Republished: Novel balloon application for rescue and realignment of a proximal end migrated pipeline flex embolization device into the aneurysmal sac: complication management

Spontaneous delayed migration or shortening after pipeline embolization device treatment of intracranial aneurysm: incidence, management, and risk factors

BACKGROUND

Studies reporting spontaneous delayed migration or shortening (SDMS) after treatment with the Pipeline Embolization Device (PED) are limited. This study aimed to evaluate the incidence of SDMS after PED treatment, propose management strategies, and identify the risk factors contributing to its occurrence.

METHODS

We retrospectively reviewed consecutive patients with an intracranial aneurysm (IA) treated with PEDs at three institutions. SDMS was classified as type I or II based on whether the PED covered the aneurysm neck.

RESULTS

The total cohort comprised 790 patients. SDMS was identified in 24 (3.04%) patients. Eighteen of the 24 patients had type I SDMS and did not require retreatment, while the remaining six patients had type II SDMS and all received retreatment. Multivariate logistic regression showed that the difference between the proximal and distal parent artery diameters (DPAD) (adjusted OR 2.977; 95% CI 1.054 to 8.405; P=0.039) and device tortuosity index (DTI) (adjusted OR 8.059; 95% CI 2.867 to 23.428; P<0.001) were independent predictors of SDMS after PED treatment, while the difference in length (DL) (adjusted OR 0.841; 95% CI 0.738 to 0.958; P=0.009) and PED plus coiling (adjusted OR 0.288; 95% CI 0.106 to 0.785; P=0.015) were protective factors.

CONCLUSION

The incidence of SDMS after PED treatment of IA was 3.04%. For patients with type I SDMS with incomplete aneurysm occlusion we recommend continuous imaging follow-up while, for patients with type II SDMS, we recommend aggressive retreatment. The DPAD and DTI were independent risk predictors of SDMS after PED treatment, while the DL and PED plus coiling were protective factors.

In-Stent Stenosis After Pipeline Embolization Device in Intracranial Aneurysms: Incidence, Predictors, and Clinical Outcomes

BACKGROUND

In-stent stenosis (ISS) is a delayed complication that can occur after pipeline embolization device use when treating intracranial aneurysms (IAs).

OBJECTIVE

To assess the incidence, predictors, and outcomes of ISS.

METHODS

This was a retrospective, multicenter, observational study. All patient data were collected from a PLUS registry study. We collected data from patients with IA who completed digital subtraction angiography at follow-up and divided patients into "non-ISS," "mild ISS," or "severe ISS" groups. Multivariate logistic regression analysis was conducted to determine predictors of ISS.

RESULTS

A total of 1171 consecutive patients with 1322 IAs participated in this study. Angiographic follow-up was available for 662 patients with 728 IAs, and the mean follow-up time was 9 months. ISS was detected in 73 cases (10.03%), including 61 mild ISS cases and 12 severe ISS cases. Univariate and multivariable analysis demonstrated that current smoking history (mild ISS: OR 2.15, 95% CI 1.122-4.118, P = .021; severe ISS: OR 5.858, 95% CI 1.186-28.93, P = .030) and cerebral atherosclerosis (mild ISS: OR 5.694, 95% CI 3.193-10.15, P = .001; severe ISS: OR 6.103, 95% CI 1.384-26.91, P = .017) were independent predictors of ISS. Compared with the other groups, the severe ISS group had higher rate of ischemic stroke (33.3%).

CONCLUSION

ISS occurs in approximately 10.03% of cases at a mean follow-up of 9 months. Statistically, current smoking history and cerebral atherosclerosis are the main predictors of ISS. Severe ISS may be associated with higher risk of neurological ischemic events in patients with IA after pipeline embolization device implantation.

Microwire navigation and microcatheter positioning by balloon manipulation for the treatment of intracranial aneurysms: A pilot study

Background and Objective:

An intracranial aneurysm (IA) is a life-threatening condition and endovascular treatment (EVT) is a demanding procedure, especially in IAs with an unfavorable anatomy. The aim of this study was to investigate the safety and efficacy of balloon-assisted microwire navigation and microcatheter positioning in the EVT of IAs with challenging anatomies.

Materials and Methods:

This retrospective study included patients that underwent balloon-assisted microwire navigation and microcatheter positioning in the EVT of IAs between September 2016 and January 2019. All EVT procedures and data collection were performed by the same two neurointerventional radiologists. Technical success and complication rates, safety, and efficiency of the balloon manipulation method were evaluated. Statistical software was used to analyze the basic descriptive data of the patients and aneurysms.

Results:

This study included 14 patients. The microwire navigation of the target artery with balloon manipulation was used in 4 aneurysms of 4 patients. Microcatheter positioning with balloon manipulation was used in 10 aneurysms of 10 patients. There was no complication caused by the balloon manipulation technique. The technical success rate was 100%.

Conclusion:

In the EVT of IAs with challenging anatomies, the presented technique is a safe and effective option without additional complications, especially in the target artery with an acute angle and in small aneurysms.

Bailout stentectomy of 47 self-expandable intracranial stents

Background

Self-expanding stents are increasingly being deployed for stent-assisted coiling or flow diversion of intracranial aneurysms. Complications related to stent misbehavior may arise, however, including lack of expansion, device displacement, or parent vessel thrombosis. We present our experience of various stent removal techniques (stentectomy) with a focus on technical and clinical outcomes.

Methods

Stentectomy was attempted either with a single device, including the Alligator, Microsnare, or Solitaire, or by combining a Microsnare with a second device. Dual techniques included in this report are the Snare-over-Stentretriever technique we developed using a Microsnare and a Solitaire, and the previously described Loop-and-Snare technique using a Microsnare and a microwire. The technical success and complication rate, as well as the clinical outcome using the mRS were analyzed.

Results

Forty-seven stentectomies were attempted in 36 patients treated for 37 aneurysms. Forty-two devices (89.3%) were successfully retrieved. Single-device stentectomy was successful in 34% of cases, compared with 74% with dual-device techniques. Of the 20 patients with a thrombosed parent or efferent vessel, 17 were successfully recanalized using stentectomy. All successful stentectomy patients made a clinically uneventful recovery, except one with a minor postoperative stroke (mRS 1 at discharge). Failed stentectomy was associated with major ischemic stroke in two patients and death in one patient. There were no stentectomy-related vessel perforations or dissections.

Conclusion

While various single devices can be used to safely retrieve dysfunctional intracranial self-expandable stents, dual-device techniques are more than twice as effective, according to our experience.

Coiling as a Rescue Strategy for Flow Diverter Prolapse into a Giant Intracranial Aneurysm

BACKGROUND

Up to 3.2% of the adult population has an unruptured intracranial aneurysm (IA). Flow diversion is a relatively new treatment technique that is especially useful for large and morphologically unfavorable IAs.

METHODS

A previously healthy woman aged 32 years presented with a 6-month history of ptosis and ophthalmoplegia of the left eye. A magnetic resonance imaging scan revealed a giant left internal carotid artery aneurysm. She was admitted for treatment using flow diversion. After delivery of the flow diverter (FD), prolapse of the proximal end of the stent into the aneurysmal sac was observed. FD stabilization was achieved by deploying multiple coils through a previously placed microcatheter to push the prolapsed end away from the aneurysmal lumen.

RESULTS

The patient had a favorable outcome, with reduction of preoperative mass effect symptoms and complete obliteration of the aneurysm persisting at the 3-month follow-up.

CONCLUSIONS

Giant IAs remain one of the most daunting clinical problems to treat. FD displacement is a rare (0.5%-0.75%) and possibly fatal complication. Currently, no clinical guidelines exist for its management. Adjunctive coiling is a possible rescue strategy for stabilizing an FD that foreshortened and prolapsed into the aneurysmal sac. Further studies are needed to identify the best approach to this complication.

Endovascular management of spontaneous delayed migration of the flow-diverter stent

BACKGROUND AND PURPOSE

Spontaneous delayed migration of the flow-diverter stent (FD) is an unusual complication that can be fatal. The purpose of this study is to report our experience and review the literature for the management of delayed FD migration.

MATERIALS AND METHODS

Between November 2013 and June 2017, 122 patients treated by FD at our institution were enrolled. We also performed a comprehensive review of the literature.

RESULTS

Six patients (4.9%) were found to have spontaneous delayed migration of their FD. The device migrated proximally in 4 patients and distally in 2 patients. One patient had temporal lobe infarction due to stent migration, and another had subarachnoid haemorrhage (SAH). Three patients were treated with a 2nd or 3rd FD, while 2 were treated with stent-assisted coiling, and one was treated with sacrifice of the parent internal carotid artery. According to our results and the literature, the prevalence rate of delayed FD migration ranges from 2.2% to 4.9%, and the mortality and morbidity rate of delayed FD migration is 40%.

CONCLUSIONS

Neuro-interventionalists should be aware of this complication and be familiar with risk factors, preventive methods and treatment options. If there is any concern regarding the size or position of the FD, early imaging follow-up and endovascular treatment should be indicated.

Internal Carotid Artery Reconstruction with a "Mega Flow Diverter": First Experience with the 6×50 mm DERIVO Embolization Device

Endoluminal reconstruction with a flow diverter device has emerged as a viable and often preferable alternative to traditional techniques for the treatment of intracranial aneurysms. Precise measurement and device selection are mandatory steps when considering flow diverters usage in order to avoid potential complications. In this sense, incomplete wall-apposition has been described as a predictive factor for immediate in-stent and delayed thrombosis after stent use. One significant usage limitation of flow diverter devices is the parent artery diameter, since the maximum opening of the sizes available are recommended for vessel diameters between 5.2–5.75 mm. Here we present the first clinical use of the largest flow diverter available, the 6×50 mm DERIVO embolization device (Acandis GmbH & Co. KG, Pforzheim, Germany), into the arterial circulation for a cervical internal carotid artery endovascular reconstruction. This is a new device for large or fusiform aneurysms requiring flow diversion, especially located in the vertebrobasilar system or extracranial segments.

Tied Pipeline: A Case of Rare Complication

A 48-year-old female with a symptomatic giant carotid cavernous aneurysm underwent endovascular treatment with multiple Pipeline Flex embolic devices (PED). The delivery catheter had to take a complicated course of multiple turns to cross the aneurysm, and its loop was tied in the aneurysm. When the catheter was to be withdrawn, it was apparent that the tied catheter had made a tight knot that bound the tail of the previous PED together. We successfully retrieved all of the system including the tied PED, and we used telescoping stents with five PEDs in the next operation. Although this is a rare complication, it is worth noting and checking to make sure that there is no knot before deploying the stent.

Salvage of Herniated Flow Diverters Using Stent and Balloon Anchoring Techniques: A Technical Note

BACKGROUND

The pipeline embolization device (PED; Medtronic, MN, USA) can sometimes herniate into the aneurysmal sac in an unexpected manner during or shortly after its deployment due to device foreshortening. In this report, we describe 2 endovascular techniques, which can be used to reposition a herniated PED construct into a more favorable alignment.

SUMMARY

In a 67-year-old patient who had an intraprocedural herniation of a PED device into a giant cavernous aneurysm, a stent anchor technique was used to reverse the herniation, reorient the PED construct, and achieve successful flow diversion. In a different patient with a giant superior hypophyseal aneurysm, a balloon anchor technique followed by deployment of an LVIS Jr (Microvention, Tustin, CA, USA) stent was used to reverse the herniation into the aneurysmal sac.

KEY MESSAGES

Stent anchor and balloon anchor techniques as described here can be used to reposition PED constructs, which have unexpectedly herniated into the aneurysm sac during attempted flow diversion for the treatment of giant aneurysms.

Prolapse of the Pipeline embolization device in aneurysms: incidence, management, and outcomes

OBJECTIVE

The Pipeline embolization device (PED) is frequently used in the treatment of anterior circulation aneurysms, especially around the carotid siphon, with generally excellent results. However, the PED has its own unique technical challenges, including the occurrence of device foreshortening or migration leading to prolapse into the aneurysm. The authors sought to determine the incidence of this phenomenon, the rescue strategies, and outcomes.

METHODS

Four institutional databases of neuroendovascular procedures were reviewed for cases of intracranial aneurysms treated with PEDs. Patient and aneurysm data as well as angiographic imaging were reviewed for all cases involving device prolapse into the aneurysm.

RESULTS

A total of 413 intracranial aneurysms were treated with PEDs during the study period, by 5 neurointerventionalists. Large and giant aneurysms (≥ 2 cm) accounted for 32 of these aneurysms. Among these 32 PEDs, prolapse into the aneurysm occurred in 3 patients, with 1 of these PEDs successfully rescued and the other 2 left in situ. No patients suffered any severe complications. The 2 patients in whom the PEDs were left in situ remained on antiplatelet therapy.

CONCLUSIONS

The PED may foreshorten or migrate during or after deployment, leading to prolapse into the aneurysm. This phenomenon appears to be associated with large and giant aneurysms, vessel tortuosity, short landing zones, and use of balloon angioplasty. Future study and follow-up is needed to further evaluate this phenomenon, but some of the observations and techniques described in this paper may help to prevent or salvage prolapsed devices.

Periprocedural outcomes and early safety with the use of the Pipeline Flex Embolization Device with Shield Technology for unruptured intracranial aneurysms: preliminary results from a prospective clinical study

BACKGROUND AND PURPOSE

The Pipeline Embolization Device (PED) has become a routine first-line option for treatment of intracranial aneurysms (IAs). We assessed the early safety and technical success of a new version of PED, Pipeline Flex Embolization Device with Shield Technology (Pipeline Shield), which has the same design and configuration but has been modified to include a surface synthetic biocompatible polymer.

MATERIALS AND METHODS

The Pipeline Flex Embolization Device with Shield Technology (PFLEX) study is a prospective, single-arm, multicenter study for the treatment of unruptured IAs using Pipeline Shield. The primary study endpoints included the occurrence of major stroke in the territory supplied by the treated artery or neurologic death at 1 year post-procedure. Secondary endpoints included the rate of Pipeline Shield-related or procedure-related serious or non-serious adverse events. Analyses were conducted to evaluate early safety findings in the 30-day post-procedure period as well as technical procedural success outcomes.

RESULTS

Fifty patients with 50 unruptured target IAs were enrolled. Mean aneurysm diameter was 8.82±6.15 mm. Thirty-eight aneurysms (76%) were small (<10 mm). Device deployment was technically successful with 98% of devices. Complete wall apposition was achieved immediately post-procedure in 48 cases (96%). No major strokes or neurologic deaths were reported in the 30-day post-procedure period.

CONCLUSIONS

The results of this first experience with the new Pipeline Flex corroborate the early safety of the device. Mid-term and long-term follow-up examinations will provide data on safety outcomes at the 6-month and 1-year follow-up periods.

CLINICAL TRIAL REGISTRATION

NCT02390037.

Evaluation of Pipeline Flex delivery system for the treatment of unruptured aneurysms

INTRODUCTION

Refinements in endovascular technology have revolutionized the treatment of intracranial aneurysms (IAs) with the development of flow-diversion technology. The first generation of the Pipelin Embolization Device (PED) has demonstrated its safety and efficacy. However, the deployment technique was a difficult task that often led to complex maneuvers. The Pipeline Flex Embolization Device (PED Flex) is the second generation and its introduction has arrived with high expectations due to a completely redesigned delivery system that intends to overcome deployment difficulties seen in the previous generation. Areas covered: Preclinical studies, mechanism of action of flow-diverters, technical aspects and deployment system of the PED Flex, and clinical outcomes with both PED generations. Expert commentary: Flow diversion has allowed us to treat lesions that would be otherwise challenging for surgical clipping or unsuitable for other endosaccular strategies. Although the experience with PED Flex is limited, initial results suggest its safety and short-term efficacy.