Somatic PDGFRB activating variants promote smooth muscle cell phenotype modulation in intracranial fusiform aneurysm.

BACKGROUND: The fusiform aneurysm is a nonsaccular dilatation affecting the entire vessel wall over a short distance. Although PDGFRB somatic variants have been identified in fusiform intracranial aneurysms, the molecular and cellular mechanisms driving fusiform intracranial aneurysms due to PDGFRB somatic variants remain poorly understood. METHODS: In this study, single-cell sequencing and immunofluorescence were employed to investigate the phenotypic changes in smooth muscle cells within fusiform intracranial aneurysms. Whole-exome sequencing revealed the presence of PDGFRB gene mutations in fusiform intracranial aneurysms. Subsequent immunoprecipitation experiments further explored the functional alterations of these mutated PDGFRB proteins. For the common c.1684 mutation site of PDGFRß, we established mutant smooth muscle cell lines and zebrafish models. These models allowed us to simulate the effects of PDGFRB mutations. We explored the major downstream cellular pathways affected by PDGFRBY562D mutations and evaluated the potential therapeutic effects of Ruxolitinib. RESULTS: Single-cell sequencing of two fusiform intracranial aneurysms sample revealed downregulated smooth muscle cell markers and overexpression of inflammation-related markers in vascular smooth muscle cells, which was validated by immunofluorescence staining, indicating smooth muscle cell phenotype modulation is involved in fusiform aneurysm. Whole-exome sequencing was performed on seven intracranial aneurysms (six fusiform and one saccular) and PDGFRB somatic mutations were detected in four fusiform aneurysms. Laser microdissection and Sanger sequencing results indicated that the PDGFRB mutations were present in smooth muscle layer. For the c.1684 (chr5: 149505131) site mutation reported many times, further cell experiments showed that PDGFRBY562D mutations promoted inflammatory-related vascular smooth muscle cell phenotype and JAK-STAT pathway played a crucial role in the process. Notably, transfection of PDGFRBY562D in zebrafish embryos resulted in cerebral vascular anomalies. Ruxolitinib, the JAK inhibitor, could reversed the smooth muscle cells phenotype modulation in vitro and inhibit the vascular anomalies in zebrafish induced by PDGFRB mutation. CONCLUSION: Our findings suggested that PDGFRB somatic variants played a role in regulating smooth muscle cells phenotype modulation in fusiform aneurysms and offered a potential therapeutic option for fusiform aneurysms.

First-generation bypass surgery for a giant fusiform aneurysm of the middle cerebral artery: an illustrative case and surgical video.

Giant fusiform aneurysms of the middle cerebral artery (MCA) are complex and rare vascular lesions with a poor natural history and challenging treatment decision-making. We report the case of a 46-year-old male with a history of chronic hypertension and a transient ischemic attack who presented with left-sided hemiparesis. A cerebral angiotomography revealed an unruptured giant fusiform aneurysm in the M2 segment of the right MCA. After carefully evaluating the procedure's risks and benefits with the patient, he underwent a low-flow bypass surgery. An anastomosis between the superficial temporal artery and the M3 segment was performed with proximal clipping of the M2 segment. The postoperative course was uneventful, with preserved bypass patency. At follow-up, the patient was neurologically intact. This report illustrates the nuances and operative techniques for treating a giant fusiform aneurysm of the M2 segment that accounted for a preserved bypass patency and optimal patient neurological recovery.

Fusiform "True" Posterior Communicating Artery Aneurysm with Basilar Artery Occlusion: A Case Report.

Isolated posterior communicating artery (PCoA) aneurysms are rare, predominantly fusiform in morphology, and rarely present with subarachnoid hemorrhage. Endovascular management of this pathology is technically challenging due to extreme tortuosity, the artery course in the subarachnoid space, sharp angulations at PCoA junctions with the parent artery, and, at times, associations with either internal carotid artery or basilar artery occlusions. We present a case of a ruptured fusiform PCoA at the junction of middle and distal third with concomitant proximal basilar artery occlusion. The PCoA reforms the posterior circulation, making it a vital artery. Stent-assisted coiling was performed with extreme difficulty in achieving distal positioning of the stents in the basilar artery/posterior cerebral artery/distal PCoA due to artery tortuosity. There was technical difficulty in the stent deployment. After changing strategies to a larger diameter laser-cut stent, endovascular treatment could be performed. There were good angiographic and clinical outcomes with stable occlusion at 6-month-follow-up.

Bypass Surgery for Vertebral Artery and Posterior Inferior Cerebellar Artery Fusiform Aneurysms: Surgical Technique and Key Lessons.

Fusiform vertebral artery (VA) aneurysms are challenging to treat due to their pathophysiology, morphology, and anatomic location.1,2 Endovascular treatments are considered to be a widely adopted safe option for this pathology.1 Open microsurgical treatment is considered for complex anatomy, important branch involvement, poor collateral flow, or failed endovascular therapy.3-7 This report aims to show the flow-replacement strategy and bypass technique for a VA aneurysm with complex anatomy and branch involvement. A 24-year-old man presented to our clinic with a bilateral fusiform VA aneurysm discovered during workup of progressive headaches. Further investigation revealed that the left-side aneurysm was mostly thrombosed and the posterior inferior cerebellar artery arose from the aneurysm dome with a fusiform enlargement within a few millimeters from the branching point. After evaluating all management options, the patient decided on surgical treatment of the left VA aneurysm. We performed an occipital artery to posterior inferior cerebellar artery end-to-side anastomosis distal to the fusiform enlargement, followed by trapping of the aneurysm and dome resection (Video 1). Antegrade flow to the distal VA was reestablished using a radial artery interposition graft, thus preventing any flow alterations that may cause growth or rupture of the contralateral aneurysm caused by increased hemodynamic stress if the ipsilateral VA flow is not preserved.8 After in-hospital physical rehabilitation, the patient was discharged with a modified Rankin Scale score of 1. The contralateral aneurysm is managed with serial imaging and treatment will ensue if there is clinical-radiologic evolution. The patient consented to the procedure and publication of his image.

Arterial Bypass in the Treatment of Complex Middle Cerebral Artery Aneurysms: Lessons Learned from Forty Patients.

OBJECTIVE: Complex middle cerebral artery (MCA) aneurysms incorporating parent or branching vessels are often not amenable to standard microsurgical clipping or endovascular embolization treatments. We aim to discuss the treatment of such aneurysms via a combination of surgical revascularization and aneurysm exclusion based on our institutional experience. METHODS: Thirty-four patients with complex MCA aneurysms were treated with bypass and aneurysm occlusion, 5 with surgical clipping or wrapping only, and 1 with aneurysm excision and primary reanastomosis. Bypasses included superficial temporal artery (STA)-MCA, double-barrel STA-MCA, occipital artery-MCA, and external carotid artery-MCA. After bypass, aneurysms were treated by surgical clipping, Hunterian ligation, trapping, or coil embolization. RESULTS: The average age at diagnosis was 46 years. Of the aneurysms, 67% were large and most involved the MCA bifurcation. Most bypasses performed were STA-MCA bypasses, 12 of which were double-barrel. There were 2 wound-healing complications. All but 2 of the aneurysms treated showed complete occlusion at the last follow-up. There were 3 hemorrhagic complications, 3 graft thromboses, and 4 ischemic insults. The mean follow-up was 73 months. Of patients, 83% reported stable or improved symptoms from presentation and 73% reported a functional status (Glasgow Outcome Scale score 4 or 5) at the latest available follow-up. CONCLUSIONS: Cerebral revascularization by bypass followed by aneurysm or parent artery occlusion is an effective treatment option for complex MCA aneurysms that cannot be safely treated by standard microsurgical or endovascular techniques. Double-barrel bypass consisting of 2 STA branches to 2 MCA branches yields adequate flow replacement in most cases.

Management of a ruptured posterior inferior cerebellar artery (PICA) aneurysm with end-to-end in situ bypass: Case report.

Dissecting posterior inferior cerebellar artery (PICA) aneurysms are uncommon lesions. Their anatomy and the location of the dissection are variable, however, they usually occurs at the origin of the PICA. Dissecting PICA aneurysms generally have non-vascular morphology involving an entire segment of the artery and cannot be cut. Nevertheless, the detection of these vascular lesions has increased latterly, so it is necessary to recognize it and take the appropriate management modalities for these injuries. In this report, we describe a case of a 73-year-old male patient, who presented a history of severe headache, associated with neck stiffness, nausea, vomiting, dizziness, hypoactivity, mental confusion, and walking difficulty. Radiographic investigation with brain computed tomography (CT) showed mild bleeding in a pre-medullary and pre-pontine cistern, and cerebral angiogram showed a dissecting PICA aneurysm. Despite being a challenging treatment, microsurgery management was the chosen modality. It was performed an end-to-end anastomosis between the p2/p3 segments, showing to be effective with good clinical and radiographic outcomes. We discussed an unusual case, reviewing the current literature on clinical presentations, the angiographic characteristics of the dissecting aneurysms of PICA, and evaluating the clinical and angiographic results of patients undergoing microsurgical treatment.

Disappearance of a Ruptured Feeding Artery Fusiform Aneurysm After the Resection of a Large Subependymoma: A Case Report.

Aneurysm formation on the tumor-feeding artery is rare, and its treatment strategies are not yet settled. We herein report the case of a 49-year-old female with a large subependymoma in the left lateral ventricle presenting remote intracerebral hemorrhage at the left posterior cingulate gyrus. Digital subtraction angiography (DSA) revealed the presence of a 5.5 mm fusiform tumor-feeding artery aneurysm on the left parieto-occipital branch of the posterior cerebral artery, considered to be the source of the hemorrhage. Three months after total tumor resection, the aneurysm subsequently disappeared on the follow-up angiography. Subependymomas are generally known as tumors with low vascularity and seldom present with symptoms such as intracerebral hemorrhage. From the subsequent disappearance of the aneurysm after the complete tumor resection, the pathophysiological cause of the aneurysm formation is assumed to be flow-related hemodynamic vessel wall stress of the feeding artery. Tumor resection alone may be a favorable first treatment strategy to avoid unnecessary brain damage since subsequent disappearance of the aneurysm can be expected. The coexistence of feeding artery aneurysms should be kept in mind, especially in cases with remote hemorrhage.

Multiple fusiform and saccular aneurysms in a person living with Human Immunodeficiency Virus.

Cerebral aneurysms secondary to human immunodeficiency virus vasculopathy are a diagnosis by exclusion and its mechanism is unknown. We report on a 21-year-old male with human immunodeficiency virus infection and suboptimal virological control, despite highly active antiretroviral therapy. An incidental discovery of multiple cerebral aneurysms occurred in this patient, who initially presented with signs of disorientation, acute psychosis, and a history of blunt cranial trauma. A non-contrasted computerized tomography scan of the encephalon showed no intracranial hemorrhage but multiple cerebral (saccular and fusiform) aneurysms. Subsequently, a non-urgent computerized tomography angiogram of the cerebral vasculature corroborated the existence of multiple cerebral aneurysms. Despite investigation, no secondary etiological factors for the aneurysmal condition were identified. The multitude of cerebral aneurysms was consequently ascribed to human immunodeficiency virus-associated vasculopathy. The patient was managed conservatively. At discharge, he was lucid and apsychotic. A unique aspect of the case is the presence of both fusiform and saccular cerebral aneurysms.

Corrigendum: Case report: Ruptured internal carotid artery fusiform aneurysm mimicking pituitary apoplexy after stereotactic radiosurgery.

[This corrects the article DOI: 10.3389/fneur.2023.1219372.].

Trapping and side-to-end superior cerebellar artery to superior cerebellar artery bypass for treatment of fusiform superior cerebellar artery aneurysm.

We describe the technical nuances of in-situ bypass for treatment of a fusiform superior cerebellar artery (SCA) aneurysm via surgical trapping and a side-to-end in-situ bypass between duplicated SCAs. Our patient is a 40-year-old male who presented with an incidental aneurysm of the proximal right superior cerebellar artery (SCA). Formal angiography was performed that demonstrated a fusiform morphology of the aneurysm, as well as a duplicated SCA on that side. After extensive counseling, the patient elected to undergo surgical clip reconstruction with possible bypass. A large frontotemporal craniotomy was performed and a combined transsylvian-subtemporal approach to the ventral anterolateral brainstem was performed. After identifying the aneurysm, the tentorium was incised posterior to the insertion of the trochlear nerve to widen the operative field. An end-to-side anastomosis between the duplicated SCAs was performed, followed by trapping of the diseased arterial segment. The patient had an oculomotor nerve palsy post-operatively, however this resolved by his six-month follow-up. In-situ bypass is a viable technique for revascularizing the SCA territory during clip reconstruction of fusiform aneurysms. A duplicated SCA allows for an SCA to SCA bypass. Incising the tentorium can increase visualization of donor and recipient vessels and facilitate performance of the anastomosis.

Use of Proximal Suboccipital Segment of Occipital Artery as Donor for Posterior Circulation Revascularization Surgery: Technical Note.

BACKGROUND: The distal suboccipital segment of the occipital artery is commonly used as a donor vessel for aneurysms of the posterior circulation requiring revascularization techniques. Isolating this segment of vessel can be challenging due to its course in and out of the various layers of the suboccipital musculature. METHODS: We describe the use of the proximal suboccipital segment of the occipital artery within the occipital groove at the lateral skull base as a donor segment for an interposition graft in revascularization surgery. We present a case detailing the use of this technique for treatment of a dissecting PICA aneurysm and photographs from cadaveric dissections demonstrating relevant anatomy. RESULTS: Our patient is a 62-year-old man who presented with a high-grade subarachnoid hemorrhage from a proximal dissecting-type aneurysm of the posterior inferior cerebellar artery (PICA). Endovascular options were limited to coil sacrifice of the parent vessel, and thus the patient was taken for a far lateral craniotomy, trapping of the aneurysm, and revascularization of the PICA territory via a saphenous vein interposition graft sewn proximally and distally to the occipital artery within the occipital groove and a cortical segment of the affected PICA, respectively. Postoperative imaging demonstrated filling of the PICA territory via the graft, and the patient ultimately recovered from his subarachnoid hemorrhage. CONCLUSIONS: The use of the proximal suboccipital segment of the occipital artery is a viable option for a donor in posterior fossa revascularization surgery.

Proximal Internal Carotid Artery Occlusion and Extracranial-Intracranial Bypass for Treatment of Fusiform and Giant Internal Carotid Artery Aneurysms.

OBJECTIVE: To discuss the treatment of intracranial fusiform and giant internal carotid artery (ICA) aneurysms via revascularization based on our institutional experience. METHODS: An institutional review board-approved retrospective analysis was performed of patients with unruptured fusiform and giant intracranial ICA aneurysms treated from November 1991 to May 2020. All patients were evaluated for extracranial-intracranial (EC-IC) bypass and ICA occlusion. RESULTS: Thirty-eight patients were identified. Initially, patients failing preoperative balloon test occlusion were treated with superficial temporal artery (STA)-middle cerebral artery (MCA) bypass and concurrent proximal ICA ligation. We then treated them with STA-MCA bypass, followed by staged balloon test occlusion, and, if they passed, endovascular ICA coil occlusion. We treat all surgical medically uncomplicated patients with double-barrel STA-MCA bypass and concurrent proximal ICA ligation. The mean length of follow-up was 99 months. Symptom stability or improvement was noted in 85% of patients. Bypass graft patency was 92.1%, and all surviving patients had patent bypasses at their last angiogram. Aneurysm occlusion was complete in 90.9% of patients completing proximal ICA ligation. Three patients experienced ischemic complications and 4 patients experienced hemorrhagic complications. CONCLUSIONS: Not all fusiform intracranial ICA aneurysms require intervention, except when life-threatening rupture risk is high or symptomatic management is necessary to preserve function and quality of life. EC-IC bypass can augment the safety of proximal ICA occlusion. The rate of complete aneurysm occlusion with this treatment is 90.9%, and long-term bypass graft-related complications are rare. Perioperative stroke is a major risk, and continued evolution of treatment is required.

Case report: Ruptured internal carotid artery fusiform aneurysm mimicking pituitary apoplexy after stereotactic radiosurgery.

Pituitary adenomas are benign tumors of the anterior pituitary gland for which surgery or pharmacological treatment is the primary treatment. When initial treatment fails, radiation therapy should be considered. There are several case reports demonstrating radiation-induced vascular injury. We report an adult patient who presented with headache and diplopia for 6 months and a sellar tumor with optic chiasm compression. The patient received transnasal surgery, and the tumor was partially removed, which demonstrated adenoma. Stereotactic radiosurgery (SRS) was arranged. However, owing to progressive tumor growth, the patient received further transnasal surgery and stereotactic radiosurgery (SRS). After 14 years, the patient reported the sudden onset of headache and diplopia, and a ruptured fusiform aneurysm from the left internal carotid artery with pituitary apoplexy was diagnosed. The patient received transarterial embolization of the aneurysm. There were no complications after embolization, and this patient was ambulatory on discharge with blindness in the left eye and cranial nerve palsies. Aneurysm formation may be a complication of SRS, and it may occur after several years. Further research is needed to investigate the pathogenesis of radiosurgery and the development of cerebral aneurysms.

Hemifacial spasm caused by unruptured fusiform vertebral aneurysm treated with endovascular coil embolization: a case report.

Hemifacial spasm due to fusiform aneurysm of the vertebral artery is extremely rare. The lateral spread response (LSR) is routinely used to monitor hemifacial spasms during microvascular decompression to predict the degree of postoperative remission of hemifacial spasm. We report a case of hemifacial spasm caused by an unruptured fusiform vertebral aneurysm treated with intravascular intervention and monitoring of LSR. A 59-year-old man was admitted to the hospital with a left facial spasm that gradually worsened for 1 year. Preoperative cerebrovascular angiography indicated fusiform aneurysms in the intracranial segment of the left vertebral artery close to the left facial nerve. The patient underwent parent artery occlusion and aneurysm embolization, and LSR was monitored intraoperatively. After intraoperative aneurysm embolization, LSR disappeared immediately. The postoperative review of cerebrovascular angiography indicated that the parent artery and aneurysm were embolized successfully, and the patient's left facial spasm was relieved after surgery. Hemifacial spasm caused by the vertebral artery fusiform aneurysm can be safely and effectively treated by parent artery occlusion and aneurysm embolization. Meanwhile, intraoperative LSR monitoring can be used to predict postoperative efficacy.

Dome Resection and End-to-End Reanastomosis for a Middle Cerebral Artery Fusiform Aneurysm of the M1 Segment: 2-Dimensional Operative Video.

Fusiform aneurysms of the middle cerebral artery (MCA) are both relatively uncommon and challenging to treat given their pathophysiology, morphology, and anatomy (e.g., perforating arteries involvement).1,2 Endovascular treatment of fusiform MCA aneurysms can achieve good outcomes in well-selected cases.3,4 Open microsurgical strategies are effective in a case of fusiform MCA aneurysms with complex anatomy or perforator involvement.2,5,6 We demonstrate the bypass strategy for resection of a fusiform M1 MCA aneurysm (Video 1). A 48-year-old female was referred for the treatment of a growing incidental right M1 MCA fusiform aneurysm. Imaging showed a tortuous M1 segment with no apparent perforator involvement, which we considered a candidate for resection and reanastomosis. A modified minipterional transsylvian approach was performed as described earlier.7,8 A double superficial temporal artery to middle cerebral artery bypass was performed to maintain flow to MCA territory and distal perforators in anticipation of a long temporary flow arrest due to complex aneurysmal dissection and reanastomosis and also to serve as long-term protective insurance. Resection and end-to-end reanastomosis will preserve the antegrade flow and prevent the risk stump thrombosis carried by a simple trapping.9,10 We cover the nuances of this technique including key steps to an efficient aneurysmal resection and complication avoidance. The patient tolerated the procedure well, and postoperative imaging showed no aneurysmal remnant and flow restoration with no evidence of stroke. We discharged the patient home with a modified Rankin scale of 0. The patient consented to the procedure and publication of his or her image.

Ruptured Fusiform Anterior Cerebral Artery Aneurysm in an Infant : Case Report and a Literature Review.

Ruptured intracranial aneurysms in infants are rare and infantile fusiform anterior cerebral artery (ACA) aneurysms are much rarer. In this report, we described the case of a 7-month-old infant with a ruptured fusiform ACA aneurysm who presented with seizure and underwent endovascular treatment. The patient was initially in a coma and the neurologic condition did not improve after treatment. The clinical characteristics of the case and literature review were discussed.

Wall enhancement predictive of abnormal hemodynamics and ischemia in vertebrobasilar non-saccular aneurysms: a pilot study.

Objective: To analyze how wall enhancement affects hemodynamics and cerebral ischemic risk factors in vertebrobasilar non-saccular intracranial aneurysms (VBNIAs). Materials and methods: Ten consecutive non-saccular aneurysms were collected, including three transitional vertebrobasilar dolichoectasia (TVBD). A wall enhancement model was quantitatively constructed to analyze how wall enhancement interacts with hemodynamics and cerebral ischemic factors. Results: Enhanced area revealed low wall shear stress (WSS) and wall shear stress gradient (WSSG), with high oscillatory shear index (OSI), relative residence time (RRT), and gradient oscillatory number (GON) while the vortex and slow flow region in fusiform aneurysms are similar to TVBD fusiform aneurysms. With low OSI, high RRT and similar GON in the dilated segment, the enhanced area still manifests low WSS and WSSG in the slow flow area with no vortex. In fusiform aneurysms, wall enhancement was negatively correlated with WSS (except for case 71, all p values < 0.05, r = -0.52 ~ -0.95), while wall enhancement was positively correlated with OSI (except for case 5, all p values < 0.05, r = 0.50 ~ 0.83). For the 10 fusiform aneurysms, wall enhancement is significantly positively correlated with OSI (p = 0.0002, r = 0.75) and slightly negatively correlated with WSS (p = 0.196, r = -0.30) throughout the dataset. Aneurysm length, width, low wall shear stress area (LSA), high OSI, low flow volume (LFV), RRT, and high aneurysm-to-pituitary stalk contrast ratio (CRstalk) area plus proportion may be predictive of cerebral ischemia. Conclusion: A wall enhancement quantitative model was established for vertebrobasilar non-saccular aneurysms. Low WSS was negatively correlated with wall enhancement, while high OSI was positively correlated with wall enhancement. Fusiform aneurysm hemodynamics in TVBD are similar to simple fusiform aneurysms. Cerebral ischemia risk appears to be correlated with large size, high OSI, LSA, and RRT, LFV, and wall enhancement.

Prognostic Factors in Patients with Unruptured Vertebral and Basilar Fusiform Aneurysms Treated with Endovascular Procedures : A Single Center Retrospective Analysis.

PURPOSE: Large vertebral and basilar fusiform aneurysms (VFA) are sometimes difficult to cure by endovascular treatment (EVT). We aimed to elucidate indicators of poor outcomes of EVT in patients with VFAs. METHODS: Clinical data from 48 patients with 48 unruptured VFAs in the Hyogo Medical University were retrospectively analyzed. The primary outcome was defined as satisfactory aneurysm occlusion (SAO) according to Raymond-Roy grading scale. The secondary and safety outcomes were a modified Rankin scale (mRS) score of 0-2 at 90 days, retreatment, major stroke, and aneurysm-related death after EVT. RESULTS: The EVT included stent-assisted coiling (n = 24; 50%), flow diverter (n = 19; 40%), and parent artery occlusion (n = 5; 10%). The SAO was less frequently observed in large or thrombosed VFAs at 12 months (64%, p = 0.021 and 62%, p = 0.014, respectively), especially when the aneurysms were both large and thrombosed (50%, p = 0.0030). Retreatment was more common in large aneurysms (29%, p = 0.034), thrombosed (32%, p = 0.011), and large thrombosed aneurysms (38%, p = 0.0036). Although the proportion of mRS 0-2 at 90 days and major stroke showed no significant differences, that of post-treatment rupture was significantly larger in large thrombosed VFAs (19%, p = 0.032). Aneurysm-related death occurred by aneurysm rupture and was more frequent in large thrombosed VFA (19%, p = 0.032). Multivariate analysis showed SAO at 12 months was less common (adjusted odds ratio, OR: 0.036, 95% confidence interval, CI 0.00091-0.57; p = 0.018), and retreatment was more common (adjusted OR 43, 95% CI 4.0-1381; p = 0.0012) in large thrombosed VFA. CONCLUSION: The large thrombosed VFAs were associated with poor outcomes after EVT including flow diverter.

Aneurysm wall enhancement, hemodynamics, and morphology of intracranial fusiform aneurysms.

Background and objective: Intracranial fusiform aneurysms (IFAs) are considered to have a complex pathophysiology process and poor natural history. The purpose of this study was to investigate the pathophysiological mechanisms of IFAs based on the characteristics of aneurysm wall enhancement (AWE), hemodynamics, and morphology. Methods: A total of 21 patients with 21 IFAs (seven fusiform types, seven dolichoectatic types, and seven transitional types) were included in this study. Morphological parameters of IFAs were measured from the vascular model, including the maximum diameter (Dmax), maximum length (Lmax), and centerline curvature and torsion of fusiform aneurysms. The three-dimensional (3D) distribution of AWE in IFAs was obtained based on high-resolution magnetic resonance imaging (HR-MRI). Hemodynamic parameters including time-averaged wall shear stress (TAWSS), oscillatory shear index (OSI), gradient oscillatory number (GON), and relative residence time (RRT) were extracted by computational fluid dynamics (CFD) analysis of the vascular model, and the relationship between these parameters and AWE was investigated. Results: The results showed that Dmax (p = 0.007), Lmax (p = 0.022), enhancement area (p = 0.002), and proportion of enhancement area (p = 0.006) were significantly different among three IFA types, and the transitional type had the largest Dmax, Lmax, and enhancement area. Compared with the non-enhanced regions of IFAs, the enhanced regions had lower TAWSS but higher OSI, GON, and RRT (p < 0.001). Furthermore, Spearman's correlation analysis showed that AWE was negatively correlated with TAWSS, but positively correlated with OSI, GON, and RRT. Conclusion: There were significant differences in AWE distributions and morphological features among the three IFA types. Additionally, AWE was positively associated with the aneurysm size, OSI, GON, and RRT, while negatively correlated with TAWSS. However, the underlying pathological mechanism of the three fusiform aneurysm types needs to be further studied.

A challenging case of recurrent and progressive fusiform anterior circulation intracranial aneurysms: illustrative case.

BACKGROUND: Intracranial fusiform aneurysms are circumferential dilations of cerebral arteries that can lead to complications including ischemic stroke due to vessel occlusion, subarachnoid hemorrhage, or intracerebral hemorrhage. Treatment options for fusiform aneurysms have expanded significantly in recent years. Microsurgical treatment options include proximal and distal surgical occlusion and microsurgical trapping of the aneurysm, usually in association with high-flow bypass procedures. Endovascular treatment options include the placement of coils and/or flow diverters. OBSERVATIONS: Here the authors report a case of aggressive surveillance and treatment of a man with multiple progressive, recurrent, and de novo fusiform aneurysms of the left anterior cerebral circulation over 16 years. Because the long-term course of his treatment coincided with the recent expansion of endovascular treatment options, he underwent every type of treatment listed above. LESSONS: This case demonstrates the wide range of therapeutic options for fusiform aneurysms and how the treatment model for these lesions has evolved.