External Validation of the ELAPSS Score for Prediction of Unruptured Intracranial Aneurysm Growth Risk / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: Prediction of intracranial aneurysm growth risk can assist physicians in planning of follow-up imaging of conservatively managed unruptured intracranial aneurysms. We therefore aimed to externally validate the ELAPSS (Earlier subarachnoid hemorrhage, aneurysm Location, Age, Population, aneurysm Size and Shape) score for prediction of the risk of unruptured intracranial aneurysm growth. METHODS: From 11 international cohorts of patients ≥18 years with ≥1 unruptured intracranial aneurysm and ≥6 months of radiological follow-up, we collected data on the predictors of the ELAPSS score, and calculated 3- and 5-year absolute growth risks according to the score. Model performance was assessed in terms of calibration (predicted versus observed risk) and discrimination (c-statistic). RESULTS: We included 1,072 patients with a total of 1,452 aneurysms. During 4,268 aneurysm-years of follow-up, 199 (14%) aneurysms enlarged. Calibration was comparable to that of the development cohort with the overall observed risks within the range of the expected risks. The c-statistic was 0.69 (95% confidence interval [CI], 0.64 to 0.73) at 3 years, compared to 0.72 (95% CI, 0.68 to 0.76) in the development cohort. At 5 years, the c-statistic was 0.68 (95% CI, 0.64 to 0.72), compared to 0.72 (95% CI, 0.68 to 0.75) in the development cohort. CONCLUSIONS: The ELAPSS score showed accurate calibration for 3- and 5-year risks of aneurysm growth and modest discrimination in our external validation cohort. This indicates that the score is externally valid and could assist patients and physicians in predicting growth of unruptured intracranial aneurysms and plan follow-up imaging accordingly.

Health-related quality of life in patients with asymptomatic unruptured intracranial aneurysms after endovascular treatment / 中国脑血管病杂志

Objective: The aim of this study was to analyze the health-related quality of life (HRQoL) and their influencing factors in patients with asymptomatic unruptured intracranial aneurysms (UIAs) after endovascular treatment. Methods: We retrospectively reviewed 44 patients with asymptomatic UIAs (56aneurysms) received endovascular treatment in Xuanwu Hospital of Capital Medical University from January 2015 to May 2017. The average follow-up time was (28 ±9) month. The clinical data of patients were collected, and the HRQoL was evaluated by the SF-36 questionnaire. The SF-36 results and influencing factors were analyzed. Results: Forty-four patients with UIAs in this study showed significantly lower body pain,physical function,and mental health in the three dimensions of the SF-36 scale than the normal population in China (75 ± 15,82 ± 15 and 71 ± 14 vs. 83 ±20,88 ± 17 and 79 ± 15;t =2.89,2. 14 and 3. 34 Respectively; all P 3 months were respective 76 ±15 and 89 ± 7 points (t = -2. 11); the differences were significant (both P 3 months were respective 73 ± 17 and 90 ± 5 (l = -2.74);the differences were significant (both P <0.05). Multivariate analysis showed that the course of disease ≤ 3 months was the independent risk factor of PCS (95% CI 2. 23 -27. 42, P = 0. 02), and sleep time<6h was the independent risk factor of MCS (95% CI 1. 44 -28. 92, P = 0. 03). 12.5% (4/32) of these patients failed to recover to normal work before treatment even after long-term recovery (28 ± 9 months). Conclusions: HRQoL results in patients with asymptomatic UIAs after endovascular treatment were lower than those in the general population in multiple dimensions of SF-36. The course of disease ≤3 months and daily sleep time < 6h are independent risk factors for PCS and MCS,respectively.

Risk assessment of chronic subdural hematoma after surgical clipping of intracranial aneurysms / 中国脑血管病杂志

Objective To compare the incidence of chronic subdural hematoma(CSDH) and its risk factors after surgical clipping unruptured intracranial aneurysms(UIA) and ruptured intracranial aneurysms (RIA). Methods From January 2006 to December 2015,410 consecutive patients with UIA and 464 patients with RIA treated with aneurysm clipping at the Department of Neurosurgery,Hanzhong Central Hospital were enrolled retrospectively. According to whether having postoperative CSDH or not(evaluating subdural effusion and its degree with head CT scan),the difference of the incidence of CSDH after aneurysm clipping in patients with UIA and RIA were compared,and logistic regression analysis was used to evaluate the risk factors for the occurrence of postoperative CSDH. Results (1) The incidence of CSDH after UIA clipping was higher than that of RIA(11.0% [45/410] vs. 3.0% [14/464]). There was significant difference (P<0.01). The rate of surgical treatment for CSDH because of the symptoms of nervous system injury in patients with UIA was higher than that in patients with RIA(35.6% [16/45] vs. 28.6% [4/14], P<0.05). (2) Multivariate logistic regression analysis showed that unruptured aneurysms (OR,2.59, 95% CI 2.19-3.06,P<0.01),subdural effusion ≥5 mm (OR,1.98,95% CI 1.94-2.03,P<0.01), and CT value≥40 HU (OR,2.87,95% CI 2.65-3.01,P<0.01) were the independent risk factors for postoperative CSDH in patients with intracranial aneurysm. Conclusions The incidence of CSDH was significantly higher than that of RIA after UIA clipping. UIA,subdural effusion ≥5 mm,and CT value ≥40 HU were the independent risk factors for CSDH of intracranial aneurysms.

Clinical features and risk factors of internal carotid artery stenosis coexisting with unruptured intracranial aneurysm / 中华内科杂志

Objective To analyze the incidence of intracranial unruptured aneurysms in patients with internal carotid artery (ICA) stenosis (≥30％),the characteristics of aneurysms and risk factors in patients with ICA stenosis and intracranial aneurysm.Methods Clinical data of patients receiving digital subtraction angiography (DSA) at Peking University Third Hospital between January 2012 and June 2015 were retrospectively reviewed to identify patients with ICA stenosis and unruptured intracranial aneurysm.Results Among 247 patients with ICA stenosis,16 patients (6.5％) with intracranial unruptured aneurysms were found including 7 females and 9 males with age from 47 to 83 years old.The severity of ICA stenosis in aneurysm group was (85.3± 13.2)％,whereas it was (77.7± 17.9)％ in non-aneurysm group.The incidence of aneurysms in male patients with ICA stenosis was 4.5％ (9/202),and 15.6％(7/45) in female patients (P＜ 0.05).The incidence of aneurysms in patients with only in cervical segment (C 1 segment) of ICA was 4.4％ (10/226),whereas that of other segment was 28.6％(6/21) (P＜0.05).Logistic multivariate regression analysis showed that gender and stenosis location were independent risk factors of aneurysms in patients with ICA stenosis.Conclusions In patients with ICA stenosis,the incidence of aneurysm is much higher than that in general population.Intracranial aneurysms are more likely to occur in women and patients with ICA stenosis other than C 1 segment.

Clinical Risk Factors Affecting Procedure-Related Major Neurological Complications in Unruptured Intracranial Aneurysms

PURPOSE: The operative risk and natural history rupture risk for the treatment of unruptured intracranial aneurysms (UIAs) should be evaluated. The purpose of this study was to report our experience with treating UIAs and to outline clinical risk factors associated with procedure-related major neurological complications. MATERIALS AND METHODS: We treated 1158 UIAs in 998 patients over the last 14 years. All patients underwent operation performed by a single microvascular surgeon and two interventionists at a single institution. Patient factors, aneurysm factors, and clinical outcomes were analyzed in relation to procedure-related complications. RESULTS: The total complication rate was 22 (2.2%) out of 998 patients. Among them, complications developed in 14 (2.3%) out of 612 patients who underwent microsurgery and in 8 (2.1%) out of 386 patients who underwent endovascular procedures. One patient died due to intraoperative rupture during an endovascular procedure. The procedure-related complication was highly correlated with age (p=0.004), hypertension (p=0.002), and history of ischemic stroke (p<0.001) in univariate analysis. The multivariate analysis revealed previous history of ischemic stroke (p=0.001) to be strongly correlated with procedure-related complications. CONCLUSION: A history of ischemic stroke was strongly correlated with procedure-related major neurological complications when treating UIAs. Accordingly, patients with UIAs who have a previous history of ischemic stroke might be at risk of procedure-related major neurological complications.

Rupture of Very Small Intracranial Aneurysms: Incidence and Clinical Characteristics

OBJECTIVE: Unruptured intracranial aneurysms are now being detected with increasing frequency in clinical practice. Results of the largest studies, including those of the International Study of Unruptured Intracranial Aneurysms, indicate that surgical and endovascular treatments are rarely justified in small aneurysms. However, we have encountered several cases of rupture of small and very small aneurysms in our clinical practice. This retrospective study analyzed the incidence and clinical characteristics of very small ruptured aneurysms. MATERIALS AND METHODS: A total of 200 patients with aneurysmal subarachnoid hemorrhage between January 2012 and December 2014 were reviewed. Various factors were analyzed, including the aneurysm location and size as well as the associated risk factors. RESULTS: The mean age of patients was 56.31 +/- 13.78 (range, 25-89) years, and the male to female ratio was 1:2.1. There were 94 (47%) small-sized ( 10 mm) aneurysms. Of these, 30 (15%) aneurysms were very small-sized (< 3 mm). The most frequent site of aneurysms was the anterior communicating artery (ACoA). However, the proportion of aneurysms at the ACoA was significantly high in very small aneurysms (53.3%, p = 0.013). Hypertension was a significant risk factor for rupture of very small aneurysms (p < 0.001). CONCLUSION: About half of our cases of ruptured aneurysms involved the rupture of small and very small aneurysms. The most common site of rupture of very small aneurysm was the ACoA. Rupture of small and very small aneurysms is unpredictable, and treatment may be considered in selected high-risk patients according to factors such as young age, ACoA location, and hypertension.

The Usefulness of the Frontolateral Approach as a Minimally Invasive Corridor for Clipping of Anterior Circulation Aneurysm

OBJECTIVE: Several studies have reported on the effectiveness of fronto-lateral craniotomy in reducing the operating time and post-operative complications. However, no study has practically evaluated this method from the cosmetic point of view. MATERIALS AND METHODS: We designed this study for comparison of the clinical differences and cosmetic outcomes between the frontolateral craniotomy and the conventional pterional craniotomy for clipping of unruptured intracranial aneurysms. We performed a retrospective analysis of the two groups based on their medical records and radiologic findings juxtaposed with their length of hospital stay, intensive care unit day and operation time, and the emergence of postoperative complication, mean size of aneurysm, and temporal depression. RESULTS: After careful comparison of the thickness of temporalis muscle between the craniotomy side and the contralateral side, the results clearly showed that the conventional pterional craniotomy group was asymmetric by a p value of 0.152 and the frontolateral craniotomy group was symmetric by a p value of 0.002. CONCLUSION: Frontolateral craniotomy could be a practical alternative for patients with an unruptured intracranial aneurysm in the anterior circulation including the posterior communicating artery, particularly those who are in a medically poor state or who highly demand minimal aesthetic mutilation.

Surgical Results of Unruptured Intracranial Aneurysms in the Elderly : Single Center Experience in the Past Ten Years

OBJECTIVE: 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. METHODS: 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). RESULTS: 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. CONCLUSION: Surgical clipping of unruptured intracranial aneurysms in elderly group could get it as a favorable outcome in well selected cases.

Guidelines for the Management of Unruptured Intracranial Aneurysm / 대한뇌혈관외과학회지

Intracranial aneurysmal rupture causes subarachnoid hemorrhage which usually leads to fatality or severe disability. Treatment of unruptured intracranial aneurysms (UIAs) can substantially reduce the risk of rupture and prevent the grave consequences, but the risk of prophylactic treatment cannot be ignored. UIAs have diverse characteristics and management strategy needs to be tailored according to their location, size and clinical status. In the absence of level I evidence, the treatment guidance often relied on expert's opinions and experience. Knowledge of the natural course and management risks of individual aneurysms can help to guide treatment decision, but the natural history is still controversial and risks are not clearly defined. The Korean Society of Cerebrovascular Surgeons (KSCVS) decided to issue a Korean version of UIA management guideline as a framework for the treatment decision and as a basis for future studies, following 'Guideline Development Manual' of the Clinical Research Center for Stroke (CRCS). The organized committee systematically reviewed relevant literature and major guidelines published between January 2000 and July 2010 and took a developmental strategy of adaptation rather than de novo methods. On the basis of interpretation of the published evidences, recommendations were synthesized, and the level of evidence and the grade of recommendation were determined using the methods adapted from those of the US Agency for Healthcare Policy and Research and CRCS. The current guideline focuses on three domains of natural history, diagnosis and treatment of UIAs. The hierarchy of evidence and the recommendation grading indicate the current level by the literature and do not indicate the necessity or the prohibition of a certain clinical practice. Accordingly, this guideline cannot provide the answer for every clinical situation and should not take precedence over the clinical judgment of responsible physicians for individual patients. The final judgment regarding the care of a particular patient must be made by the physician and patient in light of circumstances specific to that patient. This is the first version of the UIA management guideline in Korea and new evidences will be timely and continuously updated in the future guidelines.

Surgical Outcome of the Unruptured Intracranial Aneurysm / 대한뇌혈관외과학회지

OBJECT: The surgical management of patients with intracranial aneurysm continues to be controversial, but the best results of treating an aneurysm can be achieved with treating it before it ruptures. The purpose of this study is to evaluate the surgical risk of treating unruptured intracranial aneurysms. METHODS: Between January 2000 to December 2007, 46 unruptured intracranial aneurysms were treated with aneurismal neck clipping. The clinical outcome was retrospectively evaluated according to the Glasgow Outcome Scale about one month after surgery. RESULTS: The patients consisted of 24 females and 22 males. The mean age was 56.6 years (range: 37-80). For the aneurysm location, 27 (58.8%) were at the middle cerebral artery, 10 (21.7%) were at the anterior communicating artery, three (6.5%) were at the posterior communication artery, two (4.3%) were at the internal carotid artery, two (4.3%) were at the anterior choroidal artery, one (2.2%) was at the anterior cerebral artery and one (2.2%) was at the vertebral artery. The size of the aneurysm was below 5mm for 6 patients (13%), 6 to 10mm for 30 patients (65.2%), 11 to 25mm for 9 patients (19.6%) and > or =25mm for 1 patient (2.2%). The clinical outcome was good for 39 patients (84.8%), moderate disability was noted for 5 patients (10.9%) and severe disability was noted for 2 patients (4.3%). CONCLUSION: In this study, the morbidity and mortality rates were favorable compared with those of the previous reports. Our results suggest that aneurysms associated with a ruptured lesion or those larger than 10mm could be considered for treatment. These results will be very helpful to determine whether or not to proceed with surgery.

Management of Unruptured Intracranial Aneurysms in Patients with Ischemic Cerebrovascular Disease / 대한뇌혈관외과학회지

OBJECTIVE: Unruptured intracranial aneurysms (UIA) accompanied by ischemic cerebrovascular disease (CVD), will be an increasing problem for neurosurgeons in the future, as the population ages. These patients are a high-risk group of treatment. UIA associated with ischemic CVD in seventeen patients were analyzed and their managements are discussed. METHODS: In the past four years, one hundred seventy seven cases of UIAs were treated in our hospital. Among them, seventeen patients suffered from ischemic CVD before treatment of aneurysm. The age of patients varied from 40 to 78 (mean 63.2) years old. The associated ischemic CVD was that transient ischemic attack (TIA) was nine, minor completed stroke in eight patients. There was permanent neurological deficit in two patients. Microsurgical treatment underwent for ten patients and seven patients were treated with endovascular technique. RESULTS: Fourteen patients were fully recovered from surgical and endovascular management. In clipping group, hemiparesis event occurred in one patient after the surgery. The patient suffered from ischemia-related permanent neurological worsening. There were two patients who developed neurological deficit following endovascular treatment for UIA in seven patients of coiling group. One patient was recovered after rehabilitation but the other patient didn't improve left hemiparesis until discharge. This patient had bilateral paraclinoid aneurysms. We treated these lesions simultaneously and coil embolization for the aneurysm was uneventful. However, left side weakness developed after the procedure. Angiography revealed occlusion of cortical branches of middle cerebral artery and MRI scan showed hyperintense areas in the right motor cortex. CONCLUSION: Our results suggest that surgical treatment of unruptured cerebral aneurysm is not contraindicated in patients with CVD. However, the treatment of UIA accompanied by CVD should be performed only after careful examination of the factors involved in the particular ischemic episodes. Careful case selection and perioperative management are mandatory for preventing surgical complications.

Clinical Analysis of Surgical and Endovascular Treatment of Unruptured Intracranial Aneurysm / 대한뇌혈관외과학회지

OBJECTIVE: The purpose of this study was to review factors used to determine whether a patient with an unruptured intracranial aneurysm is treated using surgical therapy or endovascular therapy. METHODS: We retrospectively reviewed the records of 68 patients with 74 unruptured intracranial aneurysms who underwent embolization with Guglielmi Detachable Coil (GDC) or surgical occlusion at our institution between April 1990 and December 2005. Surgical clipping was performed in 58 consecutive patients (16 men and 42 women) with 63 unruptured intracranial aneurysms, and endovascular coiling was performed in 10 consecutive patients (4 men and 6 women) with 11 unruptured intracranial aneurysms. There were no standard selection criteria, irrespective of whether the patient was treated with endovascular coil therapy or with neurosurgical clip occlusion. RESULTS: Out of 58 patients who underwent surgical treatment, 3 (5.2%) had fair outcome. Each of these 3 had risk factors for surgical intervention: calcification, wide neck, or thrombosed giant aneurysm. GDC embolization in 1 (10%) patient with an unruptured pericallosal artery aneurysm resulted in a fair outcome due to infarction. CONCLUSION: Management decisions in patients with unruptured intracranial aneurysms require accurate assessment of the risk factors (such as aneurysm size, location, presence of calcification and/or atheroma, and patient age).

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.

Surgical Experiences of Unruptured Intracranial Aneurysms / 대한뇌혈관외과학회지

Object : This study was conducted to evaluate the surgical results of the active treatment of unruptured intracranial aneurysms (UIAs) and to suggest treatment indications. METHODS: Operations were performed on 49 patients with 52 UIAs between 1999 and 2005. Medical records and radiologic studies of the patients with UIAs were retrospectively reviewed. The clinical outcomes were evaluated in each patient by the modified Glasgow Outcome Scale (m-GOS) one month after operation. RESULTS: UIAs had a high frequency of a middle cerebral artery (MCA) and an internal carotid artery (ICA) aneurysm. Forty-four UIAs (84.6%) ranged between 5 mm to 15 mm in diameter. Fortysix UIAs were treated by clipping, 2 by wrapping, and coil embolization was used in 3 UIAs. In one patient, which had only one UIA, one procedure and one operation was performed. There was no surgical mortality. In most patients, surgical complications or neurological deteriorations were not found. In three patients, minor neurological deficits of ptosis (2 patients) and spinal subdural hematoma (1 patient) were newly developed after operation. However the patients completely recovered within 3 months after operation. Finally, the surgical mortality and morbidity rate was 0%. CONCLUSION: If the UIAs are larger than 5 mm in diameter and located in a susceptible area for rupture, surgical treatment should be considered for the UIAs. If operation is performed by an expert neurosurgeon, surgical clipping is one of the best treatment modalities with or without endovascular treatment.

Clinical Outcome of Surgery for Unruptured Intracranial Aneurysms

OBJECTIVE: To determine the rationale for treating pure unruptured intracranial aneurysms(UIAs), it is mandatory to know the risk of each treatment modality. The purpose of this study is to evaluate the surgical risk for treating UIAs. METHODS: Between December 1994 and May 2005, 147 unruptured aneurysms in 135 patients were treated. The majority of these cases (94.6%) were treated with aneurysmal neck clipping. The remainder received aneurysmal wrapping (2.7%), trapping with bypass (2.0%), or proximal occlusion (0.7%). The clinical outcomes were evaluated in each patient by the Glasgow Outcome Scale at one month post-surgery. RESULTS: The patient pool consisted of 41 males and 94 females. The mean age was 55.9 years (range: 16~82). The aneurysms were located at middle cerebral artery in 63 (42.9%), anterior communicating artery 30 (20.4%), posterior communicating artery in 26 (17.7%), internal carotid artery(ICA) in 14 (9.5%), anterior choroidal artery in 4 (2.7%) and others in 10 (6.9%). One hundred fifteen (78.2%) of aneurysms were small (25mm); 29 (19.7%) and 3 (2.1%) respectively. More than ninety percent (91.1%) of all patients recovered well. Mild to severe disability was seen in 8.7% of the patients. One patient succumbed to complications following injury to the ICA. CONCLUSION: The mortality and morbidity associated with UIA surgery at our hospital compared very favorably to the previous reported literature and with the previously established natural history of this disease.

Manangement Outcome of 372 Patients with Unruptured Intracranial Aneurysms / 대한뇌혈관학회지

OBJECTIVE: The purpose of this study was to provide management strategy and to improve management outcome of patients with unruptured intracranial aneurysms (UIA). PATIENTS AND METHODS: The authors reviewed the database as sources for identifying and analyzing patients, and analyzed the management outcome of patients with UIA. From June 1979 to June 1999, among total of 1,801 patients treated for intracranial aneurysms, 372 patients with 437 unruptured aneurysms were treated by surgery (335 patients) or neurointervention (37 patients). One hundred and forty - three patients with 158 UIA had no history of SAH from a different aneurysm (group 1), and 229 patients with 279 UIA had a ruptured aneurysm that have been repaired simultaneously or before treatment of UIA (group 2). We reviewed the rate of favorable (good, fair) and unfavorable (poor or dead) outcome one year after the treatment. RESULTS: The rate of favorable and unfavorable outcome in group 1 was 96.5% and 3.5% respectively. In Group 2, the rate was 93.5% and 6.5%. However, the most of the unfavorable outcome in group 2 came from treatment of the ruptured aneurysm, or SAH. The only significant factor contributed to unfavorable outcome in group 1 was size of UIA. Those of group 2 were age, Fisher grade, Hunt - Hess grade, and aneurysm number. Complications attributable to surgical or endovascular treatment of UIA that occurred in 38 of 372 patients (10.2%) were cerebral infarction (17), intracerebral hemorrhage (10), epidural hematoma (4), cranial nerve injury (3), infection (2), venous infarction (1), and subarachnoid hemorrhage (1). CONCLUSION: Rupture of an intracranial aneurysm is a devastating event. The safe size below which rupture is unlikely is unclear. There appears to be increased risk from unruptured aneurysms discovered in SAH patients. All unruptured aneurysms in healthy patients as well as in patients with history of SAH should be repaired.

Management of Unruptured Intracranial Aneurysms-Natural Course and Surgical Outcomes

OBJECTIVES: The best results of treating intracranial aneurysms can be achieved with treating aneurysm before they rupture. Some recent reports about the risk of the bleeding of the unruptured intracranial aneurysm(UIA) being too low(0.05% per year) compared with 1~2% of the previously reported bleeding probability, casts the question about the need for treatment of the UIAs. The purpose of this report is to review the recent reports about the risk of rupture of the UIAs and to assess the morbidity and mortality associated with surgical treatment for UIAs.

Relation between the features of unruptured intracranial aneurysm and its rupture risk:current research progress / 介入放射学杂志

Intracranial aneurysm is a common disorder. With the ongoing improvement of medical imaging technique, the chance of finding an unruptured intracranial aneurysm in clinical practice has steadily increased. The rupture of aneurysms can result in subarachnoid hemorrhage and even in life-threatening conditions. Recent researches have indicated that the rupture risk of intracranial aneurysms bears a close relationship to the aneurysm's features, such as the size, site, shape, number, growth orientation, growth rate, etc. A further understanding of the features of unruptured intracranial aneurysm is very valuable for the effective prevention of its rupture.