Use Of Flow-diverting Stents Research Articles

Surgical treatment of large and giant vertebrobasilar aneurysms manifested by brainstem compression symptoms

The study included 8 patients operated on in the period between 2014 and 2017. All patients underwent intravascular intervention; two patients had open surgery at the second stage. Intravascular intervention, both alone and in combination with open surgery, is effective treatment of VB aneurysms whose clinical picture is manifested by brainstem compression symptoms. The use of flow-diverting stents in most cases has provided good radicalness in the long-term period, without worsening the functional outcome. Treatment of fusiform aneurysms of the basilar artery trunk requires separate consideration and an individual approach due to a high risk of thrombosis of short branches feeding the brainstem.

The Use of Flow Diverting Stents to Treat Para-Ophthalmic Aneurysms.

Few publications have dealt exclusively with the use of flow diverter stents for the treatment of para-ophthalmic aneurysms. We sought to determine the efficacy of flow diverting stents (FDSs) to treat aneurysms in this specific location. We retrospectively reviewed our database of prospectively collected information for all patients treated with flow diversion for an unruptured saccular para-ophthalmic aneurysm between September 2009 and January 2016. The aneurysm fundus size, neck size, number and type of FDS, complications, and follow-up data were recorded. We identified 74 patients that matched our inclusion criteria. Of these patients, 18 patients were male (24.3%). The average fundus size was 4.8 mm, 11 aneurysms had previous coil occlusions and 63 were treated solely with flow diversion. At an initial angiographic follow-up (mean avg. 3.2 months), 71.8% of the aneurysms were occluded, and at the last follow-up (mean avg. 31.8 months), 88.9% of aneurysms were occluded. One patient suffered permanent morbidity (1.36%) secondary to interruption of the antiplatelet medication and another died (1.36%) secondary to in-stent thrombosis that was also due to an interruption in the antiplatelet medication. Treatment of saccular para-ophthalmic aneurysms with FDS is feasible and carries a high degree of technical success with low complication rates and excellent rates of aneurysm exclusion.

The Efficacy of Flow Diverter Stents in the Treatment of Wide-Necked Intracranial Aneurysms

Background: To present our findings obtained from the treatment of wide-necked intracranial aneurysms with flow diverter stents. Patients and Methods: Intracranial aneurysms were determined in 19 patients (14 females, 5 males; mean age, 56.6 years) between May 2011 and June 2014, and the patients were treated using flow diverter stents. A total of 28 flow diverter stents, including 9 Silk and 19 Pipeline stents were used. Occlusion rates evaluated with computed tomography at the end of month 6 and digital subtraction angiography after one year, intraoperative success, morbidity and mortality rates were determined. Results: A total of 20 endovascular interventions, including two interventions in two different aneurysms in one patient were performed in 19 patients. Flow diverter stents were successfully implemented for wide-necked aneurysms at a success rate of 100%. Coil treatment had previously been performed in four patients. Aneurysm occlusion rates were 77.2% at month 6 and 90.9% at the end of month 12. Conclusion: The use of flow diverter stents is a reliable and effective method in the treatment of wide-necked intracranial aneurysms with high aneurysm occlusion, and low morbidity and mortality rates.

In-stent Stenosis after p64 Flow Diverter Treatment

PurposeThere is limited information available on the incidence of in-stent stenosis (ISS) secondary to the use of flow-diverting stents in the intracranial vasculature. We sought to determine the incidence, severity, and clinical course of ISS on angiographic follow-up after treatment of saccular aneurysms with p64.MethodsWe retrospectively reviewed all patients who underwent treatment of a saccular (ruptured and unruptured) intracranial aneurysm with ≥1 p64 between 2011 and 2015. Fusiform aneurysms and dissections were excluded. Aneurysms with prior or concomitant saccular treatment (e. g., coiling, clipping) were included. Extradural targets and aneurysms with parent vessel implants other than p64 were excluded. ISS was assessed on follow-up angiography and defined as <50% (mild), 50–75% (moderate), or >75% (severe).ResultsIn total, 205 patients (147 female, 71.7%; median age 57 years), with 223 saccular aneurysms were treated with p64 and had at least 9 months of digital subtraction angiography (DSA) follow-up completed. There was no DSA follow-up available in 8 patients. ISS of any degree at any time was recognized in 65/223 (29.1%) of all target aneurysms. The maximal degree of lumen loss was <50% in 40 lesions (17.9%), 50–75% in 19 lesions (8.5%), and >75% in 6 lesions (2.7%). ISS did not cause a focal neurological deficit in any patient. No progression from stenosis to occlusion was observed. Balloon angioplasty was performed in 1 lesion and was well tolerated. In 56 lesions (84.8%), a significant reduction of ISS occurred spontaneously, 2 mild stenoses remained stable, and for 6 lesions the long-term follow-up is pending.ConclusionTreatment with p64 is associated with an overall rate of 8.5% moderate ISS (50–75%) and 2.7% severe ISS (>75%), which is comparable with the rate of ISS reported in the literature for other flow diverting stents. There is a tendency for ISS to spontaneously improve over time.

A Case of Ruptured Blood Blister-like Aneurysm Treated with Pipeline Embolization Device: Clinical Significance of Fetal-type Posterior Communicating Artery.

Blood-blister like aneurysms (BBAs) are challenging lesions because of their wide fragile neck. Flow-diverting stents (FDSs), such as the Pipeline Embolization Device (PED), have been applied to treat BBAs less amenable to more established techniques of treatment. However, the use of FDSs, including the PED, in acute subarachnoid hemorrhage (SAH) still remains controversial. We report a case of aneurysm regrowth following PED application for a ruptured BBA that overlapped the origin of the dominant posterior communicating artery (PCoA), which was successfully treated after coil trapping of the origin of the fetal-type PCoA. And, we discuss the clinical significance of the fetal-type PCoA communicating with a BBA in terms of PED failure.

Inter-rater reliability of published flow diversion occlusion scales

BackgroundWith increasing use of flow-diverting stents for the treatment of intracranial aneurysms, standardized methods and a common language to evaluate angiographic outcomes are needed. Multiple grading scales have been developed...

Application of Pipeline Embolization Device for Iatrogenic Pseudoaneurysms of the Extracranial Vertebral Artery: A Case Report and Systematic Review of the Literature.

Traumatic pseudoaneurysms of the vertebral artery (VA) are uncommon vascular lesions and definitive management is often challenging. Between 0% and 8% of craniocervical fusions are complicated by VA injury. In these cases, preserving the vertebral artery while treating the pseudoaneurysm is the goal of any treatment option. We describe the second known case of a patient with and iatrogenic extracranial vertebral artery pseudoaneurysm treated effectively using the Pipeline Embolization Device (PED) (Ev3 Neurovascular, Irvine, CA). Although there have been only two cases reported, the use of flow-diverting stents appears to be efficacious for the treatment of non-actively bleeding traumatic pseudoaneurysms.

Patency of the anterior choroidal artery covered with a flow-diverter stent.

The concept of the flow-diverter stent (FDS) is to induce aneurysmal thrombosis while preserving the patency of the parent vessel and any covered branches. In some circumstances, it is impossible to avoid dangerously covering small branches, such as the anterior choroidal artery (AChA), with the stent. In this paper, the authors describe the clinical and angiographic effects of covering the AChA with an FDS. Between April 2011 and July 2013, 92 patients with intracranial aneurysms were treated with the use of FDSs in the authors' institution. For 20 consecutive patients (21.7%) retrospectively included in this study, this involved the unavoidable covering of the AChA with a single FDS during endovascular therapy. AChAs feeding the choroid plexus were classified as the long-course group (14 cases), and those not feeding the choroid plexus were classified as the short-course group (6 cases). Clinical symptoms and the angiographic aspect of the AChA were evaluated immediately after stent delivery and during follow-up. Neurological examinations were performed to rule out hemiparesis, hemihypesthesia, hemianopsia, and other cortical signs. FDS placement had no immediate effect on AChA blood flow. Data were obtained from 1-month clinical follow-up in all patients and from midterm angiographic follow-up in 17 patients (85.0%), with a mean length of 9.8 ± 5.4 months. No patient in either group complained of transient or permanent symptoms related to an AChA occlusion. In all cases, the AChA remained patent without any flow changes. The results of this study suggest that when impossible to avoid, the AChA may be safely covered with a single FDS during intracranial aneurysm treatment, irrespective of anatomy and anastomoses.

Diffusion-weighted imaging-detected ischemic lesions associated with flow-diverting stents in intracranial aneurysms: safety, potential mechanisms, clinical outcome, and concerns.

It was initially considered safe for flow-diverting stents to cover the ostia of branching vessels during endovascular procedures for the treatment of intracranial aneurysms. As more recent evidence suggests, however, their use is not always free of ischemic concerns in terms of covered arterial ostia. The authors sought to determine the frequency of silent and clinically evident diffusion-weighted imaging (DWI)-detected abnormalities related to stent placement as a means of elucidating potential clinical risks. This is a prospective single-center study on a series of patients with intracranial aneurysms that were treated with flow-diverting stents. All patients systematically underwent an MRI protocol that included DWI before treatment, between 24 and 48 hours postprocedure, and 3 months postembolization. Effectiveness of anticoagulation treatment was assessed for all patients. Lesions seen on DWI were correlated to the parent artery and the side-branch territories and were statistically analyzed in relation to their time of occurrence and clinical presentation. The authors compared the DWI findings in these patients to findings obtained in patients treated with a stent-assisted coiling technique during the same time period. Over the course of 18 consecutive months, 38 consecutive patients (7 males and 31 females) with 49 intracranial aneurysms were treated using flow-diverting stents. Overall, 81.6% of the DWI spots found remained clinically silent during the follow-up period. Five ischemic clinical complications (13.2%) occurred in the postprocedural period. No statistically significant correlation could be established between DWI spots or aneurysm location and clinical complications or follow-up modified Rankin Scale score at 3 months. The complication rate was 7.8% (n = 3) at the 3-month follow-up, and mortality was 0%. Compared with stent-assisted coiling, use of flow-diverting stents showed a statistically significant correlation with silent DWI findings postintervention. Lesions seen on DWI resulting from the procedure are far more common than anticipated, but the technique remains safe and effective, providing an interesting alternative for "difficult" aneurysms, regardless of location. Late-occurring DWI-detected lesions distal to side arterial branches imply a local pressure gradient drop, related to flow competition by collateral networks. Further research is needed to assess the extent and significance of these events.

Use of Flow-Diverting Devices in Fusiform Vertebrobasilar Giant Aneurysms: A Report on Periprocedural Course and Long-Term Follow-Up

Fusiform vertebrobasilar giant aneurysms are a rare (<1% of all intracranial aneurysms) but challenging aneurysm subtype. Little data are available on the natural history of this aneurysm subtype and the impact of the use of flow-diverting stents on the long-term clinical and imaging follow-up. In this article, we present our experience with the treatment of fusiform vertebrobasilar giant aneurysms by flow diverting stents. We aim to stimulate a discussion of the best management paradigm for this challenging aneurysm subtype. We retrospectively identified 6 patients with fusiform vertebrobasilar giant aneurysms who had been treated with flow-diverting stents between October 2009 and March 2012 in our center. The available data were re-evaluated. The modified Rankin Scale score was assessed before intervention, during the stay in hospital, and at discharge. Six patients were identified (all male; age range, 49-71 years; median age, 60 years). Handling of material was successful in all cases. No primary periprocedural complications occurred. The mean follow-up was 13 months (15 days to 29 months). During follow-up, 3 of 6 patients had recurrent cerebral infarctions, but no patient experienced SAH. Two patients presented with acute thrombotic stent occlusion. The modified Rankin Scale score was not higher than 3 in any of the cases before intervention, whereas the best mRS score at the last follow-up was 5. Four of 6 patients died during follow-up. Endovascular treatment of fusiform vertebrobasilar giant aneurysms with flow-diverting devices is feasible from a technical point of view; however, changes in hemodynamics with secondary thrombosis are not predictable. We currently do not intend to treat fusiform vertebrobasilar giant aneurysms with flow-diverting devices until we have further understanding of the pathophysiology, natural history, and hemodynamic effects of flow diversion.

Use of Flow-Diverting Stents to Treat Para-Anastomotic Iliac Artery Aneurysms After Previous Open Aortic Prosthetic Reconstruction

To present a series of para-anastomotic iliac artery aneurysms treated with flow-diverting stents. Three patients (2 men, 1 woman; ages 70, 73, and 78 years) with previous open aortoiliac reconstructions received a 12-mm-diameter Cardiatis Multilayer Stent to treat 4 para-anastomotic iliac artery aneurysms in an attempt to preserve their ipsilateral hypogastric arteries. After 1-year follow-up, all aneurysms were successfully excluded, with complete sac thrombosis in three and partial thrombosis in one. The diameter of the aneurysm was reduced in all by a median 6 mm. At 1 year, patency of the hypogastric artery was maintained in only the patient with partial sac thrombosis. No patient developed buttock claudication. The use of flow-diverting stents for para-anastomotic iliac artery aneurysms resulted in reduction of iliac aneurysm diameter. However, intended patency of the ipsilateral hypogastric artery was not always observed. The feasibility of the technique has therefore not been shown for this specific indication.

The use of flow diverter stents in the management of traumatic vertebral artery dissections

Flow diverters constitute a new generation of flexible self-expanding stent-like devices with a high metal-surface area coverage, specifically designed for the endovascular management of complex cerebral aneurysms. Recently, other potential applications for these devices in the field of occlusive cerebrovascular disease have been described. In vertebral artery dissections causing occlusion associated with a burden of extensive clots, we have found that the reduced porosity of the diverter mesh serves as an effective barrier to in-stent clot protrusion and distal embolization. We describe the novel use of a flow diverter for the management of an occlusive traumatic vertebral artery dissection. Diverter implantation allowed subsequent angioplasty.

Solitaire FR Stent as an Adjunctive Tool for Pipeline Stent Deployment in the Treatment of Giant Intracranial Aneurysms

The use of flow-diverting stents has gained acceptance during the past few years for the treatment of numerous intracranial aneurysms, especially large or giant ones. However, successful catheterization of the distal parent artery in giant intracranial aneurysms with a microcatheter can be extremely challenging. Forming a microcatheter loop in the aneurysm sac can aid distal catheterization. We report the use of a Solitaire FR stent as an adjunctive tool in the successful treatment of 2 giant intracranial unruptured aneurysms with a Pipeline Embolization Device. After having formed a loop inside the aneurysm sac, the microcatheter was anchored distally by a Solitaire FR stent. With the Solitaire FR device opened, the loop in the giant aneurysm sac was completely reduced without loss of the microcatheter position in the distal parent artery. A Pipeline Embolization Device could be delivered in both cases without any difficulty. There were no complications. The technique described results in ideal microcatheter alignment with a secure distal position before deployment of a flow-diverting stent.

Canadian Experience with the Pipeline Embolization Device for Repair of Unruptured Intracranial Aneurysms

Flow-diverting stents, such as the PED, have emerged as a novel means of treating complex intracranial aneurysms. This retrospective analysis of the initial Canadian experience provides insight into technical challenges, clinical and radiographic outcomes, and complication rates after the use of flow-diverting stents for unruptured aneurysms. Cases were compiled from 7 Canadian centers between July 2008 and December 2010. Each center prospectively tracked their initial experience; these data were retrospectively updated and pooled for analysis. During the defined study period, 97 cases of unruptured aneurysm were treated with the PED, with successful stent deployment in 94 cases. The overall complete or near-complete occlusion rate was 83%, with a median follow-up at 1.25 years (range 0.25-2.5 years). Progressive occlusion was witnessed over time, with complete or near-complete occlusion in 65% of aneurysms followed through 6 months, and 90% of aneurysms followed through 1 year. Multivariate analysis found previous aneurysm treatment and female sex predictive of persistent aneurysm filling. Most patients were stable or improved (88%), with the most favorable outcomes observed in patients with cavernous carotid aneurysms. The overall mortality rate was 6%. Postprocedural aneurysm hemorrhage occurred in 3 patients (3%), while ipsilateral distal territory hemorrhage was observed in 4 patients (3.4%). Flow-diverting stents represent an important tool in the treatment of complex intracranial aneurysms. The relative efficacy and morbidity of this treatment must be considered in the context of available alternate interventions.

Panacea or problem: flow diverters in the treatment of symptomatic large or giant fusiform vertebrobasilar aneurysms

The use of flow-diverting stents has gained momentum as a curative approach in the treatment of complex proximal anterior circulation intracranial aneurysms. There have been some reported attempts of treating formidable lesions in the posterior circulation. Posterior circulation giant fusiform aneurysms have a particularly aggressive natural history. To date, no one approach has been shown to be comprehensively effective or low risk. The authors report the initial results, including the significant morbidity and mortality encountered, with flow diversion in the treatment of large or giant fusiform vertebrobasilar aneurysms at Millard Fillmore Gates Circle Hospital. The authors retrospectively reviewed their prospectively collected endovascular database to identify patients with intracranial aneurysms who underwent treatment with flow-diverting devices and determined that 7 patients had presented with symptomatic large or giant fusiform vertebrobasilar aneurysms. The outcomes of these patients, based on the modified Rankin Scale (mRS), were tabulated, as were the complications experienced. Among the 7 patients, Pipeline devices were placed in 6 patients and Silk devices in 1 patient. At the last follow-up evaluation, 4 patients had died (mRS score of 6), all of whom were treated with the Pipeline device. The other 3 patients had mRS scores of 5 (severe disability), 1, and 0. The deaths included posttreatment aneurysm ruptures in 2 patients and lack of improvement in neurological status related to presenting brainstem infarcts and subsequent withdrawal of care in the other 2 patients. Whether flow diversion will be an effective strategy for treatment of large or giant fusiform vertebrobasilar aneurysms remains to be seen. The authors' initial experience suggests substantial morbidity and mortality associated with the treatment and with the natural history. As outcomes data slowly become available for patients receiving these devices for fusiform posterior circulation aneurysms, practitioners should use these devices judiciously.

The Use of Flow-Diverting Stents in the Treatment of Giant Cerebral Aneurysms: Preliminary Results

The treatment of giant cerebral aneurysms has always been a challenge for neurosurgeons and neuroradiologists. Flow-diverting stents (Silk; Pipeline Embolization Device) are new endovascular devices introduced for the treatment of intracranial aneurysms without release of intrasaccular coils. They are tubular bimetallic endoluminal devices with low porosity. We have employed these stents in the Neuroradiology Unit of Bellaria Hospital (Bologna, Italy) since the end of 2008, treating nine patients with giant carotid cerebral aneurysms using nine Silk stents as soon as the device obtained the CE mark. All patients were pretreated with dual antiplatelet medications before surgery. The Silk stents were deployed through a 4F Balt introducer, which ensured an uneventful and very quick procedure. Control CT angiography or MR angiography was typically performed at discharge and one, three, six and 12 months after treatment. Post-treatment results were: four complete occlusions, three near complete occlusions (residual neck flow) with reduced volume of the aneurysm and two more than 50% reduction of intra-aneurysmal flow. A fatal hemorrhagic complication occurred in one patient, probably due to the antiplatelet treatment. The Silk stent seems a very interesting curative device to treat giant aneurysms with preservation of the parent artery and small adjacent branches. Technical improvements will certainly reduce the thrombogenic effect with the related risks.