Pipeline Embolization Device for Recurrent Cerebral Aneurysms after Microsurgical Clipping

Comparative Efficacy of Flow Diverter Devices in the Treatment of Carotid Sidewall Intracranial Aneurysms: a Retrospective, Multicenter Study

BACKGROUND

The comparative efficacy and safety of first-generation flow diverters (FDs), Pipeline Embolization Device (PED) (Medtronic, Irvine, California), Silk (Balt Extrusion, Montmorency, France), Flow Re-direction Endoluminal Device (FRED) (Microvention, Tustin, California), and Surpass Streamline (Stryker Neurovascular, Fremont, California), is not directly established and largely inferred.

PURPOSE

This study aimed to compare the efficacy of different FDs in treating sidewall ICA intracranial aneurysms.

METHODS

We conducted a retrospective review of prospectively maintained databases from eighteen academic institutions from 2009-2016, comprising 444 patients treated with one of four devices for sidewall ICA aneurysms. Data on demographics, aneurysm characteristics, treatment outcomes, and complications were analyzed. Angiographic and clinical outcomes were assessed using various imaging modalities and modified Rankin Scale (mRS). Propensity score weighting was employed to balance confounding variables. The data analysis used Kaplan-Meier curves, logistic regression, and Cox proportional-hazards regression.

RESULTS

While there were no significant differences in retreatment rates, functional outcomes (mRS 0-1), and thromboembolic complications between the four devices, the probability of achieving adequate occlusion at the last follow-up was highest in Surpass device (HR: 4.59; CI: 2.75-7.66, p < 0.001), followed by FRED (HR: 2.23; CI: 1.44-3.46, p < 0.001), PED (HR: 1.72; CI: 1.10-2.70, p = 0.018), and Silk (HR: 1.0 ref. standard). The only hemorrhagic complications were with Surpass (1%).

CONCLUSION

All the first-generation devices achieved good clinical outcomes and retreatment rates in treating ICA sidewall aneurysms. Prospective studies are needed to explore the nuanced differences between these devices in the long term.

Open Microsurgical Cerebral Aneurysm Treatment After Failed Endovascular Therapy: An Evaluation of Aneurysm Treatment Frequencies in All Neurovascular Centers Across Austria and the Czech Republic Over 20 Years

BACKGROUND AND OBJECTIVES

Endovascular treatment of cerebral aneurysms has tremendously advanced over the past decades. Nevertheless, aneurysm residual and recurrence remain challenges after embolization. The objective of this study was to elucidate the portion of embolized aneurysms requiring open surgery and evaluate whether newer endovascular treatments have changed the need for open surgery after failed embolization.

METHODS

All 15 cerebrovascular centers in Austria and the Czech Republic provided overall aneurysm treatment frequency data and retrospectively reviewed consecutive cerebral aneurysms treated with open surgical treatment after failure of embolization from 2000 to 2022. All endovascular modalities were included.

RESULTS

On average, 1362 aneurysms were treated annually in the 2 countries. The incidence increased from 0.006% in 2005 to 0.008% in 2020 in the overall population. Open surgery after failed endovascular intervention was necessary in 128 aneurysms (0.8%), a proportion that remained constant over time. Subarachnoid hemorrhage was the initial presentation in 70.3% of aneurysms. The most common location was the anterior communicating artery region (40.6%), followed by the middle cerebral artery (25.0%). The median diameter was 6 mm (2-32). Initial endovascular treatment included coiling (107 aneurysms), balloon-assist (10), stent-assist (4), intrasaccular device (3), flow diversion (2), and others (2). Complete occlusion after initial embolization was recorded in 40.6%. Seventy-one percent of aneurysms were operated within 3 years after embolization. In 7%, the indication for surgery was (re-)rupture and, in 88.3%, reperfusion. Device removal was performed in 16.4%. Symptomatic intraoperative and postoperative complications occurred in 10.2%. Complete aneurysm occlusion after open surgery was achieved in 94%.

CONCLUSION

Open surgery remains a rare indication for cerebral aneurysms after failed endovascular embolization even in the age of novel endovascular technology, such as flow diverters and intrasaccular devices. Regardless, it is mostly performed for ruptured aneurysms initially treated with primary coiling that are in the anterior circulation.

Flow Diversion as a Definitive Treatment for Recurrently Ruptured A1-A2 Anterior Cerebral Artery Aneurysm Following Clipping and Coiling

Even after clipping of intracranial aneurysms, patients may experience incomplete occlusion or the future recurrence of their treated aneurysm. This paper presents a distinctive case of a recurrent A1-A2 anterior cerebral artery aneurysm that underwent four interventions over 16 years. The aneurysm was treated with two clippings, subsequent coiling, and flow diversion for definitive treatment. The challenges encountered in managing bifurcation aneurysms are discussed, emphasizing the importance of considering hemodynamic factors, vessel geometry, and recurrence risk factors in treatment decisions. The case highlights the need for closer follow-up of ruptured bifurcation aneurysms due to the higher likelihood of recurrence. The role of flow diverters in reinforcing vessel anatomy and preventing recurrence is also highlighted.

Flow diverter retreatment for intracranial aneurysms: A meta-analysis of efficacy and feasibility

BACKGROUND

Recurrent intracranial aneurysm carries a risk of rupture and retreatment is often necessary. However, there is no consensus on the best retreatment modality of choice. Flow diverter has emerged as a promising option for this population in recent years. Given its high cost, patient selection to optimize outcomes is very important.

PURPOSE

To identify patient factors predisposing to failure of flow diverter retreatment.

METHOD

We conducted a systematic search on PubMed, Cochrane Library, Embase, Ovid/Medline, and ClinicalTrial.gov from 2000 to 2021. Studies regarding flow diverter retreatment of recurrent aneurysms were analyzed if they meet the inclusion criteria.

RESULTS

A total of twenty-six studies were identified. Among 374 patients retreated with flow diverters, about 0.86 [0.81; 0.92] were successfully occluded and only 0.06 [0.02; 0.10] had unfavorable neurological outcomes. Major complications included intracranial hemorrhage (n = 7), ischemic stroke or thromboembolic event (n = 12), and death (n = 2). In-stent stenosis was reported in 10 of the cases. Saccular aneurysms are associated with a higher occlusion rate while aneurysm location, size, status, and prior treatment modality have no significant impact on retreatment efficacy.

CONCLUSIONS

We demonstrated that flow diverter is an effective retreatment strategy except in patients with non-saccular aneurysms. It should be considered as a first-line option for patients with recurrent intracranial aneurysm.

Endovascular Management of Hemorrhagic Stroke

Significant advances in endovascular neurosurgery tools, devices, and techniques are changing the approach to the management of acute hemorrhagic stroke. The endovascular treatment of intracranial aneurysms emerged in the early 1990s with Guglielmi detachable coils, and since then, it gained rapid popularity that surpassed open surgery. Stent-assisted coiling and balloon remodeling techniques have made the treatment of wide-necked aneurysms more durable. With the introduction of flow diverters and flow disrupters, many aneurysms with complex geometrics can now be reliably managed. Arteriovenous malformations and fistulae can also benefit from endovascular therapy by embolization using n-butyl cyanoacrylate (NBCA), Onyx, polyvinyl alcohol (PVA), and coils. In this article, we describe the role of endovascular treatment for the most common causes of intracerebral and subarachnoid hemorrhages, particularly ruptured aneurysms and vascular malformations.

Flared non-flow diverting ends of the FRED flow diverter for cerebral aneurysms facilitate device anchoring at the arterial bifurcation

INTRODUCTION

The Flow Redirection Intraluminal Device (FRED) flow diverter has a unique bilayer design, with the outer scaffolding stent extending beyond the inner flow diverting component by about 3 mm at each end. Here, we describe a technique to utilize these unrestrained flared ends for precise flow diverter placement in cases where the aneurysm and an adjacent branch are in close proximity and branch jailing is not desired, such as in posterior communicating artery aneurysms.Technical note: The distal end of the FRED device is pushed out of the microcatheter at the carotid terminus. Once the distal flared ends are fully open and well situated in the terminus, ideally with at least one of the limbs in the A1 segment of the anterior cerebral artery, the device is unsheathed under gentle forward pressure. This technique stabilizes the device at the distal landing zone and prevents unintended foreshortening at the distal end. This is particularly important for aneurysms located adjacent to the carotid terminus in order to assure adequate neck coverage, as well as avoiding jailing one of the branching parent arteries. An illustrative case is provided.

CONCLUSIONS

The non-flow diverting unrestrained flared ends of the FRED stabilize the distal end of the device when deployed directly into the branches at the arterial bifurcation. The technique is useful to provide adequate neck coverage of cerebral aneurysm located directly adjacent to the bifurcation as is frequently the case with posterior communicating artery aneurysms.

Intracranial post-clipping residual or recurrent aneurysms: Current status and treatment options (Review)

Following the clipping of intracranial aneurysms, post-clipping residual or recurrent aneurysms (PCRRAs) can occur. In recent years, the incidence of PCRRAs has increased due to a prolonged follow-up period and advanced imaging techniques. However, several aspects of intracranial PCRRAs remain unclear. Therefore, the present study performed an in-depth review of the literature on PCRRAs. Herein, a summary of PCRRAs that can be divided into the following two categories is presented: i) Those occurring after the incomplete clipping of an aneurysm, where the residual aneurysm regrows into a PCRRA; and ii) those occurring after the complete clipping of an aneurysm, in which a de novo aneurysm occurs at the original aneurysm site. Currently, digital subtracted angiography remains the gold standard for the imaging diagnosis of PCRRAs as it can eliminate metallic clip artifacts. Intracranial symptomatic PCRRAs should be actively treated, particularly those that have ruptured. A number of methods are currently available for the treatment of intracranial PCRRAs; these mainly include re-clipping, endovascular treatment (EVT) and bypass surgery. Currently, re-clipping remains the most effective method used to treat PCRRAs; however, it is a very difficult procedure to perform. EVT can also be used to treat intracranial PCRRAs. EVT methods include coiling (stent- or balloon-assisted) and flow-diverting stents (or coiling-assisted). Bypass surgery can be selected for difficult-to-treat, complex PCRRAs. On the whole, following appropriate treatment, the majority of intracranial PCRRAs achieve a high occlusion rate and a good prognosis.

Expanding Indications for Flow Diverters: Distal Aneurysms, Bifurcation Aneurysms, Small Aneurysms, Previously Coiled Aneurysms and Clipped Aneurysms, and Carotid Cavernous Fistulas

Flow diverter devices have gained wide acceptance for the treatment of unruptured intracranial aneurysms. Most studies are based on the treatment of large aneurysms harboring on the carotid syphon. However, during the last years the “off-label” use of these stents has widely grown up even if not supported by randomized studies. This review examines the relevant literature concerning “off-label” indications for flow diverter devices, such as for distal aneurysms, bifurcation aneurysms, small aneurysms, recurrent aneurysms, and direct carotid cavernous fistulas.

Poor Results of Flow Diversion as Salvage Treatment for Intracranial Aneurysm Rerupture After Surgical Clip Reconstruction

Rebleeding episodes after a ruptured intracranial aneurysm has been secured are considered a significant source of patient morbidity and mortality. Theoretically, acute treatment with a flow-diversion device may offer a reasonable treatment option to prevent future bleeding and to remodel the diseased vessel segment. The authors identified two patients who underwent emergent treatment with the placement of a Pipeline Embolization Device (PED) in the setting of an acute rebleeding of a ruptured intracranial aneurysm previously treated with clip reconstruction. The first patient was a 50-year-old woman who underwent clip reconstruction for a broad-based right anterior choroidal artery aneurysm measuring approximately 2×8 mm. Clip reconstruction was achieved with a single fenestrated clip. On day 14, the patient experienced a rebleeding episode. She underwent emergent treatment with a single PED but experienced another rebleeding and died. The second patient was a 53-year-old woman who presented with a ruptured dorsal variant blister aneurysm, which was treated with clip reconstruction. On day 22, she experienced a rebleeding episode and underwent emergent treatment using two PEDs in a duplicative fashion. After the procedure, she experienced another acute rebleeding episode and died. The treatment of reruptured intracranial aneurysms in a salvage fashion with emergent placement of PEDs in two patients resulted in good technical placement of the device covering the neck of the aneurysm, yet both patients experienced additional rebleeding and did not survive. Future generations of flow diverters may have more appropriate properties that would allow their use as salvage treatment in the setting of acutely ruptured aneurysms.

Pipeline for Distal Cerebral Circulation Aneurysms

BACKGROUND

Pipeline embolization device (PED; Medtronic, Dublin, Ireland) utilization is not limited to the treatment of giant wide-necked aneurysms. It has been expanded to handle small blisters, fusiforms, and dissecting intracranial aneurysms.

OBJECTIVE

To report the use of the PED in various off-label distal cerebral circulation (DCC) arteries with a follow-up to assess clinical outcomes.

METHODS

Between 2011 and 2016, of 437 consecutive patients, 23 patients with aneurysms located in DCCs were treated with PED. Data on patient presentation, aneurysm characteristics, procedural outcomes, postoperative course, and aneurysm occlusion were gathered. To control confounding, we used multivariable logistic regression and propensity score conditioning.

RESULTS

A total of 437 patients (mean age 52.12 years; 62 women [14.2%]) underwent treatment with PED in our institution. Twenty-three of 437 (5.2%) received a pipeline in a distal artery: 11/23 middle cerebral artery, 6/23 posterior cerebral artery, 3/23 anterior cerebral artery (A1/A2, pericallosal artery), and 3/23 posterior inferior cerebellar artery. Twenty percent of the aneurysms were treated in the past, 10% had previously ruptured, and 5.9% ruptured at presentation to our hospital. The mean aneurysm size was 9.0 ± 6 mm. The mean follow-up was 12 mo (SD = 12.5). In multivariable logistic regression, no associations were found between PED deployment in DCCs and aneurysm occlusion or thromboembolic complications. PED use in DCC was associated with a good clinical outcome. Twenty-two people of 23 (95%) had a good clinical outcome in the latest follow-up.

CONCLUSION

Treatment of DCC aneurysms with PED is technically challenging mainly because of the small caliber and tortuosity of the parent arteries. The results of this study further support the safety of flow diverters in the treatment of various distal aneurysms.

Flow-diverter stents in the endovascular treatment of remnants in previously clipped ruptured aneurysms: a feasibility study

BACKGROUND

The rate of intracranial aneurysm remnants/recurrences after microsurgical clipping varies widely. The optimal management for these patients remains a matter of debate. Repeat surgery in particular bears a high risk of periprocedural complications due to anatomical distortion from prior procedures. This study aims to evaluate the risk-benefit profile of flow-diverter stents in these patients.

METHODS

The patient database of our neurovascular centre was queried to identify patients with clipped aneurysms who subsequently underwent endovascular treatment with intraluminal flow-diverter stents. The outcome analysis consisted of an assessment of clinical parameters (modified Rankin scale) and the post-interventional angiographic occlusion status (according to the Raymond-Roy occlusion classification).

RESULTS

Six patients underwent endovascular treatment with flow-diverter stents of recurrent aneurysms after clipping. Treatment was necessary in two patients due to progressive neurological deficits, and due to angiographic proof of an increasing aneurysm size in the other four patients. Median aneurysm size was 0.45 cm. All patients had a prior history of subarachnoid haemorrhage. The time from primary clipping to recurrence was 10.6 years. Complete radiological aneurysm occlusion was feasible in five out of six cases. Two patients who had experienced pre-interventional neurological deficits showed a complete remission of symptoms on last follow-up. No periprocedural morbidity or mortality was recorded and no patient required retreatment within the median follow-up.

CONCLUSION

This case series suggests that endovascular treatment with flow-diverter stents of aneurysm remnants after previous microsurgical clipping is a feasible treatment concept with a low-risk profile, which might prevent the treatment burden and risks of repeat surgery.

Reconsiderations on the use of pipeline embolization device in the treatment of intracerebral aneurysms with special angioarchitecture: fetal PCA, AVM, V-B junction and DAVF

Background

Pipeline embolization device (PED) has proved its safety and efficacy in the treatment of intracranial large and giant side-wall aneurysms. With the accumulation of treatment experience, it is an inevitable trend to expand its off-label use on aneurysms. Whether flow diversion is safe and efficient in cases with special angioarchitecture has rarely been explored.

Methods

We performed a retrospective analysis of 210 consecutive patients treated by PED for intracerebral aneurysms in our center. Except for aneurysm, those patients also presented with special angioarchitecture: Fetal PCA, AVM, V-B junction and DAVF.

Results

Nine patients were qualified for the study. 1 was with fetal PCA, the aneurysm remained patent on 4-month follow-up. 2 with ipsilateral AVMs, one patient died due to brain hemorrhage 20 days after the operation, the other one was only partially embolised on 6 month follow up. 3 aneurysms located at V-B junction, angiographic follow up on 3 months demonstrated no complete occlusion of both the aneurysms, the other patients were still on follow up. All of the 3 cases with concomitant DAVF are completely occluded during short to midterm follow up.

Conclusions

PED for aneurysms incorporated the fetal PCA and V-B junction might meet a high propensity for incomplete occlusion during short term follow up. Aneurysm with ipsilateral AVM is not suitable for PED treatment due to the risk of hemorrhage and incomplete occlusion during midterm follow up. For aneurysm with concurrent DAVF, PED treatment is safe and efficient relatively in one session or by staged operation.

Predictors of Incomplete Occlusion following Pipeline Embolization of Intracranial Aneurysms: Is It Less Effective in Older Patients?

BACKGROUND AND PURPOSE

Flow diversion with the Pipeline Embolization Device (PED) for the treatment of intracranial aneurysms is associated with a high rate of aneurysm occlusion. However, clinical and radiographic predictors of incomplete aneurysm occlusion are poorly defined. In this study, predictors of incomplete occlusion at last angiographic follow-up after PED treatment were assessed.

MATERIALS AND METHODS

A retrospective analysis of consecutive aneurysms treated with the PED between 2009 and 2016, at 3 academic institutions in the United States, was performed. Cases with angiographic follow-up were selected to evaluate factors predictive of incomplete aneurysm occlusion at last follow-up.

RESULTS

We identified 465 aneurysms treated with the PED; 380 (81.7%) aneurysms (329 procedures; median age, 58 years; female/male ratio, 4.8:1) had angiographic follow-up, and were included. Complete occlusion (100%) was achieved in 78.2% of aneurysms. Near-complete (90%-99%) and partial (<90%) occlusion were collectively achieved in 21.8% of aneurysms and defined as incomplete occlusion. Of aneurysms followed for at least 12 months (211 of 380), complete occlusion was achieved in 83.9%. Older age (older than 70 years), nonsmoking status, aneurysm location within the posterior communicating artery or posterior circulation, greater aneurysm maximal diameter (≥21 mm), and shorter follow-up time (<12 months) were significantly associated with incomplete aneurysm occlusion at last angiographic follow-up on univariable analysis. However, on multivariable logistic regression, only age, smoking status, and duration of follow-up were independently associated with occlusion status.

CONCLUSIONS

Complete occlusion following PED treatment of intracranial aneurysms can be influenced by several factors related to the patient, aneurysm, and treatment. Of these factors, older age (older than 70 years) and nonsmoking status were independent predictors of incomplete occlusion. While the physiologic explanation for these findings remains unknown, identification of factors predictive of incomplete aneurysm occlusion following PED placement can assist in patient selection and counseling and might provide insight into the biologic factors affecting endothelialization.

Treatment of Tandem Internal Carotid Artery Aneurysms Using a Single Pipeline Embolization Device: Evaluation of Safety and Efficacy

BACKGROUND AND PURPOSE

Tandem aneurysms are defined as multiple aneurysms located in close proximity on the same parent vessel. Endovascular treatment of these aneurysms has rarely been reported. Our aim was to evaluate the safety and efficacy of a single Pipeline Embolization Device for the treatment of tandem aneurysms of the internal carotid artery.

MATERIALS AND METHODS

A retrospective analysis of consecutive aneurysms treated with the Pipeline Embolization Device between 2009 and 2016 at 3 institutions in the United States was performed. Cases included aneurysms of the ICA treated with a single Pipeline Embolization Device, and they were divided into tandem versus solitary. Angiographic and clinical outcomes were compared.

RESULTS

The solitary group (median age, 58 years) underwent 184 Pipeline Embolization Device procedures for 184 aneurysms. The tandem group (median age, 50.5 years) underwent 34 procedures for 78 aneurysms. Aneurysms were primarily located along the paraophthalmic segment of the ICA in both the single and tandem groups (72.3% versus 78.2%, respectively, P = .53). The median maximal diameters in the solitary and tandem groups were 6.2 and 6.7 mm, respectively. Complete occlusion on the last angiographic follow-up was achieved in 75.1% of aneurysms in the single compared with 88.6%% in the tandem group (P = .06). Symptomatic thromboembolic complications were encountered in 2.7% and 8.8% of procedures in the single and tandem groups, respectively (P = .08).

CONCLUSIONS

Tandem aneurysms of the ICA can be treated with a single Pipeline Embolization Device with high rates of complete occlusion. While there appeared to be a trend toward higher thromboembolic complication rates, this did not reach statistical significance.

Pipeline Embolization Device in Treatment of 50 Unruptured Large and Giant Aneurysms

INTRODUCTION

Treatment of large (≥20 mm) and giant (≥25 mm) intracranial aneurysms is challenging and can be associated with a high rate of morbidity and mortality. The Pipeline Embolization Device (PED) has been used effectively for the treatment of intracranial aneurysms achieving a high rate of complete occlusion. However, its safety and efficacy in treatment of large and giant aneurysms has not been evaluated fully.

METHODS

A retrospective analysis of consecutive aneurysms treated with PED between 2009 and 2016 at 3 academic institutions within the United States was performed. Large (≥20 mm) and giant aneurysms (≥25 mm) were selected for evaluation of occlusion and complication rates following treatment with PED.

RESULTS

A total of 50 large and giant aneurysms were individually treated using PED. Aneurysms were fusiform (74%) or saccular (26%) in morphology. PED alone was used for treating 78% of the aneurysms, whereas PED with adjunctive coiling was used for treating 22%. The median length of angiographic follow-up was 13 months (mean follow up 20.4 months). At last follow-up, complete or near-complete occlusion (90-100%) was achieved in 76.9% of aneurysms. Symptomatic thromboembolic complications were encountered in 12% of procedures and symptomatic hemorrhagic complications in 8%.

CONCLUSIONS

The use of PED for the treatment of large and giant intracranial aneurysms is associated with good occlusion rates, but also a greater complication rate compared to aneurysms of smaller size. There was no significant difference in occlusion rate based on aneurysm shape or size, number of PEDs placed, or adjunctive coiling.

Pipeline embolization device for recurrence of previously treated aneurysms

OBJECTIVE

The utilization of the Pipeline embolization device (PED) has increased significantly since its inception and original approval for use in large, broad-necked aneurysms of the internal carotid artery. While microsurgical clipping and advances in endovascular techniques have improved overall efficacy in achieving complete occlusion, recurrences still occur, and the best modality for retreatment remains controversial. Despite its efficacy in this setting, the role of PED utilization in the setting of recurrent aneurysms has not yet been well defined. This study was designed to assess the safety and efficacy of PED in the recurrence of previously treated aneurysms.

METHODS

The authors reviewed a total of 13 cases in which patients underwent secondary placement of a PED for aneurysm recurrence following prior treatment with another modality. The PEDs were used to treat aneurysm recurrence or residual following endovascular coiling in 7 cases, flow diversion in 2, and microsurgical clipping in 4. The mean time between initial treatment and retreatment with a PED was 28.1 months, 12 months, and 88.7 months, respectively. Clinical outcomes, including complications and modified Rankin Scale (mRS) scores, and angiographic evidence of complete occlusion were tabulated for each treatment group.

RESULTS

All PEDs were successfully placed without periprocedural complications. The rate of complete occlusion was 80% at 6 months after PED placement and 100% at 12 months in these patients who underwent PED placement following failed endovascular coiling; there were no adverse clinical sequelae at a mean follow-up of 26.1 months. In the 2 cases in which PEDs were placed for treatment of residual aneurysms following prior flow diversion, 1 patient demonstrated asymptomatic vessel occlusion at 6 months, and the other exhibited complete aneurysm occlusion at 12 months. In patients with aneurysm recurrence following prior microsurgical clipping, the rate of complete occlusion was 100% at 6 and 12 months, with no adverse sequelae noted at a mean clinical follow-up of 27.7 months.

CONCLUSIONS

The treatment of recurrent aneurysms with the PED following previous endovascular coiling, flow diversion, or microsurgical clipping is associated with a high rate of complete occlusion and minimal morbidity.

Use of the Pipeline embolization device for recurrent and residual cerebral aneurysms: a safety and efficacy analysis with short-term follow-up

OBJECTIVE

Evaluation of the safety and efficacy of the Pipeline embolization device (PED) when used as second-line treatment for recurrent or residual, pretreated ruptured and unruptured intracranial aneurysms (IAs).

METHODS

Retrospective review of our database to include all patients who were treated with a PED for recurrent or residual IAs following surgical clipping or coiling. We evaluated neurological outcome and angiograms at discharge, 6- and 12-months' follow-up and assessed intimal hyperplasia at follow-up.

RESULTS

Twenty-four patients met our inclusion criteria. Most IAs were located in the anterior circulation (n=21). No change of preprocedure modified Rankin Scale score was seen at discharge or at any scheduled follow-up. Complete or near-complete aneurysm occlusion on 6- and 12-month angiograms was seen in 94.4% (17/18 cases) and 93.3% (14/15 cases), respectively. Complete or near-complete occlusion was seen in 100% of previously ruptured and 85.7% (6/7 cases) and 83.3% (5/6 cases) of previously unruptured cases at the 6- and 12-months' follow-up, respectively. One case of moderate intimal hyperplasia was observed at 6 months and decreased to mild at the 12-months' follow-up. No difference in device performance was observed among pretreated unruptured or ruptured IAs.

CONCLUSIONS

Treatment of recurrent or residual IAs with a PED after previous coiling or clipping is feasible and safe. There is no difference in device performance between ruptured or unruptured IAs.

A technical consideration when using flow diversion for recurrent aneurysms following stent-assisted coiling

Flow diversion (FD) is a treatment option for recurrent aneurysms including following stent-assisted coiling (SAC), although this approach is both 'off-label' and unproven. A technical challenge of FD placement may involve the microwire catching on the tines of the previously placed stent or potentially going 'in-out-in' from the central axis of the stent. We report a case and technique that assures the wire has safely remained within the central axis of the stent. The procedure was performed in standard fashion except that the intermediate catheter was passed completely through the previously placed stent after the microwire/microcatheter had crossed. The large diameter of the intermediate catheter assured that the microwire did not go 'in-out-in'. The intermediate catheter was completely withdrawn from the stent and the FD was placed in standard fashion. This technique may help to achieve complete FD opening and prevent thromboembolic complications associated with incomplete FD opening.

A technical consideration when using flow diversion for recurrent aneurysms following stent-assisted coiling

Flow diversion (FD) is a treatment option for recurrent aneurysms including following stent-assisted coiling (SAC), although this approach is both 'off-label' and unproven. A technical challenge of FD placement may involve the microwire catching on the tines of the previously placed stent or potentially going 'in-out-in' from the central axis of the stent. We report a case and technique that assures the wire has safely remained within the central axis of the stent. The procedure was performed in standard fashion except that the intermediate catheter was passed completely through the previously placed stent after the microwire/microcatheter had crossed. The large diameter of the intermediate catheter assured that the microwire did not go 'in-out-in'. The intermediate catheter was completely withdrawn from the stent and the FD was placed in standard fashion. This technique may help to achieve complete FD opening and prevent thromboembolic complications associated with incomplete FD opening.