Usefulness of CT angiography for demonstrating cerebral aneurysms

We report the usefulness of computed cerebral angiotomography (CT angiography) for demonstrating cerebral aneurysm and the clinical significance of CT angiography for ruptured cerebral aneurysm. Our modified method of CT angiography was easy and less time-consuming. Fifteen seconds after starting a single bolus injection, 1 ml/kg/25 seconds via cubital vein, of contrast medium (60% urograffin), 5 serial 5 mm thick-CT slices were scanned in every 6.5 seconds including 2 seconds of interval, beginning from an axial level 20 mm above the orbitomeatal line and ending at a level 40 mm. A total of 103 patients were examined in this report, consisting of 70 unruptured asymptomatic, 8 unruptured symptomatic (oculomotor nerve palsy) and 25 subarachnoid hemorrhage (SAH). Seven unruptured aneurysms in 4 asymptomatic cases, 2 unruptured aneurysms in 2 symptomatic cases 27 aneurysms in 24 SAH cases were suspected by CT angiography. Of these 36 aneurysms suspected by CT angiography 32 aneurysms were confirmed by cerebral angiography. The detection rate of CT angiography in this report was 89%, higher than those of previous reports. Thirteen aneurysms were located at internal carotid-posterior communicating artery (ICPC) junction. 11 at anterior communicating artery (Acom), 7 at middle cerebral artery (MCA). CT angiography showed a false positive findings in 4 cases, which were all located at Acom. Four aneurysms were not detected in CT angiography, which were all located at MCA and were very small (2-3 mm) in diameter. There were no deteriorated cases during and after CT angiography. We suggest that CT angiography is a useful and safe method for predicting the location of not only unruptured but ruptured aneurysms.     

Surgery for giant intracranial aneurysms using advanced technology

PURPOSE: Outcome of surgery for giant intracranial aneurysms is still unsatisfactory. The reason for complications is occlusion of perforators or parent arteries by the aneurysmal clipping itself or temporary occlusion of the main arteries. We report the surgical outcome of treatment of giant aneurysms using several advanced techniques which we devised to prevent these complications. MATERIALS AND METHODS: The subjects were eight patients with giant intracranial aneurysms who underwent surgery during the recent five years. Six patients had ruptured and two had unruptured aneurysms. Aneurysms were located at the ICA in five and the MCA in three patients. Aneurysmal sizes ranged from 25 to 50 mm. Preoperative 3DCTA was performed to investigate the aneurysm and the surrounding vessels in all cases. Patients with unruptured aneurysms at the ICA underwent balloon occlusion tests to check the potential for safe temporary occlusion of the parent artery, with SEP monitoring and Xe-SPECT. Intraoperative angiography and neuroendoscopes were used to prevent problems and complications which might be caused by aneurysmal clipping. RESULTS: In seven of eight cases, the aneurysmal neck was completely obliterated with clips and in one case the aneurysm was trapped with STA-MCA anastomosis. Glasgow Outcome Scale of the patients showed good recovery in six, moderately disabled (MD) in one and dead in one. The patient demonstrating MD developed hemiparesis due to vasospasm. One patient died from rebleeding of the aneurysm caused by slippage of the aneurysmal clip despite the confirmation of complete obliteration by intraoperative angiography. CONCLUSIONS: A better surgical outcome of treatment for giant aneurysms was obtained by temporary clips whose placement was based on the results of balloon occlusion test, as well as the use of intraoperative angiography and neuroendoscopes.     

Surgical treatment for subarachnoid hemorrhage of unknown etiology: consideration of radiological findings of digital subtraction angiography

At present, conventional intra-arterial angiography remains the gold-standard for the diagnosis of etiology of subarachnoid hemorrhage (SAH), but this may change as intra-arterial digital subtraction angiography (IA-DSA) or three-dimensional computerized tomography (CT) angiography improve. The purpose of this study is to investigate the reliability of IA-DSA for the diagnosis of SAH of unknown etiology. Of 184 patients admitted to our unit with proven spontaneous SAH between January, 1994, and March, 1997, 124 underwent IA-DSA. Ten were diagnosed as having SAH of unknown etiology by initial angiography; therefore, the incidence of SAH of unknown etiology based on the diagnosis of initial IA-DSA was 8.1%. Of these 10 patients, six patients were treated conservatively in the acute period. Other four patients underwent exploratory surgeries in the acute period due to a great suspicion of the presence of aneurysms. In one patient, no aneurysm was detected; in three patients aneurysms were discovered at surgery and successfully clipped. In two of three patients, aneurysms were not discovered at the suspected site, because radiological findings of a thrombosed aneurysm and infundibular dilatation of a perforator caused incorrect diagnosis of the aneurysm sites. Although the site of aneurysm diagnosed by IA-DSA is not always correct, exploratory aneurysm surgery during the acute period based on the diagnosis by IA-DSA is warranted, and IA-DSA is acceptable for the diagnosis of SAH of unknown etiology.     

Growth of asymptomatic unruptured aneurysms in follow-up study: report of three cases

The natural history of asymptomatic unruptured aneurysms that have not been subjected to surgery was studied radiologically using MRA and MRI and 3D-CT angiography (3D-CTA) commencing in 1993. We report on the growth of documented asymptomatic unruptured aneurysms in three patients. Growth of the aneurysms was followed by repeated MRA, MRI and 3D-CTA. In Case 1, a 71-year-old woman had been diagnosed as having a 3 mm unruptured anterior communicating artery aneurysm. The size of the aneurysm had expanded to 4 mm, 2 years later. This was detected during a follow-up MRA and confirmed by angiography. After this follow-up MRA, the aneurysm showed no change in size or shape for 8 years. Case 2 was that of a 75-year-old woman who had a 4.5 mm aneurysm involving the basilar artery and the superior cerebellar artery. 12 months later, an MRA was carried out as a follow-up study. This MRA revealed that the aneurysm had developed a bleb and was expanding. 8 months later the patient bled from the aneurysm and underwent surgery, but died. Before surgery, the diameter of the aneurysm, confirmed by angiogram, was 5.5 mm including the bleb. The third patient was a 66-year-old woman who had a 7 mm internal aneurysm involving the carotid artery and the posterior communicating artery. 3 years later a 3D-CTA detected the expansion of the aneurysm and development of an aneurysm bleb. 6 years later more expansion occurred and 3 months after that the patient bled from the aneurysm and underwent clipping. At that time, the diameter of the aneurysm, confirmed by angiography, was 13 mm including the bleb. In this follow-up study, patients with diagnosed asymptomatic unruptured aneurysms were followed up by MRA and MRI and 3D-CTA to determine risk factors for aneurysm rupture. We emphasize the fact that growth of an unruptured aneurysm and formation of blebs are important risk factors of aneurysm rupture.     

Surgical treatment of unruptured intracranial aneurysms

Summary The author has reviewed a series of 19 patients with unruptured aneurysms treated surgically during a 5-year period from 1976 to 1981. Unruptured aneurysms found in patients with multiple aneurysms and subarachnoid haemorrhage due to ruptured aneurysms are not included in this series. Literature on this subject is reviewed. There was no mortality and results were excellent in 7 patients with asymptomatic aneurysms. In 12 patient with symptomatic aneurysms there was no mortality and results were good to excellent in 9 patients. In 2 the results were unsatisfactory.The series included aneurysms varying in size from 5 mm to over 2.5 cm (giant aneurysm). Controversial aspects of surgery of unruptured intracranial aneurysms are discussed. The authors recommend surgical treatment of unruptured intracranial aneurysms regardless of size until such time when more definitive information is available about the natural history of these lesions.     

Unruptured cerebral aneurysms in two siblings screened by cerebral computed angiotomography

The authors report two siblings, both of whom had unruptured cerebral aneurysms found by screening examination of noninvasive cerebral computed angiotomography. Other authors have reported unruptured cerebral aneurysms detected by conventional cerebral angiography in asymptomatic relatives of families in which two or more individuals had cerebral aneurysmal rupture. It is of interest that, in our cases, the unruptured cerebral aneurysms were detected by noninvasive cerebral computed angiography in two asymptomatic siblings in a family with no history of ruptured aneurysm. To the best of our knowledge, this is the first report of detection of unruptured familial aneurysm by cerebral computed angiotomography. Case 1 is a 67-year-old female who had been complaining of dullness in the head. Cerebral computed angiotomography showed a small high density nodule, suggesting an unruptured aneurysm of the right middle cerebral artery. An aneurysm with a diameter of 4 mm was found in the right middle cerebral artery. A 72-year-old male, who was a brother of case 1, had been afraid of having cerebrovascular disease, and wanted to have a neurological examination check-up. Computed angiotomography revealed a high-density nodule in the anterior communicating artery. Conventional cerebral angiogram showed a 6 X 7 mm aneurysm. However, both of the patients refused surgical treatment. Lozano et al reviewed the previously reported familial aneurysm cases. According to them, familial aneurysm tends to rupture at a younger age and at a smaller size than non-familial aneurysm. It is well known that asymptomatic members of familial aneurysm have a risk of developing aneurysm.(ABSTRACT TRUNCATED AT 250 WORDS)     

Treatment of ruptured and unruptured internal carotid artery aneurysms.

A consecutive series of 95 patients with a total of 131 intracranial cerebral aneurysms came under observation from 1972-1978. Of these, 78 patients had operations for 106 aneurysms. Over half of the patients (41) had operations for an aneurysm of the intracranial internal carotid artery; there were 16 incidental "asymptomatic" aneurysms also found. There was no surgical mortality in this group. Medical treatment, including bed rest, antihypertensive treatment and administration of epsilon amino caproic acid followed by microsurgical obliteration of the aneurysm offers the best results for the treatment of ruptured and unruptured aneurysms.     

介入栓塞治疗未破裂动脉瘤合并脑动静脉畸形

目的探讨未破裂的动脉瘤合并脑动静脉畸形(BAVM)的介入治疗价值。方法回顾性分析23例未破裂的动脉瘤合并BAVM患者的资料。对所有患者均行介入栓塞治疗,根据Redekop分型,选择介入栓塞方式。对近端、远端血流动力型动脉瘤以弹簧圈栓塞,对团内型动脉瘤以Onyx栓塞剂栓塞。术后1周以格拉斯哥转归评分(GOS)评估治疗效果。术后3~6个月行DSA复查病灶是否复发、有无颅内出血。结果 23例患者共36个病灶,其中BAVM合并团内型动脉瘤8个、近端血流动力型动脉瘤16个、远端血流动力型动脉瘤11个、无关血流动力型动脉瘤1个。以弹簧圈栓塞16个近端血流动力型和10个远端血流动力型动脉瘤;以Onyx栓塞剂栓塞8个团内型动脉瘤;1个远端血流动力型动脉瘤因栓塞困难且动脉瘤形态规整未予栓塞,术后第6天患者死于颅内出血引起的脑疝;1个无关血流动力型动脉瘤因易于外科夹闭未予栓塞。23例中,BAVM完全栓塞7例,未完全栓塞16例。19例术后GOS评分为5分,3例为4分,1例死亡病例未评估。除1例死亡外,余22例DSA术后随访均未见复发,无颅内出血。结论介入栓塞治疗未破裂的动脉瘤合并BAVM较为安全、有效,根据各病灶血流动力学特点制定治疗方案、尽量栓塞所有病灶并积极预防术后出血有助于改善患者预后。     

Rupture of previously documented asymptomatic unruptured aneurysms--aneurysm size: risk factor for aneurysm rupture

The natural history of asymptomatic unruptured aneurysms is not clear. We conducted a follow up study of 100 patients (since 1993) with 122 asymptomatic unruptured aneurysms that had not been operated on. We report five patients with previously documented asymptomatic unruptured aneurysms smaller than 10 mm in diameter that subsequently ruptured. Among the 100 patients, five had suffered subarachnoid hemorrhage (SAH) due to rupturing of an aneurysm. Of the 5 cases, 1 was male and 4 were female, with ages ranging from 59-73 years (mean age, 68 years). The aneurysms were on the MCA in 3, on the BA-SCA in 1, on the IC-PC in 1. The maximal diameter of the aneurysms at diagnosis ranged from 4.5 to 8 mm. The period from discovery to SAH was from 4 to 69 months and the cumulative rate of rupture of the aneurysms was 1.5 percent per year. Four of the 5 cases increased in size after the rupture. In our series, 2 of the 5 cases showed enlargement and the development of an aneurysmal bleb in the follow up MRA and 3D-CTA. The present study demonstrates that five asymptomatic unruptured aneurysms less than 10 mm in diameter subsequently ruptured. We ought to seriously consider the assertion published in the New England Journal of Medicine (Dec. 10, 1998), that unruptured aneurysms less than 10 mm in diameter have a very low probability of subsequent rupture.     

Quantified aneurysm shape and rupture risk

OBJECT: The authors investigated whether quantified shape or size indices could better discriminate between ruptured and unruptured aneurysms. METHODS: Several custom algorithms were created to quantifiy the size and shape indices of intracranial aneurysms by using three-dimensional computerized tomography angiography models of the brain vasculature. Data from 27 patients with ruptured or unruptured aneurysms were evaluated in a blinded fashion to determine whether aneurysm size or shape better discriminated between the ruptured and unruptured groups. Five size and eight shape indices were calculated for each aneurysm. Two-tailed independent Student t-tests (significance p < 0.05) were used to determine statistically significant differences between ruptured and unruptured aneurysm groups for all 13 indices. Receiver-operating characteristic-area under curve analyses were performed for all indices to quantify the predictability of each index and to identify optimal threshold values. None of the five size indices were significantly different between the ruptured and unruptured aneurysms. Five of the eight shape indices were significantly different between the two lesion groups, and two other shape indices showed a trend toward discriminating between ruptured and unruptured aneurysms, although these differences did not reach statistical significance. CONCLUSIONS: Quantified shape is more effective than size in discriminating between ruptured and unruptured aneurysms. Further investigation will determine whether quantified aneurysm shape will prove to be a reliable predictor of aneurysm rupture.     

Endoscope-assisted microsurgery for intracranial aneurysms

OBJECTIVE: We discuss the role of the endoscope in the microsurgical treatment of intracranial aneurysms, analyzing its benefits, risks, and disadvantages. METHODS: This was a prospective study of 55 patients with 79 aneurysms, treated between July 1998 and June 2001, for whom the endoscope was used as an adjunct in the microsurgical treatment of their lesions. Seventy-one aneurysms were located in the anterior circulation, and eight were located in the posterior circulation. Thirty-seven patients presented with subarachnoid hemorrhage. Eighteen patients had unruptured aneurysms, of whom 5 presented with mass effect, 2 presented with transient ischemic attacks, and 11 were without symptoms. In all cases, the endoscope was used in addition to microsurgical dissection and clipping (sometimes before clipping, sometimes during clipping, and always after clipping), for observation of the neck anatomic features and perforators and verification of the optimal clip position. Intraoperative angiography was performed for all patients after aneurysm clipping. RESULTS: In the majority of cases, the endoscope was very useful for the assessment of regional anatomic features. It allowed better observation of anatomic features, compared with the microscope, for 26 aneurysms; in 15 cases, pertinent anatomic information could be obtained only with the endoscope. The duration of temporary clipping of the parent artery was significantly reduced for two patients. The clip was repositioned because of a residual neck or inclusion of the parent vessel during aneurysm clipping in six cases, and the clip position was readjusted because of compression of the optic nerve in one case. One patient experienced a small aneurysm rupture that was directly related to use of the endoscope, but this was easily controlled, with no sequelae. For many patients, the combination of the neuro-endoscope and the micro-Doppler probe made intraoperative angiography redundant. CONCLUSION: "Endoscope-assisted microsurgery" is a major advance in the microsurgical treatment of intracranial aneurysms; the endoscope allows better observation of regional anatomic features because of its magnification, illumination, and ability to "look around corners."     

Pericallosal aneurysm: A difficult challenge for microsurgery and endovascular treatment

IntroductionPericallosal artery aneurysms (PAA) represent 2 to 9% of intracranial aneurysms and their management remains difficult.ObjectiveWe aimed to report our experience to evaluate the outcome of patients with ruptured and unruptured PAA, when the treatment modality is decided in a multidisciplinary fashion.Materials and methodsIn this retrospective study, we included 28 patients (8 men and 20 women) treated for a PAA in our institution between 2002 and 2012, among the 2430 patients who underwent the treatment of an intracranial aneurysm in the same period. Fifteen patients harbored a ruptured aneurysm while 13 benefited from a prophylactic treatment. The mean age at diagnosis was 52 years (range 37 to 75 SD: ±5) in patients with ruptured aneurysm and 54.2 years (range 35 to 66 SD: ±5) in patients with unruptured aneurysm. Endovascular treatment has been performed in 9 patients while 19 patients underwent a microsurgical treatment. Clinical outcome has been assessed using the modified Rankin scale (mRS) at 3 months. Long-term imaging follow-up included a CT angiography at 36 months for clipped aneurysms and MR angiography at 6, 18 and 36 months for coiled aneurysms.ResultsThe median follow-up was 3.4 years (range 2.8 to 4.2). The mRS was ≤ 2 in all patients with unruptured aneurysms. In patients with ruptured aneurysm, the mRS was ≤ 2 at 3 months in 13 patients (87%). Persistent cognitive disorders were noted in 8 patients with ruptured aneurysm, 2 of them were considered as possibly related to the treatment. Aneurysm recurrence has been depicted in 4 patients (at 6 months in 3 patients and 1 year in 1 patient) requiring further treatment in all cases; all of them had an aneurysm remnant on immediate conventional angiography. No recurrence was noted in patients without remnant on immediate post-treatment angiography.ConclusionBoth endovascular and microsurgical treatment are challenged in this location. Multidisciplinary discussion is essential to optimize the management of patients with PAA.     

Intracranial saccular aneurysm enlargement determined using serial magnetic resonance angiography

OBJECT: The goal of this study was to determine the frequency of enlargement of unruptured intracranial aneurysms by using serial magnetic resonance (MR) angiography and to investigate whether aneurysm characteristics and demographic factors predict changes in aneurysm size. METHODS: A retrospective review of MR angiograms obtained in 57 patients with 62 unruptured, untreated saccular aneurysms was performed. Fifty-five of the 57 patients had no history of subarachnoid hemorrhage. The means of three measurements of the maximum diameters of these lesions on MR source images defined the aneurysm size. The median follow-up period was 47 months (mean 50 months, range 17-90 months). No aneurysm ruptured during the follow-up period. Four patients (7%) harbored aneurysms that had increased in size. No aneurysms smaller than 9 mm in diameter grew larger, whereas four (44%) of the nine aneurysms with initial diameters of 9 mm or larger increased in size. Factors that predicted aneurysm growth included the size of the lesion (p < 0.001) and the presence of multiple lobes (p = 0.021). The location of the aneurysm did not predict an increased risk of enlargement. CONCLUSIONS: Patients with medium-sized or large aneurysms and patients harboring aneurysms with multiple lobes may be at increased risk for aneurysm growth and should be followed up with MR imaging if the aneurysm is left untreated.     

Endovascular treatment for basilar tip aneurysms

The aim of this study was to analyze the effect of endovascular treatment of basilar (BA) tip aneurysms. The authors performed a retrospective analysis of 79 aneurysms of the BA tip that had been treated using endovascular coil embolization for the last 11 years. Fifty-six patients were women, and 23 were men. The average age of the patients was 63.7 years (range, 35-83 year). The average maximum diameter of the aneurysms was 8.0 mm (range, 2-30 mm). Forty-seven patients (60%) presented with acute subarachnoid hemorrhage (SAH), 1 patient (1%) had an unruptured aneurysm with mass effect, and 31 patients (39%) had incidental aneurysms. Immediate anatomic outcomes demonstrated complete occlusion (CO) in 53 aneurysms (67%), residual neck (RN) in 22 aneurysms (28%), and residual aneurysm (RA) in 4 aneurysms (5%). One patient died from rebleeding 6 hours after the embolization. Another patient suffered from rebleeding 6 years after the initial embolization, and was successfully treated with re-embolization. Four patients suffered from asymptomatic P1 occlusion. No symptomatic complication was observed in the unruptured group. Retreatment was performed in 5 patients, including 4 broad-neck large ruptured aneurysms and 1 giant thrombosed aneurysm. Angiographic and clinical results have been improving in recent cases in this study. Technical advances such as highly compliant balloon remodeling microcatheter and 3D-reconstructed digital angiography contributed to this improvement. Our results indicate that endovascular treatment of BA tip aneurysm is safe and effective. The long-term stability after coil embolization is still a matter of concern. Further improvement is expected.     

Rupture of bacterial intracranial aneurysms following replacement of cardiac valves

Two patients with rheumatic valvular heart disease are discussed in whom a bacterial intracranial aneurysm ruptured in relation to cardiac surgery. Cardiac surgery may predispose such aneurysms to rupture. Cerebral angiography for detecting unruptured aneurysms and surgical excision prior to valve replacement may be indicated in certain patients.     

Results of the surgical treatment of multiple aneurysms--review of 372 cases

The authors review the surgical results in 372 cases of multiple intracranial aneurysms during this 25-year period in which one of the authors (JS) performed 2,000 direct operations for aneurysms. All patients were classified into four groups according to the location of aneurysms as follows: Group 1: multiple aneurysms including anterior communicating artery aneurysm (157 cases); Group 2: multiple aneurysms of unilateral anterior circulation (72 cases); Group 3: multiple aneurysms of bilateral anterior circulation (110 cases); Group 4: multiple aneurysms including vertebrobasilar artery aneurysms (33 cases). In multiple aneurysm cases, their policy has been to treat all aneurysms, ruptured and unruptured, in a one-stage operation whenever possible. About 90% of patients in both Group 1 and Group 2 were treated by one-stage operations, while 60% of patients in Group 3 and 42% of in Group 4 were operated on in the same manner. Excellent and good results in from 73% to 81% of cases was obtained in patients of Group 1, Group 2 and Group 3. Morbidity was 14-19% and mortality was 6-8%. These results were almost equal to the results with a single aneurysm of the anterior circulation. On the other hand, the surgical results in Group 4 were poor with a mortality of 27%. Poor results were attributable to the postoperative rebleeding from the untreated vertebro-basilar aneurysms, which were thought to be unruptured aneurysms preoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)     

Growth of small unruptured intracranial aneurysm: case report

Magnetic resonance angiography (MRA) revealed silent but rapid growth of a small unruptured intracranial aneurysm until it was surgically treated to prevent rupture. Modern neuroimaging methods such as MRA and 3-dimensional computed tomography have increased opportunity to detect small unruptured cerebral aneurysms. Strict follow up is an option for the incidentally discovered small intact aneurysms using these methods.     

Surgical treatment of multiple aneurysms

Summary We review the surgical results in 372 cases of multiple intracranial aneurysms over a 25-year period in which one of us (JS) performed 2,000 direct operations for aneurysms. All patients were classified into four groups according to the location of the aneurysm: Group 1: multiple aneurysms including anterior communicating artery aneurysm (157 cases); Group 2: multiple aneurysms of unilateral anterior circulation (72 cases); Group 3: multiple aneurysms of bilateral anterior circulation (110 cases); Group 4: multiple aneurysms including vertebro-basilar artery aneurysms (33 cases).In multiple aneurysm cases, our policy has been to treat all aneurysms, ruptured and unruptured, in a one-stage operation whenever possible. About 90% of patients in both Group 1 and 2 were treated by one-stage operations, while 60% of patients in Group 3 and 42% of patients in Group 4 were operated on in the same manner.Excellent and good results in from 73% to 81% of cases were obtained in patients in Group 1, Group 2 and Group 3. Morbidity was 14–19% and mortality was 6–8%. These results were comparable to the results with a single aneurysm of the anterior circulation. On the other hand, the surgical results in Group 4 were poor with a mortality of 27%. Poor results were attributable to the postoperative rebleeding from the untreated vertebro-basilar aneurysms, which were thought to be unruptured aneurysms preoperatively.Furthermore, it was clarified that the results of early one-stage operations (within one week from onset) in patients with multiple aneurysms were satisfactory. In this group, there was good recovery in 84% of patients, 7% were disabled and 9% died. The morbidity was notably lower in patients operated on within one week than in those operated on after 8 days. Based on these results, the one-stage operation in the acute period is recommended for patients with multiple aneurysms.     

Management of intracranial infectious aneurysms: a series of 16 cases

OBJECTIVE: The purpose of this study was to better define the management of intracranial infectious aneurysms. METHODS: We present a retrospective review of the management of 16 patients with intracranial infectious aneurysms. The mean follow-up period was 86 months. RESULTS: None of the patients had a rehemorrhage during antibiotic treatment. The mortality and long-term outcome from ruptured intracranial infectious aneurysms may be better than previously thought. There was no significant difference in long-term outcome between patients with single or multiple infectious aneurysms or between patients who underwent surgical resection and those who were treated only with antibiotics. CONCLUSION: Operative treatment should be pursued for patients with ruptured infectious aneurysms. Patients with unruptured intracranial infectious aneurysms should be observed during antibiotic therapy and followed up with cerebral angiography. Surgical resection should be considered if the aneurysm enlarges and the patient's general medical condition allows general anesthesia to be tolerated.     

Does a safe size-limit exist for unruptured intracranial aneurysms?

Summary Of 1076 patients with intracranial ruptured aneurysms (RA) included in the Danish Aneurysm Study, 948 had the RA verified by angiography. Of these cases 908 RA had a maximum diameter less than 25 mm. 162 RA were <5 mm, 474 and 272 were between 5–10 mm and 11–24 mm, respectively. The average diameter of the RA according to the day of angiography after the aneurysm rupture did not differ significantly within the first 10 days. In these circumstances, using this indirect method for estimation of aneurysm rupture according to the size, we also recommend that unruptured aneurysms with a size 10 mm or less should be seriously considerated for operation.