Coil Embolization of the Azygos Anterior Cerebral Artery Aneurysm: Three Case Reports.

The azygos anterior cerebral artery (ACA) is a rare anatomical anomaly. Clipping surgery has been conducted in approximately 30 reported cases because it is frequently associated with aneurysms. However, few cases in which coil embolization was performed have been reported. We report three cases of coil embolization for distal ACA aneurysms with distal azygos ACA at our institution in 7 years. All patients were over 65-year-old women with saccular aneurysms larger than 7 mm; two with subarachnoid hemorrhage and one with an unruptured aneurysm. No patient had surgical complications associated with coil embolization. Coil embolization is also useful for large aneurysms in the distal azygos ACA, and its indication for treatment could be broadened.

[Subarachnoid hemorrhage in a young girl]. / Een meisje met een subarachnoïdale bloeding.

BACKGROUND: Subarachnoid hemorrhage in children is rare. The most common cause is trauma, followed by an arteriovenous malformation, aneurysm or tumor. CASE DESCRIPTION: We describe the case of an 11-year-old girl who developed sudden headache with nausea and vomiting during athletics training. Her neurological exam was normal. With imaging and a lumbar puncture a subarachnoid hemorrhage was diagnosed, based on a ruptured saccular aneurysm of the right middle cerebral artery. Endovascular treatment was unsuccessful, after which the aneurysm was treated surgically. Postoperative recovery was uneventful. Additional tests for underlying conditions were negative. CONCLUSION: Also in a child with acute headache, nausea, and vomiting, the diagnosis of a subarachnoid hemorrhage should be considered, even if neurological examination is normal. Expeditious diagnosis and treatment are important in order to prevent rebleeding.

Basilar artery perforator aneurysms: a comparison with non-perforator saccular aneurysms.

BACKGROUND: Basilar artery perforator aneurysms (BAPAs) are rare. There is no systematic description of their presentation, imaging, natural history and outcomes and how these compare to conventional non-perforator aneurysms. Thus, the authors in this study aimed to compare BAPAs to non-perforator aneurysms. METHODS: Cases were identified from a prospective neurovascular database, notes and imaging retrospectively reviewed and compared to a consecutive series of patients with non-perforator aneurysms. Blood volume on CT and vessel wall imaging (VWI) were compared to controls. RESULTS: 9/739 patients with aneurysmal subarachnoid haemorrhage (aSAH) harboured BAPAs. Compared to 103 with aSAH from posterior circulation aneurysms, they were more likely to be male (6/9, p = 0.008), but of equal severity (4/9 poor grade, p = 0.736) and need of CSF drainage (5/9, p = 0.154). Blood volume was similar to controls (30.2 ml vs 26.7 ml, p = 0.716). 6/9 BAPAs were initially missed on CTA. VWI showed thick (2.9 mm ± 2.7) bright enhancement (stalk ratio 1.05 ± 0.12), similar to controls with ruptured aneurysms (0.95 ± 0.23, p = 0.551), and greater than unruptured aneurysms (0.43 ± 0.11, p < 0.001). All were initially managed conservatively. Six thrombosed spontaneously. Three grew and had difficult access with few good endovascular options and were treated through a subtemporal craniotomy without complication. None rebled. At 3 months, all presenting in poor grade were mRS 3-4 and those in good grade mRS 1-2. CONCLUSIONS: Despite their small size, BAPAs present with similar volume SAH, WFNS grade and hydrocephalus to other aneurysms. They are difficult to identify on CTA but enhance strikingly on VWI. The majority thrombosed. Initial conservative management reserving treatment for growth was associated with no rebleeds or complications.

Isolated spinal artery aneurysm: etiology, clinical characteristics, and outcomes.

OBJECTIVE: Isolated spinal aneurysms (ISAs) are rare causes of subarachnoid hemorrhage (SAH), which encompass a highly heterogeneous group of clinical entities with multifarious pathogeneses, clinical characteristics, and treatment strategies. Therefore, knowledge about the ISAs remains inadequate. In this study, the authors present a comprehensive analysis of clinical data associated with ISAs at their institutions to enhance the understanding of this disease. METHODS: Patients with ISAs confirmed by spinal angiography or surgery at the authors' institutions between 2015 and 2022 were included. Data regarding clinical presentation, lesion location, aneurysm morphology, comorbidities, treatment results, and clinical outcomes were reviewed. RESULTS: Seven patients with ISAs were included in the study. Among them, 4 patients (57.1%) experienced severe headache, and 3 patients (42.9%) reported sudden-onset back pain. Additionally, lower-extremity weakness and urinary retention were observed in 2 of these patients (28.6%). Four of the aneurysms exhibited fusiform morphology, whereas the remaining were saccular. All saccular aneurysms in this series were attributed to hemodynamic factors. Conservative treatment was administered to 3 patients, 2 of whom underwent follow-up digital subtraction angiography, which showed spontaneous occlusion of both aneurysms. Four patients ultimately underwent invasive treatments, including 2 who underwent microsurgery and 2 who received endovascular embolization. One patient died of recurrent SAH, while the remaining 6 patients had a favorable prognosis at the latest follow-up assessment. CONCLUSIONS: The morphology of aneurysms may be associated with their etiology. Saccular ISAs are usually caused by pressure due to abnormally increased blood flow, whereas fusiform lesions may be more likely to be secondary to vessel wall damage. The authors found that a saccular spinal aneurysm in young patients with a significant dilated parent artery may be a vestige of spinal cord arteriovenous shunts. ISAs can be managed by surgical, endovascular, or conservative procedures, and the clinical outcome is generally favorable. However, the heterogeneous nature of the disease necessitates personalized treatment decision-making based on specific clinical features of each patient.

Ruptured basilar artery perforator aneurysm mimicking superior cerebellar artery aneurysm.

BACKGROUND AND IMPORTANCE: The diagnosis of basilar artery perforator aneurysm is difficult due to their small size, with high rates of negative angiography. Furthermore, due to the considerable variation of basilar artery perforator (BAP), even if an aneurysm originates from a BAP, it is often difficult to clearly identify its origin on angiography. CLINICAL PRESENTATION: A 46-female patient presented with World Federation of Neurological Surgeons Scale 1 subarachnoid hemorrhage. Initial imaging study, including digital subtraction angiography (DSA), revealed no vascular lesions. Two-week after admission, DSA revealed an aneurysm arising from the left superior cerebellar artery (SCA). Endovascular coil embolization was planned first. However, aneurysm selection using microcatheter was failed. Then, surgical approach was done via pre-temporal approach. We identified SCA, but there was no aneurysm. Further dissection revealed an aneurysm arising from basilar artery perforator, which was overlapped by SCA. The parent artery of the aneurysm arose from juxtaproximal to the orifice of left SCA, and crossed SCA at the juxtadistal to the aneurismal sac. Complete clip occlusion was done preserving BAP. After the surgery, the patient developed diplopia without extraoccular movement limitations. Two-month after the surgery, she was fully recovered without any neurologic deficits. CONCLUSION: It is crucial to adequately consider the possibility of open surgery as a viable option in case that endovascular treatment of aneurysms originated from the distal segment of basilar artery proves unsuccessful.

Serum Interleukin-1 Levels Are Associated with Intracranial Aneurysm Instability.

Serum interleukin-1 (IL-1) are possibly indicative of the inflammation in the intracranial aneurysm (IA) wall. This study aimed to investigate whether IL-1 could discriminate the unstable IAs (ruptured intracranial aneurysms (RIAs) and symptomatic unruptured intracranial aneurysms (UIAs)) from stable, asymptomatic UIAs. IA tissues and blood samples from 35 RIA patients and 35 UIA patients were collected between January 2017 and June 2020 as the derivation cohort. Blood samples from 211 patients with UIAs were collected between January 2021 and June 2022 as the validation cohort (including 63 symptomatic UIAs). Blood samples from 35 non-cerebral-edema meningioma patients (non-inflammatory control) and 19 patients with unknown-cause subarachnoid hemorrhage (hemorrhagic control) were also collected. IL-1ß and IL-1.ra (IL-1 receptor antagonist) were measured in serum and IA tissues, and the IL-1 ratio was calculated as log10 (IL-1.ra/IL-1ß). Based on the derivation cohort, multivariate logistic analysis showed that IL-1ß (odds ratio, 1.48, P = 0.001) and IL-1.ra (odds ratio, 0.74, P = 0.005) were associated with RIAs. The IL-1 ratio showed an excellent diagnostic accuracy for RIAs (c-statistic, 0.91). Histological analysis confirmed the significant correlation of IL-1 between serum and aneurysm tissues. IL-1 ratio could discriminate UIAs from non-inflammatory controls (c-statistic, 0.84), and RIAs from hemorrhagic controls (c-statistic, 0.95). Based on the validation cohort, the combination of IL-1 ratio and PHASES score had better diagnostic accuracy for symptomatic UIAs than PHASES score alone (c-statistic, 0.88 vs 0.80, P < 0.001). Serum IL-1 levels correlate with aneurysm tissue IL-1 levels and unstable aneurysm status, and could serve as a potential biomarker for IA instability.

Current Smoking Status Is Not a Risk Factor for Perioperative Outcomes in Patients with Aneurysmal Subarachnoid Hemorrhage Who Underwent Craniotomy Repair.

BACKGROUND: Aneurysmal subarachnoid hemorrhage is a rupture leading to blood accumulating in the subarachnoid region. Smoking status is often a risk factor for postoperative complications for vascular procedures. This study aims to retrospectively examine the effect of being a current tobacco smoker on postoperative outcomes in patients with nontraumatic subarachnoid hemorrhage. METHODS: Patients with aneurysmal subarachnoid hemorrhage who underwent craniotomy were identified in the American College of Surgeons-National Surgical Quality Improvement Program database. The 30-day perioperative outcomes of current smokers were compared with those of control individuals, who were patients who had not smoked tobacco in the past year. Postoperative outcomes included death, cardiac complications, stroke, operation time >4 hours, bleeding, and other events. In addition, this study examined the same surgical outcomes in patients older than 65 years. RESULTS: We found no significant difference between these 2 groups across all adverse outcomes analyzed. In patients aged >65 years, we again found no significant differences between these 2 groups across all adverse outcomes analyzed. CONCLUSIONS: This study shows that although current tobacco smoker status is commonly a risk factor for vascular diseases and postoperative complications, it is not a risk factor for the postoperative variables that we analyzed during craniotomy for aneurysmal subarachnoid hemorrhage. Additional research should be conducted to determine if different procedures to treat aneurysmal subarachnoid hemorrhage may have different outcomes among smokers.

Microsurgical Clipping after Failed Contour Device Embolization of an Anterior Communicating Artery Aneurysm: Technical Note.

BACKGROUND: Endovascular therapy has revolutionized the treatment of cerebral aneurysms in recent years and decades. So-called intrasaccular devices (i.e., Woven EndoBridge [WEB], MicroVention, Aliso Viejo, California, United States; or Contour, Cerus Neurovascular, Fremont, California, United States) are a promising endovascular technology, especially for wide-based aneurysms. However, long-term outcome data are currently particularly scarce for Contour and strategies for failed Contour cases are lacking. Here, we report the feasibility of microsurgical clipping after failed Contour device embolization. METHODS: Feasibility of microsurgical clipping after failed aneurysm embolization with a Contour intrasaccular device was assessed in a patient. RESULTS: We present the case of a 36-year-old male patient diagnosed with Hunt and Hess grade 1 subarachnoid hemorrhage from an anterior communicating artery aneurysm. The ruptured aneurysm was initially treated with the Contour device. After 3 months, angiographic imaging showed a clear aneurysm residual deemed not endovascularly accessible. The patient was then successfully clipped using microsurgical techniques. The patient was discharged with no neurologic abnormalities. CONCLUSION: After thorough bibliographical research, this presents the first published case report of microsurgical clipping after failed embolization with Contour. The main insights gained after clipping were that the Contour does not significantly disturb or hinder clipping. In contrast to coils in aneurysms to be clipped, the Contour can be easily compressed by the clip blades and does not have to be removed. In addition, the Contour had not migrated into the subarachnoid space and there was no abnormal scarring. Clipping appears to be a reasonable treatment strategy for failure of embolization with Contour if endovascular means are not suitable.

Subdural Hygroma After Management of Ruptured Intracranial Aneurysms: Incidence, Associated Factors, Clinical Course, and Management Options.

OBJECTIVE: To evaluate the incidence, associated factors, clinical course, and management options of subdural hygroma in patients treated for aneurysmal subarachnoid hemorrhage (aSAH). METHODS: From January 2013 until June 2022, 336 consecutive patients with aSAH underwent treatment in our center. No one patient was excluded from the study cohort. Computed tomography (CT) examinations were performed at admission, immediately after surgery and on the first postoperative day, and subsequently in case of any neurologic deterioration or, at least, once per week until discharge from the hospital. Thereafter, CT examinations were at the discretion of specialists in the rehabilitation facility, referring physicians, or neurosurgeons at the outpatient clinic. RESULTS: The length of radiologic follow-up starting from CT at admission ranged from 1 to 3286 days (mean, 673 ± 895 days; median, 150 days). Subdural hygromas developed in 84 patients (25%). An average interval until this imaging finding from the initial CT examination was 25 ± 55 days (median, 8 days; range, 0-362 days). Evaluation in the multivariate model showed that patient age ≥72 years (P < 0.0001), cerebrospinal fluid (CSF) shunting (P < 0.0001), and microsurgical clipping of ruptured intracranial aneurysm (RIA; P < 0.0001) are independently associated with the development of subdural hygroma. In 54 of 84 cases (64%), subdural hygromas required observation only. Increase of the lesion size with (5 cases) or without (10 cases) appearance of midline shift was associated with patient age <72 years (P = 0.0398), decompressive craniotomy (P = 0.0192), and CSF shunting (P = 0.0009), whereas evaluation of these factors in the multivariate model confirmed independent association of only CSF shunting (P = 0.0003). Active management of subdural hygromas included adjustment of the shunt programmable valve opening pressure, cranioplasty, external subdural drainage, or their combination. Overall, during follow-up (mean, 531 ± 824 days; median, 119 days; range, 2-3285 days) after the start of observation or applied treatment, subdural hygromas showed either decrease (50 cases) or stabilization (34 cases) of their sizes, and no one lesion showed progression again. CONCLUSIONS: The clinical course of subdural hygromas in patients treated for aSAH is generally favorable, but occasionally these lesions show progressive enlargement with or without the appearance of midline shift, which requires active management.

The Nightmare of Aneurysm Surgery: Intraoperative Rupture.

Intraoperative rupture is the most important complication of aneurysm surgery1-5 and occurs in 3 different stages: premature (before dissection), dissection, and clipping.5 We present a video of premature rupture and its management (Video 1). A 45-year-old patient presented with subarachnoid hemorrhage originating from a dorsal internal carotid artery (ICA) aneurysm of the communicating segment. Due to our sufficient experience, we preferred direct clipping in this case. The Sylvian fissure could only be partially opened due to excessive adhesions. During retraction of the frontal lobe, severe bleeding occurred. This was a premature rupture since neither the aneurysm nor the ICA had yet been seen. While aspirating the bleeding just over the rupture site with the left hand, the ICA was explored with the right hand and a temporary clip was placed. The bleeding continued, though it decreased. The aneurysm dome was rapidly explored with 1 hand, and a pilot clip was placed on the dome to stop the bleeding. Immediately afterwards, the aneurysm neck was dissected and clipped parallel to the ICA with a sideward clip. The temporary clip and pilot clip were removed. The temporary occlusion time was 7 minutes and 40 seconds. Postoperative angiogram confirmed complete aneurysm occlusion. The patient discharged with normal neurologic examination. In the literature review including 10,540 cases,1 the mean incidence of IOR is 16.6%. Therefore every neurosurgeon should be prepared for this important complication and know its management well. This case reminds us once again the golden rule of aneurysm surgery: proximal control first.

Subarachnoid haemorrhage associated with pituitary apoplexy and radiographically occult supraclinoid internal carotid artery aneurysms.

In patients with pituitary adenomas, incidental intracranial aneurysms have been documented. Previous studies have highlighted the importance of preoperative imaging in these patients. However, imaging may be limited and fail to show the presence of vascular abnormalities. In this report, we discuss a case of a man in his 30s presenting with a newly diagnosed pituitary adenoma. CT and MRI, on admission, showed a pituitary mass with extension into the right cavernous sinus. After a sudden neurological deterioration, emergent CT/CT angiography revealed pituitary apoplexy with subarachnoid extension without vascular abnormalities. Successful emergency transsphenoidal hypophysectomy was followed by digital subtraction angiography which revealed the presence of two right supraclinoid internal carotid artery aneurysms. With this case, we aim to highlight the need for further vascular imaging in patients with pituitary apoplexy and subarachnoid haemorrhage, as preoperative imaging may be negative for vascular abnormalities especially in the setting of cavernous sinus invasion.

Rathke's cleft cyst discovered with ruptured anterior communicating artery aneurysm: a case report.

INTRODUCTION: Rathke's cleft cysts are thought to have a benign clinical outcome apart from associated hypopituitarism and visual defects. Synchronous central nervous system lesions, including pituitary adenoma and intracerebral aneurysms, are rarely reported. Diagnosis of Rathke's cleft cyst after presenting with a subarachnoid hemorrhage due to a ruptured arterial aneurysm is reported only once before. CASE PRESENTATION: A 33-year-old Sri Lankan female presented with a subarachnoid hemorrhage due to a ruptured anterior communication artery aneurysm. She underwent pterional craniotomy and aneurysm clipping. She was found to have partial cranial diabetes insipidus and hypogonadotropic hypogonadism. She had a cystic lesion occupying enlarged sella turcica with characteristics of a Rathke's cleft cyst. Subsequently, she underwent trans-sphenoidal excision of the sellar lesion. Histology confirmed the diagnosis of Rathke's cleft cyst. CONCLUSIONS: Rare co-occurrence of a Rathke's cleft cyst and an anterior communicating artery aneurysm would have been missed if subtle manifestations atypical for subarachnoid hemorrhage were not further pursued. This could have led to progressive visual deterioration and hypopituitarism.

Incidence and Outcomes of Aneurysmal Subarachnoid Hemorrhage: A Multicenter Retrospective Registry-based Descriptive Trial in Kobe City.

The current study aims to evaluate the incidence and results of aneurysmal subarachnoid hemorrhage (aSAH) throughout Kobe City. Based on a multicenter retrospective registry-based descriptive trial involving all 13 primary stroke centers in Kobe City, patients with aSAH treated between October 2017 and September 2019 were studied. A total of 334 patients were included, with an estimated age-adjusted incidence of 11.12 per 100,000 person-years. Curative treatment was given to 94% of patients, with endovascular treatment (51%) preferred over surgical treatment (43%). Of the patients, 12% were treated by shunt surgery for sequential hydrocephalus with a worse outcome at 30 days or discharge (14% vs. 46%, odds ratio (OR): 0.19, 95% confidence interval (CI): 0.088-0.39, p-value <0.001). As for vasospasm and delayed cerebral ischemia, most patients were given intravenous fasudil infusion (73%), with endovascular treatment for vasospasm in 24 cases (7.2%). The fasudil group had more good outcomes (42% vs. 30%, OR: 1.64, 95% CI: 0.95-2.87, p-value = 0.075) and significantly less death (3.3% vs. 35%, OR: 0.064, 95% CI: 0.024-0.15, p-value <0.001) at 30 days or discharge. Mortality rose from 12% at 30 days or discharge to 17% at 1 year, but neurological function distribution improved over time (modified Rankin Scale 0-2 was 39% at 30 days or discharge, 53% at 60 days, and 63% at 1 year). Our retrospective registered trial presented various statistics on aSAH, summarizing the current treatment status and prognosis.

Management of Intraoperative Rupture of Intracranial Aneurysms: Agony and Ecstasy.

Intraoperative rupture (IOR) of an intracranial aneurysm is a serious complication, often with catastrophic consequences that are difficult to manage even by the best hands. Like most surgical complications, this one is better to avoid than to treat, but any vascular neurosurgeon should know how to deal with IOR of an aneurysm, because it is bound to occur. The aims of this study were to evaluate the incidence and factors associated with IOR during clipping of intracranial aneurysms, to analyze strategies for controlling hemorrhage in such cases, and to assess outcomes. Overall, 911 cases of intracranial aneurysms, which were treated surgically by the author during 26 years of his professional career, were reviewed. IOR was never noted during clipping of an unruptured intracranial aneurysm (65 cases) but was encountered in 49 of 846 cases (5.8%) presenting with subarachnoid hemorrhage. This complication occurred most often in cases of internal carotid artery aneurysms (22 cases; 45%), followed by anterior communicating artery aneurysms (12 cases; 24%), distal anterior cerebral artery aneurysms (6 cases; 12%), middle cerebral artery aneurysms (6 cases; 12%), and posterior circulation aneurysms (3 cases; 6%). IOR was mostly encountered during early surgery (within 3 days) after the ictus (26 cases; 53%) and most frequently occurred during dissection of the aneurysm (26 cases; 53%). Overall, 22 patients (45%) had good outcome, 18 (37%) had variable morbidity, and 9 (18%) died. Fatal consequences of IOR were noted only in cases of big or multilobulated internal carotid artery aneurysms. Detailed planning of the surgical procedure, application of meticulous microdissection techniques, and anticipation of possible intraoperative incidents during intervention aimed at clipping of an intracranial aneurysm can reduce the risk of IOR, as well as the associated morbidity and mortality.

A shift from open to endovascular repair in the treatment of ruptured middle cerebral artery aneurysms: a single institution experience.

PURPOSE: Middle cerebral aneurysms were underrepresented in the two largest trials (BRAT and ISAT) for the treatment of ruptured intracranial aneurysms. Recent institutional series addressing the choice between endovascular or open repair for this subset of aneurysms are few and have not yielded a definitive conclusion. We compare clinical outcomes of patients presenting with acute subarachnoid hemorrhage from ruptured middle cerebral artery aneurysms undergoing either open or endovascular repair. METHODS: We conducted a retrospective review of 138 consecutive patients with ruptured middle cerebral artery aneurysms admitted into our institution from January 2008 to March 2019 to compare endovascular and open surgical outcomes. RESULTS: Of the ruptured middle cerebral artery aneurysms, 57 underwent endovascular repair while 81 were treated with open surgery. Over the study period, there was a notable shift in practice toward more frequent endovascular treatment of ruptured MCA aneurysms (31% in 2008 vs. 91% in 2018). At discharge (49.1% vs 29.6%; p = .002) and at 6 months (84.3% vs 58.6%; p = 0.003), patients who underwent endovascular repair had a higher proportion of patients with good clinical outcomes (mRS 0-2) compared to those undergoing open surgery. Long-term follow-up data (endovascular 54.9 ± 37.9 months vs clipping 18.6 ± 13.4 months) showed no difference in rebleeding (1.8% vs 3.7%, p = 0.642) and retreatment (5.3% vs 3.7%, p = 0.691) in both groups. CONCLUSION: Our series suggests equipoise in the treatment of ruptured middle cerebral artery aneurysms and demonstrates endovascular repair as a potentially feasible treatment strategy. Future randomized trials could clarify the roles of these treatment modalities.

Endovascular and microsurgical management of blister aneurysms: a multi-centre review.

Blister aneurysms (BA) are high-risk cerebrovascular lesions accounting for 1% of intracranial aneurysms. The defective vessel wall and broad-based neck make this clinical entity difficult to treat, with high rates of re-rupture and mortality in patients presenting with acute subarachnoid haemorrhage. Blister aneurysms pose substantial challenges for both endovascular and microsurgical management. The objective of this study is to evaluate endovascular and microsurgical outcomes in intracranial blister aneurysm management across two tertiary hospitals. A review of two tertiary hospitals with a systematic imaging database search for term of "blister" in modalities from January 2010 to October 2022 was conducted. Operation reports were screened for the 5-year period since cerebral angiogram reports transitioned to surgical database. Identified reports were screened and reviewed for confirmed diagnosis by consultant neuroradiologist. A total of 21 cases of blister aneurysms managed at respective facilities were included. Sixteen cases (76%) were managed endovascularly. Four cases (19%) were managed surgically-2 with primary clipping, and 2 wrap and clipping. One case was managed conservatively (5%). Clinical outcomes were discharge disposition, aneurysm exclusion and post-operative complications. BAs have challenging considerations with high mortality and morbidity. Endovascular treatment offers a less invasive modality with lower rates of intraoperative rupture and morbidity. Mortality rates and patients discharged home were comparable. Commencement of dual anti-platelet therapy was safe in patients with flow diversion stents despite sub-arachnoid blood volume. Management of blister aneurysms is complex. Endovascular treatment shows promise for acute management but careful collaborative consideration of antithrombotic regime and requirement for further surgery should be considered.

A case of middle cerebral artery large circumferential aneurysm treated with bypass-assisted trapping surgery.

M1 large circumferential aneurysms are clinically challenging because they cannot be treated by simple neck clipping and they may involve the lenticulostriate arteries (LSAs). Although some reports have described endovascular and direct surgical treatment of these aneurysms, the optimal treatment approach remains uncertain. We report a case involving a ruptured large M1 circumferential aneurysm that was treated with bypass-assisted trapping surgery and showed favorable outcomes. The patient was a 47-year-old man presenting with subarachnoid hemorrhage. Digital subtraction angiography revealed a large circumferential aneurysm in the right middle cerebral artery M1 segment with involvement of the lateral and medial LSAs. We successfully performed trapping surgery with the assistance of a superficial temporal artery (STA)-M2 bypass while preserving the medial and lateral LSAs. Although left hemiparesis caused by medial LSA thrombosis appeared in the early postoperative period, the patient showed good recovery from symptoms with rehabilitation and could independently perform daily activities at the five-month follow-up. The treatment of M1 large circumferential aneurysms should involve considerations for prevention of rebleeding, blood supply to the distal area, and preservation of perforating arteries. The treatment strategy for this challenging aneurysm should be planned based on the patient's condition and individual anatomy.

Computational Fluid Dynamics Analysis Features in Aneurysm Development in Rats.

The investigation of how to control the development and growth of cerebral aneurysms is important for the prevention of subarachnoid hemorrhage. Although there have been several types of research studies on computational fluid dynamics (CFD) analysis of brain aneurysm development and growth, there has been no unified interpretation of the CFD analysis results. The purpose of this study is to clarify the characteristics of CFD analysis results related to the development of cerebral aneurysms using an animal model. Nineteen rat models of cerebral aneurysms were created, and the CFD analysis results between the cerebral aneurysm group [n = 10; the aneurysm was observed on magnetic resonance angiography (MRA) within 10 weeks after aneurysm induction surgery] and the nonaneurysm group (n = 9) were compared. All aneurysms were confirmed on the proximal segment of the left cerebral artery (P1), and the cross-sectional area and curvature of the left P1 were evaluated together. In the cerebral aneurysm group, there was a decrease in wall shear stress (WSS) that is consistent with the location of the aneurysm compared to the nonaneurysm group. The cross-sectional area of the left P1 gradually increased in the aneurysm group but not in the nonaneurysm group. The mean curvature in the entire left P1 was higher in the aneurysm group than in the nonaneurysm group. This study revealed that the development of cerebral aneurysms is due to changes in vascular morphology, namely, an increase in vessel diameter and a high curvature, and a decreased WSS consistent with the site of aneurysm development using this animal model.

[Ruptured Cerebral Aneurysm:Indications and Outcomes].

Selection of a reliable method to offer prompt treatment and prevent rebleeding of ruptured cerebral aneurysms is necessary because rebleeding can worsen patient outcomes. Surgical interventions for ruptured cerebral aneurysms have evolved from cervical artery ligation to clipping using a surgical microscope and endovascular coil embolization. In the International Subarachnoid Aneurysm Trial, a multicenter randomized controlled trial, the incidence of poor outcomes at 1 year after treatment was 23.7% and 30.6% in the endovascular coiling and neurosurgical clipping groups, respectively, which demonstrated the superiority of endovascular coiling over neurosurgical clipping(p = 0.0019)in patients with ruptured intracranial aneurysms. Rates of survival and independence in activities of daily living at 10 years after treatment were higher in the coiling group than in the clipping group(odds ratio: 1.34; 95% confidence interval: 1.07-1.67). The Barrow Ruptured Aneurysm Trial and several meta-analyses yielded similar results, showing the superiority of endovascular coiling over neurosurgical clipping with respect to short- and long-term clinical outcomes in patients. These results have also been reflected in the guidelines. Large clinical trials have analyzed and compared the effects of these treatments. In addition, the subsequent decade has witnessed remarkable advances in medical devices and treatment techniques for cerebral aneurysms. Clinical findings and cerebral aneurysm characteristics should be carefully evaluated to select the optimal treatment strategy for patients with ruptured cerebral aneurysms.