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1.  Coil Embolization for Intracranial Aneurysms 
Executive Summary
To determine the effectiveness and cost-effectiveness of coil embolization compared with surgical clipping to treat intracranial aneurysms.
The Technology
Endovascular coil embolization is a percutaneous approach to treat an intracranial aneurysm from within the blood vessel without the need of a craniotomy. In this procedure, a microcatheter is inserted into the femoral artery near the groin and navigated to the site of the aneurysm. Small helical platinum coils are deployed through the microcatheter to fill the aneurysm, and prevent it from further expansion and rupture. Health Canada has approved numerous types of coils and coil delivery systems to treat intracranial aneurysms. The most favoured are controlled detachable coils. Coil embolization may be used with other adjunct endovascular devices such as stents and balloons.
Intracranial Aneurysms
Intracranial aneurysms are the dilation or ballooning of part of a blood vessel in the brain. Intracranial aneurysms range in size from small (<12 mm in diameter) to large (12–25 mm), and to giant (>25 mm). There are 3 main types of aneurysms. Fusiform aneurysms involve the entire circumference of the artery; saccular aneurysms have outpouchings; and dissecting aneurysms have tears in the arterial wall. Berry aneurysms are saccular aneurysms with well-defined necks.
Intracranial aneurysms may occur in any blood vessel of the brain; however, they are most commonly found at the branch points of large arteries that form the circle of Willis at the base of the brain. In 85% to 95% of patients, they are found in the anterior circulation. Aneurysms in the posterior circulation are less frequent, and are more difficult to treat surgically due to inaccessibility.
Most intracranial aneurysms are small and asymptomatic. Large aneurysms may have a mass effect, causing compression on the brain and cranial nerves and neurological deficits. When an intracranial aneurysm ruptures and bleeds, resulting in a subarachnoid hemorrhage (SAH), the mortality rate can be 40% to 50%, with severe morbidity of 10% to 20%. The reported overall risk of rupture is 1.9% per year and is higher for women, cigarette smokers, and cocaine users, and in aneurysms that are symptomatic, greater than 10 mm in diameter, or located in the posterior circulation. If left untreated, there is a considerable risk of repeat hemorrhage in a ruptured aneurysm that results in increased mortality.
In Ontario, intracranial aneurysms occur in about 1% to 4% of the population, and the annual incidence of SAH is about 10 cases per 100,000 people. In 2004-2005, about 660 intracranial aneurysm repairs were performed in Ontario.
Treatment of Intracranial Aneurysms
Treatment of an unruptured aneurysm attempts to prevent the aneurysm from rupturing. The treatment of a ruptured intracranial aneurysm aims to prevent further hemorrhage. There are 3 approaches to treating an intracranial aneurysm.
Small, asymptomatic aneurysms less than 10 mm in diameter may be monitored without any intervention other than treatment for underlying risk factors such as hypertension.
Open surgical clipping, involves craniotomy, brain retraction, and placement of a silver clip across the neck of the aneurysm while a patient is under general anesthesia. This procedure is associated with surgical risks and neurological deficits.
Endovascular coil embolization, introduced in the 1990s, is the health technology under review.
Literature Review
The Medical Advisory Secretariat searched the International Health Technology Assessment (INAHTA) Database and the Cochrane Database of Systematic Reviews to identify relevant systematic reviews. OVID Medline, Medline In-Process and Other Non-Indexed Citations, and Embase were searched for English-language journal articles that reported primary data on the effectiveness or cost-effectiveness of treatments for intracranial aneurysms, obtained in a clinical setting or analyses of primary data maintained in registers or institutional databases. Internet searches of Medscape and manufacturers’ databases were conducted to identify product information and recent reports on trials that were unpublished but that were presented at international conferences. Four systematic reviews, 3 reports on 2 randomized controlled trials comparing coil embolization with surgical clipping of ruptured aneurysms, 30 observational studies, and 3 economic analysis reports were included in this review.
Safety and Effectiveness
Coil embolization appears to be a safe procedure. Complications associated with coil embolization ranged from 8.6% to 18.6% with a median of about 10.6%. Observational studies showed that coil embolization is associated with lower complication rates than surgical clipping (permanent complication 3-7% versus 10.9%; overall 23% versus 46% respectively, p=0.009). Common complications of coil embolization are thrombo-embolic events (2.5%–14.5%), perforation of aneurysm (2.3%–4.7%), parent artery obstruction (2%–3%), collapsed coils (8%), coil malposition (14.6%), and coil migration (0.5%–3%).
Randomized controlled trials showed that for ruptured intracranial aneurysms with SAH, suitable for both coil embolization and surgical clipping (mostly saccular aneurysms <10 mm in diameter located in the anterior circulation) in people with good clinical condition:Coil embolization resulted in a statistically significant 23.9% relative risk reduction and 7% absolute risk reduction in the composite rate of death and dependency compared to surgical clipping (modified Rankin score 3–6) at 1-year.
The advantage of coil embolization over surgical clipping varies widely with aneurysm location, but endovascular treatment seems beneficial for all sites.
There were less deaths in the first 7 years following coil embolization compared to surgical clipping (10.8% vs 13.7%). This survival benefit seemed to be consistent over time, and was statistically significant (log-rank p= 0.03).
Coil embolization is associated with less frequent MRI-detected superficial brain deficits and ischemic lesions at 1-year.
The 1- year rebleeding rate was 2.4% after coil embolization and 1% for surgical clipping. Confirmed rebleeding from the repaired aneurysm after the first year and up to year eight was low and not significantly different between coil embolization and surgical clipping (7 patients for coil embolization vs 2 patients for surgical clipping, log-rank p=0.22).
Observational studies showed that patients with SAH and good clinical grade had better 6-month outcomes and lower risk of symptomatic cerebral vasospasm after coil embolization compared to surgical clipping.
For unruptured intracranial aneurysms, there were no randomized controlled trials that compared coil embolization to surgical clipping. Large observational studies showed that:
The risk of rupture in unruptured aneurysms less than 10 mm in diameter is about 0.05% per year for patients with no pervious history of SAH from another aneurysm. The risk of rupture increases with history of SAH and as the diameter of the aneurysm reaches 10 mm or more.
Coil embolization reduced the composite rate of in hospital deaths and discharge to long-term or short-term care facilities compared to surgical clipping (Odds Ratio 2.2, 95% CI 1.6–3.1, p<0.001). The improvement in discharge disposition was highest in people older than 65 years.
In-hospital mortality rate following treatment of intracranial aneurysm ranged from 0.5% to 1.7% for coil embolization and from 2.1% to 3.5% for surgical clipping. The overall 1-year mortality rate was 3.1% for coil embolization and 2.3% for surgical clipping. One-year morbidity rate was 6.4% for coil embolization and 9.8% for surgical clipping. It is not clear whether these differences were statistically significant.
Coil embolization is associated with shorter hospital stay compared to surgical clipping.
For both ruptured and unruptured aneurysms, the outcome of coil embolization does not appear to be dependent on age, whereas surgical clipping has been shown to yield worse outcome for patients older than 64 years.
Angiographic Efficiency and Recurrences
The main drawback of coil embolization is its low angiographic efficiency. The percentage of complete aneurysm occlusion after coil embolization (27%–79%, median 55%) remains lower than that achieved with surgical clipping (82%–100%). However, about 90% of coiled aneurysms achieve near total occlusion or better. Incompletely coiled aneurysms have been shown to have higher aneurysm recurrence rates ranging from 7% to 39% for coil embolization compared to 2.9% for surgical clipping. Recurrence is defined as refilling of the neck, sac, or dome of a successfully treated aneurysm as shown on an angiogram. The long-term clinical significance of incomplete occlusion following coil embolization is unknown, but in one case series, 20% of patients had major recurrences, and 50% of these required further treatment.
Long-Term Outcomes
A large international randomized trial reported that the survival benefit from coil embolization was sustained for at least 7 years. The rebleeding rate between year 2 and year 8 following coil embolization was low and not significantly different from that of surgical clipping. However, high quality long-term angiographic evidence is lacking. Accordingly, there is uncertainty about long-term occlusion status, coil durability, and recurrence rates. While surgical clipping is associated with higher immediate procedural risks, its long-term effectiveness has been established.
Indications and Contraindications
Coil embolization offers treatment for people at increased risk for craniotomy, such as those over 65 years of age, with poor clinical status, or with comorbid conditions. The technology also makes it possible to treat surgical high-risk aneurysms.
Not all aneurysms are suitable for coil embolization. Suitability depends on the size, anatomy, and location of the aneurysm. Aneurysms more than 10 mm in diameter or with an aneurysm neck greater than or equal to 4 mm are less likely to achieve total occlusion. They are also more prone to aneurysm recurrences and to complications such as coil compaction or parent vessel occlusion. Aneurysms with a dome to neck ratio of less than 1 have been shown to have lower obliteration rates and poorer outcome following coil embolization. Furthermore, aneurysms in the middle cerebral artery bifurcation are less suitable for coil embolization. For some aneurysms, treatment may require the use of both coil embolization and surgical clipping or adjunctive technologies, such as stents and balloons, to obtain optimal results.
Information from 3 countries indicates that coil embolization is a rapidly diffusing technology. For example, it accounted for about 40% of aneurysm treatments in the United Kingdom.
In Ontario, coil embolization is an insured health service, with the same fee code and fee schedule as open surgical repair requiring craniotomy. Other costs associated with coil embolization are covered under hospitals’ global budgets. Utilization data showed that in 2004-2005, coil embolization accounted for about 38% (251 cases) of all intracranial aneurysm repairs in the province. With the 2005 publication of the positive long-term survival data from the International Subarachnoid Aneursym Trial, the pressure for diffusion will likely increase.
Economic Analysis
Recent economic studies show that treatment of unruptured intracranial aneurysms smaller than 10 mm in diameter in people with no previous history of SAH, either by coil embolization or surgical clipping, would not be effective or cost-effective. However, in patients with aneurysms that are greater than or equal to 10 mm or symptomatic, or in patients with a history of SAH, treatment appears to be cost-effective.
In Ontario, the average device cost of coil embolization per case was estimated to be about $7,500 higher than surgical clipping. Assuming that the total number of intracranial aneurysm repairs in Ontario increases to 750 in the fiscal year of 2007, and assuming that up to 60% (450 cases) of these will be repaired by coil embolization, the difference in device costs for the 450 cases (including a 15% recurrence rate) would be approximately $3.8 million. This figure does not include capital costs (e.g. $3 million for an angiosuite), additional human resources required, or costs of follow-up. The increase in expenditures associated with coil embolization may be offset partially, by shorter operating room times and hospitalization stays for endovascular repair of unruptured aneurysms; however, the impact of these cost savings is probably not likely to be greater than 25% of the total outlay since the majority of cases involve ruptured aneurysms. Furthermore, the recent growth in aneurysm repair has predominantly been in the area of coil embolization presumably for patients for whom surgical clipping would not be advised; therefore, no offset of surgical clipping costs could be applied in such cases. For ruptured aneurysms, downstream cost savings from endovascular repair are likely to be minimal even though the savings for individual cases may be substantial due to lower perioperative complications for endovascular aneurysm repair.
The two Guidance documents issued by the National Institute of Clinical Excellence (UK) in 2005 support the use of coil embolization for both unruptured and ruptured (SAH) intracranial aneurysms, provided that procedures are in place for informed consent, audit, and clinical governance, and that the procedure is performed in specialist units with expertise in the endovascular treatment of intracranial aneurysms.
For people in good clinical condition following subarachnoid hemorrhage from an acute ruptured intracranial aneurysm suitable for either surgical clipping or endovascular repair, coil embolization results in improved independent survival in the first year and improved survival for up to seven years compared to surgical clipping. The rebleeding rate is low and not significantly different between the two procedures after the first year. However, there is uncertainty regarding the long-term occlusion status, durability of the stent graft, and long-term complications.
For people with unruptured aneurysms, level 4 evidence suggests that coil embolization may be associated with comparable or less mortality and morbidity, shorter hospital stay, and less need for discharge to short-term rehabilitation facilities. The greatest benefit was observed in people over 65 years of age. In these patients, the decision regarding treatment needs to be based on the assessment of the risk of rupture against the risk of the procedure, as well as the morphology of the aneurysm.
In people who require treatment for intracranial aneurysm, but for whom surgical clipping is too risky or not feasible, coil embolization provides survival benefits over surgical clipping, even though the outcomes may not be as favourable as in people in good clinical condition and with small aneurysms. The procedure may be considered under the following circumstances provided that the aneurysm is suitable for coil embolization:
Patients in poor/unstable clinical or neurological state
Patients at high risk for surgical repair (e.g. people>age 65 or with comorbidity), or
Aneurysm(s) with poor accessibility or visibility for surgical treatment due to their location (e.g. ophthalmic or basilar tip aneurysms)
Compared to small aneurysms with a narrow neck in the anterior circulation, large aneurysms (> 10 mm in diameter), aneurysms with a wide neck (>4mm in diameter), and aneurysms in the posterior circulation have lower occlusion rates and higher rate of hemorrhage when treated with coil embolization.
The extent of aneurysm obliteration after coil embolization remains lower than that achieved with surgical clipping. Aneurysm recurrences after successful coiling may require repeat treatment with endovascular or surgical procedures. Experts caution that long-term angiographic outcomes of coil embolization are unknown at this time. Informed consent for and long-term follow-up after coil embolization are recommended.
The decision to treat an intracranial aneurysm with surgical clipping or coil embolization needs to be made jointly by the neurosurgeon and neuro-intervention specialist, based on the clinical status of the patient, the size and morphology of the aneurysm, and the preference of the patient.
The performance of endovascular coil embolization should take place in centres with expertise in both neurosurgery and endovascular neuro-interventions, with adequate treatment volumes to maintain good outcomes. Distribution of the technology should also take into account that patients with SAH should be treated as soon as possible with minimal disruption.
PMCID: PMC3379525  PMID: 23074479
2.  Endovascular Treatment of Intracerebral Mycotic Aneurysm before Surgical Treatment of Infective Endocarditis 
Texas Heart Institute Journal  2004;31(2):165-167.
Mycotic aneurysms are rarely seen in patients who have infective endocarditis, and the management of these patients remains controversial. We present the case of a patient who had infective endocarditis complicated by a mycotic aneurysm of the left middle cerebral artery. There was substantial mitral regurgitation, and Streptococcus viridans was isolated from the blood samples. Dysarthria appeared during the 4th week of the antibiotic therapy, but resolved completely 8 hours after onset. The left middle cerebral artery was embolized with platinum detachable coils. On the 7th day after the radiologic intervention, the native mitral valve was replaced with a 33-mm St. Jude Medical® bileaflet mechanical mitral prosthesis. Most mycotic aneurysms show notable regression of symptoms with effective antibiotic treatment, and a very few may diminish in size. However, it is impossible to predict the response of these aneurysms to therapy. To prevent the perioperative rupture of mycotic aneurysms and intracranial hemorrhage, priority should be given to endovascular interventions to treat cerebrovascular aneurysms in patients such as ours.
PMCID: PMC427378  PMID: 15212129
Aneurysm, infected; embolization, therapeutic; endocarditis, bacterial; intracranial aneurysm/therapy; mitral valve/surgery
3.  Chest pain with ST segment elevation in a patient with prosthetic aortic valve infective endocarditis: a case report 
Acute ST-segment elevation myocardial infarction secondary to atherosclerotic plaque rupture is a common medical emergency. This condition is effectively managed with percutaneous coronary intervention or thrombolysis. We report a rare case of acute myocardial infarction secondary to coronary embolisation of valvular vegetation in a patient with infective endocarditis, and we highlight how the management of this phenomenon may not be the same.
Case presentation
A 73-year-old British Caucasian man with previous tissue aortic valve replacement was diagnosed with and treated for infective endocarditis of his native mitral valve. His condition deteriorated in hospital and repeat echocardiography revealed migration of vegetation to his aortic valve. Whilst waiting for surgery, our patient developed severe central crushing chest pain with associated anterior ST segment elevation on his electrocardiogram. Our patient had no history or risk factors for ischaemic heart disease. It was likely that coronary embolisation of part of the vegetation had occurred. Thrombolysis or percutaneous coronary intervention treatments were not performed in this setting and a plan was made for urgent surgical intervention. However, our patient deteriorated rapidly and unfortunately died.
Clinicians need to be aware that atherosclerotic plaque rupture is not the only cause of acute myocardial infarction. In the case of septic vegetation embolisation, case report evidence reveals that adopting the current strategies used in the treatment of myocardial infarction can be dangerous. Thrombolysis risks intra-cerebral hemorrhage from mycotic aneurysm rupture. Percutaneous coronary intervention risks coronary mycotic aneurysm formation, stent infections as well as distal septic embolisation. As yet, there remains no defined treatment modality and we feel all cases should be referred to specialist cardiac centers to consider how best to proceed.
PMCID: PMC3177923  PMID: 21864374
4.  Ruptured mycotic cerebral aneurysm development from pseudoocclusion due to septic embolism 
Cerebral mycotic aneurysms are rare sequelae of systemic infections that can cause profound morbidity and mortality with rupture. Direct bacterial extension and vessel integrity compromise from septic emboli have been implicated as mechanisms for formation of these lesions. We report the 5-day development of a ruptured mycotic aneurysm arising from a septic embolism that caused a focal M1 pseudoocclusion.
Case Description:
A 14-year-old girl developed acute left-sided hemiparesis while hospitalized for subacute bacterial endocarditis that was found after she presented with a 2-week history of fever, myalgia, shortness of breath, and lethargy. Mitral valve vegetations were confirmed in the setting of hemophilus bacteremia. Brain magnetic resonance (MR) imaging and angiography confirmed middle cerebral artery infarct with focal pseudoocclusion of the distal M1 segment. Given that further middle cerebral artery territory was at risk, a trial of heparin was attempted for revascularization but required discontinuation owing to hemorrhagic conversion. Decline of the patient's mental status necessitated craniectomy for decompression. Postoperatively, her mental status improved with residual left hemiparesis. On the third postoperative day (5 days after MR angiography), the patient's neurologic condition acutely declined, with development of right-sided mydriasis. Computed tomography (CT) angiography revealed a ruptured 19 × 16 mm pseudoaneurysm arising from the M1 site of the previous occlusion. Emergent coiling of aneurysm and parent vessel followed by hematoma evacuation ensued. At discharge, the patient had residual left hemiparesis but intact speech and cognition.
Focal occlusions due to septic emboli should be considered high-risk for mycotic aneurysm formation, prompting aggressive monitoring with neuroimaging and treatment when indicated.
PMCID: PMC3841922  PMID: 24340226
Cerebral aneurysm; infective endocarditis; mycotic aneurysm; septic emboli
5.  Clinical Features of Acute Subdural Hematomas Caused by Ruptured Intracranial Aneurysms 
Spontaneous acute subdural hematomas (aSDH) secondary to ruptured intracranial aneurysms are rarely reported. This report reviews the clinical features, diagnostic modalities, treatments, and outcomes of this unusual and often fatal condition.
We performed a database search for all cases of intracranial aneurysms treated at our hospital between 2005 and 2010. Patients with ruptured intracranial aneurysms who presented with aSDH on initial computed tomography (CT) were selected for inclusion. The clinical conditions, radiologic findings, treatments, and outcomes were assessed.
A total of 551 patients were treated for ruptured intracranial aneurysms during the review period. We selected 23 patients (4.2%) who presented with spontaneous aSDH on initial CT. Ruptured aneurysms were detected on initial 3D-CT angiography in all cases. All ruptured aneurysms were located in the anterior portion of the circle of Willis. The World Federation of Neurosurgical Societies grade on admission was V in 17 cases (73.9%). Immediate decompressive craniotomy was performed 22 cases (95.7%). Obliteration of the ruptured aneurysm was achieved in all cases. The Glasgow outcome scales for the cases were good recovery in 5 cases (21.7%), moderate disability to vegetative in 7 cases (30.4%), and death in 11 cases (47.8%).
Spontaneous aSDH caused by a ruptured intracranial aneurysm is rare pattern of aneurysmal subarachnoid hemorrhage. For early detection of aneurysm, 3D-CT angiography is useful. Early decompression with obliteration of the aneurysm is recommended. Outcomes were correlated with the clinical grade and CT findings on admission.
PMCID: PMC3159885  PMID: 21892397
Acute subdural hematoma; Subarachnoid hemorrhage; Intracranial aneurysm; CT angiography
6.  An overview of intracranial aneurysms 
McGill Journal of Medicine : MJM  2006;9(2):141-146.
Intracranial aneurysms are relatively common, with a prevalence of approximately 4%. Unruptured aneurysms may cause symptoms mainly due to a mass effect, but the real danger is when an aneurysm ruptures, leading to a subarachnoid hemorrhage. Most aneurysms are asymptomatic and will not rupture, but they grow unpredictably and even small aneurysms carry a risk of rupture. Intracranial aneurysms are diagnosed and monitored with imaging including intra-arterial digital subtraction angiography, computed tomography angiography, magnetic resonance angiography, and recently transcranial Doppler ultrasonograpy has been proposed as a potential modality. Treatment options include observation, endovascular coiling, and surgical clipping. This paper will review the epidemiology, pathogenesis, clinical presentation, diagnosis, natural history, and management of unruptured saccular intracranial aneurysms.
PMCID: PMC2323531  PMID: 18523626
7.  Intracranial Aneurysms: Review of Current Treatment Options and Outcomes 
Intracranial aneurysms are present in roughly 5% of the population, yet most are often asymptomatic and never detected. Development of an aneurysm typically occurs during adulthood, while formation and growth are associated with risk factors such as age, hypertension, pre-existing familial conditions, and smoking. Subarachnoid hemorrhage, the most common presentation due to aneurysm rupture, represents a serious medical condition often leading to severe neurological deficit or death. Recent technological advances in imaging modalities, along with increased understanding of natural history and prevalence of aneurysms, have increased detection of asymptomatic unruptured intracranial aneurysms (UIA). Studies reporting on the risk of rupture and outcomes have provided much insight, but the debate remains of how and when unruptured aneurysms should be managed. Treatment methods include two major intervention options: clipping of the aneurysm and endovascular methods such as coiling, stent-assisted coiling, and flow diversion stents. The studies reviewed here support the generalized notion that endovascular treatment of UIA provides a safe and effective alternative to surgical treatment. The risks associated with endovascular repair are lower and incur shorter hospital stays for appropriately selected patients. The endovascular treatment option should be considered based on factors such as aneurysm size, location, patient medical history, and operator experience.
PMCID: PMC3134887  PMID: 21779274
subarachnoid hemorrhage; aneurysms; endovascular surgery; coiling; clipping; stents; flow diversion
8.  Infective endocarditis with cerebrovascular complications: timing of surgical intervention 
Management of infective endocarditis (IE) with cerebrovascular complications is difficult due to absence of concrete evidence. These patients usually have multiple neurological deficits and the optimal timing for cardiac operation remains controversial. The aims of this study were to present cases and discuss the treatment options for IE with cerebrovascular complications. From 1998 to 2010, 51 patients underwent operations for IE at our institution. From a review of medical records, 10 patients (19.6%) with preoperative neurological complications were identified. Data on these 10 patients were analysed. Cerebrovascular complications included cerebral infarction (n = 4, 40.0%), mycotic aneurysm (n = 1, 10.0%), mycotic aneurysm plus cerebral infarction (n = 3, 30.0%), meningitis (n = 1, 10.0%) and mycotic aneurysm with cerebral haemorrhage plus meningitis (n = 1, 10.0%). Of 5 patients having mycotic aneurysms, 3 underwent clipping before cardiac operations. The mean interval from craniotomy to cardiac operations was 26.7 ± 21.8 days. A cardiac operation was performed initially on seven patients. The mean interval from the onset of neurological deficit to cardiac operation was 7.4 ± 9.8 days. The mortality rate was 10.0%. Postoperative deterioration was not observed. Management of IE with cerebrovascular complications should be based on case-by-case multidisciplinary assessment of potential risks and benefits of intracranial and cardiac operations.
PMCID: PMC3420269  PMID: 22108940
Infective endocarditis; Cerebrovascular complications; Surgical intervention
9.  Coil Embolization of Intracranial Aneurysm in Polyarteritis Nodosa 
Interventional Neuroradiology  2013;19(2):203-208.
Polyarteritis nodosa (PAN) is a rare multisystem disease characterized by systemic necrotizing arteritis of small and medium size arteries. The skin, joints, kidneys, gastrointestinal tract and peripheral nerves are most commonly involved. Although aneurysms are commonly seen in the visceral vessels, intracranial aneurysms are rare with 15 reported cases. The intracranial aneurysms are usually multiple and located in supra- as well as infra-tentorial compartments. Most of the cases presented with subarachnoid or parenchymal hemorrhage. The aneurysms were usually small, although large cavernous aneurysms were reported in one case. Treatment guidelines are not clear regarding the management of these cases. Most patients were treated conservatively by medical management with surgical excision performed in only two cases and coiling done in one patient with cavernous aneurysms. Repeat hemorrhages or re-bleed in spite of medical treatment have also been reported.
We describe the case of a 22-year-old woman, a known case of PAN who presented with subarachnoid hemorrhage. Cerebral angiogram showed a ruptured right middle cerebral artery bifurcation aneurysm along with unruptured left middle cerebral, right posterior communicating and left posterior inferior cerebellar artery aneurysms. Her previous abdominal angiogram had revealed multiple aneurysms in visceral arteries. Successful coil embolization of the ruptured right MCA bifurcation aneurysm was performed with preservation of the parent vessel. The patient made a complete recovery and was placed on medical treatment for PAN. Follow-up MR angiography at three months revealed stable occlusion of the embolized aneurysm with no change in the unruptured aneurysms.
Although rare, PAN can be associated with intracranial aneurysms which can cause subarachnoid or parenchymal hemorrhage. Selected cases can be treated safely by coil embolization.
PMCID: PMC3670059  PMID: 23693044
polyarteritis nodosa, aneurysm, embolization
10.  Outcomes Analysis of Ruptured Distal Anterior Cerebral Artery Aneurysms Treated by Endosaccular Embolization and Surgical Clipping 
Interventional Neuroradiology  2011;17(1):49-57.
Although endovascular surgery is now widely used to treat intracranial aneurysms, no comparative studies of clipping versus endovascular surgery to address distal ACA aneurysms at the same institution are available. We compared the results of these treatment modalities to address distal ACA aneurysms at our institution.
We treated 68 patients with ruptured distal ACA aneurysms (endovascular surgery, n=13; clipping surgery, n=55). We performed a retrospective comparison of the treatment outcomes. To study the efficacy o f endovascular surgery we classified all our cases into three types: type A were small-necked aneurysms, type B were wide-necked aneurysms on the parent artery, and type C were aneurysms in which the A3 portion of the ACA arose from the aneurysmal dome near the neck.
Intraoperative hemorrhage occurred in 7.7% of aneurysms treated by endovascular surgery and in 34.5% treated by clipping surgery. In 7.7% of the endovascularly-treated aneurysms we noted coil migration during embolization surgery; venous infarction due to cortical vein injury occurred in 7.3% of clipped aneurysms. Of the endovascularly-treated aneurysms, 7.7% manifested post-embolization hemorrhage; 23.1% manifested coil compaction. In clipping surgery, postoperative rerupture occurred in 1.8% of the aneurysms; one patient presented with postoperative acute epidural hematoma. Clip dislocation was noted in 1.8% of aneurysms. Angiography was indicative of post-treatment vasospasm in 7.7% of aneurysms treated endovascularly and in 50.9% of the clipped aneurysms.
The clinical outcome showed no significant difference between endovascular surgery and clipping surgery.
PMCID: PMC3278019  PMID: 21561558
distal ACA, aneurysm, endovascular surgery, clipping surgery
11.  Endovascular Repair of Abdominal Aortic Aneurysm 
The Medical Advisory Secretariat conducted a systematic review of the evidence on the effectiveness and cost-effectiveness of endovascular repair of abdominal aortic aneurysm in comparison to open surgical repair. An abdominal aortic aneurysm [AAA] is the enlargement and weakening of the aorta (major blood artery) that may rupture and result in stroke and death. Endovascular abdominal aortic aneurysm repair [EVAR] is a procedure for repairing abdominal aortic aneurysms from within the blood vessel without open surgery. In this procedure, an aneurysm is excluded from blood circulation by an endograft (a device) delivered to the site of the aneurysm via a catheter inserted into an artery in the groin. The Medical Advisory Secretariat conducted a review of the evidence on the effectiveness and cost-effectiveness of this technology. The review included 44 eligible articles out of 489 citations identified through a systematic literature search. Most of the research evidence is based on non-randomized comparative studies and case series. In the short-term, EVAR appears to be safe and comparable to open surgical repair in terms of survival. It is associated with less severe hemodynamic changes, less blood transfusion and shorter stay in the intensive care and hospital. However, there is concern about a high incidence of endoleak, requiring secondary interventions, and in some cases, conversion to open surgical repair. Current evidence does not support the use of EVAR in all patients. EVAR might benefit individuals who are not fit for surgical repair of abdominal aortic aneurysm and whose risk of rupture of the aneurysm outweighs the risk of death from EVAR. The long-term effectiveness and cost-effectiveness of EVAR cannot be determined at this time. Further evaluation of this technology is required.
The objective of this health technology policy assessment was to determine the effectiveness and cost-effectiveness of endovascular repair of abdominal aortic aneurysms (EVAR) in comparison to open surgical repair (OSR).
Clinical Need
An abdominal aortic aneurysm (AAA) is a localized, abnormal dilatation of the aorta greater than 3 cm or 50% of the aortic diameter at the diaphragm. (1) A true AAA involves all 3 layers of the vessel wall. If left untreated, the continuing extension and thinning of the vessel wall may eventually result in rupture of the AAA. The risk of death from ruptured AAA is 80% to 90%. (61) Heller et al. (44) analyzed information from a national hospital database in the United States. They found no significant change in the incidence rate of elective AAA repair or ruptured AAA presented to the nation’s hospitals. The investigators concluded that technologic and treatment advances over the past 19 years have not affected the outcomes of patients with AAAs, and the ability to identify and to treat patients with AAAs has not improved.
Classification of Abdominal Aortic Aneurysms
At least 90% of the AAAs are affected by atherosclerosis, and most of these aneurysms are below the level of the renal arteries.(1)
An abdominal aortic aneurysm may be symptomatic or asymptomatic. An AAA may be classified according to their sizes:(7)
Small aneurysms: less than 5 cm in diameter.
Medium aneurysms: 5-7cm.
Large aneurysms: more than 7 cm in diameter.
Small aneurysms account for approximately 50% of all clinically recognized aneurysms.(7)
Aortic aneurysms may be classified according to their gross appearance as follows (1):
Fusiform aneurysms affect the entire circumference of a vessel, resulting in a diffusely dilated lesion
Saccular aneurysms involve only a portion of the circumference, resulting in an outpouching (protrusion) in the vessel wall.
Prevalence of Abdominal Aortic Aneurysms
In community surveys, the prevalence of AAA is reported to be between 1% and 5.4%. (61) The prevalence is related to age and vascular risk factors. It is more common in men and in those with a positive family history.
In Canada, Abdominal aortic aneurysms are the 10th leading cause of death in men 65 years of age or older. (60) Naylor (60) reported that the rate of AAA repair in Ontario has increased from 38 per 100,000 population in 1981/1982 to 54 per 100,000 population in 1991/1992. For the period of 1989/90 to 1991/92, the rate of AAA repair in Ontarians age 45 years and over was 53 per 100,000. (60) In the United States, about 200,000 new cases are diagnosed each year, and 50,000 to 60,000 surgical AAA repairs are performed. (2) Ruptured AAAs are responsible for about 15,000 deaths in the United States annually. One in 10 men older than 80 years has some aneurysmal change in his aorta. (2)
Symptoms of Abdominal Aortic Aneurysms
AAAs usually do not produce symptoms. However, as they expand, they may become painful. Compression or erosion of adjacent tissue by aneurysms also may cause symptoms. The formation of mural thrombi, a type of blood clots, within the aneurysm may predispose people to peripheral embolization, where blood vessels become blocked. Occasionally, an aneurysm may leak into the vessel wall and the periadventitial area, causing pain and local tenderness. More often, acute rupture occurs without any prior warning, causing acute pain and hypotension. This complication is always life-threatening and requires an emergency operation.
Diagnosis of Abdominal Aortic Aneurysms
An AAA is usually detected on routine examination as a palpable, pulsatile, and non-tender mass. (1)
Abdominal radiography may show the calcified outline of the aneurysms; however, about 25% of aneurysms are not calcified and cannot be visualized by plain x-ray. (1) An abdominal ultrasound provides more accurate detection, can delineate the traverse and longitudinal dimensions of the aneurysm, and is useful for serial documentation of aneurysm size. Computed tomography and magnetic resonance have also been used for follow-up of aortic aneurysms. These technologies, particularly contrast-enhanced computer tomography, provide higher resolution than ultrasound.
Abdominal aortography remains the gold standard to evaluate patients with aneurysms for surgery. This technique helps document the extent of the aneurysms, especially their upper and lower limits. It also helps show the extent of associated athereosclerotic vascular disease. However, the procedure carries a small risk of complications, such as bleeding, allergic reactions, and atheroembolism. (1)
Prognosis of Abdominal Aortic Aneurysms
The risk of rupture of an untreated AAA is a continuous function of aneurysm size as represented by the maximal diameter of the AAA. The annual rupture rate is near zero for aneurysms less than 4 cm in diameter. The risk is about 1% per year for aneurysms 4 to 4.9 cm, 11% per year for aneurysms 5 to 5.9 cm, and 25% per year or more for aneurysms greater than 6 cm. (7)
The 1-year mortality rate of patients with AAAs who do not undergo surgical treatment is about 25% if the aneurysms are 4 to 6 cm in diameter. This increases to 50% for aneurysms exceeding 6 cm. Other major causes of mortality for people with AAAs include coronary heart disease and stroke.
Treatment of Abdominal Aortic Aneurysms
Treatment of an aneurysm is indicated under any one of the following conditions:
The AAA is greater than 6 cm in diameter.
The patient is symptomatic.
The AAA is rapidly expanding irrespective of the absolute diameter.
Open surgical repair of AAA is still the gold standard. It is a major operation involving the excision of dilated area and placement of a sutured woven graft. The surgery may be performed under emergent situation following the rupture of an AAA, or it may be performed electively.
Elective OSR is generally considered appropriate for healthy patients with aneurysms 5 to 6 cm in diameter. (7) Coronary artery disease is the major underlying illness contributing to morbidity and mortality in OSR. Other medical comorbidities, such as chronic renal failure, chronic lung disease, and liver cirrhosis with portal hypertension, may double or triple the usual risk of OSR.
Serial noninvasive follow-up of small aneurysms (less than 5 cm) is an alternative to immediate surgery.
Endovascular repair of AAA is the third treatment option and is the topic of this review.
PMCID: PMC3387737  PMID: 23074438
12.  Pharmacological stabilization of intracranial aneurysms in mice— a feasibility study 
Background and Purpose
An increasing number of unruptured intracranial aneurysms are being detected, partly due to the increased use of brain imaging techniques. Pharmacological stabilization of aneurysms for the prevention of aneurysmal rupture could potentially be an attractive alternative approach to clipping or coiling in patients with unruptured intracranial aneurysms. We have developed a mouse model of intracranial aneurysm that recapitulates key features of intracranial aneurysms. In this model, subarachnoid hemorrhage from aneurysmal rupture causes neurological symptoms that can be easily detected by a simple neurological examination. Using this model, we tested whether anti-inflammatory agents such as tetracycline derivatives, or a selective inhibitor of matrix metalloproteinases-2 and -9 (SB-3CT) can prevent the rupture of intracranial aneurysms.
Aneurysms were induced by a combination of induced hypertension and a single injection of elastase into the cerebrospinal fluid in mice. Treatment with minocycline, doxycycline, or SB-3CT was started six days after aneurysm induction. Aneurysmal rupture was detected by neurological symptoms and confirmed by the presence of intracranial aneurysm with subarachnoid hemorrhage.
Minocycline and doxycycline significantly reduced rupture rates (vehicle vs. doxycycline = 80 vs. 35%, P < 0.05; vehicle vs. minocycline = 73 vs. 24%, P < 0.05) without affecting the overall incidence of aneurysms. However, SB-3CT did not affect the rupture rate (62 vs. 55%, P = 0.53).
Our data established the feasibility of using a mouse model of intracranial aneurysm to test pharmacological stabilization of aneurysms. Tetracycline derivatives could be potentially effective in preventing aneurysmal rupture.
PMCID: PMC3429647  PMID: 22798328
intracranial aneurysm; subarachnoid hemorrhage; intracranial hemorrhage; animal model; tetracycline; matrix metalloproteinase; inflammation
13.  Subarachnoid haemorrhage (spontaneous aneurysmal) 
Clinical Evidence  2009;2009:1213.
Subarachnoid haemorrhage (SAH) may arise spontaneously or as a result of trauma. Spontaneous SAH accounts for about 5% of all strokes. Ruptured aneurysms are the cause of 85% of spontaneous SAH. The most characteristic clinical feature is sudden-onset severe headache. Other features include vomiting, photophobia, and focal neurological deficit or seizures, or both. As the headache may have insidious onset in some cases, or may even be absent, a high degree of suspicion is required to diagnose SAH with less typical presentations.
Methods and outcomes
We conducted a systematic review and aimed to answer the following clinical questions: What are the effects of surgical treatments for people with confirmed aneurysmal subarachnoid haemorrhage? What are the effects of medical treatments to prevent delayed cerebral ischaemia in people with confirmed aneurysmal subarachnoid haemorrhage? We searched: Medline, Embase, The Cochrane Library, and other important databases up to March 2009 (Clinical Evidence reviews are updated periodically; please check our website for the most up-to-date version of this review). We included harms alerts from relevant organisations such as the US Food and Drug Administration (FDA) and the UK Medicines and Healthcare products Regulatory Agency (MHRA).
We found 6 systematic reviews, RCTs, or observational studies that met our inclusion criteria. We performed a GRADE evaluation of the quality of evidence for interventions.
In this systematic review we present information relating to the effectiveness and safety of the following interventions: endovascular coiling; surgical clipping; timing of surgery; and oral and intravenous nimodipine.
Key Points
Subarachnoid haemorrhage (SAH) may arise spontaneously or as a result of trauma. Spontaneous SAH accounts for about 5% of all strokes. Ruptured aneurysms are the cause of 85% of spontaneous SAH. This review deals with only spontaneous aneurysmal SAH. Without treatment, mortality rates of about 50% at 1 month after spontaneous aneurysmal SAH have been reported.
Treatment is aimed at prevention of re-bleeding from the same aneurysm. This can be performed by surgical clipping or by endovascular coiling. In people suitable for either procedure, endovascular coiling has lower rates of poor functional outcome compared with surgical clipping, but it is also associated with increased rate of recurrent haemorrhage from the treated aneurysm and a higher rate of re-treatment for the same aneurysm. Most evidence is in small (<11 mm) aneurysms of the anterior circulation. Therefore, the conclusions cannot be applied to all aneurysms (particularly large and giant aneurysms, and aneurysms with broad necks).Factors that should be considered when deciding on the method of treatment include the morphology of the aneurysm, the age and clinical condition of the person, and the presence or absence of a space-occupying intracranial haematoma.
We do not know the optimal timeframe for carrying out surgical clipping or endovascular coiling after aneurysmal SAH. However, early surgery will prevent re-bleeding from the aneurysm, and is preferred in most people.
Oral nimodipine reduces poor outcome (death or dependence), secondary ischaemia, and CT/MRI evidence of infarction after aneurysmal SAH.
We found no evidence on the effects of intravenous nimodipine alone.
PMCID: PMC2907802  PMID: 21726472
14.  A Clinical Analysis of Twelve Cases of Ruptured Cerebral De Novo Aneurysms 
Yonsei Medical Journal  2007;48(1):30-34.
Formation of cerebral de novo aneurysms (CDNA) is rare, and the pathogenesis remains obscure. In this study, we investigated the factors that contribute to the formation of CDNA and suggest guidelines for following patients treated for cerebral aneurysms. We retrospectively reviewed 2,887 patients treated for intracranial aneurysm at our institute from January of 1976 to December of 2005. Of those patients, 12 were readmitted due to recurrent rupture of CDNA, which was demonstrated by cerebral angiography. We assessed clinical characteristics, such as gender, size and site of rupture, past history, and the time to CDNA rupture. Of the 12 patients, 11 were female and 1 was male, with a mean age at rupture of the first aneurysm of 44.7 years (range: 30-69 years). The mean time between the first episode of subarachnoid hemorrhage (SAH) and the second was 8.9 years (range: 1.0-16.7 years). The most common site of ruptured CDNA was the internal carotid artery (5 patients, 41.7%), followed by basilar artery bifurcation (3 patients, 25.0%). In the remaining 4 patients, rupture occurred in the anterior communicating, middle cerebral, anterior cerebral (A1), or posterior cerebral (P1) arteries. In 5 cases (41.7%), the CDNA occurred contralateral to the initial aneurysm. Eleven patients (91.7%) had a past history of arterial hypertension. There was no history of habitual smoking or alcohol abuse in any of the patients. Eight patients underwent clipping for CDNA and three patients were treated with coiling. One patient who had multiple aneurysms was treated with clipping following intra-aneurysmal coiling. Assessment according to the Glasgow Outcome Scale (GOS) of the patients after the treatment was good in 10 cases (83.3%) and fair in 2 cases (16.7%). Although formation of CDNA after successful treatment of initial aneurysm is rare, several factors may contribute to recurrence. In our study, female patients with a history of arterial hypertension were at higher risk for ruptured CDNA. We recommend follow-up imaging studies every five years after treatment of the initial aneurysm, especially in women and those with a history of arterial hypertension.
PMCID: PMC2627997  PMID: 17326242
Cerebral de novo aneurysm; ruptured cerebral aneurysm
15.  Rapid aneurysm growth and rupture in systemic lupus erythematosus 
Subarachnoid hemorrhage (SAH) due to intracranial aneurysm rupture is a major neurosurgical emergency associated with significant morbidity and mortality. Rapid aneurysm growth is associated with rupture. Systemic lupus erythematosus (SLE) is a multi-system autoimmune disorder whose complications can include cerebral vasculitis and vasculopathy. Intracranial aneurysms are not known to occur more frequently in SLE patients than the general population; however, aneurysm growth rates have not been studied in SLE.
Case Description:
We present a 43-year-old female with SLE on prednisone, hydroxychloroquine, and azathioprine with moderate disease activity who presented with severe, acute-onset headache and was found to have Hunt and Hess grade II SAH due to rupture of an 8 mm saccular anterior communicating artery (ACoA) aneurysm. The patient developed severe vasospasm, re-ruptured, and was taken for angiography and embolization, which was challenging due to a high degree of vasospasm and arterial stenosis. Review of imaging from less than 2 years prior demonstrated a normal ACoA complex without evidence of an aneurysm.
We review the literature and discuss the risk factors and pathophysiology of rapid aneurysm growth and rupture, as well as the pathologic vascular changes associated with SLE. Although SLE patients do not develop intracranial aneurysm at an increased rate, these changes may predispose them to higher incidence of growth and rupture. This possibility-coupled with increased morbidity and mortality of SAH in SLE-suggests that SAH should be considered in SLE patients presenting with headache, and advocates for more aggressive treatment of SLE patients with unruptured aneurysms.
PMCID: PMC4310132  PMID: 25657862
Aneurysm growth; intracranial aneurysms; subarachnoid hemorrhage; systemic lupus erythematosus
16.  Endovascular Management of Infective Intracranial Aneurysms with Acrylic Glue 
Interventional Neuroradiology  2009;15(4):443-447.
Cerebral mycotic aneurysms (MAs) also called infective aneurysms, are uncommon and are usually encountered in patients with infective endocarditis. These aneurysms often present with intracranial hemorrhage. MAs may resolve on treatment with antibiotics alone. However prognosis with medical management alone is unpredictable. Good prognosis with surgery has been reported for single accessible ruptured MAs. However surgery is associated with significant morbidity. Endovascular treatment of MAs along with appropriate antibiotics is emerging as an acceptable option for these patients.
We describe two cases of infective endocarditis complicated by ruptured MA treated successfully by liquid embolic glue material.
PMCID: PMC3299432  PMID: 20465872
mycotic aneurysm, infective endocarditis, endovascular treatment, liquid embolic glue material
17.  Surgical Results of Unruptured Intracranial Aneurysms in the Elderly : Single Center Experience in the Past Ten Years 
As medical advances have increased life expectancy, it has become imperative to develop specific treatment strategies for intracranial aneurysms in the elderly. We therefore analyzed the clinical characteristics and outcomes of the treatment of unruptured intracranial aneurysms in patients older than 70 years.
We retrospectively reviewed the medical records and results of neuroimaging modalities on 54 aneurysms of 48 consecutive patients with unruptured intracranial aneurysms. (mean±SD age, 72.11±1.96 years; range, 70-78 years) who underwent surgical clipping over 10 years (May 1999 to June 2010).
Of the 54 aneurysms, 22 were located in the internal carotid artery, 19 in the middle cerebral artery, 12 in the anterior cerebral artery, and 1 in the superior cerebellar artery. Six patients had multiple aneurysms. Aneurysm size ranged from 3 mm to 17 mm (mean±SD, 6.82±3.07 mm). Fifty of the 54 aneurysms (92.6%) were completely clipped. Three-month outcomes were excellent in 50 (92.6%) aneurysms and good and poor in 2 each (3.7%), with 1 death (2.0%). Procedure-related complications occurred in 7 aneurysms (13.0%), with 2 (3.7%) resulting in permanent neurological deficits, including death. No postoperative subarachnoid hemorrhage occurred during follow-up. The cumulative rates of stroke- or death-free survival at 5 and 10 years were 100% and 78%, respectively.
Surgical clipping of unruptured intracranial aneurysms in elderly group could get it as a favorable outcome in well selected cases.
PMCID: PMC3158474  PMID: 21887389
Unruptured intracranial aneurysm; Surgical clipping; Elderly; Outcome
18.  What is the optimal timing for surgery in infective endocarditis with cerebrovascular complications? 
Neurologic dysfunction complicates the course of 10–40% of left-side infective endocarditis (IE). In right-sided IE, instead, when systemic emboli occur, paradoxical embolism should be considered. The spectrum of neurologic events includes embolic cerebrovascular complication (CVC), intracranial haemorrhage, ruptured mycotic aneurysm, transient ischaemic attack (TIA), meningitis, encephalopathy and brain abscess. Cardiopulmonary bypass might exacerbate neurological deficits due to: heparinization and secondary cerebral haemorrhage; hypotension and cerebral oedema in areas of the disrupted blood brain barrier. A best evidence topic was written according to a structured protocol. The question addressed was, whether there is an optimal timing for surgery in IE with CVCs. One hundred papers were found using the reported search criteria, and out of these 20 papers, provided the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results were tabulated. We found that evidence is conflicting because of lack of controlled studies. The optimal timing for the valve replacement depends on the type of neurological complication and the urgency of the operation. The new 2009 Guidelines on the prevention, diagnosis, and treatment of infective endocarditis (IE) recommend a multidisciplinary approach and to wait for 1–2 weeks of antibiotics treatment before performing cardiac surgery. However, early surgery is indicated in: heart failure (class 1 B), uncontrolled infection (class 1 B) and prevention of embolic events (class 1B/C). After a stroke, surgery should not be delayed as long as coma is absent and cerebral haemorrhage has been excluded by cranial CT (class IIa level B). After a TIA or a silent cerebral embolism, surgery is recommended without delay (class 1 level B). In intracranial haemorrhage (ICH), surgery must be postponed for at least 1 month (class 1 level C). Surgery for prosthetic valve endocarditis (PVE) follows the general principles outlined for native valve IE. Every patient should have a repeated head CT scan immediately before the operation to rule out a preoperative haemorrhagic transformation of a brain infarction. The presence of a haematoma warrants neurosurgical consultation and consideration of cerebral angiography to rule out a mycotic aneurysm.
PMCID: PMC3420303  PMID: 22108925
Infective endocarditis; Cerebrovascular complication; Brain injury; Stroke cardiac surgery; Timing
19.  What Is the Significance of a Large Number of Ruptured Aneurysms Smaller than 7 mm in Diameter? 
The International Study of Unruptured Intracranial Aneurysms (ISUIA) reported that the 5-year cumulative rupture rate of small unruptured aneurysms less than 7 mm in diameter is very low depending on the aneurysm's location. However, we have seen a large number of ruptured aneurysms less than 7 mm in clinical practice. The purpose of this study was to review our experience and to measure the size and location at which aneurysms ruptured in our patient population.
We reviewed the characteristics of aneurysms, such as size and location, from the original angiograms of patients who were admitted to our hospital between January 2004 and December 2007. All aneurysms were treated surgically or through endovascular procedures.
Interventional or surgical treatment was given to a total of 889 patients, including 568 females and 321 males. At the time of our study, 627 cases were ruptured aneurysms and 262 cases were unruptured aneurysms. Of the ruptured cases, the mean diameter of the aneurysm was 6.28 mm. We found that 71.8% of ruptured aneurysms were smaller than 7 mm in diameter, and 87.9%, were smaller than 10 mm. Based on location, the data show that anterior communicating artery aneurysms most often presented with rupture sizes less than 7 mm (76.8%) and 10 mm (92.1%) in diameter. Most ruptured aneurysms were less than 7 mm in size, although recent studies have noted that small aneurysms are less likely to rupture.
Although the natural history of unruptured intracranial aneurysms remains controversial, the aneurysm size and location play a signigicant role in determining the risk of rupture. Larger sample sizes and a long term study are needed to reveal the natural history and the rupture risk of unruptured intracranial aneurysms because the size of most ruptured aneurysms was less than 7 mm in diameter in our series.
PMCID: PMC2651552  PMID: 19274117
Size; Location; Age; Intracranial aneurysm; Rupture
20.  Ruptured peripheral aneurysms in a collateral pathway associated with stenosis of a major cerebral artery: Report of two cases 
While hemodynamic stress can result in aneurysm formation, it rarely contributes to the development of peripheral aneurysms in collateral pathways. We report two patients with ruptured distal aneurysms in a collateral pathway associated with stenosis of a major cerebral artery.
Case Description
A 67-year-old man presented with intracerebral hemorrhage in the right frontal lobe. Digital subtraction angiography (DSA) revealed severe stenosis of the right middle cerebral artery and two aneurysms in the collateral pathway of the right anterior cerebral artery. The ruptured aneurysm was trapped and resected; histologically, it was a true saccular aneurysm. The unruptured aneurysm was clipped and the patient was discharged without additional neurological deficits. The second patient was a 73-year-old woman with subarachnoid hemorrhage. DSA revealed three arterial dilations. On the 7th day of hospitalization, one of the aneurysms in a posterior inferior cerebellar artery–anterior inferior cerebellar artery anastomosis that functioned as a collateral pathway in the presence of severe basilar artery stenosis was found to be enlarged. It was treated by selective aneurysmal coil embolization with parent artery preservation. Her postoperative course was uneventful and she was discharged without any neurological deficits.
We document the successful treatment of two patients with ruptured aneurysms in the peripheral portion of a collateral pathway. We discuss the histology of peripheral aneurysms and present a review of the literature.
PMCID: PMC3130464  PMID: 21748034
Coil embolization; collateral pathway; histology; peripheral aneurysm; posterior inferior cerebellar artery–anterior inferior cerebellar artery anastomosis; true aneurysm
21.  Endovascular Treatment of Unruptured Intracranial Aneurysms 
Interventional Neuroradiology  2011;17(4):420-424.
We report the clinical and angiographic results of endovascular treatment of unruptured intracranial aneurysms.
Over a three-year period, 80 unruptured aneurysms in 74 patients were electively treated with endovascular management. One aneurysm was diagnosed during investigations for a second ruptured aneurysm, 54 aneurysms were incidentally discovered, 18 aneurysms presented with symptoms of mass effect and seven aneurysms presented with symptoms of brain stem ischemia. Mean size of the 80 unruptured aneurysms was 12.5±8.0 mm (range, 2-39 mm). Thirty-six aneurysms (45%) were small (<10 mm), 38 aneurysms (47.5%) were large (10-25 mm), and six aneurysms (7.5%) were giant (25-39 mm). Forty-eight wide-necked aneurysms (60%) were coiled with the aid of a supporting device.
The mortality rate was 1.25%, and the overall morbidity was 1.25%. Of these, one of the patients suffered a stroke, leading to severe disability (1.25%). In one patient, the aneurysm ruptured during treatment, resulting in death. Initial aneurysm occlusion was complete (100%) in 76.25% aneurysms, nearly complete (90%-98%) in 10% aneurysms and incomplete (60%-85%) in 13.75% aneurysms. Follow-up angiography was available in 67 patients with 73 treated aneurysms (91.25%) from one to 36 months (mean 9.3 months); partial reopening occurred in 7.5%, mainly large and giant aneurysms (5.5%). Additional coiling was performed in four aneurysms. There were no complications in additional treatments. At 14.1-month clinical follow-up (range, 2 to 36 months), mRS score was 0 in 78.75% patients, 1 in 10% patients, 2 in 8.75% and 3 in 1.25%. There was no aneurysmal rupture during the follow-up period. Endovascular treatment of unruptured intracranial aneurysms has low procedural mortality and morbidity rates.
PMCID: PMC3296500  PMID: 22192544
intracranial aneurysm, unruptured, embolization
22.  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.
PMCID: PMC3356859  PMID: 22661965
subarachnoid hemorrhage; aneurysm; endovascular; wall shear stress; computed fluid dynamics
23.  Genome-wide microRNA changes in human intracranial aneurysms 
BMC Neurology  2014;14(1):188.
Intracranial aneurysms are pathological dilatations of the cerebral artery, while rupture of intracranial aneurysms causes life-threatening subarachnoid hemorrhage. The molecular mechanisms of pathogenesis of intracranial aneurysms are poorly understood. MicroRNAs have fundamental roles in modulating vascular biology and disease. In the present study, we carried out a genome-wide characterization on expressions of microRNAs, and performed integrative analyses in conjunction with changes of the transcriptome in human intracranial aneurysms.
Genome-wide microRNA screening was performed in 6 intracranial aneurysmal samples and 6 normal superficial temporal arteries. Each case and control pair was individually matched with gender, age (±5 years), and high blood pressure history. Microarray analysis was performed using Agilent Human miRNA arrays.
As compared to normal arteries, we identified 157 microRNAs that were differentially expressed in the aneurysmal tissue (P < 0.05 and fold change ≥ 2), including 72 upregulated and 85 downregulated. The changed microRNAs included endothelium-enriched microRNAs such as members of the let-7 family, miR-17, miR-23b, miR-126, hsa-miR-24-1 and miR-222, and vascular smooth muscle-enriched miRNAs such as miR-143 and miR-145. Moreover, miR-1, miR-10a, miR-125b, and miR-26a, which were implicated in modulating vascular smooth muscle cell functions such as proliferation, apoptosis and shift of phenotype, were also changed. In contrast, microRNAs involved in monocyte and macrophage functions, such as miR-155, miR-146a, miR-223, and miR-124a, were not significantly changed. Bioinformatic analysis revealed that the changed microRNAs were associated with several biological processes related to aneurysm formation, including inflammation, dysregulation of extracellular matrix, smooth muscle cell proliferation, programmed cell death, and response to oxidative stress. Interestingly, we found that a subset of the potential microRNA target genes belonged to the protein translation machinery, including various eukaryotic translation initiation factors and ribosomal proteins, and this finding was highly correlated with our previous transcriptome data showing that multiple genes of the ribosomal proteins and translation initiation and elongation factors were significantly downregulated in human intracranial aneurysms.
Our results support that dysregulated microRNAs may have a pathogenic role in intracranial aneurysms. Disruption of the protein translation process may have a pathogenic role in the development of intracranial aneurysms.
Electronic supplementary material
The online version of this article (doi:10.1186/s12883-014-0188-x) contains supplementary material, which is available to authorized users.
PMCID: PMC4210474  PMID: 25300531
Intracranial aneurysm; microRNA; Microarray; Human; Cerebral vascular disease; System biology; Transcriptome; Protein translation machinery
24.  The Expanding Realm of Endovascular Neurosurgery: Flow Diversion for Cerebral Aneurysm Management 
The worldwide prevalence of intracranial aneurysms is estimated to be between 5% and 10%, with some demographic variance. Subarachnoid hemorrhage secondary to ruptured intracranial aneurysm results in devastating neurological outcomes, leaving the majority of victims dead or disabled.
Surgical clipping of intracranial aneurysms remained the definitive mode of treatment until Guglielmi detachable coils were introduced in the 1990s. This revolutionary innovation led to the recognition of neurointervention/neuroendovascular surgery as a bona fide option for intracranial aneurysms. Constant evolution of endovascular devices and techniques supported by several prospective randomized trials has catapulted the endovascular treatment of intracranial aneurysms to its current status as the preferred treatment modality for most ruptured and unruptured intracranial aneurysms. We are slowly transitioning from the era of coils to the era of flow diverters. Flow-diversion technology and techniques have revolutionized the treatment of wide-necked, giant, and fusiform aneurysms, where the results of microsurgery or conventional neuroendovascular strategies have traditionally been dismal. Although the Pipeline™ Embolization Device (ev3-Covidien, Irvine, CA) is the only flow-diversion device approved by the Food and Drug Administration for use in the United States, others are commercially available in Europe and South America, including the Silk (Balt Extrusion, Montmorency, France), Flow-Redirection Endoluminal Device (FRED; MicroVention, Tustin, CA), Surpass (Stryker, Kalamazoo, MI), and p64 (Phenox, Bochum, Germany).
Improvements in technology and operator experience and the encouraging results of clinical trials have led to broader acceptance for the use of these devices in cerebral aneurysm management. Continued innovation and refinement of endovascular devices and techniques will inevitably improve technical success rates, reduce procedure-related complications, and broaden the endovascular therapeutic spectrum for varied aneurysm morphology.
PMCID: PMC4300059  PMID: 25624975
flow diverter; intracranial aneurysm; pipeline embolization device; subarachnoid hemorrhage
25.  Treatment of aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysms by neurosurgeons in Colombia: A survey 
Trends in management of aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysms among neurosurgeons is very variable and had not been previously described in any Latin American country. This study was conducted to determine the preferences of Colombian neurosurgeons in pharmacologic, surgical, and endovascular management of patients with aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysms.
A survey-based descriptive study was performed in a sample of members from the Colombian Association of Neurosurgery. Questions about pharmacologic, surgical, and endovascular management of aneurysmal subarachnoid hemorrhage and unruptured intracranial aneurysm were carried out. We calculated the mean and the standard deviation of the results obtained from the continuous variables. The results of the categorical variables are presented as percentages.
The preference of medication with poor clinical evidence, such as magnesium sulfate, aspirin, statins, and anti-fibrinolytics was lower than 10%. The use of intravenous nimodipine and systemic glucocorticoids was as high as 31%. The availability of endovascular therapy was 69%. The indication for treatment of patients with unruptured intracranial aneurysms that required intervention was less than 13.8%. In patients with ruptured or unruptured intracranial aneurysms, coiling was the preferred method for exclusion.
Reported compliance of evidence-based clinical guidelines was similar to that described in developed countries, and even better. However, there is little agreement in treating patients with unruptured intracranial aneurysms. For other issues, the conducts reported by Colombian neurosurgeons are in accordance with the current guidelines.
PMCID: PMC3205495  PMID: 22059120
Intracranial aneurysms; national survey; subarachnoid hemorrhage

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