial nerve palsy after PED placement; angiographic evidence of occlusion or stenosis of parent artery and that of occlusion of covered side branches at 6, 12, and 18 months; and clinical and computed tomographic evidence of perforator infarction. There were five (3.5%) cases of periprocedural death or major stroke (modified Rankin Scale [mRS] > 3) (95% confidence interval [CI]: 1.3%, 8.4%), including two posttreatment delayed ruptures, two intracerebral hemorrhages, and one thromboembolism. Five (3.5%) patients had minor neurologic complications within 30 days (mRS = 1) (95% CI: 1.3%, 8.4%), including transient ischemic attack (n = 2), small cerebral infarction (n = 2), and cranial nerve palsy (n = 1). Beyond 30 days, there was one fatal intracerebral hemorrhage and one transient ischemic attack. Ten of 13 patients (95% CI: 46%, 93.8%) completely recovered from symptoms of cranial nerve palsy within a median of 3.5 months. Angiographic results at 18 months revealed a complete aneurysm occlusion rate of 84% (49 of 58; 95% CI: 72.1%, 92.2%), with no cases of parent artery occlusion, parent artery stenosis (<50%) in three patients, and occlusion of a covered side branch in two cases (posterior communicating arteries). Perforator infarction did not occur. PED placement is a reasonably safe and effective treatment for intracranial aneurysms. The treatment is promising for aneurysms of unfavorable morphologic features, such as wide neck, large size, fusiform morphology, incorporation of side branches, and posttreatment recanalization, and should be considered a first choice for treating unruptured aneurysms and recurrent aneurysms after previous treatments. http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120422/-/DC1.

Fusiform aneurysms of the vertebral artery: A hidden cause of exertional headache?

There is only one reported case of recurrent coital headache related to an unruptured saccular aneurysm of the carotid artery. We report on two cases of isolated recurrent coital/exertional headaches ipsilateral to unruptured fusiform aneurysms of the vertebral artery diagnosed by CT angiography. While one case is being managed conservatively, a vertebral stent has been set in the other. CT angiography with full visualisation of intracranial and upper cervical arteries could be used as a screening diagnostic procedure in these cases. Together with saccular aneurysms, fusiform aneurysms should be added to the IHS classification as aetiology for exertional recurrent headaches.

The safety of anticoagulation in patients with intracranial aneurysms

Background and purposeLittle is known about the safety of long-term anticoagulation in patients with unruptured saccular intracranial aneurysms, although case reports of anticoagulation in patients with fusiform and saccular aneurysms...

Comparison of hemodynamics in small, medium and large unruptured lateral intracranial saccular aneurysms at the internal carotid artery

Objective To explore and compare the hemodynamic factors in small,medium and large unruptured lateral intracranial saccular aneurysms at the Internal Carotid Artery.Method 27 patient -specific unruptured lateral intracranial saccular aneurysms at the Internal Carotid Artery were divided into small,medium and large groups based on their diameters.Results models were retrospectively constructed and analyzed by computational fluid dynamic(CFD) method.Results All these three groups displayed typical lateral aneurismal flow patterns.Larger - sized group displayed more unstable flow patterns,significantly lower wall shear stress(WSS) and higher oscillatory shear index( OSI ).Conclusions These observations indicated that more unstable flow patterns,lower WSS and higher OSI in the aneurysms might be involved in increasing the risk of rupture for larger - sized unruptured lateral intracranial saccular aneurysms. Key words: Intracranial aneurysms; Lateral type; Hemodynamics; Computational fluid dynamics; Size

Cerebral aneurysm wall thickness analysis using intraoperative microscopy: effect of size and gender on thin translucent regions

ObjectiveWall thickness is a poorly documented characteristic of cerebral aneurysms which may provide insight into adaptive aneurysmal growth, aneurysm rupture risk and response to endovascular treatment. The distribution of aneurysm...

Angiographic CT with Intravenous Contrast Injection Compared with Conventional Rotational Angiography in the Diagnostic Work-Up of Cerebral Aneurysms

Noninvasive imaging of cerebral aneurysms is still considered inferior to conventional angiography. The purpose of this study was to evaluate the diagnostic accuracy of ivACT in the assessment of intracranial aneurysms compared with 3D-DSA. We included 13 patients with 15 incidental unruptured saccular aneurysms scheduled for diagnostic angiographic work-up in our study. In each patient, we performed an ivACT and a conventional angiography including a 3D rotational run. During postprocessing, MPR images were generated for each technique. Maximal aneurysm diameter, neck diameter, aneurysm height, maximum width, bulge height, parent artery diameter, and angle between the parent artery and aneurysm apex were measured for each aneurysm. 3D-DSA and ivACT both provided images of high quality without artificial disturbances (ie, motion artifacts). Measurements of all parameters resulted in comparable values for both modalities with a strong correlation (P ≤ .001). ivACT is feasible for the noninvasive visualization of saccular cerebral aneurysms and may provide reliable diagnostic information for the assessment of aneurysm size and geometry comparable with conventional intra-arterial 3D rotational angiography. These preliminary results might be a first promising step to replacing conventional angiography in preinterventional aneurysm imaging.

Gender Differences in Cerebral Aneurysm Location

Background and Purpose: A limited number of studies consisting predominantly of ruptured aneurysms have looked at differences in anatomical distribution of aneurysms between male and females. Unlike all other causes of stroke, subarachnoid hemorrhages (SAH) occur more often in women and are thought to be a result of both hormonal influences and variation in wall shear stress. This paper retrospectively looks at a cohort of largely unruptured intracranial aneurysms to determine if there exists a gender discrepancy in the anatomic distribution of cerebral aneurysms. Methods: A retrospective review of consecutive patients with ruptured and unruptured intradural saccular cerebral aneurysms treated endovascularly was performed. Results: Six hundred eighty-two aneurysms were treated. Seventy-two percentage of the patients were women and 27% of patients presented with SAH. Among women, most aneurysms were located along the ICA (54%) while men the ACA (29%, compared to 15% in women), a discrepancy evident in both unruptured and ruptured groups. Females tended to present later in life (59 vs. 55 years), with multiple aneurysms (11 vs. 6% in men), and with SAH (28 vs. 23% in men) – the majority of these ruptured aneurysms were located at the ICA (42%), while men at the ACA (47%). Additionally, the majority (68%) of ruptured ICA aneurysms were PCOM. Conclusion: Understanding the natural history of aneurysms is imperative in treating incidentally found aneurysms. Significant differences exist between the genders in relation to aneurysm location, the most pronounced at the ICA and ACA. Previously described hormonal and hemodynamic theories behind cerebral aneurysm pathogenesis seem like plausible reasons to explain these differences.

Comparison of clinical characteristics and MR angiography appearance in patients with spontaneous intradural vertebral artery dissection with or without subarachnoid hemorrhage

It is well known that spontaneous intradural vertebral artery dissection (siVAD) is an important cause of nontraumatic subarachnoid hemorrhage (SAH). The factors that influence whether SAH develops, however, remain unclear. The aim of this study was to investigate whether clinical characteristics and imaging findings are different in patients with siVAD with SAH compared to those with siVAD without SAH. The authors conducted a retrospective, single-institution study involving patients in whom siVAD developed with or without SAH, between July 2003 and November 2010. Univariate and multivariate analyses were performed to evaluate clinical characteristics and MR angiography findings. The vertebral-union-basilar angle (VUBA) was defined as the most acute angle between line of the basilar artery trunk and line of the vertebral angle (VA) at the vertebral union on 3D MR angiograms. Among 58 patients with siVAD, 21 developed SAH. The presence of siVAD and SAH was significantly associated with higher rates of current smoking (OR 13; 95% CI 3.6-38; p < 0.0001), dissection of the dominant VA (OR 9.2; 95% CI 2.5-19; p = 0.0004), and unruptured supratentorial nondissecting saccular aneurysms (OR 11; 95% CI 2.1-19; p = 0.0025), and the VUBA of the dominant VA was significantly larger (p < 0.0001, univariate analysis). Multivariate analysis showed that these differences were still significant (p < 0.05). A larger VUBA of the dominant VA, the presence of unruptured supratentorial nondissecting saccular aneurysms, and current smoking may be factors that predict which patients with siVAD will develop SAH by dominant VAD.

Unruptured Intracranial Aneurysms

Backgrounds and Purpose- The authors evaluated the incidence of rupture of unruptured intracranial saccular aneurysm during observation. Between January 2003 and December 2006, a total of 419 patients with 529 unruptured intracranial saccular aneurysms were observed without treatment. The mean follow-up duration was 905.3 days. Aneurysm size was measured by 3-dimensional CT angiography. Clinical and 3-dimensional CT angiography follow-up were obtained every 6 months. Nineteen aneurysms ruptured during observation resulting in a 1.4% rupture rate per year. A history of subarachnoid hemorrhage (hazard ratio, 7.3; 95% CI, 2.5 to 21.2), posterior circulation aneurysm (hazard ratio, 2.9; 95% CI, 1.1 to 8), and large size were significant independent predictors for aneurysm rupture. Size, history of subarachnoid hemorrhage, and posterior circulation aneurysms were significant risk factors for prediction of rupture of unruptured intracranial saccular aneurysms.

Cerebral Saccular Aneurysm Rupture After Head Injury

When seen after head trauma, subarachnoid hemorrhage (SAH) often leads to an angiogram to look for vascular injury. Usually the study is negative; sometimes a traumatic aneurysm or dissection is seen. Occasionally, a conventional saccular aneurysm is found. The clinical history, physical examination, and computed tomography (CT) scan in such a patient may suggest that an aneurysmal SAH was the primary event, with the trauma resulting from SAH-associated incapacity. But this scenario is not usually apparent and, if a saccular cerebral aneurysm is found on angiogram after a patient has been injured, it is often difficult to know if the aneurysm is incidental, caused the SAH and trauma, or bled as a result. Most traumatic aneurysms in the carotid distribution are located at the base of the skull and are associated with skull fractures. Those located inside the cranium proper that result from nonpenetrating injury are less often linked to skull fractures. They are likely caused by contusion of the vessel, in which there is stretching or torsion of the wall. By analogy, similar forces acting on the wall of pre-existing cerebral aneurysms should cause some to bleed. Given a conservative estimate that 2% of the population harbors unruptured saccular aneurysms, a certain percentage of traumatic SAH must be caused by trauma-induced aneurysmal rupture. A couple of published case reports have verified this mechanism, though the intensity of the trauma in these cases was quite severe. The case presented here suggests that, if SAH is seen after trauma in a pattern suggestive of aneurysmal rupture, there should be a low threshold for looking for and treating “nontraumatic” saccular aneurysms. Mild to moderate trauma should not exclude such consideration.

Estrogen-TNF interactions and vascular inflammation

cardiovascular disease (CVD), especially coronary heart disease (CHD), is by far the leading cause of death in women ([29][1], [40][2]). As the prevalence of these diseases increases after menopause, much effort has been devoted to determining whether endogenous estrogen confers a protective effect

Intracranial Aneurysm Associated with Perianeurysmal Fat Tissue Lesion and Parenchymal Cystic Changes

The purpose of this report is to describe the seven-year clinical and neuroradiological follow-up of a perianeurysmal fatty lesion and perianeurysmal parenchymal cystic changes accompanying an asymptomatic unruptured wide-neck saccular aneurysm of the right middle cerebral artery trifurcation incidentally discovered in a 27-year-old male. The possible mechanisms of development are discussed. Notably, the close anatomical association between the two malformative lesions should rule out an incidental coexistence. Possible explanations include i) congenital structural deficiency of the cerebral vessel wall occurring at the same time of the formation of the fatty lesion, ii) fatty lesion inducing degeneration of the cerebral vessel wall possibly by limiting the nutrition of the smooth muscle cells, and iii) fatty lesion secreting some factors inducing weakness of the arterial wall to hemodynamic stress. Finally, both these lesion should lead to further impairment of perforating arteries resulting in areas of perianeurysmal encephalomalacia.

Advances in endovascular aneurysm treatment: are we making a difference?

Recent advancements in endovascular aneurysm repair, including bioactive and expansile coils and intracranial stents, hold promise for improved aneurysm occlusion rates. We report the immediate and midterm clinical and angiographic outcomes of a consecutive series of patients treated since the advent of these technologies. Clinical and radiological records of 134 patients with 142 aneurysms treated between 2001 and 2004 were retrospectively evaluated by an independent neurologist. Endovascular procedures were analyzed by an independent neuroradiologist blinded to all clinical information. Seventy-two ruptured and 60 un-ruptured saccular aneurysms, nine fusiform and one post-traumatic aneurysm were treated. Matrix coils were used in 53% of saccular aneurysms and HydroCoils in 13% of all aneurysms. Neuroform stents were deployed in 19% of aneurysms. Angiographic total or subtotal occlusion was achieved in 76% of cases and in 96% at last follow-up. Aneurysm recanalization was observed in 14% over a mean follow-up of 12 months, and 18% of aneurysms were retreated. Clinically relevant complications occurred in 6.0%, resulting in procedure-related morbidity of 0.6% and 0.6% mortality at 6 months. No aneurysm bled over a cumulative 1,347 months of observation. Newer embolization technologies can be exploited successfully even in more complex aneurysms with very low morbidity and mortality.

Headache attributed to unruptured saccular aneurysm, mimicking hemicrania continua

Unruptured cerebral arterial aneurysms most often remain asymptomatic, but they may cause headache or other symptoms or signs. We describe herewith a case of headache attributed to an unruptured nternal carotid artery aneurysm, clearly mimicking the phenotype of hemicrania continua. Potential pathophysiological explanations and recommendations for recognition of similar cases are discussed.

Clinical Features of Aneurysms of the Posterior Cerebral Artery: A 15-year Experience with 21 Cases

To investigate the characteristic clinical behavior and develop guidelines for the clinical management of posterior cerebral artery aneurysms, we reviewed 21 cases treated during a 15-year period. Between 1988 and 2002, we treated 21 patients (10 male, 11 female; mean age, 49.8 yr) with posterior cerebral artery aneurysms at Kumamoto University Hospital and its affiliated hospitals. Data relating to the clinical, radiological, and surgical approaches were analyzed. There were 20 saccular aneurysms, 6 of which were giant or large aneurysms, and 1 dissecting aneurysm. Of the 21 patients, 15 presented with subarachnoid hemorrhage; in 3 patients, an unruptured saccular aneurysm was found incidentally during an evaluation for other cerebral pathological conditions. Two patients presented with progressive homonymous hemianopsia because of the mass effect of the aneurysm, and 1 patient experienced the sudden onset of homonymous hemianopsia because of thrombosis of the aneurysm and afferent artery. Open or endovascular surgery was performed in 19 patients: 14 made a good recovery, 2 had a moderate disability because of angiospasm or infarction after aneurysm trapping, 1 had a severe disability because of angiospasm and cerebral contusion, and 2 died because of severe angiospasm. Of 2 conservatively treated patients, 1 made a good recovery but the other died as a result of rebleeding. Posterior cerebral artery aneurysms have specific clinical characteristics compared with aneurysms located elsewhere. The aneurysmal site and size and the surgical technique did not significantly influence treatment outcomes.

The presence of tandem endothelial nitric oxide synthase gene polymorphisms identifying brain aneurysms more prone to rupture

It is becoming apparent that the presence of certain genetic variations (polymorphisms) may increase the individual's susceptibility to cardiovascular diseases, even in the absence of a family history. We hypothesized that brain aneurysms more prone to rupture may be identified on the basis of an individual's genotype for endothelial nitric oxide synthase (eNOS), a critical vasomodulatory protein found to be increasingly relevant to the pathobiology of aneurysms. Patients' clinical data were recorded prospectively. Genomic DNA was isolated from blood samples obtained from individuals presenting consecutively to the Mayo Clinic with ruptured (58 patients) or unruptured (49 patients) intracranial saccular aneurysms. Using polymerase chain reaction and gene microarray technology, the following eNOS genetic polymorphisms were studied: intron-4 27-base pair variable number of tandem repeats (27 VNTR); promoter single nucleotide polymorphism (T-786C SNP); and exon-7 SNP (G894T SNP). Both groups of patients had similar demographic and clinical characteristics. For all three polymorphisms, variant alleles (p < or = 0.003) and their corresponding genotypes (p < or = 0.006) were found two to four times more frequently in patients with ruptured aneurysms than in patients with unruptured aneurysms. Strikingly, the odds ratio for presenting with a ruptured brain aneurysm among individuals demonstrating the copresence of all three variant alleles was 11.4 (95% confidence interval 1.7-75.9, p = 0.004). The authors have uniquely identified a set of tandem eNOS gene variations whose presence can be used to identify patients with aneurysms likely to rupture. We believe that if this finding is reproducible in a large multicenter study, in addition to known anatomical factors a rapid and cost-effective screening tool will become available to clinicians as a genetic aid to predict the risks of rupture in patients presenting with unruptured intracranial aneurysms.

Stratification of outcome for surgically treated unruptured intracranial aneurysms.

The combination of low anticipated rupture rates for many unruptured aneurysms, better delineation of treatment risks, and the availability of alternative modalities of treatment have led to heightened scrutiny of the surgical management of unruptured intracranial aneurysms. Most reports to date have provided aggregate data concerning surgical treatment risks. This study was performed to better delineate risk estimates for the surgical treatment of patients with unruptured intracranial aneurysms according to a patient's risk profile with regard to age, aneurysm location, and aneurysm size. We studied 493 patients who were treated with surgical clipping of 604 unruptured saccular aneurysms. Information regarding aneurysm size, location, patient age, and 6-month or greater outcome were gathered prospectively from 1992 to 1999. Multivariate analysis was performed to identify independent risk factors for outcome. On the basis of the model, risk stratification curves were generated. In our series, the mean patient age was 53 years, and the mean lesion size was 8.8 mm. Lesion locations included the internal carotid artery (n = 259, 43%), the middle cerebral artery (n = 174, 28%), the anterior cerebral artery (n = 99, 17%), and the vertebrobasilar artery (n = 67, 11%). Multivariate analysis revealed that aneurysm size (beta = 0.122, P < 0.001), patient age (beta = 0.0308, P < 0.05), and vertebrobasilar location (beta = 1.37, P = 0.0080) were independently associated with high risk of poor outcome or death. Small aneurysms in the anterior circulation in young patients carry a very low treatment risk (approximately 1%), and treatment in elderly individuals (ages 70 years and older) with large lesions (greater than 10 mm), carries a significant risk of poor outcome (5% in the anterior circulation, 15% in the posterior circulation). The nomograms generated by this study should be particularly useful in discussing with patients the risks and benefits of surgical treatment of unruptured aneurysms.

Stratification of Outcome for Surgically Treated Unruptured Intracranial Aneurysms

OBJECT The combination of low anticipated rupture rates for many unruptured aneurysms, better delineation of treatment risks, and the availability of alternative modalities of treatment have led to heightened scrutiny of the surgical management of unruptured intracranial aneurysms. Most reports to date have provided aggregate data concerning surgical treatment risks. This study was performed to better delineate risk estimates for the surgical treatment of patients with unruptured intracranial aneurysms according to a patient’s risk profile with regard to age, aneurysm location, and aneurysm size. METHODS We studied 493 patients who were treated with surgical clipping of 604 unruptured saccular aneurysms. Information regarding aneurysm size, location, patient age, and 6-month or greater outcome were gathered prospectively from 1992 to 1999. Multivariate analysis was performed to identify independent risk factors for outcome. On the basis of the model, risk stratification curves were generated. RESULTS In our series, the mean patient age was 53 years, and the mean lesion size was 8.8 mm. Lesion locations included the internal carotid artery (n = 259, 43%), the middle cerebral artery (n = 174, 28%), the anterior cerebral artery (n = 99, 17%), and the vertebrobasilar artery (n = 67, 11%). Multivariate analysis revealed that aneurysm size (β = 0.122, P < 0.001), patient age (β = 0.0308, P < 0.05), and vertebrobasilar location (β = 1.37, P = 0.0080) were independently associated with high risk of poor outcome or death. CONCLUSION Small aneurysms in the anterior circulation in young patients carry a very low treatment risk (approximately 1%), and treatment in elderly individuals (ages 70 years and older) with large lesions (greater than 10 mm), carries a significant risk of poor outcome (5% in the anterior circulation, 15% in the posterior circulation). The nomograms generated by this study should be particularly useful in discussing with patients the risks and benefits of surgical treatment of unruptured aneurysms.

Aneurysm observation versus intervention: A literature review

Aneurysmal subarachnoid hemorrhage (SAH) is a devastating illness that affects persons at the peaks of their lives. The 1990s witnessed rapid growth in noninvasive vascular imaging technologies, which allowed safe diagnosis of unruptured saccular intracranial aneurysms. Presently, it is unclear who will benefit from screening. Mass screening is neither feasible nor cost-effective. The current literature suggests that persons in a family with two or more relatives with a history of SAH are most likely to benefit from screening. Individuals with a history of SAH, with aneurysms greater than 10 mm in diameter or with symptomatic aneurysms are clearly at increased risk for SAH. These aneurysms should be treated, though the method of treatment remains open to question. Treatment of older patients or those with smaller aneurysms has been modeled by decision analysis, but has yet to be verified in a prospective clinical trial. Future directions for aneurysm management are explored. [Neurol Res 2002; 24: S84-S95]

Risk of subarachnoid hemorrhage after surgical treatment of unruptured cerebral aneurysms.

Recent progress in noninvasive imaging techniques has resulted in increased detection of unruptured aneurysms. Although many neurosurgeons advocate surgical intervention for such unruptured aneurysms, the long-term results of surgery for unruptured aneurysms have not been carefully investigated. We analyzed 173 consecutive patients who had unruptured intracranial saccular aneurysm(s) detected by angiography that was performed for reasons other than subarachnoid hemorrhage (SAH). Of those, 115 cases were surgically treated and studied. All patients were followed up for either SAH, repeat treatment of aneurysms, or death. The median follow-up period was 8.8 years. Four of the 115 patients suffered SAH either from a de novo aneurysm (2) or from regrowth of clipped aneurysm (1), or from regrowth after wrapping (1). Additionally, 1 patient also suffered SAH from an unstudied basilar aneurysm. One patient was incidentally found to have de novo aneurysm and underwent reoperation 14 years after the first operation. The cumulative risk for SAH for the 114 cases excluding the basilar aneurysm case was 1.4% in 10 years and 12.4% in 20 years. Although this study confirmed the long-term efficacy of clipping unruptured aneurysms, the risk of SAH was high compared with that in the general population, even after treatment. Considering the high mortality rate of SAH, long-term follow-up by angiography may be warranted for patients with surgically treated unruptured aneurysms.