Microguidewire-Assisted Repositioning of a Protruding Coil After Aneurysm Embolization

Abstract

Introduction

Coil protrusion is a rare but potentially serious complication of intracranial aneurysm embolization. Although several solutions exist, many raise procedural costs or require dual antiplatelet therapy. This case highlights a safe, cost-effective method for repositioning a protruding coil using only a microcatheter and microguidewire.

Clinical Presentation

An elderly patient with a left MCA bifurcation aneurysm experienced coil protrusion during embolization. A microguidewire, shaped and advanced via the inferior MCA trunk as a fulcrum, successfully repositioned the coil without extra devices or antiplatelet therapy. Post-procedure imaging confirmed stable repositioning without ischemic or hemorrhagic events. The patient developed moderate vasospasm, treated medically, and showed significant functional recovery after three months.

Conclusion

This specific technique provides a simple, effective, and economical alternative for managing coil protrusion, minimizing risks and costs while potentially improving outcomes in both standard and complex aneurysm cases.

Resumo

Introdução

A protrusão da espiral é uma complicação rara, porém potencialmente grave, da embolização de aneurismas intracranianos. Embora existam diversas soluções, muitas aumentam os custos do procedimento ou exigem terapia antiplaquetária dupla. Este caso destaca um método seguro e econômico para reposicionar uma espiral protrusa utilizando apenas um microcateter e um microguia.

Apresentação

Clínica Um paciente idoso com aneurisma da bifurcação da artéria cerebral média esquerda apresentou protrusão da espiral durante a embolização. Um microguia, moldado e avançado através do tronco inferior da artéria cerebral média como fulcro, reposicionou a espiral com sucesso, sem a necessidade de dispositivos adicionais ou terapia antiplaquetária. Os exames de imagem pós-procedimento confirmaram o reposicionamento estável, sem eventos isquêmicos ou hemorrágicos. O paciente desenvolveu vasoespasmo moderado, tratado clinicamente, e apresentou recuperação funcional significativa após três meses.

Conclusão

Esta técnica específica oferece uma alternativa simples, eficaz e econômica para o manejo da protrusão da espiral, minimizando riscos e custos, além de potencialmente melhorar os resultados em casos de aneurismas tanto simples quanto complexos.

Keywords

intracranial aneurysm - embolization - therapeutic - coils

Palavras-chave

aneurisma intracraniano - embolização - terapêutico - molas

Introduction

Endovascular coil embolization is a well-established treatment for cerebral aneurysms, but coil migration remains a rare and important complication that can occur either during or after the procedure.[1] Delayed coil migration, although infrequent, has been reported and is particularly associated with small, broad-based aneurysms, often presenting technical challenges for neuro-interventionalists.[2] In some cases, patients may remain asymptomatic despite migration, and management strategies such as stent-assisted techniques can be effective in securing the migrated coil and preventing further complications.[3] The choice between conservative management, endovascular retrieval, or surgical intervention depends on the clinical scenario, with endovascular techniques like snare or stent retriever devices often preferred for immediate retrieval when necessary.[4] Awareness of the risk factors and prompt recognition of coil migration are essential for optimizing patient outcomes in the treatment of cerebral aneurysms.[5] This will describe a case of successful recovery of a migrated coil following cerebral aneurysm embolization.

Results

An elderly patient with a history of uncontrolled hypertension presented with a sudden onset of severe headache, which progressed to right-sided hemiparesis, aphasia, and altered mental status. Non-contrast cranial computed tomography (CT) revealed a diffuse SAH with intraventricular extension and a thick hematoma in the Sylvian fissure. Additionally, an intraparenchymal hemorrhage was identified in the left temporal lobe, measuring 6,0 × 2,1 cm in its largest axial dimensions. Angio-CT scan identified a lobulated saccular aneurysm at the bifurcation of the left middle cerebral artery (MCA). The patient was promptly transferred to the interventional neuroradiology unit for emergency endovascular embolization of the aneurysm ([Fig. 1]).

Fig. 1 (A) Axial non-contrast computed tomography demonstrating subarachnoid hemorrhage, mainly located ate the left silvian fissure. (B, C) Anteroposterior and lateral views of a left internal carotid angiogram revealing an aneurysm arising from the bifurcation of the left MCA (white arrow). (D) Three-dimensional volumetric reconstruction of DSA depicting a multilobulated, irregular aneurysm at the MCA bifurcation.

Although the procedure of implanting the coil was successful, it was found to be protruding. Consequently, the microguidewire-assisted technique was utilized to reposition the protruding coil loop back into the cast after an unsuccessful attempt to position it with a balloon. Additionally, the use of stents was discarded due to the need to use dual antiplatelet therapy, which is accompanied by a higher risk of rebleeding.[6]

The procedure used the distal tip of a Synchro 0.014 microguidewire that was shaped into a “J” and inserted into the SL-10 microcatheter. This system was advanced to approximately 1 cm proximal to the MCA bifurcation. In sequence, the distal tip of the microguidewire was directed toward the inferior MCA trunk, serving as a fulcrum for the maneuver. Then the microguidewire was advanced distally, exerting controlled pressure on the protruding coil. Once stabilized, the microguidewire and microcatheter were further advanced, generating sufficient force to reposition the coil back into the cast ([Figs. 2] and [3]).

Fig. 2 Step-by-step technique. (A) Angiographic visualization of the protruding coil loop within the MCA. (B) A microguidewire with a “J”-shaped tip is advanced until it gains support from the inferior trunk of the MCA. (C) The microguidewire is further advanced independently, allowing it to curve and create the lever-like effect. (D) Maximum tension is applied to the microguidewire alone until it reaches a point where it no longer exerts sufficient radial force on the coil. (E) At this stage, the microguidewire and microcatheter are advanced together to push the protruding coil back into the cast. (F) Final fluoroscopic acquisition demonstrating the successful repositioning of the protruding coil.

Fig. 3 Schematic Illustration of the Microguidewire-Assisted Technique. The microguidewire exerts force on the protruding coil through a lever-like mechanism to reposition it into the coil cast. (A) Traditional technique using the arterial branch post-bifurcation as the fulcrum. (B) Alternative technique using the parent artery itself as the fulcrum.

Postoperative imaging confirmed successful coil repositioning without ischemic or hemorrhagic complications. The patient developed moderate vasospasm, which was managed medically, and showed significant functional recovery in three months, with mild residual hemiparesis.

Importantly, this technique allowed for high technical success without adding devices or costs, and avoided dual antiplatelet therapy, making it a highly practical option for urgent and complex cases. Its ability to increase technical success and reduce complication rates positions it as a promising tool to improve overall outcomes in endovascular aneurysm treatment.

Discussion

As a treatment for brain aneurysms, coil placement is accompanied by certain complications depending on the site of the aneurysm, the surgical technique, and other patient-specific characteristics and comorbidities.[7] These include: thromboembolic events, aneurysm rupture, incomplete occlusion, infection, and protrusion. In this sense, the latter is responsible for an elevation in the risk of sequelae when it migrates, as it is a cause of thromboembolic events, perforation, erosion, and even rebleeding.[8]

Under this perspective, when there are indications of a possible migration event, it becomes necessary to correct the coil's placement in the most effective and yet less distressing approach. One of the techniques broadly used, with diverse adaptations and variations, is the snare-assisted retrieval technique, which generally consists of the capture and repositioning or removal of the displaced coil using a microsnare device that loops around the coil under fluoroscopic guidance.[9] [10] [11] However, this form of intervention is found to be more commonly used in cases of migration and not necessarily in the correction of the position of a protruding coil.[11]

Regarding the use of the procedure described in this paper, it would be recommended in cases where the protruding coil could not have its position resolved with conventional treatment.[12] This intervention has a more extensive reach in narrower vessels, as it has a lower caliber and a high level of maneuverability, allowing it to nudge and be redirected to the affected region. It also reduces the need for coil removal due to its capability of correcting coil placement. Other benefits include the already cited: additional option in the failure of previous procedures and the avoidance of the risk of rebleeding that accompanies the use of stents.

The Microguidewire-Assisted Repositioning technique is still a procedure that is not much explored in the literature and still has some limitations since the success of the procedure is closely associated with the surgeon's experience, and its practicality does not include other coil-associated complications if not protrusion. In this scenario, this technical note strengthens the feasibility of microguidewire-assisted repositioning as a procedure that is favorable to the patient's outcome. Yet, it is noticeable that further studies with comparison populations would be valuable to better establish standardized protocols and to ascertain the comparative safety and efficacy of this technique versus traditional coil retrieval methods.

Conclusion

In conclusion, this article highlights the safety and effectiveness of the microguidewire-assisted technique for coil repositioning during the endovascular treatment of complex cerebral aneurysms. Faced with a critical scenario involving diffuse subarachnoid hemorrhage, temporal hematoma, and significant neurological deficits, prompt and precise intervention was essential for a favorable outcome. The use of a shaped microguidewire enabled successful coil repositioning in a minimally invasive manner, without the need for additional devices or dual antiplatelet therapy, thereby reducing the risk of thromboembolic complications and procedural costs. The patient's favorable clinical recovery further supports this technique as a viable, safe, and cost-effective tool in the endovascular management of challenging aneurysms, particularly in emergent settings.

Conflict of Interest

The authors declare no conflict of interest

• References

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Publikationsverlauf

Eingereicht: 13. August 2025

Angenommen: 10. November 2025

Artikel online veröffentlicht:
29. Dezember 2025