Stent retriever use for retrieval of displaced microcoils: a consecutive case series

Retrieval of n-Butyl Cyanoacrylate Cast Migrated to the Dorsalis Pedis and Posterior Tibial Artery During Embolization of the Deep Circumflex Iliac Artery Using the Stent Retriever Device: A Case Report

CLINICAL IMPACT

This case highlights the innovative application of stent retriever devices for retrieving migrated NBCA casts, traditionally used for stroke management in peripheral arterial occlusions. This adaptation offers clinicians a new, effective tool for managing embolization complications, such as unintended material migration that can cause severe ischemia. Implementing this technique could change clinical practice by providing a reliable method to swiftly address and resolve potentially limb-threatening situations, thereby improving patient outcomes and procedural safety. This advancement in interventional radiology enhances clinicians' ability to handle complex embolic events with greater confidence and efficacy.

A Novel Microsnare and Microwire Coil Retrieval Technique

Coil migration during endovascular embolization is a complication that can result in thromboembolic occlusion leading to potentially large infarcts if not removed. Microsnares are commonly used to remove migrated coils. Current techniques, however, struggle in cases where the microsnare is unable to loop over and secure a free end of the coil. We present a case in which a microsnare combined with a microwire successfully removed a migrated coil in a patient with a bleeding hepatic pseudoaneurysm post-embolization. This technique proved beneficial when traditional methods were insufficient, especially in small vessels or coil packs that cannot be snared. The synergy of the microsnare and microwire technique presents a promising solution for challenging migrated coil retrievals.

Strategy of stretched Coils: Insights from a single center experience

OBJECTIVE

A stretched coil, characterized by excessive elongation within the parent artery during a coil embolization procedure, poses a significant risk of forming a thrombus. This study reports on cases of stretched coils spanning 16 years and discusses effective assessment methods and treatment strategies.

METHOD

Retrospective analysis of the institutional database comprising 14 cases where stretched coils were observed during coil embolization procedures was conducted, starting from January 2007.

RESULTS

Among the 14 cases, four involved coil embolization for subarachnoid hemorrhage due to ruptured aneurysm, while the remaining cases were unruptured aneurysms. Starting in 2017, vaso-computed tomography (vaso-CT) was employed in nine cases to evaluate the proximal end of the stretched coils. Reimplantation was performed in 3 cases. Among them, two cases were relieved by pushing the coil delivery wire or microwire, while one case underwent balloon-assisted reimplantation. The stretched coils were removed in three cases by pulling. A rescue gooseneck microsnare technique was applied in one case. The stent was fixed in five cases. In two cases, no additional procedures were performed. Thrombosis is a potential complication that occurred in three cases of stretched coils.

CONCLUSION

Many studies have addressed coil stretching and introduced various rescue methods, but relying solely on angiography for diagnosis or applying an inappropriate rescue technique can lead to ischemic stroke. This study emphasized the importance of vaso-CT as a tool for accurately identifying the proximal end of a stretched coil. Additionally, we aimed to facilitate the selection of an appropriate rescue technique.

A Unique Technique to Adjust Snare Position for Coil Retrieval in Tortuous Vessel During Aneurysm Coil Embolization: A Technical Case Report

OBJECTIVE

Although snares are useful devices to retrieve an intravascular foreign body, the control of snares is often difficult. We present a safe and effective technique to adjust snare position in the tortuous vessel for coil retrieval during endovascular coil embolization.

METHODS

We describe a case of a protruding coil during coil embolization that was successfully retrieved using a unique technique to adjust snare position and discuss additional intraprocedural bailout strategies for retrieving a coil during endovascular coil embolization.

RESULTS

The patient was a 44-year-old female with unruptured right internal carotid artery (ICA) aneurysm that had grown over a 1.5-year period. Coil embolization was performed. After detachment of final coil and microcatheter removal, the final coil protruded into the ICA and floated. Coil retrieval using a snare was attempted, but the snare could not be placed around the coil tail and coil retrieval could not be achieved. The following technique was used to allow adjustment of snare position. First, a microguidewire and a microcatheter were guided into the M2 and M1 segment of the middle cerebral artery as monorail guides of the snare, respectively. Next, the snare was advanced over the microcatheter. Around C2 segment of the ICA, the microcatheter and the snare were manipulated as a unit. Thus, the snare could be placed around the protruding coil tail and the coil was retrieved successfully.

CONCLUSIONS

This technique may be widely adapted for various situations when using a snare.

Retrieval of Migrated Coils From Distal Cerebral Vasculature Using Stent Retriever: A Case Series

The incidence of coil dislocation during an endovascular embolization of intracranial aneurysm is low but it can lead to serious thrombo-embolic complications. Therefore, coil displacement/migration often requires either retrieval or fixation of the errant coil with a stent. There are no standard recommended methods of coil retrieval. We present a series of three cases in which off-label application of a stent retriever allowed successful retrieval of herniated coils.

Parent artery stenting as a rescue management for stretched coils during cerebral aneurysms embolization: Report of three cases and review of literature

BACKGROUND

Displacement of a stretched coil into the parent artery during intracranial aneurysm coiling is a challenging situation where the risk of acute intravascular thrombosis might be a life-threatening condition. The usual way of management is coil snaring, yet in some cases, it might not be feasible to retrieve the coil. Parent artery rescue stenting had already been described as a way of management in acutely thrombosed parent arteries during aneurysm coiling.

CASE REPORTS

We present three cases with an inadvertent displacement of the unraveled coils into the parent artery for which rescue stenting was carried out to crush the coil against the vessel wall aiming to eliminate its thrombogenic effect. Our preliminary experience is that rescue stenting of the parent artery for stretched coil could be a convenient effective option particularly in case of failed/risky snaring with no notable immediate or long-term complications.

REVIEW AND DISCUSSION

We review the reported cases of stretched coils with or without further unraveling and fracture and discuss the possible consequences, salvage methods, and clinical outcomes. Neurointerventionists should be aware of this complication and get acquainted with bailout strategies.

Stentectomy of a Balloon-Mounted Stent From Vertebrobasilar Circulation: A Technical Report and Literature Review

Stents are being widely used in the neuroendovascular field more often for assisted coiling of aneurysms and treatment of atherosclerotic stenosis. Stent detachment and embolization are one of the most feared complications associated with poor clinical outcomes. Many techniques have been detailed in the literature for extracting such dislodged stents. We describe a case of retrieval of an inadvertently detached balloon-mounted stent from the intracranial left vertebral artery. This occurred in a 58-year-old male patient with a history of diabetes mellitus whose stenting procedure was planned for severe intracranial atherosclerotic disease of bilateral vertebral arteries causing recurrent posterior circulation ischemic events. Stentectomy was performed successfully using a stent retriever. Intracranial vertebral artery stenting was eventually accomplished with excellent clinical outcomes.

Emergency surgical removal of a migrated coil during embolization of a giant internal carotid artery aneurysm: illustrative case

BACKGROUND

Coil migration during endovascular treatment for an intracranial aneurysm is rare. When it occurs intraoperatively, it often mandates prompt endovascular retrieval or, as a salvage maneuver, microsurgical extraction if it fails endovascularly.

OBSERVATIONS

The authors presented a case of immediate coil migration during embolization of a giant intracranial cavernous segment of the internal carotid aneurysm. The patient immediately underwent emergency surgical extraction after unsuccessful endovascular retrieval attempts. The migrated coil was successfully removed through the M1 segment of the middle cerebral artery. The patient had full recovery without new neurological deficits. Four years after the incident, she was living independently. Previous case reports of emergency surgical removal of immediate coil migration were provided.

LESSONS

Surgical extraction of migrated coil after unfeasible endovascular retrieval served as an alternative salvage procedure. Hybrid neurological angiography in the operating suite may prevent unnecessary transfer and provide better real-time visualization of the migrated coil.

Retrieval of Displaced Woven EndoBridge Intrasaccular Flow Disruptor Using Solitaire Platinum Revascularization Device

The Woven EndoBridge (WEB; MicroVention, Aliso Viejo, CA, USA) intrasaccular flow disruptor is a therapeutic option for wide neck bifurcation intracranial aneurysms that does not require the use of adjunctive techniques such as stents or balloon remodeling. As with other endovascular devices, displacement of the WEB is a recognized complication. Few reports have been published regarding the management of this type of complication. We describe a case of retrieval of a displaced WEB using a Solitaire Platinum revascularization device (Medtronic, Minneapolis, MN, USA). Interventionists should be aware of this option in the management of such a complication.

Treatment of Ruptured and Nonruptured Aneurysms Using a Semisolid Iodinated Embolic Agent

Saccular aneurysms (SAs) are focal outpouchings from the lateral wall of an artery. Depending on their morphology and location, minimally invasive treatment options include coil embolization, flow diverter stents, stent-assisted coiling, and liquid embolics. Many drawbacks are associated with these treatment options including recanalization, delayed healing, rebleeding, malpositioning of the embolic or stent, stent stenosis, and even rupture of the SA. To overcome these drawbacks, a nanoclay-based shear-thinning hydrogel (STH) is developed for the endovascular treatment of SAs. Extensive in vitro testing is performed to optimize STH performance, visualization, injectability, and endothelialization in cell culture. Femoral artery saccular aneurysm models in rats and in pigs are created to test stability, efficacy, immune response, endothelialization, and biocompatibility of STH in both ruptured and unruptured SA. Fluoroscopy and computed tomography imaging consistently confirmed SA occlusion without recanalization, migration, or nontarget embolization; STH is also shown to outperform coil embolization of porcine aneurysms. In pigs with catastrophic bleeding due to SA rupture, STH is able to achieve instant hemostasis rescuing the pigs in long-term survival experiments. STH is a promising semisolid iodinated embolic agent that can change the standard of medical practice and potentially save lives.

The Removal of a Fractured Guidewire During Mechanical Thrombectomy. a Case Report

Recent randomized controlled trials have transformed the treatment of acute ischemic stroke. Mechanical or aspiration thrombectomy is the main treatment option for occlusions of large intracranial vessels. Despite its high technical success rate, endovascular thrombectomy can sometimes be complicated by anatomical peculiarities or device failures. The most frequent complications are related to vessel dissection or vessel perforation by devices while navigating intricate anatomy. Rarer still are technical device failures, like spontaneous stent-retriever detachment, which occurred with older generation retrievers. This case reports a rare device failure, which, to the best of our knowledge, has not been reported in the literature so far, namely a microwire fracture in the middle cerebral artery. This was successfully removed with an Eric stent-retriever. The potential causes and possible management strategies are discussed.

Bailout Technique for Coil Unraveling with a KUSABI Exchange Catheter: A Case Report

Objective

Coil unraveling is a rare, yet dangerous complication of endovascular coiling. In this study, we report a patient in whom an intraoperatively unraveled coil was successfully retrieved using a KUSABI exchange catheter, which is used in the field of cardiovascular medicine to facilitate catheter exchange in coronary interventions.

Case Presentation

The patient was a 90-year-old woman. To treat an unruptured aneurysm of the right internal carotid artery, endovascular coil embolization was performed. During the filling step, the coil started to unravel. Early attempts to retrieve the unraveled coil using a microsnare were complicated when the ensnared part broke off during the process. The broken tip of the unraveled coil was maneuvered inside the guiding catheter, after which a KUSABI catheter was inflated inside the guiding catheter to press and immobilize the unraveled coil against its inner lumen. This fragment of the unraveled coil was extricated from the patient by retracting the entire guiding catheter assembly. We guided a microsnare along the remaining unraveled coil to capture the intact part of the coil, and eventually retrieval was successful.

Conclusion

To our knowledge, no study has reported retrieval with a KUSABI trapping balloon catheter for the management of coil unraveling. However, this method is considered effective. We report this case and review the literature.

Rescue Maneuver of Migrated Coil Using the ERIC Device after Previous Attempts with Conventional Stentrievers

Coil prolapse or migration is a rare but potentially serious complication that may occur during aneurysm embolization, with no standard management currently described. Here we describe our experience with the Embolus Retriever with Interlinked Cages (ERIC) device^® (Microvention, Aliso Viejo, CA, USA) for the retrieval of prolapsed or migrated coils in a case series and Flow-Model analysis. First, a retrospective review was performed using our institution database for patients in which coil prolapse or migration occurred during aneurysm embolization, and data was collected and analyzed. Second, an in vitro Flow-Model analysis was performed comparing the ERIC device^® with other stent retrievers for coil retrieval. In 2 cases, the ERIC device^® successfully retrieved the displaced coil from intracranial circulation in 1 pass, after failure with other devices. In the Flow-Model, again the ERIC device^® achieved success for retrieving a detached coil, whereas 2 other different stent retrievers failed to capture the coil after 2 attempts. The ERIC device^® appears to be a safe and effective tool for retrieving a prolapsed or migrated coil from the intracranial circulation.

Rescue balloon-assisted remodeling technique for protrusion of coil loop: A case report

RATIONALE

Among the possible complications during endovascular embolization of intracranial aneurysms, coil protrusion into the parent artery is associated with parent artery occlusion or thromboembolic of the distal arteries. There is no clearly established management strategy for coil protrusion. This report demonstrates our experience with balloon-assisted remodeling to reposition a protruded coil loop.

PATIENT CONCERNS

A 53-year-old man was admitted to our hospital with severe bursting headache, nausea, and vomiting. Computed tomography showed subarachnoid hemorrhage and digital subtraction angiography revealed an anterior communicating artery aneurysm. We decided to obliterate the aneurysm with endovascular embolization using detachable coils.

DIAGNOSIS

A small loop protruded into the parent artery during the removal of the microcatheter.

INTERVENTIONS

We performed successful repositioning of the protruded coil loop using balloon inflation.

CONCLUSION

The rescue balloon-assisted remodeling technique was useful in the management of protrusion of a small coil loop into the parent artery during endovascular coil embolization of an intracranial aneurysm. The procedure was associated with minimal complications.

Endovascular retrieval of a dislocated pushable coil in the common hepatic artery using a cerebral stent retriever

BACKGROUND

This is case of removing a dislocated pushable coil from the common hepatic artery (CHA) as a possible complication of using pushable coils in the embolization of an upper gastrointestinal bleeding (UGIB) from the gastroduodenal artery (GDA) by using a pRESET stent retriever (Phenox, Bochum, Germany) which is utilized mainly for treatment of endovascular stroke.

CASE PRESENTATION

An 88-year-old female patient was referred to our hospital to get an emergency embolization of the GDA causing an UGIB with a relevant drop of the hemoglobin level. During the routine embolization of the GDA using pushable coils, a complete dislocation of the last coil into the CHA took place leading to a relevant slowing down of the arterial blood flow to the liver. A decision was thereby made to remove the dislocated coil to avoid further possible complications which was successfully achieved.

CONCLUSIONS

Various stent retrievers have been proven to be effective in removing dislocated coils during intracerebral coiling of different pathologies. This case report is to our knowledge the first case report proving the high efficacy and safety of using yet another stent retriever, namely a pRESET stent retriever in removing a fully dislocated coil in the abdominal vessels, namely in this case the CHA.

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.

Acute Coils Migration Causing Significant M3 Branch Occlusion: A Case Report of Rescue Surgery with Superficial Temporal Artery-Middle Cerebral Artery Bypass

We describe an uncommon case of acute coils migration with significant occlusion of M3 branch and our management of this complication. Ballon-assisted coil placement was performed for an unruptured intracavernous internal carotid artery aneurysm in a 62-year-old woman. After coil placement and balloon deflection, we observed coils migration with significant occlusion of M3 branch. After early clinical deterioration without other neurological symptoms, we decided to perform superficial temporal artery-middle cerebral artery (STA-MCA) bypass to ensure blood flow distal to the occlusion. The patient was discharged without neurological deficit. To the best of our knowledge, this is the first case report about STA-MCA bypass to treat acute coils migration. This technique could represent a successful rescue therapy in case of acute coils migration that cannot be retrieved by endovascular tools or in case where distal and deep location of migrated coils controindicate surgical removal.

Mechanical Thrombectomy for Delayed Thrombosis of Pipeline Embolization Device

BACKGROUND

In-stent thrombosis is a potentially dangerous complication of flow diversion for cerebral aneurysms. The optimal management strategy for such thrombosis is not known. Here we present a case of acute ischemic stroke caused by occlusion of a Pipeline Embolization Device (PED) construct placed 18 months earlier for treatment of a fusiform middle cerebral artery aneurysm. This was successfully treated with mechanical thrombectomy with good neurologic outcome.

CASE DESCRIPTION

A 40-year-old woman presented with acute onset of left-sided weakness and occlusion of the right middle cerebral artery harboring a PED construct. Intraarterial glycoprotein IIb/IIIa inhibitor was administered without success. Mechanical thrombectomy was then performed using a stent retriever and aspiration, and the patient was loaded with dual antiplatelet therapy. The patient showed initial neurologic improvement but several hours later demonstrated recurrent symptoms due to reocclusion of the PED construct. This was again treated with mechanical thrombectomy followed by an intravenous P2Y12 inhibitor infusion. She ultimately made an excellent neurologic recovery with persistent patency of the PED construct.

CONCLUSIONS

Mechanical thrombectomy with a stent retriever and aspiration is a therapeutic option for treatment of delayed thrombosis of a flow-diverting stent.

Removal of distal fragments of liquid embolic agents during arteriovenous malformation embolization using the TIGERTRIEVER 13: a technical report

BACKGROUND

Arteriovenous malformations (AVMs) are vascular lesions that may be treated by an endovascular approach using liquid embolic agents but the control of the liquid embolic agent remains poor and a potential complication may be distal migration of embolic material. The TIGERTRIEVER 13 is a new stent retriever designed for stroke thrombectomy and has a version ideal for distal occlusions. We report our experience in the removal of embolic agent which had migrated into the distal vessels using the TIGERTRIEVER during PHIL/Onyx embolization of AVMs.

CLINICAL PRESENTATIONS

Three patients with brain and spinal AVMs underwent endovascular embolization. During trans-arterial embolization of the AVM with PHIL/Onyx, retrograde filling of distal arterial feeders was followed by migration into the normal arterial branches (cortical middle cerebral artery, distal posterior cerebral artery, and anterior spinal artery). This resulted in occlusion or sluggish distal flow in these branches with potential significant neurological deficits. In all three cases, a Headway Duo microcatheter was navigated distally in the occluded vessel beyond the embolic material using a Traxcess microwire. The TIGERTRIEVER 13 was deployed with recanalization of the vessel after a single attempt. In all three patients there were no complications related to the retrieval of embolic agent.

CONCLUSION

Distal migrated embolic agents such as PHIL or Onyx can be removed from various arterial vascular territories using stent retrievers dedicated to small vessels.

Coil migration during or after endovascular coiling of cerebral aneurysms

BACKGROUND

Coil migration is a complication of endovascular coiling of cerebral aneurysms that has not been well studied.

OBJECTIVE

To report the frequency, risk factors, management strategies, and outcomes of coil migration.

METHODS

This was a retrospective analysis of the clinical and radiological data of patients who underwent cerebral aneurysm coiling complicated by coil migration at five neuroendovascular centers in the United States, Canada, and France between 2008 and 2018.

RESULTS

Eighteen cases of coil migration met our study criteria with an occurrence of 0.3% (18/6071 cases) (procedural migration: 55%, delayed migration: 45%). The mean aneurysm maximal diameter, neck, and height to neck ratio in migration cases were 3.4±1.4 mm (range 2-7.6 mm), 2.4±0.9 mm (range 1.2-4.4 mm), and 1.4±0.4 (range 1-2.15), respectively. The 2 mm diameter coil was the most common (39%, range 1-2.5 mm) migrated coil. The length of the migrated coil was ≤4 cm in 95% of cases.Patients managed conservatively (5/18, 28%) did well. Thromboembolic and/or hemorrhagic complications were noted in 6/10 migration patients treated by endovascular modalities and in all migration patients who underwent surgical treatment (4/4). Three deaths occurred (3/18, 17%) related to high Hunt and Hess grade subarachnoid hemorrhage.

CONCLUSION

Coil migration is an uncommon but important complication of cerebral aneurysm coiling. Small aneurysms, aspect ratio <1.6, and small coils are significant risk factors. Endovascular treatment, such as using a stent retriever, can be considered for procedural, proximal migration, and/or in cases of vessel occlusion. Delayed or distal migration should be managed conservatively.

Endovascular Retrieval of Dislodged Neurovascular Devices with a Stentriever: Case Series and Technical Review

PURPOSE

Endovascular treatment of neurovascular disorders is now well established as effective and safe; however, the nature of the intracranial vasculature poses unique challenges. The unintentional dislodgement or fracture of a device and its migration within cerebral vessels is a complication with serious potential morbidity that must be managed urgently. In this series, the authors describe 7 cases of a stentriever being used to remove foreign objects from within the cerebral vasculature.

METHODS

A retrospective search of all interventional neurovascular procedures performed in 2017 at a tertiary metropolitan hospital was performed to identify cases of dislodged devices.

RESULTS

Five dislodged endovascular coils, 1 microcatheter, and 1 fractured stentriever were technically successfully retrieved. In 6 of the cases, the foreign object was successfully removed with a stentriever alone, whereas 1 case used a J-tip wire and a "J-tip flick" to manipulate the coil and facilitate retrieval. Stentrievers, particularly when used alone, confer the advantages of speed, cost, as well as being tailor-made for cerebral vessels. They also allow continuous blood flow when deployed, a critical advantage when considering cerebral perfusion. Critical techniques include the gradual deployment of the stentriever alongside the foreign object to allow its entanglement and partial resheathing, so that the foreign object can become pinned within the microcatheter. Stentrievers do remain limited by vessel caliber and are less able to entangle larger, stiffer devices.

CONCLUSION

The migration of foreign devices during neurointerventional procedures is a serious complication requiring urgent treatment. This case series highlights the efficacy and advantages of using a stentriever and suggests its consideration as a first-line technique in recovering dislodged foreign bodies in the cerebral vasculature.

Snare technique for endovascular retrieval of coil extending to the atrium after embolization of a dural arteriovenous fistula

BACKGROUND

No data exist regarding retrieval of displaced or stretched coil extending to the right atrium after endovascular embolization of cerebrovascular diseases. We describe a snare technique for retrieval of a displaced coil extending to the right atrium after embolization of dural arteriovenous fistula (DAVF).

METHODS

A 35-year-old female with a DAVF underwent transjugular coil embolization that failed with displaced coil extending to the right atrium at an outside hospital. After admission to our hospital, Onyx embolization of the DAVF was performed through left facial vein-inner canthus vein-superior ophthalmic vein to the cavernous sinus. Post-embolization angiography showed complete occlusion of the DAVF. Then we attempted to snare the tip of the displaced coil that extended to the right atrium through femoral vein-inferior vena cava approach. However, current snare techniques failed to retrieve the extended coil after several attempts. Then one week later, we used a modified dual microcatheter and microwire technique to retrieve the displaced coil. One suite of microcatheter and microwire was used to produce a handmade snare device (HMD). The other suite of microcatheter and microwire was used to assist the HMD to snare the displaced coil.

RESULTS

Through transjugular vein approach, we used our modified dual microcatheter and microwire snare technique (handmade snare device system) to retrieve the extended coil. After several attempts, the extended coil in the atrium was successfully retrieved. Post-procedure angiography and cardiac examinations did not show any signs of abnormality.

CONCLUSIONS

For displaced coil extending to the right atrium after transvenous embolization, our method of modified dual microcatheter technique with HMD snare device system is an effective method to retrieve the extending coil.

Magnetic wires: A novel design for neuroendovascular coil retrieval

The present study aimed to evaluate the operation, application and safety of a novel prototype device designed for the retrieval of a migrated coils, an intraprocedural complication of endovascular aneurysm treatment, compared with the widely used Solitaire AB stent retriever. The prototype retrieval device, referred to as magnetic wires, consisted of two microwires that were joined by a small magnetic ring near to the tips. To retrieve a coil, the wires are advanced through the dislodged coil one at a time and then capture the target coil in a chopstick-like manner, as their tips are attracted to the magnet. In vitro tests were performed five times for each retrieval device using a pulsing flow circulator to compare retrieval effectiveness. In vivo efficacy testing was performed in 5 male piglets. The left and right carotid arteries were used to assess the magnetic wires and the Solitaire retriever, respectively. While the two devices successfully retrieved coils in vitro at a rate of 100%, the magnetic wires did so in a shorter time. In vivo, the magnetic wires successfully captured the migrated coils in 3/5 cases (60%), whereas the Solitaire AB stent retriever was successful 4/5 cases (80%). Endothelial injury was observed following magnetic wires retrieval in 1/5 cases (20%) and following use of the Solitaire AB stent retriever in 3/5 cases (60%). These results demonstrate the feasibility and safety of this novel prototype coil retrieval device, which with further development has the potential to be an optimal device for the retrieval of dislodged coils.

Endovascular Retrieval of Migrated Coil within the Distal Middle Cerebral Artery Using Stentriever Device

BACKGROUND

Displacement of endovascular coils during endovascular embolization of an intracranial aneurysm is a potentially life-threatening complication. Several methods for coil retrieval have been described, including the use of microsnares and microforceps retrieval devices. With the recent surge of stentriever implementation in the treatment of ischemic stroke, some operators are now using such devices in the retrieval of migrated coils. We present a case of a balloon-assisted coil embolization of a communicating segment internal carotid artery aneurysm, complicated by coil migration far distally into the middle cerebral artery, which was retrieved successfully with a stentriever. To the best of our knowledge, this is the furthest migration of a coil to be successfully retrieved with a stentriever. We review conservative and invasive management of displaced coils and the technical advantages of stentrievers over retrieval devices.

METHODS

The patient's medical records were retrospectively reviewed, including clinical and radiographic information. This study received institutional review board approval.

RESULTS

The patient was treated with balloon-assisted coil embolization of the internal carotid artery aneurysm. The migrated coil was retrieved successfully using a novel application of a stentriever.

CONCLUSIONS

In certain situations, a stentriever does not mandate complete ensnaring of the target to be retrieved and thus need not always be deployed distal to a migrated coil mass to be successful. Due to the mechanical advantage of strut-engagement, stentrievers can afford to be positioned in relatively suboptimal positions, and this is especially useful in cases involving tortuous and small distal vessels (<2 mm diameter).

Rescue therapy with stent retrievers for thromboembolism during endovascular treatment of intracranial aneurysms

Thromboembolism is the most frequent complication in endovascular treatment of intracranial aneurysms, causing disability and death. As stent retrievers have achieved high rates of arterial recanalization in the management of ischemic stroke, these devices were tested as rescue therapy of thromboembolism during aneurysm embolization. We retrospectively analyzed 10 consecutive patients with transprocedural arterial occlusion, treated with mechanical thrombectomy at a single center. Good angiographic recanalization was achieved in eight cases, mTICI 3, 2b and 2a in five, three and two patients, respectively, without additional complications or any deaths. Five patients showed complete recovery (mRS 0) and all patients showed improvement of disability (average mRS 1.1) over a mean follow-up period of 31 months. Eight patients had good clinical recovery, while two remained with deficits (mRS 3 and 4). The study found that the stent retriever is a valuable, rapid and effective tool for restoring blood flow, improving the safety of endovascular treatment.

Balloon-assisted coil embolization and large stent delivery for cerebral aneurysms with a new generation of dual lumen balloons (Copernic 2L)

Introduction

Dual coaxial lumen balloon microcatheters through which small stents can be delivered have recently been described. We report a series of a new type of dual lumen balloon catheter with a parallel lumen design enabling enhanced inflation and deflation properties through which larger stents may be deployed, including flow diverters (FD).

Methods

All aneurysms that were treated with a Copernic 2L (COP2L) dual lumen balloon catheter at our institution between February 2014 and December 2016 were assessed. Patient demographics, aneurysm characteristics, clinical and angiographic follow-up, as well as adverse events were analyzed.

Results

A total of 18 aneurysms in 16 patients (14 women) were treated with the COP2L. Mean maximal aneurysm diameter was 6.4 mm, mean neck size was 3.3 mm (min 1; max 6.3), and mean aneurysm height/width was 1.1 (min 0.5; max 2.1). The COP2L was used for balloon-remodeled coiling exclusively in 2 aneurysms; coiling and FD stenting in 8; coiling and braided stent delivery in 3; coiling, braided and FD stenting in 1; and FD stenting without coiling in 4 (stenting alone). The rate of Roy–Raymond 1 (complete occlusion) changed from 22% in the immediate postoperative period to 100% at 3 months (mean imaging follow-up 8.2 months). There were three technical complications (3/16, 18.7%), including a perforation and two thromboembolic asymptomatic events that were rapidly controlled with the COP2L. There was no immediate or delayed morbidity or mortality (modified Rankin Scale score 0–1 in 100% of patients).

Conclusion

The COP2L is a new type of dual lumen balloon catheter that may be useful for balloon and/or stent-assisted coiling of cerebral aneurysms. The same device can be used to deliver stents up to 4.5 mm and to optimize stent/wall apposition or serve as a life-saving tool in case of thromboembolic or hemorrhagic events. Long-term efficacy and safety need to be further assessed with larger case-controlled cohorts.

Current Treatment Strategies for Intracranial Aneurysms: An Overview

Intracranial aneurysm is a leading cause of stroke. Its treatment has evolved over the past 2 decades. This review summarizes the treatment strategies for intracranial aneurysms from 3 different perspectives: open surgery approach, transluminal treatment approach, and new technologies being used or trialed. We introduce most of the available treatment techniques in detail, including contralateral clipping, wrapping and clipping, double catheters assisting coiling and waffle-cone technique, and so on. Data from major trials such as Analysis of Treatment by Endovascular approach of Non-ruptured Aneurysms (ATENA), Internal Subarachnoid Trial (ISAT), Clinical and Anatomical Results in the Treatment of Ruptured Intracranial Aneurysms (CLARITY), and Barrow Ruptured Aneurysm Trial (BRAT) as well as information from other clinical reports and local experience are reviewed to suggest a clinical pathway for treating different types of intracranial aneurysms. It will be a valuable supplement to the current existing guidelines. We hope it could help assisting real-time decision-making in clinical practices and also encourage advancements in managing the disease.

Delayed asymptomatic coil migrations toward different arteries after aneurysmal embolization: case report

Delayed coil migration after endovascular treatment with detachable coils, particularly several months after treatment, is extremely rare. In this report, the authors describe a 77-year-old female in whom delayed coil migration to the anterior cerebral artery and posterior communicating artery (PCoA) developed 3 months after an uncomplicated aneurysm embolization. The patient was successfully retreated with a closed-cell stent. Computational fluid dynamics (CFD) revealed high wall shear stress (WSS) and multiple vortices in the residual cavity of the initially treated aneurysm. CFD could be useful to detect and predict this complication, and a stent-assisted technique could be an important treatment option.

Stand-alone coil embolization of anterior communicating artery aneurysms: Efficacy and technical issues

OBJECTIVE

We report our experience with endovascular coiling of anterior communicating artery aneurysms with special consideration of angiographic and clinical outcomes and periprocedural complications.

MATERIALS AND METHODS

The analysis included treatment results of 28 patients with ruptured and unruptured aneurysms. The aneurysm size ranged from 1.8 to 9.8 mm (mean 5.2, SD 1.7). Clinical examinations with the use of modified Rankin Score and angiographic outcomes were evaluated initially post-embolization and at a minimum follow-up of six months.

RESULTS

Initial post-treatment complete and near-complete aneurysm occlusion was achieved in 27 (96%) cases and incomplete occlusion in one (4%) case. Imaging follow-up, performed in 15 (53.6%) patients, showed no change in the degree of occlusion in 11 (73%), coil compaction in one (7%) and progressive occlusion in three (20%) patients. Three (20%) patients underwent a second coil embolization. The procedure-related severe morbidity and mortality rate was 6.4% (2/31). Coil prolapse was present in one (3.2%) case and intraprocedural aneurysm rupture in three (9.6%) cases. The clinical follow-up evaluation achieved in 19 (67.9%) patients showed no change in 17 (89.5%) patients and improvement in two (10.5%) patients.

CONCLUSIONS

Although the efficacy of coil embolization of anterior communicating artery aneurysms is unquestionable and the procedure-related complications are acceptable, they should not be neglected. Further investigations are needed to better understand protective factors, as well as to establish unequivocally appropriate management strategy of these complications.

Retrieval of a migrated coil with a handmade microwire-snare device

BACKGROUND

Intraprocedural coil migration during endovascular treatment of intracranial aneurysms is associated with potential vessel occlusion and thromboembolic complications. There is no standard management strategy for coil migration. Here, we describe our experience with using a handmade microwire-snare device (HMD) to retrieve a migrated coil.

METHODS

The HMD consists of a 0.017-inch microcatheter, a 0.014-inch microwire, and a 4-0 silk thread. The ring of the microwire-snare device can open, close, and twist in a figure eight pattern for coil entwinement. In addition, the ring can be shaped as needed to navigate tortuous vessels or capture the migrated coil.

RESULTS

The HMD was successfully used to retrieve two migrated coils. In the first case, the coil was displaced in the M2 branch of the middle cerebral artery. In the second case, the coil loop prolapsed into the parent artery. In both cases, control cerebral angiograms performed after retrieval confirmed the patency of the vessels and a lack of thromboembolic complications. At the 3-month follow-up, magnetic resonance angiography demonstrated stable patency of the affected vessels.

CONCLUSIONS

The HMD is a cost-effective, easy-to-use, safe, and universally available device for retrieving migrated coil(s) during intracranial aneurysm embolization procedures.

Quantitative assessment of device-clot interaction for stent retriever thrombectomy

PURPOSE

Rapid revascularization in emergent large vessel occlusion with endovascular embolectomy has proven clinical benefit. We sought to measure device-clot interaction as a potential mechanism for efficient embolectomy.

METHODS

Two different radiopaque clot models were injected to create a middle cerebral artery occlusion in a patient-specific vascular phantom. A radiopaque stent retriever was deployed within the clot by unsheathing the device or a combination of unsheathing followed by pushing the device (n=8/group). High-resolution cone beam CT was performed immediately after device deployment and repeated after 5 min. An image processing pipeline was created to quantitatively evaluate the volume of clot that integrates with the stent, termed the clot integration factor (CIF).

RESULTS

The CIF was significantly different for the two deployment variations when the device engaged the hard clot (p=0.041), but not the soft clot (p=0.764). In the hard clot, CIF increased significantly between post-deployment and final imaging datasets when using the pushing technique (p=0.019), but not when using the unsheathing technique (p=0.067). When we investigated the effect of time on CIF in the different clot models disregarding the technique, the CIF was significantly increased in the final dataset relative to the post-deployment dataset in both clot models (p=0.004-0.007).

CONCLUSIONS

This study demonstrates in an in vitro system the benefit of pushing the Trevo stent during device delivery in hard clot to enhance integration. Regardless of delivery technique, clot-device integration increased in both clot models by waiting 5 min.

Endovascular retrieval of a dislocated coil in the peroneal artery with a stent retriever

We present a patient who underwent successful removal of a fully detached platinum coil from the peroneal artery using a Solitaire^™ stent retriever (Covidien, Irvine, CA) that is usually used in endovascular stroke treatment.

Early surgical removal of migrated coil/stent after failed embolization of intracranial aneurysm

OBJECT

Distal coil or stent migration is a rare, but potentially morbid complication of intracranial aneurysm embolization. At present, there is no established standard of surgical evacuation of displaced material-in particular, there is no consensus on the optimum time for such intervention. The authors report their positive experiences with an ultra-early surgical evacuation of 2 migrated coils and a flow-diverter stent.

METHODS

Uncontrolled coil or stent migration occurred in 3 (0.75%) of approximately 400 patients treated between 1999 and 2012 in the authors' institution. In all 3 cases, the materials moved from their intended position to the middle cerebral artery (MCA). Surgical evacuation was started immediately (within half an hour) after a futile attempt of removing them via intraarterial route, under the same anesthesia and with no active reversal of heparinization.

RESULTS

No excessive bleeding was observed. Displaced coils were extracted through an incision of a branch of MCA-the anterior temporal artery, the stent was removed through a direct incision of MCA. Recombinant tissue plasminogen activator (rtPA) was injected to the stem of the internal carotid artery toward the end of the procedure, with no discernible adverse effects. Two patients were discharged with no deficit (Glasgow Outcome Scale [GOS] Score 5); the other patient was conscious with mild hemiparesis (GOS Score 4) at discharge.

CONCLUSIONS

The experiences of these 3 cases suggest that immediate removal of a migrated stent/coil is feasible and may be effective. Indirect access to the MCA through its branch helps to shorten the time of temporary clipping of the artery to a minimum. Maintaining active heparinization and direct intraarterial injection of rtPA are helpful in promoting blood flow in the MCA.

Simultaneous stent expansion/balloon deflation technique to salvage failed balloon remodeling

Herniation, with possible embolization, of coils into the parent vessel following aneurysm coiling remains a frequent challenge. For this reason, balloon or stent assisted embolization remains an important technique. Despite the use of balloon remodeling, there are occasions where, on deflation of the balloon, some coils, or even the entire coil mass, may migrate. We report the successful use of a simultaneous adjacent stent deployment bailout technique in order to salvage coil prolapse during balloon remodeling in three patients. Case No 1 was a wide neck left internal carotid artery bifurcation aneurysm, measuring 9 mm×7.9 mm×6 mm with a 5 mm neck. Case No 2 was a complex left superior hypophyseal artery aneurysm, measuring 5.3 mm×4 mm×5 mm with a 2.9 mm neck. Case No 3 was a ruptured right posterior communicating artery aneurysm, measuring 4 mm×4 mm×4.5 mm with a 4 mm neck. This technique successfully returned the prolapsed coil mass into the aneurysm sac in all cases without procedural complications. The closed cell design of the Enterprise VRD (Codman and Shurtleff Inc, Raynham, Massachusetts, USA) makes it ideal for this bailout technique, by allowing the use of an 0.021 inch delivery catheter (necessary for simultaneous access) and by avoiding the possibility of an open cell strut getting caught on the deflated balloon. We hope this technique will prove useful to readers who may find themselves in a similar predicament.

Simultaneous stent expansion/balloon deflation technique to salvage failed balloon remodeling

Herniation, with possible embolization, of coils into the parent vessel following aneurysm coiling remains a frequent challenge. For this reason, balloon or stent assisted embolization remains an important technique. Despite the use of balloon remodeling, there are occasions where, on deflation of the balloon, some coils, or even the entire coil mass, may migrate. We report the successful use of a simultaneous adjacent stent deployment bailout technique in order to salvage coil prolapse during balloon remodeling in three patients. Case No 1 was a wide neck left internal carotid artery bifurcation aneurysm, measuring 9 mm×7.9 mm×6 mm with a 5 mm neck. Case No 2 was a complex left superior hypophyseal artery aneurysm, measuring 5.3 mm×4 mm×5 mm with a 2.9 mm neck. Case No 3 was a ruptured right posterior communicating artery aneurysm, measuring 4 mm×4 mm×4.5 mm with a 4 mm neck. This technique successfully returned the prolapsed coil mass into the aneurysm sac in all cases without procedural complications. The closed cell design of the Enterprise VRD (Codman and Shurtleff Inc, Raynham, Massachusetts, USA) makes it ideal for this bailout technique, by allowing the use of an 0.021 inch delivery catheter (necessary for simultaneous access) and by avoiding the possibility of an open cell strut getting caught on the deflated balloon. We hope this technique will prove useful to readers who may find themselves in a similar predicament.

Retrieval of migrated coils with stent retrievers: an animal study

BACKGROUND AND PURPOSE

Coil migration is a potentially serious complication of endovascular aneurysm treatment. The aim of the study was to systematically investigate the effectiveness of coil retrieval with a stent retriever in an animal model.

MATERIALS AND METHODS

A total of 148 coils of various types and sizes were placed into arteries of varying diameters in a porcine in vivo model. Coil retrieval was performed by placing a Trevo ProVue stent retriever over the coil and trying to trap a part of the platinum coil within the stent mesh by advancing the microcatheter over the stent or simply by retrieving the stent without trying to trap the coil by advancing the microcatheter.

RESULTS

Coil retrieval was successful in 101 of 102 cases (99%), in which trapping of the coil within the stent retriever by advancing the microcathter was applied. When we only pulled back the stent without trapping the coil, retrieval was successful in only 5 of 46 cases (11%). Coil type, coil structure (2D versus 3D), actual coil shape in the affected vessel, investigator experience, aspiration, coil localization, and vessel diameter had no significant influence on retrieval outcome. There was no case of vessel perforation.

CONCLUSIONS

Retrieval of migrated platinum coils with a stent retriever is an effective treatment option for migrated coils when the correct technique is applied.

Periprocedural complications associated with endovascular treatment of intracranial aneurysms in 1764 cases

Background

Intracranial aneurysms are increasingly treated with endovascular treatment. Based on our observation that cerebral complications are associated with this treatment, we predict that the number of intraprocedural complications will rise as a result of this trend.

Methods

Between January 2007 and December 2013, 1739 patients underwent 1764 detachable coil embolizations to treat intracranial aneurysms (637 ruptured and 1127 unruptured). We reviewed their records and images to evaluate the periprocedural complications and related morbidity and mortality.

Results

61 complications occurred during coil embolization and 33 periprocedural complications occurred within 1 week. These complications were observed in 8.6% of ruptured aneurysm embolization procedures (55/637) and in 3.5% of unruptured aneurysm embolization procedures (39/1127). There were 17 (0.96%) cerebral thromboembolisms, 34 (1.93%) intraprocedural aneurysm ruptures, 8 (0.45%) coil migrations, 13 (0.74%) postprocedural aneurysmal ruptures, and 22 (1.24%) neurologic deficits or transient neurologic deficits related to embolization. 63 complications had no neurologic consequences, 3 were associated with transient neurologic morbidity, 15 resulted in persistent neurologic morbidity on discharge, and 12 resulted in death. The procedure-related neurologic morbidity and mortality rates for all 1764 procedures were 0.85% in ruptured aneurysms and 0.68% in unruptured aneurysms.

Conclusions

The periprocedural complication rate was higher in ruptured aneurysms than in unruptured aneurysms. The main causes of morbidity and mortality were thromboembolisms, intraprocedural aneurysm perforations, and postprocedural aneurysmal ruptures. While some periprocedural complications are inevitable, we can minimize the occurrence of such complications by advancing our skill and experience, thereby improving patient prognosis.

Manual Aspiration Technique to Retrieve a Prematurely Detached Coil during Cerebral Aneurysm Embolization

Coil herniation, premature deployment, and fracture are procedure associated complications of endovascular aneurysm embolization that optimally necessitate coil retrieval when feasible. Several published techniques describe different strategies for managing coil complications including various snare retrieval devices, alligator retrieval devices, stent fixation, and open surgical resection of coils when distal blood flow is compromised. We report a novel technique employed to retrieve a prematurely detached coil during an aneurysm embolization using a syringe fixed to the microcatheter to carefully aspirate a loose coil with direct fluoroscopic visualization. This technique can only be utilized in the circumstance where the proximal end of the coil remains in the microcatheter. Conventional techniques of coil retrieval and stenting are discussed and compared to the rational for using the manual aspiration technique.

Intraprocedural retrieval of migrated coils during endovascular aneurysm treatment with the Trevo Stentriever device

Coil migration during endovascular treatment of intracranial aneurysms occurs in 2-6% of cases. As endovascular coiling of aneurysms has become increasingly popular and as endovascular technology continues to rapidly evolve, the prevalence of intraprocedural coil migration will invariably rise. Since coil masses are highly thrombogenic, migration out of the aneurysm sac into the parent artery may result in large territory infarcts which subsequently manifest as significant neurological morbidity. Therefore safe and timely retrieval of migrated coils is essential to avoiding poor angiographic and clinical outcomes. A 66-year-old woman with an unruptured 5 × 3mm, wide-necked posterior communicating artery aneurysm was referred for endovascular treatment. During coiling with the dual catheter technique, both initially deployed coils dislodged from the aneurysm sac and migrated distally into the middle cerebral artery. After failed retrieval with an Alligator device (Chestnut Medical Technologies, Menlo Park, CA, USA), we used two Trevo devices (Concentric Medical, Mountain View, CA, USA) in succession to successfully retrieve the migrated coils. The aneurysm was then occluded with stent-assisted coil embolization. There were no post-procedural angiographic or clinical complications. The patient was subsequently discharged home without neurological deficit. This case illustrates the first use of the Trevo device for retrieval of migrated coils during endovascular treatment of an intracranial aneurysm to our knowledge. Due to the lack of guidelines defining the standard management of intraprocedural coil migration, current strategies are based on retrospective review of published reports and expert opinion. We present a unique and effective method for endovascular retrieval of displaced coils using a Trevo Stentriever device.