无蛛网膜下腔出血的大脑中动脉动脉瘤破裂

目的总结无蛛网膜下腔出血（SAH）的大脑中动脉（MCA）动脉瘤破裂的临床特点。方法对6例在首次CT扫描上表现为脑内出血（ICH），或壁内出血（IMH）而无SAH的MCA动脉瘤破裂患者的临床表现、影像学检查、治疗方法和预后进行回顾性总结。结果本组首次CT扫描时间为起病后0—2d，表现为单纯ICH者4例，IMH者2例。DSA和手术证实为MCA动脉瘤破裂。开颅动脉瘤切除1例，夹闭5例，其中4例同时行血肿清除术。术后无死亡。结论MCA动脉瘤破裂首次CT扫描可仅表现为ICH或IMH而无SAH，与动脉瘤的部位、出血量以及CT扫描时间相关。     

Intracerebral haematomas from aneurysm rupture: Their clinical significance

Summary Two series of patients (814 cases altogether) with ruptured intracranial aneurysms are analyzed in order to try to outline the clinical significance of space-occupying intracerebral haematomas (ICH) which may accompany SAH. In particular the question of whether intracerebral clots are or are not to be taken into account in planning emergency surgery is debated.From the reported series, it would appear that ICH after aneurysm rupture seldom lead to increasing intracranial hypertension warranting urgent surgery. This evolution was observed in approximately 5% of patients with expanding ICH. In 35% the intracerebral effusions were associated with irreversible lesions and in 20% the initial symptomatology definitely improved. Finally, in a relatively high percentage of cases (about 40%) ICH lacked of clinical significance.Brandtet al. [Brandt L, Sonesson B, Ljunggren B, Saveland H (1987), Ruptured middle cerebral artery aneurysm with intracerebral haemorrhage in younger patients appearing moribund: emergency operation, Neurosurgery 20, 925–929] have just reported 4 cases of huge ICH from ruptured MCA in young moribund patients successfully submitted to ultraemergency surgery, on the basis of CT alone without angiography. 3 patients survived with moderate disability. This report would indicate unsuspected therapeutic possibilities in some hyperacute cases. Unfortunately, the circumstances which had been given in the cases reported by Brandtet al. are seldom gathered.     

Emergency surgery for haematoma-forming aneurysmal haemorrhage

Patients with intracerebral haematomas (ICH) secondary to aneurysmal bleeds usually have a poor prognosis or die if treated conservatively. Younger patients with rupture of a middle cerebral artery (MCA) aneurysm and temporal haematomas have the potential to return to useful life. They should be assessed separately from other subarachnoid haemorrhage (SAH) patients and considered for emergency surgery. Seven such cases are presented, five made an acceptable recovery. The experience of other units as represented in the literature is considered.     

Observation of de novo formation and growth of an intracranial aneurysm: a case report

We observed a de novo formation and growth of an aneurysm in a 43-year-old woman who was followed up after treatment of a subarachnoid hemorrhage (SAH). In 2002, the patient, whose mother had a history of SAH, presented with SAH at the age of 36. Three-dimensional computed tomography angiography (3D-CTA) and digital subtraction angiography showed an aneurysm in the right internal carotid-posterior communicating artery. The aneurysm was clipped and postoperative course was uneventful without neurological deficit. The patient was followed up by 3D-CTA and magnetic resonance angiography every 6 months, because of an untreated small aneurysm, 3 mm in diameter, in the left middle cerebral artery (MCA). The MCA aneurysm remained unchanged but a de novo aneurysm, 1.5 mm in diameter, developed in the right anterior cerebral artery (ACA) 6 years after the first surgery. The ACA aneurysm grew to 4 mm in diameter during the following 10 months but the MCA aneurysm remained unchanged. Both aneurysms were clipped in one session. The MCA aneurysm had a smooth wall but the ACA aneurysm had an irregular and thin wall. The postoperative course was uneventful. Young female patients who have developed SAH with familial history, like this case, should receive long-term follow up to check whether a de novo aneurysm has developed.     

Primary intracerebral and aneurysmal subarachnoid hemorrhage in Izumo City, Japan. Part II: management and surgical outcome

OBJECT: The purpose of this study was to assess the overall management and surgical outcome of primary intracerebral hemorrhage (ICH) and aneurysmal subarachnoid hemorrhage (SAH) among the 85,000 residents of Izumo City, Japan. METHODS: During 1991 through 1996, 267 patients with ICH and 123 with SAH were treated in Izumo. Of the 267 patients with ICH, 25 underwent hematoma removal by open craniotomy or suboccipital craniectomy and 34 underwent stereotactic evacuation of the hematoma, whereas aneurysm clipping was performed in 71 of the 123 patients with SAH; operability rates were thus 22% for ICH and 58% for SAH (p < 0.0001). The overall 30-day survival rates were 86% for ICH and 66% for SAH (p < 0.0001) and the 2-year survival rates were 73% and 62% (p = 0.0207), respectively. In patients who underwent surgery, 30-day and 2-year survival rates were 93% for ICH and 100% for SAH (p = 0.0262), and 75% for ICH and 97% for SAH (p = 0.0002), respectively. In patients with ICH, the most important predictors of 30-day case-fatality rates were the volume of the hematoma, the Glasgow Coma Scale (GCS) score, rebleeding, and midline shifting, whereas those for 2-year survival were the GCS score, age, rebleeding, and hematoma volume. In patients with SAH, the most important determinants of 30-day case-fatality rates were the GCS score and age, whereas only the GCS score had a significant impact on 2-year survival. CONCLUSIONS: The overall survival rates for patients with ICH or SAH in Izumo were more favorable than those in previously published epidemiological studies. However, despite improved surgical results, the overall management of ICH and SAH still produced an unsatisfactory outcome, mainly because of primary brain damage.     

Subarachnoid hemorrhage and intracerebral hematoma caused by aneurysms of the anterior circulation: influence of hematoma localization on outcome

Additional space-occupying intracerebral hematoma (ICH) in patients suffering from subarachnoid hemorrhage (SAH) is a known predictor for poor outcome. Emergent clot evacuation might be mandatory. However, data concerning the influence of ICH location on outcome is scarce. Therefore, we analyzed the influence of ICH location on clinical course and outcome in patients with SAH and additional ICH. One hundred seventy-four patients were treated with aneurysmal SAH and additional ICH between September 1999 and May 2012. Information including patient characteristics, treatment, and radiological findings were prospectively entered into a database. Patients were stratified according to ICH location and neurological outcome. Neurological outcome was assessed according to modified Rankin Scale (mRS). ICH location was temporal (58.6 %), frontal (28.7 %), and perisylvian ICH (12.6 %); 63.8 % presented in poor admission status and favorable outcome was achieved in 35.6 %. In the multivariate analysis, favorable outcome was associated with young age, ICH <50 ml, and good admission status. The location of ICH was not associated with outcome. The current data confirms that a significant number of patients with ICH after aneurysm rupture achieve favorable outcome. Prognostic factor for favorable outcome are “age,” “size of the hematoma,” and “admission status.” The location of the ICH seems not to be associated with outcome.     

Characteristics and management of ruptured distal middle cerebral artery aneurysms

Summary Objective. Distal middle cerebral artery (dMCA) aneurysms are very rare with a reported frequency of 2–6%. Typically, patients with ruptured distal MCA aneurysms have poor clinical outcomes because often there is both a subarachnoid haemorrhage (SAH) and an intracerebral haematoma (ICH). The goals of this study were to identify the characteristics of the distal MCA aneurysms and evaluate the optimal treatment for a good outcome. Methods. The clinical, neuroradiological and operative records of 8 patients with a ruptured distal MCA aneurysm who underwent surgical management were reviewed retrospectively. The outcomes were presented according to the Glasgow Outcome Scale (GOS). Results. The clinical characteristics of the patients with ruptured dMCA aneurysms included the following: (1) a fusiform appearance in five out of eight (63%) patients. (2) Mean aneurysm size of 9.4 mm (range 2–35 mm). (3) The location being M2 (insular segment) in three, M2-3 junction in three, and M3 (opercular segment) in two patients. (4) Brain CT images revealed both SAH and an ICH in six of eight (75%) patients with the mean size of the ICH being 10 cc (range 5–25 cc). (5) Re-bleeding occurred in four out of eight (50%) of patients. All patients underwent early surgical treatment and the procedures used for surgical repair were, clipping in five patients, trapping in two, and trapping with end-to-end bypass surgery in one patient. Clinical outcomes were poor in two patients (death) due to severe brain swelling. Conclusions. In this study, dMCA aneurysms had a fusiform shape and a high re-bleeding rate; if ruptured, there was generally ICH and SAH. A good clinical outcome was associated with adequate control of brain swelling and early surgery to prevent re-bleeding.     

Acute subdural hematoma without subarachnoid hemorrhage caused by ruptured A1-A2 junction aneurysm. Case report

A 54-year-old man was admitted to our hospital with complaint of sudden headache. The patient had suffered two episodes of transient headache before admission. Computed tomography (CT) revealed acute subdural hematoma (ASDH) on the right side of the cerebral convexity with bilateral extension along the tentorium cerebelli without signs of subarachnoid hemorrhage (SAH) or intracerebral hemorrhage (ICH). Three-dimensional CT angiography and conventional cerebral angiography revealed a left A1-A2 junction aneurysm. Neck clipping of the aneurysm was performed. The aneurysm extended inferiorly, with the dome embedded in the chiasmatic cistern and tightly adhered to the arachnoid membrane. There was no evidence of hematoma in the subarachnoid space. The patient was discharged without neurological deficit. Ruptured aneurysms resulting in ASDH without SAH or ICH are very rare. Radiological investigation such as three-dimensional CT angiography should be performed to find the causative aneurysm in a patient with ASDH with a history of repeated headaches and without traumatic signs or episodes, and the appropriate treatment should be planned with expediency.     

Ruptured internal carotid artery bifurcation aneurysm presenting with only intracerebral hemorrhage without subarachnoid hemorrhage--case report

A 55-year-old man presented with intracerebral hemorrhage (ICH) without subarachnoid hemorrhage (SAH) manifesting as acute onset of consciousness disturbance and right hemiparesis. Computed tomography showed ICH mainly localized in the left putamen, but no evidence of SAH. Magnetic resonance angiography demonstrated a cerebral aneurysm originating from the bifurcation of the left internal carotid artery, which was considered to be responsible for the ICH. The patient underwent emergent intravascular surgery for coil embolization of the aneurysm, and his neurological symptoms gradually recovered with rehabilitation after surgery. Although ICH without SAH is a rare presentation of cerebral aneurysm, ruptured cerebral aneurysm should be considered as a potential cause of ICH. The localization and extent of ICH may be suggestive of latent cerebral aneurysm in such cases.     

Surgical management of unruptured aneurysms: prognostic indicators

BACKGROUND: The treatment of unruptured aneurysms (UA) remains controversial. Therefore, it has become necessary to define various prognostic indicators in the surgical treatment of unruptured aneurysms not associated with previously ruptured aneurysms. METHODS: During a 6-year period, 78 unruptured aneurysms were managed. The results of management were retrospectively reviewed to define the prognostic indicators. RESULTS: There were 104 patients with unruptured aneurysms who underwent surgical treatment. Seventy-five patients without previous subarachnoid hemorrhage (SAH) were selected for data analysis. Eighty-seven percent of the aneurysms were on the anterior circulation. The most common location was the middle cerebral artery (MCA) followed by the posterior communicating artery (PCom), ophthalmic artery, and anterior communicating artery (ACom). Six percent were found on the basilar artery. The mean size of aneurysms was 12.5 mm (range = 3-30 mm, SD = 7.4). At surgery, rupture of the aneurysm was encountered in eight cases with temporary control of the parent vessel being required in 31 procedures. In four cases, intraoperative angiography warranted clip reapplication. The Glasgow Outcome Scale (GOS) was used as an outcome measure. Surgical treatment resulted in good outcome (GOS 1) in 87% and 10.7% had fair outcome; 2.3% were in GOS 3 (severe disability) at 6 month follow-up. There was no mortality. Logistic regression identified significant relationships between GOS and intraoperative rupture (p < 0.0002), rupture and size (p < 0.003), and size and age (p < 0.01). CONCLUSIONS: Large size aneurysms were associated with intraoperative rupture, which had a strong correlation with poor outcome. Increased age showed a linear relationship with the size of the aneurysm. Overall results of treatment for UA are gratifying. There was no mortality. Early diagnosis and surgical extirpation of UA may reduce both intraoperative difficulties as well as poor outcome probability.     

Diagnostic cerebral angiography in spontaneous intracranial haemorrhage: a guide for developing countries

OBJECTIVE: Spontaneous intracranial haemorrhage constitutes 18-40% of all stroke cases. Indications for cerebral angiography to find underlying potentially treatable vascular abnormalities are not clear. This study determined which intracranial haemorrhage patients need cerebral angiography by correlating computed tomography (CT) findings, age and hypertension history with cerebral angiography findings. METHODS: A total of 54 patients (8-79 years) with intracranial haemorrhage who underwent both CT examination and six-vessel cerebral angiography were studied over a 2-year period. Cerebral angiography was repeated within 6 weeks if the first angiogram was negative. RESULTS: Angiography detected vascular lesions in 50% of cases (aneurysm 38.9% and arteriovenous malformation, AVM, 11.1%). In the aneurysm group, angiographic yield was 34.3% whereas in the AVM group, it was 37.9%. Subarachnoid haemorrhage (SAH) combined with other types of haemorrhage (such as intracerebral haemorrhage, ICH) was not significantly correlated with the likelihood of finding a vascular lesion, both aneurysm and AVM (p = 0.157). Age less than 50 years had significant correlation (p = 0.021) in the AVM group as well as in the aneurysm group (p < 0.001). A history of hypertension was associated with both aneurysm (p = 0.039) and AVM (p = 0.008). No patients with deep intracerebral haematoma had vascular lesions. The presence of an intravascular haemorrhage (IVH) had significant correlation with aneurysm (p = 0.008) but not AVM. There was no significant difference in mean age between patients with and without a vascular lesion (p = 0.134). CONCLUSION: Cerebral angiography is justified in patients with ICH accompanied by pure SAH (p = 0.001). Other factors associated with finding a vascular lesion were a history of hypertension and the presence of IVH. Diagnostic cerebral angiography is indicated for patients with ICH and SAH and IVH with a history of hypertension, regardless of age.     

Three-dimensional computerized tomography angiography-guided surgery of acutely ruptured cerebral aneurysms

OBJECT: The aim of this study was to assess whether aneurysm surgery can be performed in patients with ruptured cerebral aneurysms by using three-dimensional computerized tomography (3D-CT) angiography alone, without conventional catheter angiography. METHODS: In a previous study, 60 patients with subarachnoid hemorrhage (SAH) from ruptured aneurysms were prospectively evaluated using both 3D-CT and conventional angiography, which resulted in a 100% accuracy for 3D-CT angiography in the diagnosis of ruptured aneurysms, and a 96% accuracy in the identification of associated unruptured aneurysms. The results led the authors to consider replacing conventional angiography with 3D-CT angiography for use in diagnosing ruptured aneurysms, and to perform surgery aided by 3D-CT angiography alone without conventional angiography. Based on the results, 100 consecutive patients with SAH who had undergone surgery in the acute stage based on 3D-CT angiography findings have been studied since December 1996. One hundred ruptured aneurysms, including 41 associated unruptured lesions, were detected using 3D-CT angiography. In seven of 100 ruptured aneurysms, which included four dissecting vertebral artery aneurysms, two basilar artery (BA) tip aneurysms, and one BA-superior cerebellar artery aneurysm, 3D-CT angiography was followed by conventional angiography to acquire diagnostic confirmation or information about the vein of Labbé, which was needed to guide the surgical approach for BA tip aneurysms. All of the ruptured aneurysms were confirmed at surgery and treated successfully. Ninety-three patients who underwent operation with the aid of 3D-CT angiography only had no complications related to the lack of information gathered by conventional angiography. The 3D-CT angiography studies provided the authors with the aneurysm location as well as surgically important information on the configuration of its sac and neck, the presence of calcification in the aneurysm wall, and its relationship to the adjacent vessels and bone structures. CONCLUSIONS: The authors believe that 3D-CT angiography can replace conventional angiography in the diagnosis of ruptured aneurysms and that surgery can be performed in almost all acutely ruptured aneurysms by using only 3D-CT angiography without conventional angiography.     

Flow dynamics analysis in patients with a ruptured middle cerebral artery aneurysm. A case report

Despite advancement of diagnostic and treatment modalities, subarachnoid hemorrhage (SAH) is still an entity of neurosurgical emergency with poor outcome. Recent reports indicated that hemodynamic stress might play an important role in rupture or the growth of cerebral aneurysms, but there is no consensus about how or which hemodynamic factor contribute to this phenomenon. In this report, magnetic resonance (MR)-based flow dynamics analysis was performed for a patient with SAH and the data obtained were directly compared with intraoperative findings. This 74-year-old woman was admitted for sudden onset headache. Head computed tomography scan showed SAH on the right sylvian fissure and intracerebral hematoma on the right temporal tip. Digital subtraction angiography showed a right middle cerebral artery aneurysm, which was considered to be the ruptured one. The aneurysm had two blebs, and the bleb around the aneurysm tip was exposed to low magnitude and high oscillation of wall shear stress (WSS). On the other hand, another bleb was exposed to high magnitude and low oscillation of WSS. Next day, the patient underwent open surgery and intraoperative findings showed the aneurysm tip was the ruptured point. MR-based flow dynamics analysis might be a useful diagnostic modality for patients with SAH. Although low magnitude and high oscillation of WSS might contribute to the aneurysm rupture, further case accumulation is necessary to reach a conclusion whether or not this is so.     

Successfully Treated Isolated Posterior Spinal Artery Aneurysm Causing Intracranial Subarachnoid Hemorrhage: Case Report

There are very few published reports of rupture of an isolated posterior spinal artery (PSA) aneurysm, and consequently the optimal therapeutic strategy is debatable. An 84-year-old man presented with sudden onset of restlessness and disorientation. Neuroradiological imaging showed an intracranial subarachnoid hemorrhage (SAH) with no visible intracranial vascular lesion. Spinal magnetic resonance imaging (MRI) detected a localized subarachnoid hematoma at Th10–11. Both contrast-enhanced spinal computed tomography and enhanced MRI and magnetic resonance angiography revealed an area of enhancement within the hematoma. Superselective angiography of the left Th12 intercostal artery demonstrated a faintly enhanced spot in the venous phase. Thirteen days after the onset of symptoms, a small fusiform aneurysm situated on the radiculopial artery was resected. The patient''s postoperative course was uneventful and he was eventually discharged in an ambulatory condition. To our knowledge, this 84-year-old man is the oldest reported case of surgical management of a ruptured isolated PSA aneurysm. This case illustrates both the validity and efficacy of this therapeutic approach.     

Subdural hematoma due to ruptured intracranial aneurysm.

Subdural hematoma (SDH) was observed in 15 of 484 cases of aneurysmal subarachnoid hemorrhage (SAH). There were four males and 11 females, with ages ranging from 39 to 75 years. The clinical grades (Hunt and Hess) on admission were 11 in three cases, III in two, IV in four, and V in six. The ruptured aneurysms were located in the middle cerebral artery (MCA) in six cases, anterior communicating artery in three, internal carotid artery in two, and distal anterior cerebral artery (ACA) in two, with two cases unconfirmed. A high proportion of aneurysms occurred in the MCA and distal ACA. Aneurysmal neck clipping and removal of SDH were performed in the acute stage of seven cases, without intraoperative rerupture. The outcomes 1 year after SAH of the seven patients undergoing surgery were good recovery in five, but in two, vegetative state due to preoperative rerupture or medical complications. All eight patients without surgical intervention died. A good prognosis for patients with ruptured intracranial aneurysms accompanied by SDH can be expected with direct surgical intervention in the acute stage, even if the clinical grade on admission is poor.     

Intracranial bacterial aneurysms--report of two cases with special reference to operative indications

Two cases of intracranial bacterial aneurysms caused by bacterial endocarditis are reported. Case 1 was a 20-year-old male who underwent mitral valve annuloplasty because of mitral regurgitation due to mitral valve prolapse syndrome 3 year prior to this admission. He was referred when a large intracerebral hemorrhage of the right frontal lobe ruptured into the lateral ventricle was seen in computed tomography (CT) scan on admission. An aneurysm at the distal portion of precentral artery of the middle cerebral artery (MCA) was found by right carotid angiography. Emergency evacuation of the hematoma and trapping of the aneurysm were performed. Another three aneurysms, located at the distal portion of contralateral left precentral artery of MCA, the left posterior cerebral artery (PCA) and the right anterior falx artery were found in the subsequent angiogram. The latter two aneurysms developed while receiving antibiotics. The aneurysms of PCA and MCA were trapped surgically. However, the aneurysm of anterior falx artery disappeared spontaneously under antibiotic therapy without surgery. Case 2 was a 21-year-old female who underwent cardiac surgery one month prior to presentation for aortic insufficiency and coarctation of the aorta. She was referred to our clinic because of sudden loss of consciousness, aphasia and right hemiparesis. CT scan and left carotid angiography showed a large hematoma in the left frontal lobe and an aneurysm at the distal portion of the opercular-frontal artery. Emergency ventricular drainage was performed. The operation for evacuation of the hematoma and clipping of aneurysm was performed 10 days later. However, at the operation the aneurysm neck was only partially clipped in order to prevent the obstruction of efferent vessels.(ABSTRACT TRUNCATED AT 250 WORDS)     

Postoperative rupture of an untreated aneurysm on the 3rd day after subarachnoid hemorrhage surgery

A 58-year-old male presented with severe consciousness disturbance and left hemiparesis. Computed tomography (CT) revealed subarachnoid hemorrhage (SAH) and acute subdural hematoma caused by a ruptured right middle cerebral artery aneurysm. The aneurysm was clipped and the hematoma was evacuated. The patient had almost recovered without new neurological deficits on the next day. Arterial systolic blood pressure was postoperatively controlled within 120 to 150 mmHg. Continuous ventricular and cisternal drainage from the level 10 cm above the external auditory meatus was performed to drain bloody cerebrospinal fluid and prevent vasospasm. Three days after surgery, the patient suddenly lapsed into a coma. CT demonstrated diffuse SAH and bilateral intraventricular hemorrhage caused by rupture of an anterior communicating artery aneurysm. Neck clipping was performed immediately. Unfortunately, the patient died of primary damage due to SAH 3 days after the second surgery. In this case, cisternal drainage was probably important in the aneurysm rupture because of decreased intracranial pressure and change in the perianeurysm environment. Postoperative management of patients with residual untreated aneurysms must consider the possibility that cisternal drainage may result in higher transmural pressure, leading to rupture of the untreated aneurysms.     

Ipsilateral hemiparesis caused by subarachnoid hemorrhage in a patient with a ruptured middle cerebral artery aneurysm: a case report

The authors report a patient with a ruptured middle cerebral artery (MCA) aneurysm who presented with ipsilateral hemiparesis. A computed tomographic (CT) scan and cerebral angiograms suggested that the ipsilateral hemiparesis was most likely due to compression by hematoma of the secondary motor area in the island of Reil. Two other cases that demonstrated ipsilateral motor weakness after rupture of MCA aneurysms have been reported. We emphasize not only the importance of considering dysfunction of the secondary motor area in patients with hemiparesis, but also the difficulty in differentiating ipsilateral secondary motor area dysfunction from contralateral primary motor area dysfunction in certain cases without CT scanning and angiography.     

Ruptured aneurysm of the distal anterior cerebral artery: clinical features and surgical strategies

Ruptured aneurysms of the distal anterior cerebral artery (ACA) are relatively rare and surgical management provides some unique technical challenges. This retrospective analysis of 20 patients with distal ACA aneurysms evaluated the clinical features and surgical strategies. The characteristic findings were small and common concurrent aneurysms, and frequent intracerebral hematoma (ICH). Aneurysms were divided by location on the genu (n = 13), infracallosal (n = 5), and supracallosal portions (n = 2). All patients except one underwent surgery via an interhemispheric route. Unilateral craniotomy was performed for aneurysms on the genu portions without massive ICH. Bilateral craniotomies were selected for aneurysm located on the infracallosal portion or combined with massive ICH. No intraoperative rupture was observed. Favorable outcomes were achieved in 15 of 20 patients, and only one patient died. The preoperative Hunt and Kosnik grade was closely correlated with the outcome.     

Ruptured infectious aneurysm of the distal middle cerebral artery manifesting as intracerebral hemorrhage and acute subdural hematoma--case report

A 21-year-old woman with severe mitral valve regurgitation due to infectious endocarditis was transferred to our institute in a deep coma with intracerebral hemorrhage and acute subdural hematoma. She had no history of head injury. Brain computed tomography revealed left frontoparietal intracerebral hematoma and adjacent acute subdural hematoma that were evacuated on the day of admission, but the distal middle cerebral artery (MCA) aneurysm remained undetected. Follow-up cerebral angiography demonstrated the distal MCA aneurysm, which had enlarged by 25% at 2 weeks following the first operation. The aneurysm originated from a branch of the angular artery and was successfully resected on Day 22. Histological examination of the aneurysm section showed no infectious nature, but the final diagnosis was infectious intracranial aneurysm based on the presence of infectious endocarditis.