Management of brain AVM procedural hemorrhagic complication by the “security” catheter technique

Summary

Since the introduction of Onyx as a liquid embolic agent for the treatment of brain arteriovenous malformation (AVM), higher endovascular cure rates have been achieved. This may be partially attributed to its non-adhesive property, which allows longer intranidal progression of the embolic agent before solidification. However, Onyx reflux around the microcatheter can form a highly viscous plug, thereby constraining the microcatheter during its retrieval. Also, during the maneuver, arterial stretching can lead to vascular rupture and result in acute bleeding, a potentially fatal complication that demands immediate treatment. This report describes a new treatment strategy for the rapid management of such a complication. The technique consists of the placement of a second microcatheter about 2 cm proximal to the AVM nidus in the same artery containing the intranidal microcatheter. After conclusion of embolization, if rupture occurs during intranidal microcatheter retrieval, the second microcatheter that is already in place can promptly be used to control the bleeding.

Introduction

The treatment of intracranial arteriovenous malformation (AVM) is still considered a complex procedure that frequently involves the association of two or even three different techniques [1], such as endovascular embolization, neurosurgery and radiosurgery. In its earlier days, the availability of permanent liquid embolic material for endovascular AVM embolization was restricted to only adhesive embolic agents. The initial experience with these embolic agents revealed low cure rates [2], as they played only a secondary role as adjunctive therapy for surgery or radiosurgery [3], [4]. However, since the introduction of Onyx (ev3, Irvine, CA, USA), a non-adhesive embolic material, higher rates of complete AVM occlusion have been obtained by endovascular embolization as the sole treatment, as shown by several studies [5], [6].

Nevertheless, although Onyx has no adhesive properties, its deposition around the microcatheter can form a high-viscosity plug, imprisoning the microcatheter and making its removal difficult and, in some cases, impossible without vascular tearing. The complication is directly related to the amount of Onyx reflux around the catheter, duration of the injection and tortuosity of arterial access.

Rupture of the arterial pedicle during microcatheter retrieval is a serious and potentially fatal complication. The immediate treatment of this complication is mandatory, requiring prompt endovascular closure of the bleeding point. For this reason, this report describes a simple technique to optimize prompt control of the complication in selected cases where such rupture may be more prone to happen.