Spontaneous hepatic artery pseudoaneurysm rupture as a first presentation of polyarteritis nodosa.

A man in his 70s presented with a sudden onset stabbing back pain radiating to the chest and pre-syncopal symptoms. He underwent urgent investigations, including a CT angiogram aorta which did not reveal any abnormalities within the thorax, abdomen or pelvis and no cause of symptoms was identified. After being discharged, he re-presented 2 days later with syncopal episodes, abdominal pain and a significant drop in haemoglobin levels. This time, a CT mesenteric angiogram showed two hepatic artery pseudoaneurysms and a large haemoperitoneum. Following a hepatic artery embolisation, a workup showed that the likely cause of the pseudoaneurysms was a rare first presentation of polyarteritis nodosa. This case highlights the importance of considering the possibility of an aneurysmal rupture, especially when common causes of an acute abdomen have been excluded, and not relying on previous negative investigations to exclude pathology, as the outcomes can be detrimental.

[Analysis of intracranial saccular aneurysm wall: neuroimaging and histopathological correlates]. / Issledovanie stenki intrakranial'nykh meshotchatykh anevrizm: neirovizualizatsionnye i gistopatologicheskie korrelyaty.

BACKGROUND: Contrast enhancement of intracranial aneurysm wall during MRI with targeted visualization of vascular wall correlates with previous aneurysm rupture and, according to some data, may be a predictor of further rupture of unruptured aneurysms. OBJECTIVE: To analyze possible causes of aneurysm contrast enhancement considering morphological data of aneurysm walls. MATERIAL AND METHODS: The study included 44 patients with intracranial aneurysms who underwent preoperative MRI between November 2020 and September 2022. Each aneurysm was assessed regarding contrast enhancement pattern. Microsurgical treatment of aneurysm was accompanied by resection of its wall for subsequent histological and immunohistochemical analysis regarding thrombosis, inflammation and neovascularization. Specimens were subjected to histological and immunochemical analysis. Immunohistochemical analysis was valuable to estimate inflammatory markers CD68 and CD3, as well as neurovascularization marker SD31. RESULTS: Aneurysms with contrast-enhanced walls were characterized by higher number of CD3+, CD68+, CD31+ cells and parietal clots. Intensity of contrast enhancement correlated with aneurysm wall abnormalities. CONCLUSION: Contrast enhancement of aneurysm wall can characterize various morphological abnormalities.

Verification of a simplified aneurysm dimensionless flow parameter to predict intracranial aneurysm rupture status.

OBJECTIVES: Aneurysm number (An) is a novel prediction tool utilizing parameters of pulsatility index (PI) and aneurysm geometry. An has been shown to have the potential to differentiate intracranial aneurysm (IA) rupture status. The objective of this study is to investigate the feasibility and accuracy of An for IA rupture status prediction using Australian based clinical data. METHODS: A retrospective study was conducted across three tertiary referral hospitals between November 2017 and November 2020 and all saccular IAs with known rupture status were included. Two sets of An values were calculated based on two sets of PI values previously reported in the literature. RESULTS: Five hundred and four IA cases were included in this study. The results demonstrated no significant difference between ruptured and unruptured status when using An ≥1 as the discriminator. Further analysis showed no strong correlation between An and IA subtypes. The area under the curve (AUC) indicated poor performance in predicting rupture status (AUC1 = 0.55 and AUC2 = 0.56). CONCLUSIONS: This study does not support An ≥1 as a reliable parameter to predict the rupture status of IAs based on a retrospective cohort. Although the concept of An is supported by hemodynamic aneurysm theory, further research is needed before it can be applied in the clinical setting. ADVANCES IN KNOWLEDGE: This study demonstrates that the novel prediction tool, An, proposed in 2020 is not reliable and that further research of this hemodynamic model is needed before it can be incorporated into the prediction of IA rupture status.

Evaluation of flow diverter use in acutely ruptured vertebral artery dissecting Aneurysms: A focus on safety and efficacy for rapid Aneurysm obliteration.

OBJECTIVE: Flow diverter device (FDD) has emerged as the reconstruction technique for treating ruptured dissecting vertebral artery Aneurysms (VADA), but data on feasibility regarding re-rupture risk and timing of Aneurysm obliteration following FDD treatment is still limited. Therefore, this study aimed to evaluate the safety and efficacy of FDD in the treatment of VADAs presenting with subarachnoid hemorrhage (SAH). METHODS: We retrospectively reviewed patients with ruptured VADA presenting with subarachnoid hemorrhage who underwent FDD placement at our institution between 2015 and 2023. Patient demographic data, Aneurysm configuration, and occlusion status were analyzed. RESULTS: Thirteen patients with SAH from VADA rupture underwent FDD implantation. The average size of the largest diameter of the Aneurysm was 11.2 mm (range 6.5-21 mm). Eight of 13 (61.5 %) patients had their Aneurysms completely obliterated within 2 weeks after the procedure. The small dissecting Aneurysm (d = 0.636, p = 0.002) and degree of intra-Aneurysmal contrast stasis (d = 0.524, p = 0.026) were associated with rapid Aneurysm occlusion, according to the Somer's d coefficient. There were no ischemic or hemorrhagic complications at the average clinical follow-up of 28.4 months (range 5-67 months) and average angiographic follow-up of 20.1 months (range 3-60 months). A favorable outcome (mRS 0-2) was achieved in 12 patients (92.3 %). CONCLUSIONS: FDD is safe and effective for the reconstruction of acutely ruptured VADAs. In addition, our study emphasizes that small dissecting Aneurysms tend to be rapidly obliterated after flow diversion, which eliminates the risk of re-rupture during the acute phase of subarachnoid hemorrhage.

Cerebrospinal fluid volume as an early radiological factor for clinical course prediction after aneurysmal subarachnoid hemorrhage. A pilot study.

BACKGROUND: The pathological mechanisms following aneurysmal subarachnoid hemorrhage (SAH) are poorly understood. Limited clinical evidence exists on the association between cerebrospinal fluid (CSF) volume and the risk of delayed cerebral ischemia (DCI) or cerebral vasospasm (CV). In this study, we raised the hypothesis that the amount of CSF or its ratio to hemorrhage blood volume, as determined from non-contrast Computed Tomography (NCCT) images taken on admission, could be a significant predictor for CV and DCI. METHODS: The pilot study included a retrospective analysis of NCCT scans of 49 SAH patients taken shortly after an aneurysm rupture (33 males, 16 females, mean age 56.4 ± 15 years). The SynthStrip and Slicer3D software tools were used to extract radiological factors - CSF, brain, and hemorrhage volumes from the NCCT images. The "pure" CSF volume (VCSF) was estimated in the range of [-15, 15] Hounsfield units (HU). RESULTS: VCSF was negatively associated with the risk of CV occurrence (p = 0.0049) and DCI (p = 0.0069), but was not associated with patients' outcomes. The hemorrhage volume (VSAH) was positively associated with an unfavorable outcome (p = 0.0032) but was not associated with CV/DCI. The ratio VSAH/VCSF was positively associated with, both, DCI (p = 0.031) and unfavorable outcome (p = 0.002). The CSF volume normalized by the brain volume showed the highest characteristics for DCI prediction (AUC = 0.791, sensitivity = 0.80, specificity = 0.812) and CV prediction (AUC = 0.769, sensitivity = 0.812, specificity = 0.70). CONCLUSION: It was demonstrated that "pure" CSF volume retrieved from the initial NCCT images of SAH patients (including CV, Non-CV, DCI, Non-DCI groups) is a more significant predictor of DCI and CV compared to other routinely used radiological biomarkers. VCSF could be used to predict clinical course as well as to personalize the management of SAH patients. Larger multicenter clinical trials should be performed to test the added value of the proposed methodology.

Spontaneous occlusion of ruptured microaneurysm formed on postoperative transosseous anastomosis after indirect revascularization in a patient with moyamoya disease.

A 40-year-old female with a history of ischemic moyamoya disease treated with indirect revascularization at ages 12 and 25 years presented with a sudden severe headache. Imaging studies revealed focal parenchymal hemorrhage and acute subdural hematoma, confirming a microaneurysm formed on the postoperative transosseous vascular network as the source of bleeding. Conservative management was performed, and no hemorrhage recurred during the 6-month follow-up period. Interestingly, follow-up imaging revealed spontaneous occlusion of the microaneurysm. However, due to the rarity of this presentation, the efficacy of conservative treatment remains unclear. Further research on similar cases is warranted.

Pearls & Oy-sters: What Came First, the Bleed or the Fall?: An Aneurysmal Subdural Hemorrhage.

Acute subdural hemorrhages are a common emergency presentation often associated with trauma. However, in the absence of significant trauma, it is important to consider alternative causes. In this case, a 58-year-old woman with trivial trauma after a sudden collapse had bilateral subdural hemorrhages on CT. CT-angiogram revealed anterior communicating artery aneurysm, which had ruptured. This case explores intracerebral aneurysms as a rare cause of subdural hemorrhage that is important to consider in the absence of significant trauma.

Flow Diverter Combined with Coil Embolization for Acutely Ruptured Intracranial Aneurysms: A Single Center Experience.

BACKGROUND: Extensive research has confirmed the safety and effectiveness of flow diverters in the treatment of unruptured intracranial aneurysms. However, their use in cases of acute rupture remains a subject of debate. METHODS: This study was conducted as a single-center retrospective investigation from January 2018 to January 2022 and included patients with acutely ruptured intracranial aneurysms (within three days of rupture) who were treated using the Pipeline Embolization Device with adjunctive coil embolization. Patient demographics, operative procedures, and outcomes were analyzed. Antiplatelet therapy included intra-arterial tirofiban and postoperative dual therapy with clopidogrel and aspirin. RESULTS: A total of 21 patients (5 males, 16 females) diagnosed with acutely ruptured intracranial aneurysms were included in this study. The aneurysm types included 7 blood blister-like aneurysms (30.0%), 3 dissecting (14.3%), and 1 fusiform aneurysm (4.8%). Perioperative complications occurred in 2 patients (9.5%), and both cases involved thrombogenesis. Nineteen patients completed digital subtraction angiography during follow-up, with an average follow-up time of 8.7 months (5 - 18 months). Results showed a complete embolization rate of 94.7% (18/19), with a partial aneurysm still present in 1 patient. A total of 90.4% (19/21) of patients had a favorable prognosis (modified Rankin Scale score = 0 - 2). CONCLUSIONS: The Pipeline Embolization Device with adjunctive coil embolization proved to be a viable option for managing acutely ruptured intracranial aneurysms, notwithstanding the potential for ischemic complications.

Bivalirudin as a substitute for heparin in neurointervention for patients with heparin-induced thrombocytopenia.

OBJECTIVES: Heparin-induced thrombocytopenia is a known complication of heparin exposure with potentially life-threatening sequelae. Direct thrombin inhibitors can be substituted for heparin in patients with heparin-induced thrombocytopenia that require anticoagulation. However, the use of direct thrombin inhibitors as a substitute for heparin has not been widely reported in the neuroendovascular literature. MATERIALS AND METHODS: Here we report the first use of the direct thrombin inhibitor bivalirudin in a neuroendovascular procedure as a substitute for heparin in a patient with a ruptured pseudoaneurysm and heparin-induced thrombocytopenia, and review the literature on the use of bivalirudin and argatroban for such patients. RESULTS: Bivalirudin was safely and effectively used in the case reported, with no thrombotic or hemorrhagic complications. Our literature review revealed a paucity of studies on the use of heparin alternatives, including bivalirudin, in neuroendovascular procedures in patients with heparin-induced thrombocytopenia. CONCLUSIONS: Heparin-induced thrombocytopenia is an important iatrogenic disease process in patients undergoing neuroendovascular procedures, and developing protocols to diagnose and manage heparin-induced thrombocytopenia is important for healthcare systems. While further research needs to be done to establish the full range of anticoagulation options to substitute for heparin, our case indicates bivalirudin as a potential candidate.

Ruptured aneurysm in collateral arteries with blood-flow impairment of posterior inferior cerebellar artery: a report of three cases.

Herein, we report three cases of cerebellar hemorrhage due to a ruptured small aneurysm located on a collateral artery compensating for one or more stenotic or occluded major cerebellar arteries. In each case, endovascular distant parent artery occlusion of both the collateral artery and aneurysm was performed to prevent rebleeding. A ruptured small aneurysm in a collateral artery may be observed in patients with hemorrhage in an atypical cerebellar region, especially in cases of stenosis or occlusion of the vertebral artery or posterior inferior cerebellar artery. Thus, cerebral angiography is recommended to rule out collateral artery aneurysm.

Endovascular treatment of wide-neck bifurcation aneurysms using pCONUS2 HPC bridging device with single antiplatelet: A Case Series.

RATIONALE: Wide neck bifurcation aneurysms (WNBA) are technically challenging for both surgical and endovascular treatments. Endovascular treatment for WNBA often requires dual antiplatelet therapy (DAPT) post stent insertion. Novel devices such as the pCONUS2 HPC neck bridging device have an HPC coating which reduces the device thrombogenicity. This theoretically allows for use of single antiplatelet therapy (SAPT), which would be advantageous, particularly in treating ruptured aneurysms. This case series aims to evaluate the safety of SAPT regimen only post stent insertion, by presenting our center early clinical experience in using pCONUS2 HPC neck bridging device in patients that are not suitable for DAPT. PATIENT CONCERNS: We report the cases of 3 patients (2 females, 1 male; range: 64-71 years old) who underwent coil embolization for WNBA using the pCONUS2 HPC device (2 unruptured WNBA, and 1 ruptured WNBA). As all 3 patients were allergic to Aspirin, they could only be started on SAPT post endovascular therapy. DIAGNOSIS: All 3 patients were diagnosed with WNBA on angiographic studies. Patient 1 had an unruptured left middle cerebral artery aneurysm; Patient 2 had a ruptured basilar tip aneurysm; Patient 3 had an unruptured anterior communicating artery (ACOM) aneurysm. INTERVENTIONS: All 3 WNBA were treated with pCONUS2 HPC neck bridging device. OUTCOMES: There were no immediate complications. The immediate angiographic result of aneurysm treatment in Patient 1 and Patient 2 demonstrated incomplete occlusions, with delayed complete occlusion of aneurysm in Patient 1 and growth of aneurysmal neck in Patient 2 on follow-up angiograms (range: 6-9 months). No major thrombo-embolic or hemorrhagic complications in the first 2 patients. For Patient 3, the immediate angiographic result of the treated aneurysm demonstrated complete occlusion. However, the patient readmitted 11 days post procedure with cerebral infarction, scoring 5 on the modified Rankin scale on discharge. LESSONS: pCONUS2 HPC as a neck bridging device in treating WNBA has yet to be shown superior to traditional techniques and devices. The theoretical advantage of HPC coating reducing its thrombogenicity requiring only SAPT is yet to be proven safe in clinical practice.

ARISE I Consensus Review on the Management of Intracranial Aneurysms.

BACKGROUND: Intracranial aneurysms (IAs) remain a challenging neurological diagnosis associated with significant morbidity and mortality. There is a plethora of microsurgical and endovascular techniques for the treatment of both ruptured and unruptured aneurysms. There is no definitive consensus as to the best treatment option for this cerebrovascular pathology. The Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts discussed best practices and the most promising approaches to improve the management of brain aneurysms. METHODS: A group of experts from academia, industry, and federal regulators convened to discuss updated clinical trials, scientific research on preclinical system models, management options, screening and monitoring, and promising novel device technologies, aiming to improve the outcomes of patients with IA. RESULTS: Aneurysm, Arteriovenous Malformation, and Chronic Subdural Hematoma Roundtable Discussion With Industry and Stroke Experts suggested the incorporation of artificial intelligence to capture sequential aneurysm growth, identify predictors of rupture, and predict the risk of rupture to guide treatment options. The consensus strongly recommended nationwide systemic data collection of unruptured IA radiographic images for the analysis and development of machine learning algorithms for rupture risk. The consensus supported centers of excellence for preclinical multicenter trials in areas such as genetics, cellular composition, and radiogenomics. Optical coherence tomography and magnetic resonance imaging contrast-enhanced 3T vessel wall imaging are promising technologies; however, more data are needed to define their role in IA management. Ruptured aneurysms are best managed at large volume centers, which should include comprehensive patient management with expertise in microsurgery, endovascular surgery, neurology, and neurocritical care. CONCLUSIONS: Clinical and preclinical studies and scientific research on IA should engage high-volume centers and be conducted in multicenter collaborative efforts. The future of IA diagnosis and monitoring could be enhanced by the incorporation of artificial intelligence and national radiographic and biologic registries. A collaborative effort between academic centers, government regulators, and the device industry is paramount for the adequate management of IA and the advancement of the field.

MR Imaging of the Cerebral Aneurysmal Wall for Assessment of Rupture Risk.

The evaluation of unruptured intracranial aneurysms requires a comprehensive and multifaceted approach. The comprehensive analysis of aneurysm wall enhancement through high-resolution MRI, in tandem with advanced processing techniques like finite element analysis, quantitative susceptibility mapping, and computational fluid dynamics, has begun to unveil insights into the intricate biology of aneurysms. This enhanced understanding of the etiology, progression, and eventual rupture of aneurysms holds the potential to be used as a tool to triage patients to intervention versus observation. Emerging tools such as radiomics and machine learning are poised to contribute significantly to this evolving landscape of diagnostic refinement.

Aneurysms Located beyond the Origin of the Major Branches in the Posterior Circulation.

AIM: To evaluate the clinical and radiological features, treatment modalities, and outcomes of unusual aneurysms located beyond the origin of the major branches in the posterior circulation, and to introduce changes in the recent treatment trends due to rapid innovations in endovascular technology. MATERIAL AND METHODS: This was a retrospective study of patients who underwent treatment for these unusual aneurysms, including those that were identified in regular follow-up after treatment, between March 2009 and April 2023. Medical information including the radiological features of the aneurysms, incidences of rebleeding, associated vascular diseases, treatment modalities, and outcomes, was documented. RESULTS: A total of 22 cases consisting of two unruptured and 20 ruptured aneurysms were included. Their locations were the posterior cerebral artery in four cases, the superior cerebellar artery in three, the anterior inferior cerebellar artery in two, and the posterior inferior cerebellar artery in 13. Sixteen were saccular, five fusiform, and one blister-like. Eight were pseudo-aneurysms and pre- or intra-operative rebleeding occurred in 13 (65%) of 20 cases with ruptured aneurysms. Five aneurysms coexisted with causative vascular diseases such as arteriovenous malformation, moyamoya disease, or dolichoectasia. Four cases were treated by microsurgical operations and 18 by endovascular operations. In one of the microsurgical cases and five of the endovascular cases, parent arteries were sacrificed. Stents were used in six cases, including low-profile stents in four. Intermediate guiding catheters were used in seven cases for distal access. Full recoveries were seen in 17 cases and death occurred in three. CONCLUSION: Treatments for these aneurysms are technically demanding due to the high rate of rebleeding, difficult accessibility, and inevitable necessity of sacrifice of the parent artery in some cases. However, advancing endovascular techniques and devices enable distal access to the lesion and help preserve the parent artery.

Large Single-Center Experience with Short-Term Follow-up of Neqstent-Assisted Coiling.

BACKGROUND AND PURPOSE: Endovascular treatment of wide-neck bifurcation aneurysms has historically proved difficult with variable outcomes. Different endovascular techniques such as balloon-assisted coiling, stent-assisted coiling, or intrasaccular devices provide a varied range of efficacy and safety. Neqstent-assisted coiling is a new device and technique that aim to provide a maximum of both. We analyzed the early clinical and radiologic outcomes after the use of this new technique and device in our practice. MATERIALS AND METHODS: This study was a retrospective analysis of ruptured and unruptured intracranial aneurysms treated with the Neqstent. The primary radiologic outcomes were quantified on DSA, CTA, or MRA using the modified Raymond-Roy criteria. The outcomes were defined as immediate complete occlusion (modified Raymond-Roy criteria 1) and complete (modified Raymond-Roy criteria 1) and adequate occlusion (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2) at 6 months posttreatment. The primary safety outcome was the rate of device-related adverse events. Secondary safety outcomes included time to discharge and change in the mRS score at 6-month follow-up. RESULTS: Twenty patients were treated with the Neqstent from November 2020 to January 2023. Nine had unruptured aneurysms, and 11 were patients with subarachnoid haemorrhage due to ruptured aneurysms. Eighteen of 20 aneurysms (90%) treated demonstrated complete occlusion (modified Raymond-Roy criteria 1) on immediate postembolization angiograms. Sixteen of 17 aneurysms treated (94.1%) remained adequately occluded on 6-month follow-up (modified Raymond-Roy criteria 1 and modified Raymond-Roy criteria 2). Immediate postoperative complications occurred in 2 patients; only 1 patient had residual neurologic deficits at 6 months (mRS = 2). CONCLUSIONS: Management of large, wide-neck aneurysms remains difficult, with high rates of recurrence and complications. The use of the Neqstent shows promising short-term results for the treatment of complex wide-neck aneurysms. Initial complication rates for our cohort were relatively high. However, this result is likely related to the initial learning experience of device deployment and the use of antiplatelets.

Sutton-Kadir Syndrome can be treated safely with endovascular embolisation alone.

INTRODUCTION: Sutton-Kadir Syndrome (SKS) describes true inferior pancreaticoduodenal artery (IPDA) aneurysms in the setting of coeliac artery (CA) stenosis or occlusion. Although rare, SKS aneurysms can rupture and cause morbidity. Due to its rarity and lack of controlled treatment data, correct treatment for the CA lesion is currently unknown. Our aim was to assess if endovascular embolisation alone was safe and effective in treatment of SKS aneurysms, in emergent and elective settings. Secondary objectives were to describe presentation and imaging findings. METHODS: A retrospective cohort study of patients treated at Sir Charles Gairdner Hospital between January 2014 and December 2021 was done. Data on presentation, diagnostics, aneurysm characteristics, CA lesion aetiology, treatment and outcomes were extracted from chart review. RESULTS: Twenty-four aneurysms in 14 patients were identified. Rupture was seen in 7/15 patients. Most aneurysms (22/24) were in the IPDA or one of its anterior or posterior branches. Median arcuate ligament (MAL) compression was identified in all. There was no difference in median (IQR) maximal transverse diameter between ruptured and non-ruptured aneurysms (6 mm (9), 12 mm (6), P = 0.18). Of ruptures, 6/7 had successful endovascular embolisation and 1/7 open surgical ligation. Of non-ruptures, 6/7 had successful endovascular embolisation, 1/7 open MAL division then endovascular CA stenting and aneurysm embolisation. No recurrences or new aneurysms were detected with computed tomography or magnetic resonance angiography over a median (IQR) follow-up period of 30 (10) months in 12 patients. CONCLUSION: Endovascular embolisation of SKS aneurysms without treatment of MAL compression is safe and effective in both the emergent and elective settings.

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.