Use Of Flow Diverters Research Articles

Expanding the use of flow diverters beyond their initial indication: treatment of small unruptured aneurysms

BackgroundExperience with the endovascular treatment of unruptured small intracranial aneurysms by flow diverter devices is still limited.ObjectiveTo assess the safety and efficacy of the SILK flow diverter (SFD) in the...

Pipeline flow diversion of ruptured blister aneurysms of the supraclinoid carotid artery using a single-device strategy.

OBJECTIVE Ruptured blister aneurysms remain challenging lesions for treatment due to their broad, shallow anatomy and thin, fragile wall. Historical challenges with both open microsurgical approaches and intrasaccular endovascular approaches have led to increased use of flow diversion for management of these aneurysms. However, the optimum paradigm, including timing of treatment, use of dual antiplatelet therapy, and number of flow-diverter devices to use remains unknown. The authors describe their experience with ruptured blister aneurysms treated with flow diversion at their institution, and discuss rates of rebleeding and number of devices used. METHODS All patients presenting with subarachnoid hemorrhage from a ruptured blister aneurysm and treated with Pipeline flow diversion were identified. Patient demographic data, clinical status and course, need for external ventricular drain (EVD), timing of treatment, and angiographic details and follow-up were recorded. RESULTS There were 13 patients identified (11 women and 2 men), and 4 had multiple aneurysms. Two aneurysms were treated on initial angiography, with average time to treatment of 3.1 days for the remainder, after discussion with the family and institution of dual antiplatelet therapy. Device placement was technically successful in all patients, with 2 patients receiving 2 devices and the remainder receiving 1 device. There was 1 intraoperative complication, of a wire perforation causing intracerebral hemorrhage requiring decompressive craniectomy. Three patients had required EVD placement for management of hydrocephalus. There was no rebleeding from the target lesion; however, one patient had worsening intraventricular hemorrhage and another had rupture of an unrecognized additional aneurysm, and both died. Of the other 11 patients, 10 made a good recovery, with 1 remaining in a vegetative state. Nine underwent follow-up angiography, with 5 achieving complete occlusion, 2 with reduced aneurysm size, and 2 requiring retreatment for aneurysm persistence or enlargement. There were no episodes of delayed rupture. CONCLUSIONS Pipeline flow diversion is a technically feasible and effective treatment for ruptured blister aneurysms, particularly in good-grade patients without hydrocephalus. Patients with a worse grade on presentation and requiring EVDs may have higher risk for bleeding complications and poor outcome. There was no rebleeding from the target lesion with use of a single device in this series.

Flow diversion of tandem cerebral aneurysms: a multi-institutional retrospective study.

OBJECTIVE Flow diversion has proven to be an efficacious means of treating cerebral aneurysms that are refractory to other therapeutic means. Patients with tandem aneurysms treated with flow diversion have been included in larger, previously reported series; however, there are no dedicated reports on using this technique during a single session to treat this unique subset of patients. Therefore, the authors analyzed the outcomes of patients who had undergone single-session flow diversion for the treatment of tandem aneurysms. METHODS The authors conducted a retrospective review of flow diversion with the Pipeline embolization device (PED) for the treatment of tandem aneurysms in a single session at 2 participating medical centers: University of Utah, Salt Lake City, Utah, and Barrow Neurological Institute, Phoenix, Arizona. Patient demographic data, aneurysm characteristics, treatment strategy and results, complications, and follow-up data were collected from the medical record and analyzed. RESULTS Between January 2011 and December 2015, 17 patients (12 female, 5 male) with a total of 38 aneurysms (mean size 4.7 ± 2.7 mm, mean ± SD) were treated. Sixteen patients had aneurysms in the anterior circulation, and 1 patient had tandem aneurysms in the posterior circulation. Twelve patients underwent only placement of a PED, whereas 5 underwent adjunctive coil embolization of at least 1 aneurysm. One PED was used in each of 9 patients, and 2 PEDs were required in each of 8 patients. There were 2 intraprocedural complications; however, in both instances, the patients were asymptomatic at the last follow-up. The follow-up imaging studies were available for 15 patients at a mean of 7 months after treatment (216 days, range 0-540 days). The mean initial Raymond score after treatment was 2.7 ± 0.7, and the mean final score was 1.3 ± 0.7. CONCLUSIONS In this series, the use of flow diversion for the treatment of tandem cerebral aneurysms had an acceptable safety profile, indicating that it should be considered as an effective therapy for this complicated subset of patients. Further prospective studies must be performed before more definitive conclusions can be made.

Flow Diversion in Ruptured Intracranial Aneurysms: A Meta-Analysis.

Flow diversion is now an established technique to treat unruptured intracranial aneurysms not readily amenable to endovascular coil embolization or open microsurgical occlusion. The role of flow-diverting devices in treating ruptured aneurysms is less clear. To estimate rates of angiographic occlusion and good clinical outcome in patients with ruptured intracranial aneurysms treated with flow-diverting devices. Systematic review of Ovid MEDLINE, PubMed, Cochrane databases, and EMBASE from inception to December 2015 for articles that included ruptured aneurysms treated with flow diversion. One hundred seventy-two records were screened, of which 20 articles contained sufficient patient and outcome data for inclusion. Clinical and radiologic characteristics, procedural details, and outcomes were extracted from these reports. Aggregated occlusion rates and clinical outcomes were analyzed by using the Fisher exact test (statistical significance, α = .05). Complete occlusion of the aneurysm was achieved in 90% of patients, and favorable clinical outcome was attained in 81%. Aneurysm size greater than 7 mm was associated with less favorable clinical outcomes (P = .027). Aneurysm size greater than 2 cm was associated with a greater risk of rerupture after treatment (P < .001). Observational studies and case reports may be affected by reporting bias. Although not recommended as a first-line treatment, the use of flow diverters to treat ruptured intracranial aneurysms may allow high rates of angiographic occlusion and good clinical outcome in carefully selected patients. Aneurysm size contributes to treatment risk because the rerupture rate following treatment is higher for aneurysms larger than 2 cm.

Flow diversion in the treatment of aneurysms: a randomized care trial and registry.

OBJECTIVE The Flow Diversion in the Treatment of Intracranial Aneurysm Trial (FIAT) was designed to guide the clinical use of flow diversion, an innovative method to treat intracranial aneurysms, within a care trial and to study safety and efficacy. METHODS FIAT, conducted in 3 Canadian hospitals, proposed randomized allocation to flow diversion or standard management options (observation, coil embolization, parent vessel occlusion, or clip placement), and a registry of non-randomized patients treated with flow diversion. The primary safety outcome was death or dependency (modified Rankin Scale score > 2) at 3 months, to be determined for all patients who received flow diversion at any time. The primary efficacy outcome was angiographic occlusion at 3-12 months combined with an independent clinical outcome. RESULTS Of 112 participating patients recruited between May 2, 2011, and February 25, 2015, 78 were randomized (39 in each arm), and 34 received flow diversion within the registry. The study was halted due to safety concerns. Twelve (16%) of 75 patients (95% CI 8.9%-26.7%) who were allocated to or received flow diversion at any time were dead (n = 8) or dependent (n = 4) at 3 months or more, crossing a predefined safety boundary. Death or dependency occurred in 5 (13.2%) of 38 patients randomly allocated and treated by flow diversion (95% CI 5.0%-28.9%) and in 5 (12.8%) of 39 patients allocated to standard treatment (95% CI 4.8%-28.2%). Efficacy was below expectations of the trial hypothesis: 16 (42.1%) of 38 patients (95% CI 26.7%-59.1%) randomly allocated to flow diversion failed to reach the primary outcome, as compared with 14 (35.9%) of 39 patients allocated to standard treatment (95% CI 21.7%-52.9%). CONCLUSIONS Flow diversion was not as safe and effective as hypothesized. More randomized trials are needed to determine the role of flow diversion in the management of aneurysms. Clinical trial registration no.: NCT01349582 (clinicaltrials.gov).

Aneurysms with persistent patency after treatment with the Pipeline Embolization Device

The Pipeline Embolization Device (PED) was approved for the treatment of intracranial aneurysms from the petrous to the superior hypophyseal segment of the internal carotid artery. However, since its approval, its use for treatment of intracranial aneurysms in other locations and non-sidewall aneurysms has grown tremendously. The authors report on a cohort of 15 patients with 16 cerebral aneurysms that incorporated an end vessel with no significant distal collaterals, which were treated with the PED. The cohort includes 7 posterior communicating artery aneurysms, 5 ophthalmic artery aneurysms, 1 superior cerebellar artery aneurysm, 1 anterior inferior cerebellar artery aneurysm, and 2 middle cerebral artery aneurysms. None of the aneurysms achieved significant occlusion at the last follow-up evaluation (mean 24 months). Based on these observations, the authors do not recommend the use of flow diverters for the treatment of this subset of cerebral aneurysms.

F.04 Flow diversion in the treatment of aneurysms: A randomized care trial and registry

Background: The Flow diversion in the treatment of Intracranial Aneurysm (FIAT) trial was designed to guide the clinical use of flow diversion. Methods: FIAT proposed randomized allocation flow diversion or standard management (observation, coiling, parent vessel occlusion, or clipping), and a registry of non-randomized patients treated with flow diversion. Primary safety outcome was death or dependency (mRS &gt; 2) at 3 months. Primary efficacy outcome was angiographic occlusion at 3-12 months combined with independent clinical outcome. Results: Of 112 participating patients recruited, 78 were randomized, and 34 received flow diversion within the registry. The study was halted for safety concerns. Twelve of 73 patients (16.4%; CI [9.7% -26.7%]) who were allocated or received flow diversion at any time were dead (n=8) or dependent (n=4) at 3 months or more, crossing a predefined safety boundary. Death or dependency occurred in 5 of 36 patients randomly allocated flow diversion and in 5 of 36 patients allocated standard treatment (13.9%; [6.1%-28.7%]). Efficacy was below hypothesized expectations: 15 of 36 patients (41.7%; [27.1%-57.8%]) randomly allocated flow diversion failed to reach the primary outcome, as compared to 11 of 36 patients allocated standard treatment (30.1%; [18.0%-46.9%]). Conclusions: Flow diversion was not as safe and effective as hypothesized. More randomized trials are needed.

Direct carotid cavernous sinus fistulae: vessel reconstruction using flow-diverting implants

PurposeRetrospective evaluation of our experience with the use of flow diverters (FD) for the endovascular treatment of direct carotid-cavernous sinus fistulae (diCCF).MethodsBetween 2011 and 2015, 14 consecutive patients with 14 diCCF were treated with FD alone or in combination with other implants in a single institution.ResultsA total of 21 sessions were performed in 14 patients. FD placement was technically successful in all cases without an adverse event. Patients were treated with FD alone (n = 5), FD and covered stents (n = 2), FD and coils (n = 7). A total of 59 FD (24 Pipeline Embolization Device, Medtronic; 35 p64 Flow Modulation Device, phenox), 291 coils, and 3 stent grafts were used. Three of 14 diCCF were completely occluded after the 1st session, a minor residual shunt was found in 7/14, and in the remaining 4/14 patients, the shunt volume was reduced significantly. The mean follow-up period encompassed 20 months. Additional treatment included transvenous coil occlusion (n = 3) and/or further FD deployment (n = 5). An asymptomatic internal carotid artery (ICA) occlusion was encountered in 2 patients, related to an interruption of antiaggregation. At the last follow-up, 10/14 patients were free from ocular symptoms (71 %), 2 had residual exophthalmos, and no patient had clinical deterioration.ConclusionThe usage of FD for the treatment of diCCF is straightforward. Injury of the cranial nerves can be avoided. In most cases, ocular symptoms improve. Several FD layers and/or an adjunctive venous coil occlusion are required. Complete occlusion of a diCCF may take weeks or months and long-term antiaggregation is required. In the future, a flexible stent graft might be a better solution.

The Use of Flow Diversion for the Treatment of Intracranial Aneurysms: Expansion of Indications.

Flow diversion is a novel concept for treating anatomically challenging intracranial aneurysms and has gained increasing acceptance. Flow diverter stents, such as the Pipeline Embolization Device (PED) (ev3-Covidien, Irvine, CA, USA), are approved for treating unruptured large and giant aneurysms from the internal carotid artery between the superior hypophyseal and cavernous segments. However, technological advances and recent clinical results suggest that flow diversion can be safely and effectively used in treating ruptured aneurysms, posterior circulation aneurysms, and distal anterior circulation aneurysms. In this brief review, we aim to investigate the recent evidence on the utilization of PEDs in these controversial vascular territories and to discuss whether the indications for flow diversion can be expanded.

Next day discharge after elective intracranial aneurysm coiling: is it safe?

BackgroundThere is a paucity of literature on early discharge after elective aneurysm treatment. We hypothesize that patient discharge on the next day is not associated with an increase in post-discharge...

Flow Diversion versus Standard Endovascular Techniques for the Treatment of Unruptured Carotid-Ophthalmic Aneurysms.

Over the past few years, flow diversion has been increasingly adopted for the treatment of intracranial aneurysms, especially in the paraclinoid and paraophthalmic carotid segment. We compared clinical and angiographic outcomes and complication rates in 2 groups of patients with unruptured carotid-ophthalmic aneurysms treated for 7 years by either standard coil-based techniques or flow diversion. From February 2006 to December 2013, 162 unruptured carotid-ophthalmic aneurysms were treated endovascularly in 138 patients. Sixty-seven aneurysms were treated by coil-based techniques in 61 patients. Flow diverters were deployed in 95 unruptured aneurysms (77 patients), with additional coiling in 27 patients. Complication rates, clinical outcome, and immediate and long-term angiographic results were retrospectively analyzed. No procedure-related deaths occurred. Four procedure-related thromboembolic events (6.6%) leading to permanent morbidity in 1 case (1.6%) occurred in the coiling group. Neurologic complications were observed in 6 patients (7.8%) in the flow-diversion group, resulting in 3.9% permanent morbidity. No statistically significant difference was found between complication (P = .9) and morbidity rates (P = .6). In the coiling group (median follow-up, 31.5 ± 24.5 months), recanalization occurred at 1 year in 23/50 (54%) aneurysms and 27/55 aneurysms (50.9%) at the latest follow-up, leading to retreatment in 6 patients (9%). In the flow-diversion group (mean follow-up, 13.5 ± 10.8 months), 85.3% (35/41) of all aneurysms were occluded after 12 months, and 74.6% (50/67) on latest follow-up. The retreatment rate was 2.1%. Occlusion rates between the 2 groups differed significantly at 12 months (P < .001) and at the latest follow-up (P < .005). Our retrospective analysis shows better long-term occlusion of carotid-ophthalmic aneurysms after use of flow diverters compared with standard coil-based techniques, without significant differences in permanent morbidity.

Fate of the Ophthalmic Artery After Treatment With the Pipeline Embolization Device.

Flow diverters have emerged as a major tool in the treatment of cerebral aneurysms. A crucial issue with the use of flow diverters is the patency of side branches covered by the device, most importantly the ophthalmic artery (OA). To assess the patency of the OA after coverage with the pipeline embolization device (PED). All patients who had a PED covering the OA and in whom angiographic follow-up was available were included in the study. The patency of the OA at follow-up was systematically evaluated by 2 authors who were not involved in the procedure. Of 95 treated patients, the OA was covered by 1 PED in 81 patients (85%) and by 2 PEDs in 14 patients (15%). Mean angiographic follow-up was 7.5 months, ranging from 3 to 24 months. At the latest follow-up, the OA remained patent in 85 patients (89%), showed diminished flow in 4 patients (4%), and was occluded in 6 patients (7%). Only 1 patient had clinical symptoms related to OA occlusion. In multivariable analysis, larger aneurysm size predicted OA occlusion (P = .04). There was also a strong trend for younger age (P = .06) and coverage by more than 1 device (P = .07). Treatment of internal carotid artery aneurysms with the PED preserves the patency of the OA in most cases. The occlusion of the OA in the few cases where it occurs is usually a clinically irrelevant event. Minimizing the number of PEDs across the OA is crucial to preserve its patency.

Abstract 107: Flow-Diversion for Ophthalmic Segment Aneurysms. Clinical/Angiographic Outcomes and the Fate of the Ophthalmic Artery

Introduction: Flow diverters have emerged as an important tool in the management of intracranial aneurysms. This study aims to assess the visual outcomes, the obliteration rate and the need for retreatment of ophthalmic segment aneurysms (OSA) treated by the pipeline embolization device (PED). The study also systematically assesses a crucial issue with the use of flow diverters namely the patency of the ophthalmic artery (OA). Methods: Forty-one patients harboring 44 OSA treated by flow-diversion and 95 patients with internal carotid artery (ICA) aneurysms who had one or more PEDs covering the OA and in whom angiographic follow-up was available were identified. Complication rates, the need for re-treatment, aneurysm occlusion rates, the evolution of visual symptoms, and the evolution of headache/retro-orbital pain were registered. The patency of the OA at follow-up was systematically evaluated by two investigators. Results: The technical success rate was 100% for OSA. The complication rate was 2.27% and the mortality rate was 0%. At final angiographic follow-up, 77.27% of patients with OSA had complete occlusion, 6.81% had near-complete occlusion, and 15.90% had incomplete occlusion. Of symptomatic OSA, complete resolution or significant improvement was noted in 72.72%, while worsening of symptoms occurred in 4.54%. Also, 22% of patients had no significant changes in their symptoms. Of 95 patients with ICA aneurysms, the OA was covered by 1 PED in 81 patients (85%) and by 2 PEDs in 14 patients (15%). Mean angiographic follow-up time was 7.5 months. At the latest follow-up, the OA remained patient in 85 patients (89%), showed diminished flow in 4 patients (4%), and was occluded in 6 patients (7%). Only one patient (1%) had clinical symptoms related to OA occlusion. In multivariable analysis, younger age, larger aneurysm size and coverage by more than 1 device predicted OA occlusion. Conclusion: Flow-diversion appears to be an appealing option for OSA. The PED also preserves the patency of the OA in most cases. The occlusion of the OA in the few cases where it occurs is usually a clinically irrelevant event. Minimizing the number of PEDs across the OA is a crucial factor to preserve its patency.

Flow-diversion for ophthalmic segment aneurysms.

The use of flow-diversion to treat ophthalmic segment aneurysms (OSA) has not been well evaluated. To assess the visual outcomes, the obliteration rate, and the need for retreatment of OSA treated by the pipeline embolization device (PED). Patients who underwent treatment with PED for OSA from 2009 to 2014 were selected and retrospectively reviewed. Patient's age, sex, mode of presentation, and aneurysm size were recorded. The complication rates, the need for retreatment (due to recurrence of the aneurysm or worsening symptoms), the aneurysm occlusion rates, the evolution of visual symptoms, and the evolution of headache/retro-orbital pain were registered. Forty-one patients harboring 44 OSA treated by flow-diversion were identified. Females constituted 87.80% (37/41) of the cohort. The mean age was 59.16 ± 12.54 years. At final angiographic follow-up, 77.27% (34/44) had complete occlusion, 6.81% (3/44) had near-complete occlusion, and 15.90% (7/44) had incomplete occlusion. Of the 22 symptomatic OSA, complete resolution or significant improvement was noted in 72.72% (16/22), while worsening of symptoms occurred in 4.54% (1/22). Five patients out of 22 (22.72%; 5/22) had no significant changes in their symptoms. The complication rate was 2.27% (1/44). The mortality rate was 0%. The low complication rate, the high obliteration rate, and the high rate of improvement in the visual symptoms make flow-diversion an appealing option for the treatment of OSA.

Persistent aneurysm growth following pipeline embolization device assisted coiling of a fusiform vertebral artery aneurysm: a word of caution!

The complex morphology of vertebrobasilar fusiform aneurysms makes them one of the most challenging lesions treated by neurointerventionists. Different management strategies in the past included parent vessel occlusion with or without extra-intracranial bypass surgery and endovascular reconstruction by conventional stents. Use of flow diversion has emerged as a promising alternative option with various studies documenting its efficacy and safety. However, there are various caveats associated with use of flow diversion in patients with fusiform vertibrobasilar aneurysms especially in patients presenting with acute subarachnoid hemorrhage (SAH). We report a rare case of persistent aneurysmal growth after coiling and placement of the Pipeline Embolization Device (PED; ev3, Irvine, California, USA) for SAH from a fusiform vertebral artery aneurysm. As consequences of aneurysm rupture can be devastating especially in patients with a prior SAH, the clinical relevance of recognizing and understanding such patterns of failure cannot be overemphasized as highlighted in the present case.

P-002 The Financial Impact of Flow Diverters on The Endovascular Treatment of Cerebral Aneurysms

IntroductionIf flow-diverters are to become the preferred mode of treating aneurysms then other than their efficacy, an analysis of their financial impact against coiling is warranted.MethodologyAn IRB approved retrospective analysis...

E-042 Use of Flow Diverters in Vessels less than 2.5 mm during Intracranial Aneurysm Treatment

Introduction/purposePipeline Embolization Device (PED) is currently indicated for treatment of large and complex intracranial aneurysms centerd along the cavernous/intradural segment of the internal carotid artery (ICA) proximal to the Posterior...

Primary endovascular treatment of post-irradiated carotid pseudoaneurysm at the skull base with the Pipeline embolization device

BackgroundA post-irradiated carotid pseudoaneurysm at the skull base can cause life-threatening blowout syndrome. Conventional treatments include parent vessel occlusion, endovascular coiling or covered stenting. Use of the Pipeline embolization device...

Delayed ipsilateral parenchymal hemorrhage following treatment of intracranial aneurysms with flow diverter

The use of flow diverters (FDs) has shown promising results, particularly in the treatment of large or complex intracranial aneurysms. However, some complications can occur both during and after FD treatment, including delayed ipsilateral parenchymal hemorrhage (DIPH). The clinical presentation, etiopathogeny, and management of this complication are not well understood. We report a series of four patients with DIPH and discuss the potential mechanisms and modalities of treatment. Four patients treated with FDs and presenting with DIPH were diagnosed in two different centers. Clinical and imaging data were reviewed before and after the procedure. Characteristics of the intraparenchymal hematomas, the modalities of treatment, and clinical course were analyzed. Intraparenchymal hemorrhage occurred 1 to 4 days after aneurysm treatment with FDs. All hemorrhages were situated in the ipsilateral hemisphere and were anatomically remote from the treated aneurysm. The four patients were treated with emergency surgery (hematoma evacuation). All patients had a favorable clinical outcome (mRS = 1) at midterm evaluation. Follow-up imaging showed good permeability of the FD in all subjects and complete aneurysm occlusion in all patients. From the literature review, DIPH appears to be more frequent than delayed aneurysm rupture and may be a cause of increasing concern for the use of flow diverters. However, the mechanisms of DIPH are not completely understood. Surgical evacuation of the hematoma seems to be feasible with acceptable safety and good clinical outcomes.

E-029 Flow Diverter Treatment of a Ruptured Anterior Cerebral Artery Blister Aneurysm

Introduction“Blister” type aneurysms (BA) are rare, atypical vascular lesions with fragile wall, broad base, difficult visualisation on imaging and high risk of rupture. Endovascular treatment of these aneurysms remains very...