Perianeurysmal brain inflammation after flow-diversion treatment

Perianeurysmal vasogenic oedema (PAVO): A single centre 10-year retrospective review

INTRODUCTION

Perianeurysmal Vasogenic Oedema (PAVO) is a rare but important complication of endovascular treatment of intracranial aneurysms. Many potential risk factors have been identified including age, aneurysm size, aneurysm location, immunological profile, type of coil used, diabetes, hypertension, and smoking. PAVO can cause persistent post-procedural symptoms, subsequently increasing post-embolization morbidity.

METHODS

A 10-year retrospective review was conducted between 2011 and 2021 at Royal Preston Hospital, Preston, UK.

RESULTS

We identified 8 patients that fit our inclusion criteria. This included 6 (75%) females and 2 (25%) males. The mean age was 64. All patients had anterior circulation aneurysms with the middle cerebral artery (MCA) being the most common site. The mean aneurysm size was 12 mm. Our patients were managed with a range of endovascular techniques. One patient had pre-treatment PAVO while 7 patients had post-embolization PAVO. Five patients were symptomatic, and 3 cases were asymptomatic with only radiological evidence of PAVO. Five patients were managed with varying courses of dexamethasone. PAVO resolution was achieved in 4 cases. The oedema significantly improved in 3 cases, but transiently progressed in 1 case.

CONCLUSIONS

PAVO is a rare but important complication of endovascular management of intracranial aneurysms. We have shown that patients can be effectively managed with steroids with resultant oedema regression and symptomatic improvement. Many risk factors have been associated with PAVO, but further research is needed to better understand their role in PAVO development and help develop other therapeutic options.

Long-term outcomes and dynamic changes of in-stent stenosis after Pipeline embolization device treatment of intracranial aneurysms

BACKGROUND

Flow diverters have revolutionized the treatment of intracranial aneurysms. However, the delayed complications associated with flow diverter use are unknown.

OBJECTIVE

To evaluate the incidence, severity, clinical outcomes, risk factors, and dynamic changes associated with in-stent stenosis (ISS) after treatment with a Pipeline embolization device (PED).

METHODS

Patients who underwent PED treatment between 2015 and 2020 were enrolled. The angiographic, clinical, and follow-up data of 459 patients were independently reviewed by four neuroradiologists to identify ISS. Binary logistic regression was conducted to determine ISS risk factors, and an ISS-time curve was established to demonstrate dynamic changes in ISS after PED implantation.

RESULTS

Of the 459 treated patients, 69 (15.0%) developed ISS. At follow-up, nine patients (2.0%) with ISS demonstrated reversal, while 18 (3.9%) developed parental artery occlusion. A total of 380 patients (82.8%) achieved complete aneurysm occlusion (O'Kelly-Marotta grade D). Patients with posterior-circulation aneurysm (OR=2.895, 95% CI (1.732 to 4.838; P<0.001) or balloon angioplasty (OR=1.992, 95% CI 1.162 to 3.414; P=0.037) were more likely to develop ISS. Patients aged >54 years (OR=0.464, 95% CI 0.274 to 0.785; P=0.006) or with a body mass index of >28 kg/m2 (OR=0.427, 95% CI 0.184 to 0.991; P=0.026) had a lower ISS risk. Intimal hyperplasia initiated by PED placement peaked within 1 year after the procedure, rarely progressed after 12 months, and tended to reverse within 24 months.

CONCLUSIONS

ISS is a common, benign, and self-limiting complication of PED implantation in the Chinese population.

Reconstruction of the sphenoid sinus erosion or dehiscence after treatment of unruptured intracavernous aneurysms with flow diverter stents

BACKGROUND

Intracavernous carotid aneurysms (ICCAs) are rare, frequently asymptomatic, with a low rupture risk, which, however, can lead to life-threatening epistaxis. The aim of this study was to assess the effect of the treatment of asymptomatic ICCAs with flow diverters (FD) on sphenoid bone erosion or dehiscence in a selected cohort of patients.

METHODS

We retrospectively reviewed all asymptomatic ICCAs with sphenoid bone erosion or dehiscence detected on cone beam CT (CBCT) and treated with FD between December 2018 and December 2022. Patients were followed-up with CBCT and bone reconstruction was blindly evaluated by two interventional neuroradiologists and classified as unchanged, partial, or complete.

RESULTS

A total of 10 patients (women: 90%, mean age 58 years) treated with an FD for an asymptomatic ICCA with associated sphenoid bone erosion or dehiscence were included in this cohort. Sphenoid bone erosion was present in seven patients and dehiscence was observed in the remaining three. After treatment with FD, complete reconstruction of the sphenoid sinus wall occurred in seven cases, and partial reconstruction in two cases. Sphenoid bone erosion remained unchanged after treatment in only one patient.

CONCLUSIONS

The decision to treat asymptomatic and unruptured ICCAs remains challenging due to their benign natural history and low hemorrhagic risk. The presence of sphenoid sinus erosion or dehiscence should not be overlooked since it could be considered as an indication for prophylactic treatment of life-threatening epistaxis. The mechanisms of bone erosion by the aneurysm and of reconstruction after treatment are still to be fully elucidated.

Flow Diverter Stenting for Symptomatic Intracranial Internal Carotid Artery Aneurysms: Clinical Outcomes and Factors for Symptom Improvement

Flow diverter (FD) stenting is expected to improve cranial nerve symptoms caused by aneurysms via the theoretical reduction of the mass effect by promoting spontaneous thrombosis through the flow diversion effect. However, the factors involved in symptom improvement after treatment remain unclear. This study was performed to identify factors for symptom improvement after FD stenting and the symptom improvement rate of each impaired cranial nerve. We retrospectively evaluated 33 patients who underwent FD stenting for symptomatic internal carotid artery aneurysms at our institution from January 2016 to June 2021. Twenty-three (69.7%) patients had resolved or improved symptoms after 1 year of treatment. The optic nerve was affected in 12 patients; the oculomotor nerve, in 16; the trigeminal nerve, in 2; and the abducens nerve, in 13. There was no statistically significant difference in the symptom improvement rate of each impaired cranial nerve. The patients were classified into the improved and nonimproved groups based on their symptoms after 1 year of treatment, and the factors related to the symptoms were analyzed. The time from onset to treatment was significantly shorter in the improved group than in the nonimproved group (197.1 and 800 days, respectively; p = 0.023). There were no significant differences in age, aneurysm diameter, adjunctive coil embolization, partial thrombosis, change in mass diameter on magnetic resonance imaging, or aneurysm occlusion rate on angiography between the two groups. These results suggest that early treatment after the onset of aneurysm-induced cranial neuropathies increases the likelihood of symptom improvement.

Unique image findings around "kissing" distal anterior cerebral artery aneurysms in addition to perianeurysmal edema: A case report

Background

Some aneurysms cause edema formation in the surrounding brain parenchyma and are thought to reflect various phenomena occurring in the aneurysm. Some authors highlighted perianeurysmal edema (PAE) as a finding that indicates higher risk of rupture of the aneurysm. On the other hand, there are no reports of image changes in the surrounding brain parenchyma of aneurysm other than edema formation.

Case Description

We describe a 63-year-old man with unique signal change in the surrounding brain parenchyma of "kissing" distal anterior cerebral artery aneurysms completely different from PAE. The large and partially thrombosed aneurysm presented well-defined signal change surrounding brain parenchyma in addition to PAE. Intraoperative findings revealed the signal change as a space of retaining serous fluid. Drain the fluid and clipping was made for the both anterior cerebral artery aneurysms. The postoperative course was uneventful and his headache was improved the day after the surgery. The perianeurysmal signal change was also disappeared immediately after the surgery except for the PAE.

Conclusion

This case demonstrates a rare phenomenon of signal change around the aneurysm, and there is a possibility that the unique finding exists as an early manifestation of intracerebral hematoma associated with aneurysm rupture.

Progressive volume reduction and long-term aneurysmal collapse following flow diversion treatment of giant and symptomatic cerebral aneurysms

Background

The primary goal of conventional endovascular and microvascular approaches is the clinical and radiological resolution of the symptomatic aneurysm-induced mass effect. This study assessed the volume changes and mass effect reduction due to sac shrinkage after treatment with flow diverter stents (FD) for unruptured cerebral aneurysms.

Methods

We analyzed retrospectively 36 symptomatic aneurysms that were larger or equal to 25 mm in diameter in patients treated at our center from January 2016 to April 2022. Radiological and clinical outcomes were analyzed, including aneurysmal volume changes and resolution of aneurysm-related symptoms.

Results

At 6 months, 25 aneurysms decreased in size, 2 remained unchanged, and 9 aneurysms demonstrated a post-treatment dimensional increase. At 12 months, 30 aneurysms showed a progressive radiological volume reduction. Either no change or negligible shrinkage was observed in the remaining six aneurysms. At 24 months, 32 aneurysms showed aneurysmal shrinkage by a mean 47% volume loss with respect to baseline. At the last follow-up, all 13 patients who had presented with third cranial nerve palsy showed improvements. Complete reversal of the pretreatment edematous changes was confirmed in all cases. The overall post-treatment complication rate was 8.3%, as 3 patients experienced non-fatal delayed rupture of their aneurysm. There was no mortality in this study.

Conclusion

Flow diversion could effectively induce progressive aneurysmal shrinkage and resolution of the mass effect associated with giant symptomatic cerebral aneurysms.

Transcriptome-Based Dissection of Intracranial Aneurysms Unveils an “Immuno-Thermal” Microenvironment and Defines a Pathological Feature-Derived Gene Signature for Risk Estimation

Immune inflammation plays an essential role in the formation and rupture of intracranial aneurysm (IA). However, the current limited knowledge of alterations in the immune microenvironment of IA has hampered the mastery of pathological mechanisms and technological advances, such as molecular diagnostic and coated stent-based molecular therapy. In this study, seven IA datasets were enrolled from the GEO database to decode the immune microenvironment and relevant biometric alterations. The ssGSEA algorithm was employed for immune infiltration assessment. IAs displayed abundant immune cell infiltration, activated immune-related pathways, and high expression of immune-related genes. Several immunosuppression cells and genes were also coordinately upregulated in IAs. Five immune-related hub genes, including CXCL10, IL6, IL10, STAT1, and VEGFA, were identified from the protein-protein interaction network and further detected at the protein level. CeRNA networks and latent drugs targeting the hub genes were predicted for targeted therapy reference. Two gene modules recognized via WCGNA were functionally associated with contractile smooth muscle loss and extracellular matrix metabolism, respectively. In blood datasets, a pathological feature-derived gene signature (PFDGS) for IA diagnosis and rupture risk prediction was established using machine learning. Patients with high PFDGS scores may possess adverse biological alterations and present with a high risk of morbidity or IA rupture, requiring more vigilance or prompt intervention. Overall, we systematically unveiled an “immuno-thermal” microenvironment characterized by co-enhanced immune activation and immunosuppression in IA, which provides a novel insight into molecular pathology. The PFDGS is a promising signature for optimizing risk surveillance and clinical decision-making in IA patients.

Treatment of Anterior Circulation Aneurysms in the Internal Carotid Artery With Flow Diverters

Several studies have shown the efficacy and feasibility of flow diversion for the endovascular treatment of wide-necked and otherwise anatomically challenging intracranial aneurysms (IA). Technological advances have led to successful long-term occlusion rates and a safety profile for flow-diverter stents that parallels other endovascular and open surgical options for these lesions. With growing indications for use of the Pipeline Embolization Device (PED, Medtronic, Dublin, Ireland) to include IAs up to the internal carotid artery (ICA) terminus, understanding the nuances of this technology is increasingly relevant. Furthermore, there is a growing body of literature on the use of flow diversion to treat distal (up to A2, M2, and P2), ruptured, and posterior circulation aneurysms, although these applications are "off-label" at present. In this manuscript, we discuss the expanding role of flow diversion in the ICA and compare this technique with other endovascular options for the treatment of ICA IAs. We also discuss technical nuances of the deployment of flow diverters for the treatment of challenging lesions and in difficult and tortuous anatomy.

Flow-diverting stent and delayed intracranial bleeding: the case for discussing acquired von Willebrand disease

A unique feature of the flow-diverting stent (FDS) has rendered it useful in the endovascular treatment of selected intracranial aneurysms for the last decade. Delayed aneurysmal rupture and intracranial parenchymal bleeding are two leading hemorrhagic complications after FDS. It has recently been shown for the first time that there is a relationship between FDS and reduced level of vWF activity in patients undergoing endovascular cerebral aneurysm treatment. Here, the current literature is reviewed in the context of this novel finding to propose an illustrative scenario that conceptually links implantation of FDS to delayed intracranial bleeding, through the mechanism of shear-induced activation of vWF. In this scenario, after FDS implantation, sustained release of activated vWF in association with platelets plays a pivotal role in the mechanisms of delayed intracranial hemorrhages.

Reduced Activity of von Willebrand Factor after Flow-Diverting Stent Implantation for Intracranial Aneurysms: A Link to Acquired von Willebrand Disease?

BACKGROUND AND PURPOSE

Vascular devices generating high shear stress can cause type 2A acquired von Willebrand disease, which is characterized by low von Willebrand factor activity accompanied by hemorrhagic complications. The braided mesh structure of flow-diverting stents with a relatively small strut size can create abnormally high shear stress while arterial blood flows through the stent struts into the aneurysm, and flow-diverting stent may be associated with reduced von Willebrand factor activity.

MATERIALS AND METHODS

Aneurysmal morphologic parameters and patient data were examined retrospectively among patients who had an unruptured intracranial aneurysm treated with a flow-diverting stent. The RISTOtest (test for whole blood ristocetin-induced platelet aggregation) for von Willebrand factor activity, as well as tests for aspirin and clopidogrel/prasugrel effectiveness, were performed immediately before the endovascular procedure and 24 hours later by multiple electrode aggregometry.

RESULTS

A total of 39 patients with 56 aneurysms were recruited, and statistical analyses were performed in 32 patents with 49 aneurysms. Compared with the baseline values, von Willebrand factor activity was reduced in 16 patients but increased in 23 patients. Aneurysmal variables (eg, neck area, volume, volume-to-neck area ratio, size ratio, and morphologic index) clearly distinguished patients with reduced von Willebrand factor activity from those with nonreduced von Willebrand factor activity. The receiver operating characteristic curve showed that the morphologic index and volume had the highest discriminative power, with an area under the curve of 0.99.

CONCLUSIONS

In high-volume/large-neck aneurysms, flow-diverting stent implantation can cause reduced von Willebrand factor activity, which may be linked causally to acquired von Willebrand disease.

Thrombosis of Large Aneurysm Induced by Flow-Diverter Stent and Dissolved by Direct Factor Xa Inhibitor

BACKGROUND

Antiplatelet agents are typically administered before and after treatment using flow-diverter stents (FDS) to prevent thrombotic complications, but the effects of anticoagulants are unclear. We present a patient with a giant aneurysm treated with an FDS. The thrombus within the aneurysm was dissolved when a direct factor Xa inhibitor was administered to treat lower limb venous thrombosis that occurred secondary to steroid use.

CASE DESCRIPTION

A 60-year-old woman with a 30-mm giant thrombosed aneurysm in the cavernous segment of the right internal carotid artery presenting with headache and right abducens nerve palsy was treated by placing an FDS. Diplopia and increased pain in her right eye appeared on postoperative day 7, and both were alleviated by continuous oral administration of prednisolone. Angiography 3 months postoperatively revealed that the aneurysm thrombosis had progressed, and there were signs of healing. However, at the same time, lower limb venous thrombosis occurred, which was treated by continuous edoxaban. Six months after surgery, her headaches worsened and angiography showed that the aneurysm was again contrast enhanced and that the thrombus within the aneurysm had dissolved. After discontinuing edoxaban 9 months after surgery, the aneurysmal thrombosis had again rapidly progressed.

CONCLUSIONS

Administration of a direct factor Xa inhibitor during healing after placing an FDS may cause dissolution of an existing thrombus; therefore factor Xa inhibitors must be used with caution.

Cerebral Abscess Following Endovascular Treatment of Aneurysm: Report of 2 Cases and Review of the Literature

INTRODUCTION

Endovascular treatment is growing in popularity globally as an important treatment option for intracranial aneurysms. Cerebral infection as a complication of endovascular treatment of aneurysms is sufficiently rare that only 6 isolated cerebral abscess cases have been reported thus far.

CASE REPORT

In this report, we present 2 cerebral abscesses from 3 institutions, which developed after coil embolization of anterior communicating artery and middle cerebral artery aneurysms.

CONCLUSION

This report was written to discuss the possible mechanisms underlying cerebral abscess after endovascular treatment of aneurysms and to suggest potential treatment and prevention methods.

The Role of Collateral Circulation in Branch Vessel Occlusion After Flow Diversion

BACKGROUND

Flow diversion for treatment of intracranial aneurysms frequently necessitates covering adjacent branch vessels. Although branch vessel occlusion is common, associated clinical deficits are rare. It has been hypothesized that clinically silent branch vessel occlusion is due to underlying collateral circulation. To study the role of collateral circulation in covered branch vessel occlusion, we assessed collateral vessels and altered branch vessel flow on transfemoral catheter angiography in patients undergoing flow diversion of intracranial aneurysms.

METHODS

Angiograms obtained before treatment, immediately after treatment, and during follow-up were evaluated for branch vessel flow patterns and associated collateral circulation in a consecutive retrospective cohort of 84 patients from 2011 to 2017 with branch vessel coverage related to aneurysm flow diversion using the Pipeline embolization device.

RESULTS

We identified 142 branch vessels covered by the Pipeline device construct for treatment of 89 aneurysms, predominately in the anterior circulation (>90%). Collateral circulation was observed in approximately one third of these vessels and was associated with diminished (P < 0.001) or absent (P < 0.001) flow on follow-up angiography. Only 2 of 80 terminal branch vessels (no collaterals) were occluded, and these occurred in a patient with Pipeline device construct thrombosis. Altered branch vessel flow was not associated with vascular risk factors, treatment technique, or outcome measures, including new or worsening neurologic deficit.

CONCLUSIONS

Altered flow in branch vessels covered during flow diversion reflects underlying collateral circulation and is not associated with downstream ischemic deficits.

Bailout Strategies and Complications Associated with the Use of Flow-Diverting Stents for Treating Intracranial Aneurysms

Background

Flow-diverting stents (FDS) have revolutionized the endovascular management of unruptured, complex, wide-necked, and giant aneurysms. There is no consensus on management of complications associated with the placement of these devices. This review focuses on the management of complications of FDS for the treatment of intracranial aneurysms.

Summary

We performed a systematic, qualitative review using electronic databases MEDLINE and Google Scholar. Complications of FDS placement generally occur during the perioperative period.

Key Message

Complications associated with FDS may be divided into periprocedural complications, immediate postprocedural complications, and delayed complications. We sought to review these complications and novel management strategies that have been reported in the literature.

Temporary Worsening of Perianeurysmal Edema Following Clipping of a Partially Thrombosed Giant Pericallosal Artery Aneurysm

We present a case of a partially thrombosed giant aneurysm of the pericallosal artery that experienced a temporary worsening of perianeurysmal edema after clipping. A 66-year-old man presented with progressive weakness of the right leg. Imaging studies revealed a partially thrombosed giant aneurysm at the bifurcation of the left pericallosal artery with concomitant perianeurysmal edema. The aneurysm was thought responsible for the symptoms of the patient, and he agreed to undergo clipping surgery. The aneurysmal neck was clipped using two long aneurysm clips without dissecting the aneurysmal dome. The patient woke up from anesthesia with the right-sided hemiparesis, which progressed to hemiplegia by 12 h after surgery. Brain computed tomography revealed worsening of the perianeurysmal edema. Fortunately, his symptoms resolved completely by 2 weeks after surgery with conservative management. Perianeurysmal edema is frequently observed in patients with partially thrombosed giant aneurysms. Although worsening of perianeurysmal edema is a relatively common complication of endovascular procedures, its occurrence after clipping has rarely been reported. The worsening may have been induced by release of inflammatory cytokines from aneurysm wall, which was rendered ischemic due to obliteration of the vasa vasorum by the clips. Perianeurysmal edema may develop or worsen after clipping of a partially thrombosed giant aneurysm if the interface between the aneurysm and surrounding brain is not fully dissected.

Perianeurysmal vasogenic oedema (PAVO) following aneurysm embolisation: a unique case of asymptomatic long-term progression and review of the literature

Perianeurysmal vasogenic oedema is a recognised although rare phenomenon following endovascular treatment of certain intracranial aneurysms. We present a unique case of asymptomatic perianeurysmal vasogenic oedema following bare platinum coil embolisation of an incidentally discovered right middle cerebral artery aneurysm that slowly increased over a period of 6 years before stabilising and regressing. During this time, the coiled aneurysm per se remained completely stable on serial magnetic resonance angiography.

Leptomeningeal Enhancement Is Associated with Transient Neurologic Deficits after Flow Diversion of Intracranial Aneurysms

OBJECTIVE

To evaluate the relationship between blood-brain barrier disruption and transient neurologic deficits (TNDs) after neuroendovascular interventions (NEIs) using postcontrast T2/FLAIR (pcFLAIR) imaging.

METHODS

This is a prospective study of 41 consecutive patients undergoing flow diversion therapy for unruptured aneurysm treatment. Patients underwent postprocedural magnetic resonance imaging within 24 hours of the procedure, including diffusion-weighted imaging (DWI) and pcFLAIR sequences. Regression analyses were performed to identify risk factors for developing TNDs.

RESULTS

In total, 13 patients (31.7%) developed neurologic complications ranging from visual field defects to dense hemiplegia. All deficits were transient, resolving spontaneously within 72 hours. Five of 13 patients (38.5%) with TNDs had presence of lesions on DWI whereas the remaining 8 patients (61.5%) did not. In contrast, all patients who developed TNDs had leptomeningeal enhancement on pcFLAIR imaging, and no patient with normal pcFLAIR imaging developed TNDs. Regression analysis revealed the extent of pcFLAIR enhancement is associated with development of postprocedure neurologic deficits (P < 0.0001). Video electroencephalography monitoring was performed in 4 symptomatic patients manifesting severe deficits. In all instances electroencephalography demonstrated ipsilateral hemispheric slowing and eventual resolution corresponding to ensuing clinical improvement. Only 1 of these 4 patients presented with a lesion on DWI.

CONCLUSIONS

This study challenges conventional dogma that TNDs are ischemic in etiology and suggests blood-brain barrier impairment may be a potential alternative mechanism. These findings are applicable to stroke and other reversible neurologic diseases.

Update on flow diverters for the endovascular management of cerebral aneurysms

Flow diversion has become a well-accepted option for the treatment of cerebral aneurysms. Given the significant treatment effect of flow diverters, numerous options have emerged since the initial Pipeline embolization device studies. In this review, the authors describe the available flow diverters, both endoluminal and intrasaccular, addressing nuances of device design and function and presenting data on complications and outcomes, where available. They also discuss possible future directions of flow diversion.

Rescue Therapy for Procedural Complications Associated With Deployment of Flow-Diverting Devices in Cerebral Aneurysms

Flow diverting devices (FDDs) have revolutionized the treatment of morphologically complex intracranial aneurysms such as wide-necked, giant, or fusiform aneurysms. Although FDDs are extremely effective, they carry a small yet significant risk of intraprocedural complications. As the implementation of these devices increases, the ability to predict and rapidly treat complications, especially those that are iatrogenic or intraprocedural in nature, is becoming increasingly more necessary.

Our objective in this paper is to provide a descriptive summary of the various types of intraprocedural complications that may occur during FDDs deployment and how they may best be treated. A systematic and qualitative review of the literature was conducted using electronic databases MEDLINE and Google Scholar. Searches consisted of Boolean operators “AND” and “OR” for the following terms in different combinations: “aneurysm,” “endovascular,” “flow diverter,” “intracranial,” and “pipeline.”

A total of 94 papers were included in our analysis; approximately 87 of these papers dealt with periprocedural endovascular (mainly related to FDDs) complications and their treatment; 7 studies concerned background material. The main categories of periprocedural complications encountered during deployment of FDDs are failure of occlusion, parent vessel injury and/or rupture, spontaneous intraparenchymal hemorrhage, migration or malposition of the FDDs, thromboembolic or ischemic events, and side branch occlusion

Periprocedural complications occur mainly due to thromboembolic events or mechanical issues related to device deployment and placement. With increasing use and expanding versatility of FDDs, the understanding of these complications is vital in order to effectively manage such situations in a timely manner.

Headache and endovascular procedures

The International Classification of Headache Disorders (ICHD-3 beta) includes headache attributed to intracranial endovascular procedures (EVPs). The aim of this review is to describe the clinical and pathophysiological aspects of headache related to vascular lesions and EVPs. Current studies regarding this issue are contradictory, although generally favouring headache improvement after EVPs. Further large studies are needed to adequately assess the effect of EVPs on headache.

Periprocedural safety of Pipeline therapy for unruptured cerebral aneurysms: Analysis of 279 Patients in a multihospital database

The relative safety of unruptured aneurysm treatment with coiling versus flow diversion therapy is unknown. Most data available on flow diversion reflect highly focused patient groups and very experienced operators. We evaluated a national, multihospital patient database to examine periprocedural morbidity and mortality in patients treated with endovascular flow diversion therapy. The Premier Perspective database was used to identify patients hospitalized between May 2011 and March 2013 for unruptured aneurysm who underwent flow diversion therapy with a Pipeline embolization device. The risk of in-hospital mortality and morbidity was determined using ICD 9 codes. A total of 279 unruptured aneurysm patients at 18 medical centers underwent endovascular therapy with a Pipeline device. Adverse outcomes included in-hospital mortality in two cases (0.7%), discharge to long-term care in 22 cases (7.9%), ischemic complications in 14 cases (5.0%), hemorrhagic complications in four cases (1.4%), and postoperative neurological complications in nine cases (3.2%). This study of a large cohort of patient hospitalizations in the United States provides preliminary data on flow diversion in a "real world" scenario and demonstrates that the periprocedural morbidity and mortality is not negligible and must be considered in the context of the natural history of the aneurysms that are being treated.

Short-term efficacy of pipeline embolization device for treating complex intracranial aneurysms

OBJECTIVE

To observe the short-term efficacy of Pipeline embolization divice (PED) for the treatment of complex intracranial aneurysms.

METHODS

The clinical data of 29 consecutive patients with 32 intracranial aneurysms treated with PED between April 2015 to September 2016 were analyzed retrospectively. There were 3 small aneurysm, 15 large aneurysms, 8 giant aneurysms, 5 fusiform ayneurysms and 1 recidivation. The vessels include 25 anterior circulation and 4 posterior circulation.

RESULTS

We treated 31 aneurysms with 30 PEDs and all of the stents were implanted successfully. 1 case of single aneurysm was multiple divices implanted and 1 case of 3 aneurysms were treated by single PED. 12 of the 29 patients were implanted PED only, 17 were implanted PED with coils, 2 underwent balloon remodeling after the PED implanted. The ostia of 19 ophthalmic arteries, 10 posterior communicating arteries, 4 posterior inferior cerebellar arteries and 1 anterior cerebral artery were covered by PED during procedures; 1 ophthalmic arteries and 1 posterior communicating artery disappeared, no branch vessels occlusion and parent artery stenosis occurred.Hemorrhagic complacations occurred in 2 patients, 2 hours and 5 days after procedure respectively. Radiographic follow-up examnations were carried out in 24 patients and revealed complete occlusion in 21 patients, uncomplete occlusion in 3 patients. No neurological injure occurred in 27 patients who received a clinical follow-up.

CONCLUSION

PED provide a safe and effective methord for the treatment of intracranial complex aneurysms like wide-neck aneurysms, fusiform aneurysms, giant aneurysms in low risk of procedural complications and high rates of aneurysm occlusion.

Intracranial Aneurysms Treated by Flow-Diverting Stents: Long-Term Follow-Up with Contrast-Enhanced Magnetic Resonance Angiography

PURPOSE

Long-term data on aneurysm treatment with flow-diverting stents are still sparse, and follow-up protocols differ widely between institutions. We present long-term results, with a focus on the usefulness of contrast-enhanced MR angiography (ceMRA).

MATERIALS AND METHODS

Interventions and follow-up imaging of patients with aneurysms treated by flow-diverting stents ("Pipeline," "Silk" and "FRED" models) without additional coiling were analyzed. All MRI scans included dedicated two-phase ceMRA. Aneurysm occlusion rates, size of the aneurysmal sac and complications were evaluated on MRI and digital subtraction angiography (DSA), where available. The ability of ceMRA to depict aneurysm occlusion and stent patency was graded on a three-point scale.

RESULTS

Twenty-five patients with 102 MRI scans were included. The median duration of follow-up was 830 days. Aneurysm occlusion rates were 52% at 3 months (10 of 19 patients), 72% at 6 months (18/25) and 84% overall (21/25). Shrinkage of the aneurysmal sac was found in 19 patients (76%) and in 12 cases to <50% of the original size (48%). CeMRA assessability of aneurysmal occlusion was graded as good in all cases. When compared to DSA (18 cases), ceMRA had a sensitivity of 100% and specificity of 91% regarding aneurysm remnant detection. Assessability of the stent lumen varied and was limited in most cases.

CONCLUSIONS

Flow-diverter treatment achieves high occlusion rates and can cause major aneurysm shrinkage. CeMRA is highly valuable regarding imaging of the aneurysmal sac. There are limitations regarding the assessability of the stent lumen on ceMRA.

LEVEL OF EVIDENCE

Level 4, Case Series.

Characteristics of Headache After an Intracranial Endovascular Procedure: A Prospective Observational Study

BACKGROUND

Two editions of the International Classification of Headache Disorders (ICHD) diagnostic criteria for "Headache attributed to an intracranial endovascular procedure" have been published, in 2004 and 2013.^1,2 Despite studies that have suggested that the former is not very practical, the ICHD-3 beta did not contain major changes. Moreover, so far no consensus exists regarding characteristics of headache after intracranial endovascular procedure. Thus, there is a need for sound suggestions to improve the ICHD-3 beta diagnostic criteria.

METHODS

Using a prospective design, we identified consecutive patients with unruptured intracranial aneurysms (UIAs) with neuroendovascular treatment from January 2014 to December 2014.

RESULTS

In total, 73 patients were enrolled, and 58 patients ultimately completed the 6-month follow-up. After the procedure, five of the 29 patients (17.2%) with pre-existing headache experienced marked worsening after the procedure, while seven of the 29 patients without prior headache developed new-onset headache post-procedurally. The headaches started within 24 hours, with a mean duration of 24-72 hours. The headaches were moderate to severe. The eligibility of these events to be considered headaches caused by neuroendovascular procedures according to the ICHD-3 beta diagnostic criteria for designation was far from ideal.

CONCLUSIONS

Most cases of markedly worsening headaches and new-onset headaches started within 24 hours and persisted longer than that specified in the ICHD-3 beta diagnostic criteria. Moreover, considering that some items are not very practical, the ICHD-3 beta diagnostic criteria should be revised in the light of recent literature reports.

Long-term Follow-up of In-stent Stenosis After Pipeline Flow Diversion Treatment of Intracranial Aneurysms

BACKGROUND:

There is scant information on in-stent stenosis after flow diversion treatment of intracranial aneurysms with the Pipeline Embolization Device (PED).

OBJECTIVE:

To assess the incidence, severity, nature, and clinical consequences of in-stent stenosis on angiographic follow-up after treatment with the PED.

METHODS:

A retrospective study of patients who underwent aneurysm treatment with the PED was conducted. In-stent stenosis was assessed on subsequent follow-up angiography. Intimal hyperplasia was defined as a uniform growth process beyond the limits of the metallic mesh at &lt;25%. In-stent stenosis represented an area of parent vessel narrowing, most often focal, graded as mild (25%-50%), moderate (50%-75%), or severe (&gt;75%).

RESULTS:

Between June 2011 and April 2015, 80 patients were treated with the PED. Angiographic follow-up was available for 51 patients (representing 76% of available or 64% of all patients). Mean follow-up was 12.5 months. In-stent stenosis was detected in 5 patients (9.8%) at a median of 6 months. Stenosis was mild in 4 of 5 (80%) and moderate in 1 of 5 (20%) patients. There were no cases of severe stenosis. No stenosis caused flow limitation, clinical symptoms, or required re-treatment. Additional follow-up angiography was available in 2 of 5 stenosis patients showing marked improvement. Sixteen patients (31%) had intimal hyperplasia, and 28 patients (55%) had no stenosis. Asymptomatic stent occlusion occurred in 2 patients (4%) related to medication noncompliance.

CONCLUSION:

Treatment with the PED was associated with a 9.8% rate of in-stent stenosis, detected on first angiographic follow-up, at a median of 6 months. None were symptomatic or required re-treatment, and they showed significant improvement on follow-up.

Two-stage reconstructive overlapping stent LEO+ and SILK for treatment of intracranial circumferential fusiform aneurysms in the posterior circulation

Intracranial circumferential fusiform aneurysms of the posterior circulation involving arterial branches or perforating vessels are difficult to treat. This article shows an endovascular reconstruction technique not yet described, using a telescoping self-expandable stent (LEO+) and flow-diverter device (SILK) at different surgical times. Two patients with circumferential fusiform aneurysm, one being an aneurysm of the segments P2 and P3 of the posterior cerebral artery, diagnosed after a headache, and the other a partially thrombosed aneurysm of the lower basilar artery, diagnosed following ischemia of the brain stem. Endovascular treatment was performed by means of a vascular reconstruction technique that used at different surgical times: overlapping; a telescoped self-expandable stent, LEO+; and a flow-diverter device, SILK. Angiographic control was carried out at 6 and 12 months, to evaluate arterial patency, flow maintenance in the arterial branches and perforating vessels, and thrombosis of the aneurysm. The combined use at different surgical times of the self-expandable stent and flow-diverter device was technically successful in both patients. There were no complications during the procedure, nor in the long-term follow-up with full arterial vascular reconstruction, maintenance of cerebral perfusion and complete aneurysm occlusion at the 6- and 12-month angiographic follow-up. There was no aneurysm recanalization nor intra-stent stenosis. Circumferential fusiform aneurysm of the posterior circulation involving arterial branches or perforating vessels to the brain stem may be treated with this arterial reconstruction technique at different surgical times, using the self-expandable stent called LEO+ and the flow-diverter device SILK, minimizing the risk of complications and failure of the endovascular technique, with the potential for arterial reconstruction with thrombosis of the aneurysmatic sac, as well as flow maintenance in the eloquent arteries, in this type of cerebral aneurysm.

Flow Diversion for Intracranial Aneurysm Management: A New Standard of Care

Endovascular treatment of intracranial aneurysms with complex morphologies such as giant, wide-necked, or fusiform aneurysms is challenging. Stent-assisted coiling and balloon-assisted coiling are alternative techniques to treat such complex aneurysms, but studies have shown less-than-expected efficacy, as suggested by their high rate of recanalization. The management of complex aneurysms via microsurgery or conventional neuroendovascular strategies has traditionally been poor. However, over the last few years, flow-diverting stents (FDS) have revolutionized the treatment of such aneurysms. FDS are implanted within the parent artery rather than the aneurysm sac. By modifying intra-aneurysmal and parent-vessel flow dynamics at the aneurysm/parent vessel interface, FDS trigger a cascade of gradual intra-aneurysmal thrombosis. As endothelialization of the FDS is complete, the parent vessel reconstructs while preserving the patency of normal perforators and side branch vessels. As with any intervention, the practice and application of flow-diversion technology is inherent, with risks that include vessel rupture or perforation, in-stent thrombosis, perforator occlusion, procedural and delayed hemorrhages, and perianeurysmal edema. Herein, we review the devices, their mechanisms of actions, clinical applications, complications, and ongoing studies.

Treatment of Intracranial Aneurysms With Pipeline Embolization Device: Newer Applications and Technical Advances

OPINION STATEMENT

Pipeline embolization device (PED) is a flow diverter used in the endovascular treatment of intracranial aneurysms, particularly those with unfavorable configurations. It works by causing progressive flow redirection leading to thrombosis within the aneurysm. PED was initially approved for adults with large or giant wide-necked (≥4 mm or no discernible neck) aneurysms of the internal carotid artery (ICA) from the petrous to the superior hypophyseal segments. Studies have shown a superior aneurysm occlusion rate of 85 % at 6 months for the PED and mortality ranging from 2.6 to 4 %. There appears to be a knowledge gap in terms of the duration of dual antiplatelet therapy and efficacy of assessing platelet inhibition. However, increasing operator experience and favorable longer-term outcome data have led to the exploration of PED for a wide array of off-label uses. Given the paucity of good-quality studies comparing PED with other endovascular/surgical treatment options, several multicenter randomized trials are currently underway to answer these important questions.

[Endovascular treatment of large and giant intracranial aneurysms using flow-diverting stents]

OBJECTIVE

The objective was to evaluate the efficacy of treatment of patients with large and giant cerebral arterial aneurysms using flow-diverting stents (FDSs).

MATERIAL AND METHODS

The treatment outcomes of 210 patients with large and giant intracranial aneurysms were analyzed. The study included patients with both asymptomatic and symptomatic aneurysms (manifested by SAH or pseudotumorous course). The rate of giant aneurysms was 62.3%.

RESULTS

The technical success rate was 96%. In the perioperative period, the rate of clinically significant complications was 2.8%; the postoperative mortality was 3.3%. In the long-term period, total thrombosis of the aneurysm was observed in the majority of cases (80%) in the period from 4 to 12 months. Complete regression of clinical symptoms was observed in 26% of the cases, partial regression in 35%, and deterioration in 6% (of them, 4.9% of the cases were clinically significant). The long-term mortality was 2.5%.

CONCLUSION

FDS is a highly efficient device for remodeling of the arterial lumen at the level of large, giant and fusiform intracranial aneurysms that significantly reduces the number of deconstructive operations and decreases the risk of ischemic complications of endovascular treatment for this complex vascular pathology.

Near-Complete Resolution of Clinical and Radiographic Findings After Endovascular Embolization of a Giant Serpentine A1 Aneurysm

BACKGROUND

Giant serpentine aneurysms are complex intracranial lesions, associated with a poor prognosis if left untreated. Treatment usually involves surgical trapping of the aneurysm with arterio-arterial anastomosis; however, recent endovascular management has been implemented for the management of such aneurysms.

CASE DESCRIPTION

We report the unique case of a 71-year-old woman who presented with visual deficits due to the mass effect of a giant serpentine aneurysm arising from the A1 segment of the anterior cerebral artery. Because of its location proximal to a widely patent anterior communicating artery, angiographic cure was achieved with sacrifice of the A1 segment. Clinical and radiographic follow-up demonstrated resolution of the presenting symptoms and near-complete obliteration of the aneurysm.

CONCLUSIONS

Thrombosed giant serpentine aneurysms can show dramatic resolution of mass effect with endovascular treatment.

The Silk flow-diverter stent for endovascular treatment of intracranial aneurysms

Flow diverter (FD) stents represent a new endovascular technique developed for the treatment of complex intracranial aneurysms (wide neck, fusiform, large, and giant aneurysms) that are challenging for classic endovascular techniques such as coiling, balloon-assisted coiling and stent-assisted coiling. Low porosity, high metal coverage, and high pore density are the main properties of FD stents. These properties induce hemodynamic changes redirecting the blood flow away from the aneurysm and into the parent artery leading to gradual thrombosis of the aneurysm. FD stents also provide scaffolding for subsequent neoendothelial proliferation, and vessel wall remodeling. This is considered as a paradigm shift compared to prior endovascular methods, which predominantly aimed at providing treatment inside the aneurysmal sac. This paper describes in detail the first released FD stent, the Silk flow-diverter stent (Balt Extrusion, Montmorency, France), its mechanism of action and deployment technique. It reviews the pertinent literature regarding safety, efficacy and potential risks and complications associated with the use of this stent.

Headache, cerebral aneurysms, and the use of triptans and ergot derivatives

BACKGROUND

Uncertainty exists regarding the correlation between unruptured cerebral aneurysms and their role in headache etiology. It is also unclear whether surgical endovascular treatment may improve or worsen the headache, and if there are predictable factors for headache outcome such as pre-existing headache features, aneurysm characteristics, or other medical history. There is debate regarding safe treatment of migraine in patients with aneurysms, both before and after endovascular treatments. Particularly, there is hesitancy to use the triptans and ergot derivatives such as dihydroergotamine because of their vasoconstrictive effects and concern for adverse events related to the aneurysm such as aneurysmal instability and rupture.

OBJECTIVE

To review the literature regarding the anatomy, pathophysiology, and association between headache, untreated vs surgically treated aneurysms, and the use of triptans and ergot derivatives for migraine treatment in this setting.

CONCLUSION

Associations between some headaches and aneurysms may exist. Some chronic headaches may respond to surgical aneurysm repair while others may worsen. These associations are undefined by current literature because of variable results, study methods, and limited data. Prospective studies are needed which incorporate pre- and post-procedure headache character and diagnosis, aneurysm characteristics, type of aneurysm repair, associated risk factors for worsening post-procedure headache, and ultimately combining all of these data to better predict headache outcome following surgical aneurysm treatment. Lastly, the caution and avoidance of triptan and ergot derivative use for migraine in the setting of aneurysm is not supported by the current evidence, and much of this concern may be excessive and unwarranted, although more evidence confirming safety is needed.

Characteristics and outcomes of varied treatment modalities for partially thrombosed intracranial aneurysms: a review of 35 cases

OBJECTIVE

The purpose of this study was to analyze the characteristics of partially thrombosed intracranial aneurysms (PTIAs) in terms of location, shape, size, and symptoms, and to assess outcome according to the type of treatment.

METHODS

We reviewed the radiological and clinical findings of 35 cases of PTIAs followed in our institution between 2006 and 2011. We divided all treatment modalities into two groups. Patients in group A (n = 15) were treated by blood flow blockage from the lesion of the pathogenic segment of the parent where the PTIAs originated, and patients in group B (n = 20) were only treated with obliteration of the remnant perfused aneurysmal sac. Radiological and clinical outcomes of treatment were compared between the two groups.

RESULTS

Group A showed complete occlusion in 15 cases (100 %) compared to six cases (30.0 %) in group B (p < 0.001). No cases required retreatment in group A, while six cases (30.0 %) underwent retreatment in group B (p = 0.027). In terms of clinical outcome, 12 cases (80.0 %) showed symptomatic improvement in group A compared to eight cases (40.0 %) in group B (p = 0.037). Nine cases (60.0 %) showed improvement in postoperative GOS at six months compared to initial preoperative GOS in group A versus four (20.0 %) in group B (p = 0.032).

CONCLUSION

PTIAs should be treated by preventing blood flow from the lesion of the pathogenic segment of the parent artery where PTIAs originate. This treatment approach is associated with better clinical and radiological outcomes.

Perianeurysmal edema as a predictive sign of aneurysmal rupture

Subarachnoid hemorrhage following intracranial aneurysmal rupture is a major cause of morbidity and mortality. Several factors may affect the probability of rupture, such as tobacco and alcohol use; size, shape, and location of the aneurysm; presence of intraluminal thrombus; and even the sex of the patient. However, few data correlate such findings with the timing of aneurysmal rupture. The authors report 2 cases of middle-age women with headache and MRI findings of incidental aneurysms. Magnetic resonance imaging showed evidence of surrounding parenchymal edema, and in one case there was a clear increase in edema during follow-up, suggesting a progressive inflammatory process that culminated with rupture. These findings raise the possibility that bleb formation and an enlargement of a cerebral aneurysm might be associated with an inflammatory reaction of the aneurysm wall resulting in perianeurysmal edema and subsequent aneurysmal rupture. There may be a temporal link between higher degree of edema and higher risk for rupture, including risk for immediate rupture.

Incidence and risk factors of postoperative headache after endovascular coil embolization of unruptured intracranial aneurysms

BACKGROUND

Endovascular coil embolization for unruptured intracranial aneurysms (UIAs) has gained popularity because of its low morbidity and mortality in a short-term context. However, Headache is sometimes brought about or worsened after endovascular treatment, and this complaint may lead to perplexing situations, albeit infrequently. The aim of this study is to estimate the practical incidence and risk factors of postoperative headache in patients with endovascular embolization of UIAs.

METHOD

One hundred and thirty patients who underwent endovascular treatment of UIAs between March 2006 and May 2012 were enrolled according to inclusion criteria. From a retrospective chart review, the patients who had worsening or newly developed headache from postoperative day 1 to in-hospital stay were investigated for analyzing risk factors of post-embolization headache. Factors based on patients' demographics, anatomical and radiological features of the lesions, treatment, utilized devices and outcome were investigated, and statistically verified.

RESULTS

Headache occurred or was exacerbated in 32 patients (24.6 %). Of these, 30 patients showed improvement within days, but two patients with previous migraine history complained of intermittent headache over 3 months after the embolization. Univariate comparison between the headache group and the non-headache group showed that internal carotid artery (ICA) segment aneurysm, stent-assisted coiling, and no history of hypertension were associated with post-embolization headache (p < 0.05). However, stent-assisted coiling and no history of hypertension were significantly associated with post-embolization headache in logistic regression analysis (p < 0.05).

CONCLUSIONS

In the current study, stent-assisted coiling and no history of hypertension were important risk factors for headache in patients undergoing endovascular coil embolization for UIAs. Further investigations are still necessary to confirm the correlation of other factors which did not reach statistical significance in post-embolization headache in this limited study.

Flow diverters for intracranial aneurysms

Flow diverters (pipeline embolization device, Silk flow diverter, and Surpass flow diverter) have been developed to treat intracranial aneurysms. These endovascular devices are placed within the parent artery rather than the aneurysm sac. They take advantage of altering hemodynamics at the aneurysm/parent vessel interface, resulting in gradual thrombosis of the aneurysm occurring over time. Subsequent inflammatory response, healing, and endothelial growth shrink the aneurysm and reconstruct the parent artery lumen while preserving perforators and side branches in most cases. Flow diverters have already allowed treatment of previously untreatable wide neck and giant aneurysms. There are risks with flow diverters including in-stent thrombosis, perianeurysmal edema, distant and delayed hemorrhages, and perforator occlusions. Comparative efficacy and safety against other therapies are being studied in ongoing trials. Antiplatelet therapy is mandatory with flow diverters, which has highlighted the need for better evidence for monitoring and tailoring antiplatelet therapy. In this paper we review the devices, their uses, associated complications, evidence base, and ongoing studies.