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1.  Coil Embolization for Intracranial Aneurysms 
Executive Summary
Objective
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.
Background
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
Methods
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.
Results
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.
Diffusion
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.
Guidelines
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.
Conclusion
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.  Endovascular Repair of Abdominal Aortic Aneurysm 
EXECUTIVE SUMMARY
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.
OBJECTIVE
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).
BACKGROUND
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
4.  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.
doi:10.14797/mdcj-10-4-214
PMCID: PMC4300059  PMID: 25624975
flow diverter; intracranial aneurysm; pipeline embolization device; subarachnoid hemorrhage
5.  Endovascular Repair of Descending Thoracic Aortic Aneurysm 
Executive Summary
Objective
To conduct an assessment on endovascular repair of descending thoracic aortic aneurysm (TAA).
Clinical Need
Aneurysm is the most common condition of the thoracic aorta requiring surgery. Aortic aneurysm is defined as a localized dilatation of the aorta. Most aneurysms of the thoracic aorta are asymptomatic and incidentally discovered. However, TAA tends to enlarge progressively and compress surrounding structures causing symptoms such as chest or back pain, dysphagia (difficulty swallowing), dyspnea (shortness of breath), cough, stridor (a harsh, high-pitched breath sound), and hoarseness. Significant aortic regurgitation causes symptoms of congestive heart failure. Embolization of the thrombus to the distal arterial circulation may occur and cause related symptoms. The aneurysm may eventually rupture and create a life-threatening condition.
The overall incidence rate of TAA is about 10 per 100,000 person-years. The descending aorta is involved in about 30% to 40% of these cases.
The prognosis of large untreated TAAs is poor, with a 3-year survival rate as low as 25%. Intervention is strongly recommended for any symptomatic TAA or any TAA that exceeds twice the diameter of a normal aorta or is 6 cm or larger. Open surgical treatment of TAA involves left thoracotomy and aortic graft replacement. Surgical treatment has been found to improve survival when compared with medical therapy. However, despite dramatic advances in surgical techniques for performing such complex operations, operative mortality from centres of excellence are between 8% and 20% for elective cases, and up to 50% in patients requiring emergency operations. In addition, survivors of open surgical repair of TAAs may suffer from severe complications. Postoperative or postprocedural complications of descending TAA repair include paraplegia, myocardial infarction, stroke, respiratory failure, renal failure, and intestinal ischemia.
The Technology
Endovascular aortic aneurysm repair (EVAR) using a stent graft, a procedure called endovascular stent-graft (ESG) placement, is a new alternative to the traditional surgical approach. It is less invasive, and initial results from several studies suggest that it may reduce mortality and morbidity associated with the repair of descending TAAs.
The goal in endovascular repair is to exclude the aneurysm from the systemic circulation and prevent it from rupturing, which is life-threatening. The endovascular placement of a stent graft eliminates the systemic pressure acting on the weakened wall of the aneurysm that may lead to the rupture. However, ESG placement has some specific complications, including endovascular leak (endoleak), graft migration, stent fracture, and mechanical damage to the access artery and aortic wall.
The Talent stent graft (manufactured by Medtronic Inc., Minneapolis, MN) is licensed in Canada for the treatment of patients with TAA (Class 4; licence 36552). The design of this device has evolved since its clinical introduction. The current version has a more flexible delivery catheter than did the original system. The prosthesis is composed of nitinol stents between thin layers of polyester graft material. Each stent is secured with oversewn sutures to prevent migration.
Review Strategy
Objectives
To compare the effectiveness and cost-effectiveness of ESG placement in the treatment of TAAs with a conventional surgical approach
To summarize the safety profile and effectiveness of ESG placement in the treatment of descending TAAs
Measures of Effectiveness
Primary Outcome
Mortality rates (30-day and longer term)
Secondary Outcomes
Technical success rate of introducing a stent graft and exclusion of the aneurysm sac from systemic circulation
Rate of reintervention (through surgical or endovascular approach)
Measures of Safety
Complications were categorized into 2 classes:
Those specific to the ESG procedure, including rates of aneurysm rupture, endoleak, graft migration, stent fracture, and kinking; and
Those due to the intervention, either surgical or endovascular. These include paraplegia, stroke, cardiovascular events, respiratory failure, real insufficiency, and intestinal ischemia.
Inclusion Criteria
Studies comparing the clinical outcomes of ESG treatment with surgical approaches
Studies reporting on the safety and effectiveness of the ESG procedure for the treatment of descending TAAs
Exclusion Criteria
Studies investigating the clinical effectiveness of ESG placement for other conditions such as aortic dissection, aortic ulcer, and traumatic injuries of the thoracic aorta
Studies investigating the aneurysms of the ascending and the arch of the aorta
Studies using custom-made grafts
Literature Search
The Medical Advisory Secretariat searched The International Network of Agencies for Health Technology Assessment and the Cochrane Database of Systematic Reviews for health technology assessments. It also searched MEDLINE, EMBASE, Medline In-Process & Other Non-Indexed Citations, and Cochrane CENTRAL from January 1, 2000 to July 11, 2005 for studies on ESG procedures. The search was limited to English-language articles and human studies.
One health technology assessment from the United Kingdom was identified. This systematic review included all pathologies of the thoracic aorta; therefore, it did not match the inclusion criteria. The search yielded 435 citations; of these, 9 studies met inclusion criteria.
Summary of Findings
Mortality
The results of a comparative study found that in-hospital mortality was not significantly different between ESG placement and surgery patients (2 [4.8%] for ESG vs. 6 [11.3%] for surgery).
Pooled data from case series with a mean follow-up ranging from 12 to 38 months showed a 30-day mortality and late mortality rate of 3.9% and 5.5%, respectively. These rates are lower than are those reported in the literature for surgical repair of TAA.
Case series showed that the most common cause of early death in patients undergoing endovascular repair is aortic rupture, and the most common causes of late death are cardiac events and aortoesophageal or aortobronchial fistula.
Technical Success Rate
Technical success rates reported by case series are 55% to 100% (100% and 94.4% in 2 studies with all elective cases, 89% in a study with 5% emergent cases, and 55% in a study with 42% emergent cases).
Surgical Reintervention
In the comparative study, 3 (7.1%) patients in the ESG group and 14 (26.5%) patients in the surgery group required surgical reintervention. In the ESG group, the reasons for surgical intervention were postoperative bleeding at the access site, paraplegia, and type 1 endoleak. In the surgical group, the reasons for surgery were duodenal perforation, persistent thoracic duct leakage, false aneurysm, and 11 cases of postoperative bleeding.
Pooled data from case series show that 9 (2.6%) patients required surgical intervention. The reasons for surgical intervention were endoleak (3 cases), aneurysm enlargement and suspected infection (1 case), aortic dissection (1 case), pseudoaneurysm of common femoral artery (1 case), evacuation of hematoma (1 case), graft migration (1 case), and injury to the access site (1 case).
Endovascular Revision
In the comparative study, 3 (7.1%) patients required endovascular revision due to persistent endoleak.
Pooled data from case series show that 19 (5.3%) patients required endovascular revision due to persistent endoleak.
Graft Migration
Two case series reported graft migration. In one study, 3 proximal and 4 component migrations were noted at 2-year follow-up (total of 5%). Another study reported 1 (3.7%) case of graft migration. Overall, the incidence of graft migration was 2.6%.
Aortic Rupture
In the comparative study, aortic rupture due to bare stent occurred in 1 case (2%). The pooled incidence of aortic rupture or dissection reported by case series was 1.4%.
Postprocedural Complications
In the comparative study, there were no statistically significant differences between the ESG and surgery groups in postprocedural complications, except for pneumonia. The rate of pneumonia was 9% for those who received an ESG and 28% for those who had surgery (P = .02). There were no cases of paraplegia in either group. The rate of other complications for ESG and surgery including stroke, cardiac, respiratory, and intestinal ischemia were all 5.1% for ESG placement and 10% for surgery. The rate for mild renal failure was 16% in the ESG group and 30% in the surgery group. The rate for severe renal failure was 11% for ESG placement and 10% for surgery.
Pooled data from case series show the following postprocedural complication rates in the ESG placement group: paraplegia (2.2%), stroke (3.9%), cardiac (2.9%), respiratory (8.7%), renal failure (2.8%), and intestinal ischemia (1%).
Time-Related Outcomes
The results of the comparative study show statistically significant differences between the ESG and surgery group for mean operative time (ESG, 2.7 hours; surgery, 5 hours), mean duration of intensive care unit stay (ESG, 11 days; surgery, 14 days), and mean length of hospital stay (ESG, 10 days; surgery, 30 days).
The mean duration of intensive care unit stay and hospital stay derived from case series is 1.6 and 7.8 days, respectively.
Ontario-Based Economic Analysis
In Ontario, the annual treatment figures for fiscal year 2004 include 17 cases of descending TAA repair procedures (source: Provincial Health Planning Database). Fourteen of these have been identified as “not ruptured” with a mean hospital length of stay of 9.23 days, and 3 cases have been identified as “ruptured,” with a mean hospital length of stay of 28 days. However, because one Canadian Classification of Health Interventions code was used for both procedures, it is not possible to determine how many were repaired with an EVAR procedure or with an open surgical procedure.
Hospitalization Costs
The current fiscal year forecast of in-hospital direct treatment costs for all in-province procedures of repair of descending TAAs is about $560,000 (Cdn). The forecast in-hospital total cost per year for in-province procedures is about $720,000 (Cdn). These costs include the device cost when the procedure is EVAR (source: Ontario Case Costing Initiative).
Professional (Ontario Health Insurance Plan) Costs
Professional costs per treated patient were calculated and include 2 preoperative thoracic surgery or EVAR consultations.
The professional costs of an EVAR include the fees paid to the surgeons, anesthetist, and surgical assistant (source: fee service codes). The procedure was calculated to take about 150 minutes.
The professional costs of an open surgical repair include the fees of the surgeon, anesthetist, and surgical assistant. Open surgical repair was estimated to take about 300 minutes.
Services provided by professionals in intensive care units were also taken into consideration, as were the costs of 2 postoperative consultations that the patients receive on average once they are discharged from the hospital. Therefore, total Ontario Health Insurance Plan costs per treated patient treated with EVAR are on average $2,956 (ruptured or not ruptured), as opposed to $5,824 for open surgical repair and $6,157 for open surgical repair when the aneurysm is ruptured.
Conclusions
Endovascular stent graft placement is a less invasive procedure for repair of TAA than is open surgical repair.
There is no high-quality evidence with long-term follow-up data to support the use of EVAR as the first choice of treatment for patients with TAA that are suitable candidates for surgical intervention.
However, short- and medium-term outcomes of ESG placement reported by several studies are satisfactory and comparable to surgical intervention; therefore, for patients at high risk of surgery, it is a practical option to consider. Short- and medium-term results show that the benefit of ESG placement over the surgical approach is a lower 30-day mortality and paraplegia rate; and shorter operative time, ICU stay, and hospital stay.
PMCID: PMC3382300  PMID: 23074469
6.  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.
doi:10.1093/icvts/ivr010
PMCID: PMC3420303  PMID: 22108925
Infective endocarditis; Cerebrovascular complication; Brain injury; Stroke cardiac surgery; Timing
7.  Ruptured Intracranial Mycotic Aneurysm in Infective Endocarditis: A Natural History 
Case Reports in Medicine  2010;2010:168408.
Mycotic aneurysms are a rare cause of intracranial aneurysms that develop in the presence of infections such as infective endocarditis. They account for a small percentage of all intracranial aneurysms and carry a high-mortality rate when ruptured. The authors report a case of a 54-year-old man who presented with infective endocarditis of the mitral valve and acute stroke. He subsequently developed subarachnoid hemorrhage during antibiotic treatment, and a large intracranial aneurysm was discovered on CT Angiography. His lesion quickly progressed into an intraparenchymal hemorrhage, requiring emergent craniotomy and aneurysm clipping. Current recommendations on the management of intracranial Mycotic Aneurysms are based on few retrospective case studies. The natural history of the patient's ruptured aneurysm is presented, as well as a literature review on the management and available treatment modalities.
doi:10.1155/2010/168408
PMCID: PMC2946581  PMID: 20885918
8.  Stromal Cell-Derived Factor-1 Is Associated with Angiogenesis and Inflammatory Cell Infiltration in Aneurysm Walls 
Journal of neurosurgery  2013;120(1):10.3171/2013.9.JNS122074.
Object
A small percentage of cerebral aneurysms rupture, but when they do, the effects are devastating. Current management of unruptured aneurysms consist of surgery, endovascular treatment, or watchful waiting. If the biology of how aneurysms grow and rupture were better known, a novel drug could be developed to prevent unruptured aneurysms from rupturing. Ruptured cerebral aneurysms are characterized by inflammation-mediated wall remodeling. We studied the role of stromal cell-derived factor-1 (SDF-1) in inflammation-mediated wall remodeling in cerebral aneurysms.
Methods
Human aneurysms; murine carotid aneurysms; and murine intracranial aneurysms were studied by immunohistochemistry. Flow cytometry analysis was performed on blood from mice developing carotid aneurysms or intracranial aneurysms. The effect of SDF-1 on endothelial cells and macrophages was studied by chemotaxis cell migration assay and capillary tube formation assay. Anti-SDF-1 blocking antibody was given to mice and compared to control (vehicle)-administered mice for its effects on the walls of carotid aneurysms and the development of intracranial aneurysms.
Results
Human aneurysms, murine carotid aneurysms, and murine intracranial aneurysms, all express SDF-1; and mice with developing carotid aneurysms or intracranial aneurysms have increased progenitor cells expressing CXCR4, the receptor for SDF-1 (P<0.01 and P<0.001, respectively). Human aneurysms and murine carotid aneurysms have endothelial cells, macrophages, and capillaries in the walls of the aneurysms; and the presence of capillaries in the walls of human aneurysms is associated with presence of macrophages (P=0.01). SDF-1 promotes endothelial cell and macrophage migration (P<0.01 for each), and promotes capillary tube formation (P<0.001). When mice are given anti-SDF-1 blocking antibody, there is a significant reduction in endothelial cells (P<0.05), capillaries (P<0.05), and cell proliferation (P<0.05) in the aneurysm wall. Mice given anti-SDF-1 blocking antibody develop significantly fewer intracranial aneurysms (33% versus 89% in mice given control IgG)(P<0.05).
Conclusions
These data suggest SDF-1 associated with angiogenesis and inflammatory cell migration and proliferation in the walls of aneurysms, and may have a role in the development of intracranial aneurysms.
doi:10.3171/2013.9.JNS122074
PMCID: PMC3877706  PMID: 24160472
aneurysm; inflammation; stromal cell-derived factor-1; angiogenesis; wall remodeling
9.  Subarachnoid haemorrhage (spontaneous aneurysmal) 
Clinical Evidence  2009;2009:1213.
Introduction
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).
Results
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.
Conclusions
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
10.  Multi-Modality Treatment for Intracranial Arteriovenous Malformation Associated with Arterial Aneurysm 
Objective
Intracranial arteriovenous malformation (AVM) associated with aneurysm has been infrequently encountered and the treatment for this malady is challenging. We report here on our clinical experience with AVMs associated with arterial aneurysms that were managed by multimodality treatments, including clipping of the aneurysm, microsurgery, Gamma-knife radiosurgery (GKS) and Guglielmi detachable coil (GDC) embolization.
Methods
We reviewed the treatment plans, radiological findings and clinical courses of 21 patients who were treated with GKS for AVM associated with aneurysm.
Results
Twenty-seven aneurysms in 21 patients with AVMs were enrolled in this study. Hemorrhage was the most frequent presenting symptom (17 patients : 80.9%). Bleeding was caused by an AVM nidus in 11 cases, aneurysm rupture in 5 and an undetermined origin in 1. Five patients were treated for associated aneurysm with clipping followed by GKS for the AVM and 11 patients were treated with GDC embolization combined with GKS for an AVM. Although 11 associated aneurysms remained untreated after GKS, none of them ruptured and 4 aneurysms regressed during the follow up period. Two aneurysms increased in size despite the disappearance of the AVM nidus after GKS and then these aneurysms were treated with GDC embolization.
Conclusion
If combined treatment using microsurgery, GKS and endovascular treatment can be adequately used for these patients, a better prognosis can be obtained. In particular, GKS and GDC embolization are considered to have significant roles to minimize neurologic injury.
doi:10.3340/jkns.2009.46.2.116
PMCID: PMC2744020  PMID: 19763213
Arteriovenous malformation; Aneurysm; Radiosurgery; Endovascular treatment; GDC embolization
11.  Outcomes Analysis of Ruptured Distal Anterior Cerebral Artery Aneurysms Treated by Endosaccular Embolization and Surgical Clipping 
Interventional Neuroradiology  2011;17(1):49-57.
Summary
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
12.  Combined Endovascular and Microsurgical Procedures as Complementary Approaches in the Treatment of a Single Intracranial Aneurysm 
Objective
Both endovascular coil embolization and microsurgical clipping are now firmly established as treatment options for the management of cerebral aneurysms. Moreover, they are sometimes used as complementary approaches each other. This study retrospectively analyzed our experience with endovascular and microsurgical procedures as complementary approaches in treating a single aneurysm.
Methods
Nineteen patients with intracranial aneurysm were managed with both endovascular and microsurgical treatments. All of the aneurysms were located in the anterior circulation. Eighteen patients presented with SAH, and 14 aneurysms had diameters of less than 10 mm, and five had diameters of 10-25 mm.
Results
Thirteen of the 19 patients were initially treated with endovascular coil embolization, followed by microsurgical management. Of the 13 patients, 9 patients had intraprocedural complications during coil embolization (intraprocedural rupture, coil protrusion, coil migration), rebleeding with regrowth of aneurysm in two patients, residual sac in one patient, and coil compaction in one patient. Six patients who had undergone microsurgical clipping were followed by coil embolization because of a residual aneurysm sac in four patients, and regrowth in two patients.
Conclusion
In intracranial aneurysms involving procedural endovascular complications or incomplete coil embolization and failed microsurgical clipping, because of anatomical and/or technical difficulties, the combined and complementary therapy with endovascular coiling and microsurgical clipping are valuable in providing the best outcome.
doi:10.3340/jkns.2008.43.1.21
PMCID: PMC2588162  PMID: 19096540
Cerebral aneurysm; Clipping; Coil embolization; Complementary therapy
13.  Endovascular treatment of intracranial aneurysms by interventional neurologists: first year single-center experience 
Background
Endovascular embolization of ruptured intracranial aneurysms provides an adequate treatment and long-term results with less morbidity and mortality (M&M) compared with surgical treatment. Since the last decade more and more ruptured and unruptured intracranial aneurysms (IA) undergo endovascular embolization in the United States. We present our experience of the initial one year periprocedural M&M at Paul L. Foster School of Medicine (PLFSM), Texas Tech Health Science Center (TTUHSC) in El Paso, Texas.
Methods
Demographics, technical aspects of the endovascular procedure and clinical assessment, including several commonly used scales to assess the severity in case of subarachnoid hemorrhage were collected. Perioperative complications were classified as minor and major. All data is prospectively collected in a local database. Only endovascular treated aneurysms were included in the study
Results
During the first year of opening of the interventional neurology program at our school of medicine (March 2011 and March 2012), a total 45 ruptured and unruptured intracranial aneurysms were treated with endovascular embolization. Two thirds of the patients (n = 27) presented with a ruptured IA. Within those with a ruptured aneurysm, the most median Hunt and Hess grade was 3. By large the vast majority of treated IA were in the anterior circulation and more than half measured 7–12 mm. Only three unruptured IA were <7 mm (average 5.5 mm). Complications occurred in seven patients (15%), four of them were minor without any clinical sequelae. The remaining three included; intracranial dissection and aneurysmal rupture resulting in both hemorrhagic or ischemic stroke and death in only one patient.
Conclusion
The first year experience of interventional neurology services at Paul L. Foster School of Medicine in El Paso, Texas demonstrates successful treatments with comparable national rates of morbidity and mortality.
Abbreviations
Anterior cerebral artery
Anterior communicating artery
Endovascular surgical neuroradiology
Hunt and Hess scale
Intracranial aneurysm
Internal carotid artery
Middle cerebral artery
Morbidity and mortality
Subarachnoid hemorrhage
Posterior communicating artery
Paul L. Foster School of Medicine
Texas Tech University Health Science Center
Vertebral artery
PMCID: PMC4132939  PMID: 25132904
subarachnoid hemorrhage; endovascular treatment; intracranial aneurysm; aneurysm coiling; cerebral angiography
14.  Endovascular Treatment of Very Small Intracranial Aneurysms 
Interventional Neuroradiology  2011;17(3):299-305.
Summary
The endovascular treatment of intracranial aneurysms 3 mm or less is considered controversial. The purpose of this study is to report angiographic and clinical results following coiling of such aneurysms and compare them to those of larger aneurysms (> 3 mm).
Between November 1999 and November 2009 endovascular treatment was attempted in 956 consecutive intracranial aneurysms. Of 956 aneurysms, 111 aneurysms were very small aneurysms with a maximal diameter of 3 mm or less. We conducted a retrospective analysis of angiographic and clinical outcome following coiling of very small aneurysms and subsequently comparing it to the results of larger aneurysms.
Coiling initially failed in eight aneurysms. In the remaining 103 aneurysms endovascular treatment was accomplished and immediate angiographic results showed complete aneurysm occlusion in 43 aneurysms, nearly complete aneurysm occlusion in 54 aneurysms and less than 90% aneurysm occlusion in six aneurysms. Complications occurred in the treatment of 15 aneurysms, including eight procedural ruptures, six thromboembolic events and one case of early hemorrhage. Compared with larger aneurysms, treatment of very small aneurysms was associated with a higher rate of procedural ruptures (7.2% versus 4.4%) and procedural mortality (4.7% versus 2.7%) but a lower procedural morbidity (1.9% versus 4.0%). However none of these differences reached statistical significance (p = 0.186, p= 0.388, respectively). The retreatment rate was higher for the larger aneurysms (8.2% and 6.3%), but this was not significant either (p= 0. 496). At nine-month follow-up significantly more small aneurysms were found to have a stable occlusion grade compared to large aneurysms.
Endovascular treatment of very small aneurysms is feasible with a lower retreatment rate compared to large aneurysms (> 3 mm). However the data also suggest that endovascular treatment of very small aneurysms might be associated with an increased risk of procedural ruptures and mortality. At nine-month follow-up results indicate significantly less compaction in the very small aneurysms.
PMCID: PMC3396036  PMID: 22005691
intracranial aneurysm, endovascular treatment, complication, outcome, subarachnoid hemorrhage, intraprocedural rupture
15.  Immediate and follow-up results for 44 consecutive cases of small (<10 mm) internal carotid artery aneurysms treated with the pipeline embolization device 
Background:
The pipeline embolization device (PED) provides effective, durable and safe endovascular reconstruction of large and giant intracranial aneurysms. However, 80% of all cerebral aneurysms found in the general population are less than 10 mm in size. Treatment of small aneurysms (<10 mm) with flow diverters may be advantageous over endosaccular modalities that carry risks of procedural rupture during aneurysm access or coil placement.
Methods:
We retrospectively reviewed a prospective, single-center aneurysm database to identify all patients with small (<10 mm) internal carotid artery (ICA) aneurysms who underwent endovascular treatment using the PED. Patient demographics, aneurysm characteristics, procedural details, complications, and technical and clinical outcomes were analyzed.
Results:
Forty-four cases were performed in 41 patients (age range 31-78 years). PED was successfully implanted in 42 cases. A single PED was used in 37/42 (88%) cases. Mean postprocedure hospital stay was 1.7 ± 0.3 days and 98% of patients were discharged home. Major complication occurred in one patient (2.3%), who died of early subarachnoid hemorrhage. Transient neurological deficit, delayed intracerebral hemorrhage (asymptomatic), and delayed groin infection occurred in one patient each. Follow-up rate was 91.8% (45 aneurysms in 35 patients) with a mean follow-up of 4.0 ± 1.9 months. By 6 months post-PED implantation, angiographic success (complete or near complete aneurysm occlusion) was observed in 80%. Mild (<50%), asymptomatic, nonflow limiting in-stent stenosis was observed in 5.4% (2/37 cases). All the 35 patients with follow-up remained at preprocedure neurological baseline.
Conclusion:
Small (<10 mm) ICA aneurysm treatment with PED implantation is safe and carries a high rate of early angiographic success.
doi:10.4103/2152-7806.117711
PMCID: PMC3779399  PMID: 24083050
Cerebral aneurysms; flow diverter; pipeline embolization device
16.  Clinical Analysis of Giant Intracranial Aneurysms with Endovascular Embolization 
Objective
The purpose of this study was to perform a clinical analysis of nine patients with giant aneurysms managed with endovascular embolization.
Methods
From March 2000 to September 2009, nine cases of giant intracranial aneurysms were treated (five unruptured and four ruptured). The nine patients included two males and seven females who were 47 to 72 years old (mean, 59.2 years old). The types of giant intracranial aneurysms were eight internal carotid artery aneurysms and one vertebral artery aneurysm. Treatment for each aneurysm was chosen based on anatomic relationships, aneurysmal factors, and the patients' clinical state. Three patients underwent endovascular coiling with stent and six initially underwent endovascular coiling alone. Medical records, operation records, postoperative angiographies, and follow-up angiographies were reviewed retrospectively.
Results
Eight out of nine patients showed good clinical outcomes. (six were excellent and two were good) after a mean follow-up period of 27.9 months. Six (67%) of the nine patients had a near-complete occlusions on the post-operative angiogram (mean, 13.5 months after the procedure). Occlusion rates of 90% or higher were obtained for eight (89%) of all the patients. One patient died due to multiple organ failure. Stents were ultimately required at some point for managing four aneurysms. Two patients needed additional procedures because of aneurysm regrowth.
Conclusion
Endovascular treatment could be an alternative option for managing giant aneurysms adjuvant to surgical intervention.
doi:10.7461/jcen.2012.14.1.22
PMCID: PMC3471252  PMID: 23210026
Giant intracranial aneurysm; endovascular coiling
17.  The Merits of Endovascular Coil Surgery for Patients with Unruptured Intracranial Aneurysms 
Objective
The purpose of this study was to report the morbidity, mortality, angiographic results, and merits of elective coiling of unruptured intracranial aneurysms.
Methods
Ninety-six unruptured aneurysms in 92 patients were electively treated with detachable coils. Eighty-one of these aneurysms were located in the anterior circulation, and 15 were located in the posterior circulation. Thirty-six aneurysms were treated in the presence of previously ruptured aneurysms that had already undergone operation. Nine unruptured aneurysms presented with symptoms of mass effect. The remaining 51 aneurysms were incidentally discovered in patients with other cerebral diseases and in individuals undergoing routine health maintenance. Angiographic and clinical outcomes and procedure-related complications were analyzed.
Results
Eight procedure-related untoward events (8.3%) occurred during surgery or within procedure-related hospitalization, including thromboembolism, sac perforation, and coil migration. Permanent procedural morbidity was 2.2% ; there was no mortality. Complete occlusion was achieved in 73 (76%) aneurysms, neck remnant occlusion in 18 (18.7%) aneurysms, and incomplete occlusion in five (5.2%) aneurysms. Recanalization occurred in 8 (15.4%) of 52 coiled aneurysms that were available for follow-up conventional angiography or magnetic resonance angiography over a mean period of 13.3 months. No ruptures occurred during the follow-up period (12-79 months).
Conclusion
Endovascular coil surgery for patients with unruptured intracranial aneurysms is characterized by low procedural mortality and morbidity and has advantages in patients with poor general health, cerebral infarction, posterior circulation aneurysms, aneurysms of the proximal internal cerebral artery, and unruptured aneurysms associated with ruptured aneurysm. For the management of unruptured aneurysms, endovascular coil surgery is considered an attractive alterative option.
doi:10.3340/jkns.2008.43.6.270
PMCID: PMC2588249  PMID: 19096631
Endovascular coil surgery; Complication; Unruptured intracranial aneurysm
18.  Endovascular Treatment of Intracranial Ruptured Aneurysms Associated with Arteriovenous Malformations: a Clinical Analysis of 14 Hemorrhagic Cases 
Interventional Neuroradiology  2011;17(1):78-86.
Summary
This study investigated and summarized endovascular therapeutic strategies for intracranial ruptured aneurysms associated with arteriovenous malformations (AVMs). Between June 2005 and June 2009, we identified 16 aneurysms in 14 hemorrhagic cases of intracranial AVM using digital subtraction angiography (DSA). Of the 16 aneurysms, 14 were ruptured and two were unruptured. Aneurysms were classified as types I to IV, and were treated. Aneurysm treatment was followed by AVM treatment via various therapies, including embolization, gamma knife radiotherapy, or follow-up and observation to reduce the risk of aneurysm rupture or intracranial hemorrhage. Over a follow-up period ranging from six months to one year, none of the patients had aneurysm ruptures or intracranial hemorrhage. Most (13/14) patients had a Glasgow Outcome Scale (GOS) score of 5, and one patient had a score of 4. Sixteen aneurysms were treated successfully, as confirmed by DSA examination, and no AVMs re-grew. Clinical therapeutic strategies for intracranial ruptured aneurysms associated with AVMs should include aneurysm treatment first to reduce the risk of rupture and intracranial hemorrhage, eventually leading to a better prognosis.
PMCID: PMC3278018  PMID: 21561563
aneurysm, arteriovenous malformation, endovascular treatment
19.  Leo Stent for Endovascular Treatment of Broad-Necked and Fusiform Intracranial Aneurysms 
Interventional Neuroradiology  2007;13(3):255-269.
Summary
The advent of intracranial stents has widened the indications for endovascular treatment of broad-necked and fusiform aneurysms. Leo stent is a self-expandable, nitinol, braided stent dedicated to intracranial vessels. The aim of this study is to present our experience in endovascular treatment of broad-necked and fusiform intracranial aneurysms using self-expanding, nitinol Leo stents.
Between February 2004 and November 2006, 25 broad-necked and three fusiform aneurysms in 28 patients were treated using Leo stents in our centre. There were 18 patients who experienced acute subarachnoid haemorrhage due to aneurysm rupture, two patients who experienced SAH at least 12 months ago and in eight patients aneurysms were found incidentally. Aneurysms were located as follows: internal carotid artery15, basilar artery5, basilar tip3, posterior inferior cerebral artery2, M1/M2 segment1, A2 segment1 and vertebral artery1.
There were no difficulties with stent deployment and delivery. All patients after acute SAH (n=18) underwent stent implantation and coil embolization in one procedure. The remaining patients underwent coil embolization in a staged procedure. Immediate aneurysm occlusion of more than 95% was achieved in all patients who underwent stent placement and coil embolization in one procedure. There were three thromboembolic complications encountered in patients in an acute setting of SAH, preloaded only on acetylsalicylic acid. Use of abciximab led to patency within the stent and parent vessel. However, one of these patients presented rebleeding from the aneurysm during administration of abciximab and died.
Application of Leo stents in cases of broadnecked and fusiform intracranial aneurysms is safe and effective with a low complication rate.
PMCID: PMC3345341  PMID: 20566117
endovascular, intracranial aneurysm, Leo, stent, fusiform
20.  Technical challenges to surgical clipping of aneurysmal regrowth with coil herniation following endovascular treatment – a case report 
In recent years, technical developments have made endovascular procedures attractive therapeutic options and enabled the endovascular surgeon to redefine the management of cerebral aneurysms. However, as the number of aneurysms undergoing endovascular therapy has grown, so has the number of patients with incompletely treated aneurysms who are presenting for further management. In cases of failure of endovascular treatment caused by either incomplete occlusion or regrowth of the aneurysm, a complementary treatment is often necessary. Surgical treatment of these patients is challenging. We present a case of a ruptured posterior cerebral artery aneurysm treated initially with endovascular coiling that left behind significant residual aneurysmal sac. Regrowth of the aneurysm documented on follow-up was treated surgically. At surgery, the coil was found to have herniated through the aneurysmal sac into the subarachnoid space, and the aneurysm was successfully clipped without removing the coils. We review the regrowth of aneurysms following endovascular therapy and potential problems and challenges of surgically managing these lesions.
doi:10.1186/1752-1947-1-168
PMCID: PMC2217529  PMID: 18053204
21.  Chest pain with ST segment elevation in a patient with prosthetic aortic valve infective endocarditis: a case report 
Introduction
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.
Conclusion
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.
doi:10.1186/1752-1947-5-408
PMCID: PMC3177923  PMID: 21864374
22.  Pipeline embolization device (PED) for neurovascular reconstruction: initial experience in the treatment of 101 intracranial aneurysms and dissections 
Neuroradiology  2011;54(4):369-382.
Introduction
The purpose of this study was to evaluate the safety and efficacy of the recently available flow diverter “pipeline embolization device” (PED) for the treatment of intracranial aneurysms and dissections.
Methods
Eighty-eight consecutive patients underwent an endovascular treatment of 101 intracranial aneurysms or dissections using the PED between September 2009 and January 2011. The targeted vessels include 79 (78%) in the anterior circulation and 22 (22%) in the posterior circulation. We treated 96 aneurysms and 5 vessel dissections. Multiple devices were implanted in 67 lesions (66%).
Results
One technical failure of the procedure was encountered. Immediate exclusion of the target lesion was not observed. Angiographic follow-up examinations were carried out in 80 patients (91%) with 90 lesions and revealed complete cure of the target lesion(s) in 47 (52%), morphological improvement in 32 lesions (36%), and no improvement in 11 lesions (12%). Six major complications were encountered: one fatal aneurysm rupture, one acute and one delayed PED thrombosis, and three hemorrhages in the dependent brain parenchyma.
Conclusion
Our experience reveals that the PED procedure is technically straightforward for the treatment of selected wide-necked saccular aneurysms, fusiform aneurysms, remnants of aneurysms, aneurysms with a high likelihood of failure with conventional endovascular techniques, and dissected vessels. While vessel reconstruction, performed after dissection, is achieved within days, remodeling of aneurysmal dilatations may take several months. Dual platelet inhibition is obligatory. Parenchymal bleeding into brain areas dependent on the target vessel is uncommon.
doi:10.1007/s00234-011-0948-x
PMCID: PMC3304061  PMID: 21881914
Flow diverter; Pipeline embolization device; Aneurysm; Dissection
23.  Management of neurological complications of infective endocarditis in ICU patients 
Patients with infective endocarditis (IE) are generally referred to the intensive care unit (ICU) for one or more organ dysfunctions caused by complications of IE. Neurologic events are frequent causes of ICU admission in patients with IE. They can arise through various mechanisms consisting of stroke or transient ischemic attack, cerebral hemorrhage, mycotic aneurysm, meningitis, cerebral abscess, or encephalopathy. Most complications occur early during the course of IE and are a hallmark of left-sided abnormalities of native or prosthetic valves. Occlusion of cerebral arteries, with stroke or transient ischemic attack, accounts for 40% to 50% of the central nervous system complications of IE. CT scan is the most easily feasible neuroimaging in critically unstable patients. However, magnetic resonance imaging is more sensitive and when performed should follow a standardized protocol. In patients with ischemic stroke who are already receiving oral anticoagulant therapy, this treatment should be replaced by unfractionated heparin for at least 2 weeks with a close monitoring of coagulation tests. Mounting evidence shows that, for both complicated left-sided native valve endocarditis and Staphylococcus aureus prosthetic valve endocarditis, valve replacement combined with medical therapy is associated with a better outcome than medical treatment alone. In a recent series, approximately 50% of patients underwent valve replacement during the acute phase of IE before completion of antibiotic treatment. After a neurological event, most patients have at least one indication for cardiac surgery. Recent data from literature suggest that after a stroke, surgery indicated for heart failure, uncontrolled infection, abscess, or persisting high emboli risk should not be delayed, provided that the patient is not comatose or has no severe deficit. Neurologic complications of IE contribute to a severe prognosis in ICU patients. However, patients with only silent or transient stroke had a better prognosis than patients with symptomatic events. In addition, more than neurologic event per se, a better predictor of mortality is neurologic dysfunction, which is associated with location and extension of brain damage. Patients with severe neurological impairment and those with brain hemorrhage have the worse outcome.
doi:10.1186/2110-5820-1-10
PMCID: PMC3224466  PMID: 21906336
24.  Endovascular Coil Embolization After Clipping: Endovascular Treatment of Incompletely Clipped or Recurred Cerebral Aneurysms 
Objective
The presence of a cerebral aneurysm remnant after surgical clipping is associated with a risk of regrowth or rupture. For these recurred aneurysms, coil embolization can be considered as a treatment option. We retrospectively reviewed cases of ruptured or regrown aneurysms after clipping treated by endovascular coil embolization.
Materials and Methods
We conducted a retrospective review of patients with ruptured or recurred aneurysm after clipping, who underwent coil embolization between January 1995 and December 2013. We evaluated clinical information and the outcomes of these cases.
Results
Eight patients were treated by endovascular coil embolization after surgical clipping. Six aneurysms were located in the anterior communicating artery, one in the posterior communicating artery, and one in the middle cerebral artery bifurcation. All patients were initially treated by surgical clipping because of a ruptured aneurysm. Aneurysm recurrence at the initial clipping site was detected in all cases. The median interval from initial to second presentation was 42 months. In four patients, aneurysms were detected before rupture and the four remaining patients presented with recurrent subarachnoid hemorrhage. All patients were treated by coil embolization and showed successful occlusion of aneurysms without complications.
Conclusion
Endovascular coil embolization can be a safe and successful treatment option for recurred aneurysms after clipping.
doi:10.7461/jcen.2014.16.3.262
PMCID: PMC4205253  PMID: 25340029
Intracranial aneurysm; Recurrence; Coil embolization; Clipping
25.  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

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