Selective coil embolization through flow-directed microcatheter for intracranial arteriovenous malformations

Coil embolization of distal vascular lesion using a 1.5 Fr Marathon microcatheter and 'free-running' technique

In distal vascular lesions, such as the distal anterior inferior cerebellar artery or posterior inferior cerebellar artery (PICA) dissecting aneurysm, and dural arteriovenous fistula (dAVF) and arteriovenous malformation (AVM), super-selective catheterization and embolization using liquid agents, such as NBCA or Onyx liquid embolic system, is the preferred treatment.1 2 We used a flow-directed 1.5 Fr Marathon microcatheter (Medtronic, Minneapolis, MN, USA) for embolization because commonly used detachable coil-compatible microcatheters can be too short or rigid for superselection.3-6 We designed an in vitro coil compatibility test for the Marathon microcatheter and developed a 'free-running' technique (video 1). Using this technique, we trapped the distal PICA dissecting aneurysm and embolized the fistula points of dAVF precisely and safely without affecting adjacent normal structures, which can occur when applying liquid embolizing agents.1-3 After reviewing the case, we determined that this technique can also potentially be applied for implementing the pressure cooker technique7 and combining the management of AVM.4neurintsurg;jnis-2023-020893v1/V1F1V1Video 1Free-running technique via 1.5 Fr Marathon microcatheter.

Use of Detachable Coils Without the Need of a Double Marker Microcatheter: Technical Note

When using detachable coils for cerebral aneurysm embolization, it is necessary to place a microcatheter with radiopaque markers at 2 sites (tip and 3 cm proximal from the tip) in most cases. Detachable coils that can be positioned independently from the proximal marker may facilitate new applications utilizing their characteristics. Herein, we report 2 cases that were treated with new applications. Detachable coils that function to electrically detect the moment they come out of the microcatheter were used. In one patient with a large aneurysm with an irregular shape, coil embolization was applied by advancing the catheter more than 3 cm from the aneurysm neck to the caudally protruded compartment near the proximal end of the neck, which was difficult to reach with the coil. In the other patient with cerebral arteriovenous malformation (AVM), microcatheters for AVM without a proximal marker were used for coil embolization before Onyx injection: Coil embolization was applied through one microcatheter to a site more proximal than the tip of the other microcatheter, followed by Onyx injection through the distal catheter, by which the nidus was continuously penetrated from the initiation of injection, obtaining an effect similar to that of the plug and push technique. Through the use of detachable coils, which are not dependent on the visibility of the proximal marker, the limitation of catheter positioning is reduced and the applicable types of catheter increase, which may facilitate to enable its use for new clinical indications.

Coil embolization through the Marathon microcatheter: Advantages and pitfalls

Due to technical limitations, small, distal, and tortuous intracranial pathology is sometimes out of reach of the current armamentarium of microcatheters designed for intracranial coil embolization. The Marathon microcatheter (Medtronic, Minneapolis, Minnesota, USA), designed specifically for the delivery of Onyx, is longer and more flexible than most coil delivery catheters. We report on nine patients (three with arteriovenous fistula, three with arteriovenous malformation, two with intracranial aneurysm, and one with tumor) where Marathon was used to deliver commercially available platinum coils. We also conducted laboratory compatibility testing and conclude that the Marathon can be used as a coil delivery catheter for Barricade coils (Blockade Medical, Irvine, California, USA) with diameter less than 0.012 in.

A Novel Method for Super-selective Coil Embolization Using an Extremely Soft Bare Coil through a Liquid Embolic Delivery Microcatheter

Endovascular coil embolization for intracranial aneurysms, arteriovenous malformations (AVMs), dural arteriovenous fistulas (AVFs), and hypervascular tumors are recognized as an effective adjunctive or curative treatment. In this setting, it is sometimes difficult to navigate a coil delivery microcatheter to the target point of a tiny, tortuous vessel. We herein present a case series of a novel method that enabled super-selective coil embolization using an extremely soft bare, electrodetachable coil (ED extrasoft^® coil) through a liquid embolic delivery microcatheter (Marathon^®). The Marathon^® catheter was successfully placed at the target point of the tiny, tortuous vessel, and coil embolization was achieved in all 16 patients with 9 AVMs, 2 distal aneurysms, 2 AVFs, and 3 meningiomas. The primary ED extrasoft^® coil and delivery wire have a very small radius, and the coil is rapidly detachable with an alarm notice from the generator even under Marathon^® with one marker. We believe that this technique can provide safe and efficient embolization for selected patients.

Aneurysm coil embolization using a 1.5-fr distal outer diameter microcatheter

The current assortment of microcatheters widely used for aneurysm coil embolization may not be well suited for several anatomic variants, including excessive vascular tortuosity and small aneurysms less than 3 mm. Longer microcatheters designed with a smaller caliber that can accommodate and deliver coils may be of use in these situations. This case series and literature review illustrates the advantages and limitations of the Marathon microcatheter (Covidien, Irvine, CA, USA) when used for coil embolization of cerebral aneurysms. Despite some technical compromises including the distal marker, length, and the risk of buckling, the Marathon microcatheter was able to adequately deliver coils to achieve satisfactory occlusion of cerebral aneurysms. We found unique advantages with regards to length and smaller distal outer diameter (OD). These results may serve as a guide for the further development of a microcatheter used for coil embolization that has the features of a smaller distal OD and longer length.