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.

Dissecting and fusiform aneurysms of the superior cerebellar artery: anatomy, clinical presentation, and treatment outcomes.

The management of superior cerebellar aneurysms is still controversial. Although several techniques are available, the deep localization of the lesion and the limited number of cases increase the complexity of decision-making for optimal treatment. Only a few cases of dissecting and fusiform aneurysms of the superior cerebellar artery (SCA) are described in the literature, many of which are without long follow-ups. The study aims to offer an exhaustive retrospective analysis of patients affected by SCA fusiform and dissecting aneurysms treated at our institution from 2008 to 2023, highlighting outcomes and complications. Moreover, a comprehensive narrative review was performed. A total of seven patients were treated at our institution. After a title and abstract screen, fifty-five papers met the criteria for inclusion in the review. In our case series, conservative treatment was proposed as the first therapeutic option in four cases (57.1%), while endovascular treatment (EVT) was in three cases (42.9%). A good recovery was observed in 66% of patients presenting with subarachnoid hemorrhage (SAH), while every patient without SAH achieved a good clinical outcome. A poor outcome was observed only in one patient with a dissecting aneurysm causing SAH, who also suffered a pontine infarction. In the literature review, conservative treatment was proposed as a first therapeutic option in eleven cases (16.6%), open microsurgical techniques in 19 patients (28.8%), and EVT in 31 patients (46.9%). Fatal outcome was documented in five patients (7.5%), all characterized by the rupture of the vascular lesion, while 6.1% of cases had non-fatal poor outcomes.

Dolichoectasia: a brain arterial disease with an elusive treatment.

INTRODUCTION: Dolichoectasia is a form of brain large artery disease associated with a high risk of mortality and morbidity. Progressive enlargement of arterial size is a predictor of mortality, but there are no specific treatments for arresting or slowing down dilatation. Additionally, dilated brain arteries can cause flow stagnation, which can trigger thrombosis and cause stroke. Pathology and genetic studies indicate a possible role for increased matrix metalloproteinase activation in arterial dilatation and thus in the pathophysiology of dolichoectasia. Therefore, therapeutic interventions aimed at slowing down arterial dilatation and preventing thrombosis could hypothetically play a role in treating patients with dolichoectasia. METHODS: We present four patients with dolichoectasia that exemplify therapeutic challenges worth discussing in the context of the current literature. Two patients were treated off-label with doxycycline (based on its antiMMP properties) and with apixaban, one patient was put on warfarin and later switched to aspirin, and the fourth patient underwent endovascular treatment. RESULTS: We report four cases, all men 50 years or older. Of the two patients treated with doxycycline, we noted a slowdown of the basilar artery (BA) growth, but the BA continued to grow in the other patient. Of the two patients who received apixaban, none had a subsequent stroke in 5 and 4 years of follow-up, respectively. One patient was admitted with a fatal BA thrombosis and rupture, and pathological examination of the brain arteries demonstrated advanced arterial wall degeneration but no atherosclerosis. DISCUSSION: These cases exemplify the challenges of treating people with dolichoectasia and highlight the need for better evidence regarding the best possible treatment for this population.

Surgical treatment of hemifacial spasm caused by fusiform vertebral artery aneurysm: case report and literature review.

BACKGROUND: Root exit zone (REZ) compression by a fusiform vertebral artery (VA) aneurysm is a rare cause of hemifacial spasm (HFS). We report a case of successful microvascular decompression (MVD) for the treatment of HFS caused by a fusiform VA aneurysm. We also review the relevant literature and demonstrate the effectiveness of surgical treatment. CASE DESCRIPTION: A 64-year-old man presented with a 2-year and 4-month history of progressive involuntary facial twitching on the right side. Radiological examination revealed a fusiform right VA aneurysm. The REZ that was compressed by the aneurysm and the underlying anterior inferior cerebellar artery (AICA) was surgically decompressed by transposing the VA and AICA and wrapping the aneurysm. Immediately post-operation, the patient's symptoms disappeared. For 7 years and 4 months postoperatively, there was no symptom recurrence or increase in aneurysm size. CONCLUSION: MVD is an effective treatment for HFS caused by a fusiform VA aneurysm because symptoms are likely to improve immediately after treatment.

Telescoping flow diverters for a pediatric fusiform distal anterior cerebral artery aneurysm: technical case report.

BACKGROUND AND IMPORTANCE: Pediatric intracranial aneurysms are rare, with fusiform aneurysms of the distal anterior circulation even more so. A limited number of prior reports detail the management of this pathology. CLINICAL PRESENTATION: We report a case of a 15-year-old boy presenting with new-onset headache found to have a 3.1 cm × 1.4 cm × 1.4 cm fusiform partially thrombosed aneurysm of the A2 segment of the left anterior cerebral artery. Subsequent treatment with flow diversion resulted in the placement of five telescoping PEDs (2.5 mm × 20 mm, 2.75 mm × 20 mm, 2.75 mm × 20 mm, 3 mm × 25 mm, and 3 mm × 20 mm) from the left pericallosal artery to the left A1 segment. Catheter-based angiography at 6 months post-placement indicated normal vessel caliber, no residual aneurysm, and no in-stent stenosis. The patient's headache resolved after treatment. CONCLUSION: Telescoping PEDs are a feasible low-risk treatment option for long-segment fusiform distal ACA aneurysms in children that can have optimal clinical and radiographic outcomes.

Flow diversion of fusiform intracranial aneurysms.

Fusiform aneurysms are less common than saccular aneurysms, but have higher associated mortality and rebleeding rates. Recently, flow diversion has emerged as a possible treatment option. The purpose of this study was to determine the safety and efficacy of the Pipeline Embolization Device (PED) for the treatment of ruptured and unruptured fusiform aneurysms. This was a retrospective analysis of patients with fusiform intracranial aneurysms treated with a PED at a quaternary care center between January 2012 and September 2019. Occlusion rates, neurologic morbidity/mortality, and other clinical variables were analyzed. Twenty-nine patients with 30 fusiform aneurysms were treated with a PED. Sixteen aneurysms (53%) were located in the anterior circulation and 14 aneurysms (47%) were in the posterior circulation. The mean maximal diameter of the aneurysms was 10.1 ± 5.6 mm (range 2.3-25 mm). Angiographic and clinical follow-up were available for 28 aneurysms (93%). The median follow-up was 17.4 months (IQR 4.8 to 28 months) and occlusion rates were graded according to the O'Kelly-Marotta (OKM) scale. Of patients with DSA follow-up, 15 aneurysms (60%) were completely occluded (OKM D) and 19 aneurysms (76%) had a favorable occlusion result (OKM C1-3 and D). The overall complication rate was 26.7% with a neurological morbidity rate of 6.7% and neurological mortality rate of 3.4%. Flow diversion can be an effective treatment for both ruptured and unruptured fusiform aneurysms. Nevertheless, complete occlusion rates are lower than for saccular aneurysms. Therefore, flow diversion should be considered only if other more direct treatment options, such as clipping or stent/coiling are not applicable. Flow diversion should be used cautiously in patients presenting with rupture.

Comparison of surgical and endovascular treatments for fusiform intracranial aneurysms: systematic review and individual patient data meta-analysis.

Fusiform intracranial aneurysms (FIA) are associated with significant morbidity and mortality. We carried out a systematic review and meta-analysis of individual participant data with propensity score adjustment to compare the functional and angiographic outcomes between surgical and endovascular approaches to FIA. We conducted a systematic review for articles on the treatment of FIA with individual patient-level detailing. Data from patients treated for FIA in our institution from 2010 to 2018 were also collected. The primary studied outcome was morbidity, and secondary outcomes were angiographic results and retreatment. Propensity score-adjusted mixed-effects logistic regression models evaluated treatment options, stratified by anatomical location. Compiling original and published data, there were 312 cases, of which 79 (25.3%) had open surgery, and 233 (74.5%) were treated with endovascular procedures. There were no differences between treatment groups, for neither cavernous ICA (OR 1.04, 95% CI 0.05-23.6) nor supraclinoid aneurysms (OR 7.82, 95% CI 0.65-94.4). Both size (OR 1.11, 95% CI 1.03-1.19) and initial mRS (OR 2.0, 95% CI 1.2-3.3) were risk factors for morbidity, independent of location. Neither age nor rupture status influenced the odds of posterior morbidity. Unfavorable angiographic outcomes were more common in the endovascular group for supraclinoid and vertebrobasilar aneurysms (χ2, P < 0.01). There were no differences between morbidity of surgical and endovascular treatments for FIA, regardless of aneurysm location. Size and initial mRS were correlated with functional outcomes, whereas age and rupture status were not. Microsurgery seems to yield better long-term angiographic results compared to endovascular procedures.

Giant Vertebrobasilar Fusiform Aneurysm Mass Effect Heralds Rapid in Situ Thrombosis and Ischemic Stroke in the Setting of Ulcerative Colitis.

Here we describe a case of brainstem infarction secondary to rapid thrombus formation in a giant vertebrobasilar fusiform aneurysm (GVBFA) that was preceded clinically by several months of headaches and dizziness initially attributable to mass effect. Less than a month after initial identification of the aneurysm, a large partially-occluding thrombus formed leading to infarction of the brainstem. Interestingly, this patient also had ulcerative colitis, which has been associated with acquired hypercoagulability. Balancing risk versus benefit in the management of GVBFA to prevent morbidity and mortality is very challenging; thus more information is needed to better stratify treatment options for patients, particularly those that may have an accelerating clinical course or co-morbidities that increase clotting risk.

Kosaki overgrowth syndrome: A novel pathogenic variant in PDGFRB and expansion of the phenotype including cerebrovascular complications.

Heterozygous activating variants in platelet-derived growth factor, beta (PDGFRB) are associated with phenotypes including Kosaki overgrowth syndrome (KOGS), Penttinen syndrome and infantile myofibromatosis (IM). Here, we present three new cases of KOGS, including a patient with a novel de novo variant c.1477A > T p.(Ser493Cys), and the oldest known individual age 53 years. The KOGS phenotype includes characteristic facial features, tall stature, scoliosis, hyperelastic thin skin, lipodystrophy, variable intellectual and neurological deterioration, and abnormalities on brain imaging. Long-term outcome is unknown. Our cases confirm the phenotypic spectrum includes progressive flexion contractures, camptodactyly, widely spaced teeth, and constriction rings. We also propose novel occasional features including craniosynostosis, ocular pterygia, anterior chamber cleavage syndrome, early osteoporosis, increased pigmentation, recurrent haematomas, predisposition to cellulitis, nail dystrophy, carpal tunnel syndrome, recurrent hypoglycaemia in infancy, joint dislocation, and splenomegaly. Importantly, we report fusiform aneurysm of the basilar artery in two patients. Complications include thrombosis and stroke in the oldest reported patient and fatal rupture at the age of 21 in the patient with the novel variant. We conclude that cerebrovascular complications are part of the phenotypic spectrum of KOGS and KOGS-like disorders and suggest vascular imaging is indicated in these patients.

Activating variants in PDGFRB result in a spectrum of disorders responsive to imatinib monotherapy.

More than 50 individuals with activating variants in the receptor tyrosine kinase PDGFRB have been reported, separated based on clinical features into solitary myofibromas, infantile myofibromatosis, Penttinen syndrome with premature aging and osteopenia, Kosaki overgrowth syndrome, and fusiform aneurysms. Despite their descriptions as distinct clinical entities, review of previous reports demonstrates substantial phenotypic overlap. We present a case series of 12 patients with activating variants in PDGFRB and review of the literature. We describe five patients with PDGFRB activating variants whose clinical features overlap multiple diagnostic entities. Seven additional patients from a large family had variable expressivity and late-onset disease, including adult onset features and two individuals with sudden death. Three patients were treated with imatinib and had robust and rapid response, including the first two reported infants with multicentric myofibromas treated with imatinib monotherapy and one with a recurrent p.Val665Ala (Penttinen) variant. Along with previously reported individuals, our cohort suggests infants and young children had few abnormal features, while older individuals had multiple additional features, several of which appeared to worsen with advancing age. Our analysis supports a diagnostic entity of a spectrum disorders due to activating variants in PDGFRB. Differences in reported phenotypes can be dramatic and correlate with advancing age, genotype, and to mosaicism in some individuals.

Wall enhancement of intracranial saccular and fusiform aneurysms may differ in intensity and extension: a pilot study using 7-T high-resolution black-blood MRI.

PURPOSE: To evaluate and compare wall enhancement patterns in saccular and fusiform intracranial aneurysms using high-resolution black-blood MRI at 7 T. METHODS: Thirty-one patients with 32 unruptured intracranial aneurysms (21 saccular and 11 fusiform) underwent 7-T black-blood MRI. Aneurysm wall enhancement (AWE) was categorized as follows: no wall enhancement (NWE), focal wall enhancement (FWE), and uniform wall enhancement (UWE). The degree of enhancement was scored as follows: 0 (no enhancement), 1 (signal intensity (SI) of the aneurysm wall less than that of the pituitary infundibulum), and 2 (equal to that of the pituitary infundibulum). The chi-squared test was used to compare the AWE pattern and degree between saccular and fusiform aneurysms. RESULTS: In saccular aneurysms, 12/21 (57%) enhanced. Of these, 9 showed FWE (5 grade 1 and 4 grade 2), and 3 showed UWE (2 grade 1 and 1 grade 2). In fusiform aneurysms, 11/11 (100%) enhanced. Of these, 1 showed FWE and 10 showed UWE. All fusiform aneurysms had grade-2 enhancement. Fusiform aneurysms had more extensive and higher SI AWE than saccular aneurysms (p < 0.01) despite having a similar size (6.9 ± 3.0 mm vs. 8.0 ± 2.9, p = 0.23). For saccular aneurysm, larger aneurysm size was correlated with higher degree of enhancement with Pearson's r = 0.64 (p = 0.002). CONCLUSION: Intracranial fusiform aneurysms had enhancement of higher SI and that covered a more extensive area than saccular aneurysms, which might indicate differences in vessel wall pathology. KEY POINTS: • Intracranial aneurysm wall enhancement can be reliably characterized by 7-T black-blood MRI. • AWE in intracranial fusiform aneurysms presents over a larger surface area and with greater signal intensity as compared with that in saccular aneurysms, which might indicate differences in pathology. • Stronger signal intensity of AWE correlates with the aneurysm size in saccular aneurysms.

[Resection of a giant fusiform aneurysm of the pericallosal artery with «hemi-bonnet bypass¼ procedure (case report and literature review)]. / Vyklyuchenie gigantskoi fuziformnoi anevrizmy perikalleznoi arterii s primeneniem obkhodnogo shuntirovaniya po tipu «hemi-bonnet bypass¼. Sluchai iz praktiki i obzor literatury.

A 30-year-old woman with giant fusiform aneurysm of the azygos anterior cerebral artery is reported. Clipping of the aneurysm followed by modeling of pericallosal artery was performed in 2017. However, further enlargement of the aneurysm has been observed for subsequent 2 years. The patient underwent redo surgery with excision of the aneurysm followed by «hemi-bonnet bypass¼ procedure (anastomosis between superficial temporal artery and anterior cerebral artery with radial artery as an interposition graft). Literature data on reconstructive surgery in the treatment of complex pericallosal artery aneurysms are reviewed.

Evaluation of flow changes after telescopic stenting of a giant fusiform aneurysm of the vertebrobasilar junction.

BACKGROUND: The use of flow-diverters for non-saccular cerebral posterior circulation aneurysms requires complex deployment techniques and is associated with high mortality and morbidity. Therefore, further studies are required to clarify the effect of stenting on post-treatment hemodynamics in such aneurysms. In this study, we evaluated flow alterations in a treated giant fusiform aneurysm of the vertebrobasilar junction and correlated them with the clinical outcome. METHODS: A patient-specific aneurysm model was acquired by rotational angiography, and three SILK flow-diverters (4.5 × 40, 5 × 40 and 5.5 × 40 mm) were virtually deployed in series along the basilar and right vertebral arteries. Image-based blood flow simulations before and after the treatment were performed under realistic pulsatile flow conditions. The flow reduction, velocity and wall shear stress (WSS) distribution, streamlines and WSS-derived parameters were evaluated before and after the treatment. RESULTS: The computed velocity streamlines showed substantial alterations of the flow pattern in the aneurysm and successful redirection of blood flow along the series of flow-diverters with no flow through the overlapping stents. The obtained flow reduction of 86% was sufficient to create thrombogenic flow conditions. Moreover, a 6.2-fold increase in relative residence time and a decrease by 87% of time-averaged WSS contributed to a successful treatment outcome observed during the follow-up. CONCLUSIONS: We found a correlation between the numerically predicted flow alterations and the available treatment outcome. This shows the potential of image-based simulations to be used in clinical practice for treatment planning and estimation of possible risk factors associated with a complex stent deployment in fusiform aneurysms of the posterior circulation.

Vascular complications in pediatric craniopharyngioma patients: a case-based update.

PURPOSE: Craniopharyngiomas remain a challenging entity for neurosurgeons because of their deep-seated, midline location, and intimate relationship with critical neurovascular structures. With high long-term survival rates, patients with craniopharyngioma are likely to experience significant late morbidity related to both disease and therapy. METHOD AND RESULTS: In this paper, we present two cases of late vascular complications after multi-modal treatment of craniopharyngioma. CONCLUSION: Available data suggests that pediatric patients with craniopharyngioma represent a particularly vulnerable group.

Endovascular management of basilar artery occlusion secondary to fusiform aneurysm with intraluminal thrombus.

Acute basilar artery occlusion is one of the most devastating subtypes of ischemic stroke with an extremely high morbidity and mortality rate. The most common causes include embolism, large-artery atherosclerosis, penetrating small-artery disease, and arterial dissection. The heart and vertebral arteries are the main source of emboli in embolic basilar occlusions. The authors present an uncommon acute basilar occlusion secondary to a fusiform aneurysm with intraluminal thrombus. The patient underwent a mechanical thrombectomy with successful recanalization, but persistent intraluminal thrombus. The authors discuss the management dilemma and describe their choice for placement of flow diverter stents.The video can be found here: https://youtu.be/XzBdgxJPSWQ.

Endovascular management of fusiform aneurysms in the posterior circulation: the era of flow diversion.

Fusiform aneurysms are uncommon compared with their saccular counterparts, yet they remain very challenging to treat and are associated with high rates of rebleeding and morbidity. Lack of a true aneurysm neck renders simple clip reconstruction or coil embolization usually impossible, and more advanced techniques are required, including bypass, stent-assisted coiling, and, more recently, flow diversion. In this article, the authors review posterior circulation fusiform aneurysms, including pathogenesis, natural history, and endovascular treatment, including the role of flow diversion. In addition, the authors propose an algorithm for treatment based on their practice.

Partial wrap-clipping of the entrance of the pseudolumen of a fusiform aneurysm in the posterior inferior cerebellar artery: a technical note.

BACKGROUND: Fusiform aneurysms in the posterior inferior cerebellar artery (PICA) are rare and challenging to treat. Surgical treatment options for a fusiform aneurysm in the PICA include trapping with/without bypass and wrap-clipping, when elimination of the pathological wall from the systemic circulation and prevention of perforator injury are important. In addition, lower cranial nerve impairment due to surgical manipulation should also be avoided. METHOD: A fusiform-shaped aneurysm was found in a proximal part of the PICA by magnetic resonance angiography undertaken for evaluation of repeated vertigo in a 36-year-old man. The patient underwent direct surgery via a lateral suboccipital transcondylar fossa approach. The entrance of the pseudolumen was the only part to be wrapped and obstructed by clip application, through the corridor between the acoustic and glossopharyngeal nerves to avoid lower cranial nerve injury. RESULTS: Indocyanine green (ICG) videoangiography demonstrated obliteration of pseudolumen and patency of peripheral PICA and perforator contributing to the medulla oblongata. The postoperative course was uneventful without periprocedural complications, including dysphagia and hoarseness. CONCLUSIONS: Partial wrap-clipping technique for obstruction of the entrance into a pseudolumen is one of alternatives for dissecting fusiform-shaped aneurysm in the PICA. ICG videoangiography was helpful to confirm the obliteration of the pseudolumen and patency of parent vessel and perforators.

Bilateral Fusiform Aneurysms of the Internal Carotid Arteries Presenting with Subarachnoid Hemorrhage.

Fusiform aneurysms of cerebral arteries are less prevalent than saccular aneurysms and are rarely associated with subarachnoid hemorrhage (SAH). In this article, we report SAH due to a rare case of bilateral fusiform aneurysm of the supraclinoid segment of the internal carotid arteries (ICAs) (C4 segment of the ICA).

Bypass surgery to treat symptomatic fusiform dilation of the internal carotid artery following craniopharyngioma resection: report of 2 cases.

Fusiform dilation of the internal carotid artery (FDICA) is an infrequent vascular complication following resection of suprasellar lesions in the pediatric population, and its course appears to be benign without apparent clinical symptoms. However, data correlating symptomatic FDICA with bypass surgery are scarce. The authors here report 2 symptomatic cases that were treated using internal maxillary artery bypass more than 5 years after total removal of a craniopharyngioma at an outside institution. Both cases of FDICA were resected to relieve the mass effect and to expose the craniopharyngioma. The postoperative course was uneventful, and radiological imaging revealed graft conduit patency. To the authors' knowledge, this is the first reported use of extracranial to intracranial bypass to treat FDICA following removal of a suprasellar lesion. Their findings suggest that bypass surgery is a useful therapeutic approach for symptomatic cases of FDICA and total removal of recurrent craniopharyngioma. Moreover, the indications for surgical intervention and treatment modalities are discussed in the context of previous relevant cases.

The predictors of endoleaks after endovascular repair of experimentally produced fusiform carotid aneurysm in canine.

OBJECTIVE: Endoleaks constitute the main concern regarding the use of covered stents in the treatment of intracranial aneurysms. We investigated immediate/late endoleaks after stent-graft placement for the treatment of experimentally created carotid fusiform aneurysm (FA) in a canine model. MATERIAL AND METHODS: Eighteen carotid FAs in nine dogs receiving covered stents were followed. Their procedural and angiographic data were collected immediately and six months after stenting. Univariate analysis and multivariate logistic regression analysis were performed to determine the factors predictive of immediate/late endoleaks. Receiver operating characteristic curve analysis was performed to determine the best cutoff values of the independent factors. RESULTS: All carotid FAs were successfully treated with Willis covered stents and received a six-month follow-up. The rate of immediate and late endoleaks after stenting was 38.89% and 16.67%, respectively. Anchoring length was identified as independent predictor of immediate endoleaks (P =0.037) and its best cutoff value was 3.06 mm (95% confidence interval: 2.39-3.72). No parameters were identified to be independent predictors of late endoleaks. CONCLUSIONS: Treating carotid FAs with Willis covered stents is technically feasible. Most endoleaks heal spontaneously and significantly correlate with anchoring length.