Onyx migration in the endovascular management of intracranial dural arteriovenous fistulas

Hairball-Like Migration of "Onyx Threads" into the Draining Vein during Transarterial Embolization of a Dural Arteriovenous Fistula: A Case Report and Experimental Validation

Transarterial embolization using Onyx is a well-established treatment for dural arteriovenous fistulas (DAVFs). However, complications can arise when Onyx migrates into the venous side, impairing the draining veins. We encountered a case where Onyx, injected through the arterial side, strayed into the jugular vein, forming a hairball-like structure. Our study aimed to investigate the underlying mechanism of this unusual phenomenon. We postulated that Onyx precipitates into thread-like shapes when passing through extremely narrow openings. To test this, we extruded Onyx from a syringe through a 27-gauge needle into a silicone tube with flowing water. By varying the flow speed, we observed the hardening behavior of Onyx. Under slow flow, the extruded Onyx quickly solidified at the needle tip, forming a round mass. Conversely, high-speed flow resulted in Onyx being dispersed as small pieces. We successfully replicated the formation of "Onyx threads" under continuous slow flow conditions, similar to our case. This phenomenon occurs when Onyx unexpectedly migrates to the draining vein through a tiny opening during transarterial embolization for arteriovenous shunt diseases. Early recognition and appropriate measures are necessary to prevent occlusive complications in the draining veins and the pulmonary system.

Migration of vascular embolisation material from the intravascular space to surrounding interstitial tissues in arteriovenous malformations

We present the case of a young man active duty in the military who initially presented with pelvic pain and fullness during sexual activity. Extensive workup showed a large pelvic arteriovenous malformation (AVM). He underwent over 10 interventional radiology procedures to embolise his AVM and suffered multiple postoperative complications resulting in exploratory laparotomies, bowel resections and ultimately a colostomy. Six years after his embolisation procedures, he was found on imaging to have gluteal fluid collections with metallic particles, presumed to be migrated Onyx from his angioembolisations as a result of non-target embolisation. Current literature does not document other instances of Onyx material migrating from an intravascular source to interstitial tissue.

A Case of Curative Onyx Embolization for Tentorial dAVF via Low-flow Feeders with Temporary Balloon Occlusion of High-flow Feeders

Objective

For curative Onyx embolization of dural arteriovenous fistulas (dAVF) with multiple feeders, it is essential to select the optimal target artery as well as to control the blood flow at the fistula point. We report a case of tentorial dAVF (TdAVF) treated by Onyx embolization under flow control using balloon catheters.

Case Presentation

A 66-year-old male was admitted to our hospital for treatment of TdAVF detected incidentally by MRI, which revealed a dilated and tortuous vein around the cerebellum. Cerebral angiography demonstrated a TdAVF, fed mainly by bilateral middle meningeal arteries (MMA) and bilateral occipital arteries (OA), with the fistula point at the torcular and venous drainage to the two superior vermian veins (SVVs). Onyx 18 was injected from the low-flow feeder of the MMA under flow control by occluding the high-flow feeder of the OA using balloon catheters, obliterating the arteriovenous shunt.

Conclusion

In treatment of TdAVF involving low- and high-flow feeders, Onyx embolization via the low-flow feeder with temporary balloon occlusion of other high-flow feeders is a useful method. This technique makes it easier for Onyx to penetrate the fistula point.

Retrieval of a migrated N-butyl-2 cyanoacrylate cast using a snare-kit system during dural AVF embolization: A case report

N-butyl-2 cyanoacrylate (NBCA) is a liquid embolic material that is widely used in various endovascular procedures because of its permanent and rapid vascular occluding effect regardless of the coagulation profile of the patient. However, NBCA migration to unintended vessels may result in serious complications. This report describes the retrieval of a migrated NBCA cast from the transverse-sigmoid sinus during dural arteriovenous fistula embolization using a transvenous snaring technique.

Delayed migration of Squid 18 following embolisation of a direct carotico-cavernous fistula

We report a case of delayed migration of Squid 18 following treatment of a direct carotico-cavernous fistula.

Surgical removal of embolic material after its unexpected migration through extracranial-intracranial anastomosis in the treatment of Barrow Type D carotid-cavernous fistula: case report

Endovascular occlusion via the transvenous route is the favored treatment for indirect carotid-cavernous fistulas (CCFs). However, transarterial embolization can be used as an alternative method in patients with an inaccessible venous route. The authors present the case of a 49-year-old woman with a 2-month history of chemosis and proptosis in her right eye. Angiography demonstrated a Barrow Type D CCF. Transarterial Onyx embolization through the accessory meningeal artery was performed after an unsuccessful transvenous approach. Unexpected Onyx migrations to the cerebral arteries were detected while injecting the embolic material. Three hours after failed attempts to retrieve the Onyx cast endovascularly, it was microsurgically removed from the right middle cerebral artery. To the authors' knowledge, this is the first report of the surgical removal of Onyx from a normal cerebral artery.

Efficacy and limitations of transarterial acrylic glue embolization for intracranial dural arteriovenous fistulas

The efficacy and limitations of transarterial acrylic glue embolization for the treatment of intracranial dural arteriovenous fistulas (DAVFs) were investigated. Thirty-four DAVFs treated by transarterial embolization using n-butyl cyanoacrylate were retrospectively reviewed. The locations of DAVFs were the transverse-sigmoid sinus in 11, tentorium in 10, cranial vault in 9, and superior sagittal sinus, jugular bulb, foramen magnum, and middle cranial fossa in 1 each. Borden classification was type I in 7, type II in 3, and type III in 24. Eight patients had undergone prior transvenous coil embolization. Complete obliteration rate was 56% immediately after embolization, 71% at follow-up angiography, and 85% after additional treatments (1 transvenous embolization and 4 direct surgery). Complications occurred in three patients, consisting of asymptomatic vessel perforations during cannulation in two patients and leakage of contrast medium resulting in medullary infarction in one patient. Transarterial glue embolization is highly effective for Borden type III DAVF with direct cortical venous drainage, but has limitations for Borden type I and II DAVFs in which the affected sinus is part of the normal venous circulation. Onyx is a new liquid embolic material and is becoming the treatment of choice for DAVF. The benefits of glue embolization compared to Onyx embolization are high thrombogenicity, and relatively low risks of cranial nerve palsies and of excessive migration into the draining veins of high flow fistula. Transarterial glue embolization continues to be useful for selected patients, and complete cure can be expected in most patients with fewer complications if combined with transvenous embolization or direct surgery.

Fistula component of cerebral arteriovenous malformations: morphologic change after stereotactic radiosurgery and outcome of embolisation

BACKGROUND

The angioarchitecture of arteriovenous fistulas (AVFs) of cerebral arteriovenous malformation (CAVM) after stereotactic radiosurgery (SRS) remain unclear. The purpose of this study is to report the angiographic change of AVF components of CAVMs after SRS and outcomes of endovascular embolisation.

METHODS

From 2002 to 2012, a total of 523 CAVMs had been treated primarily by SRS with more than 3-year latency. Among these databases, there were 19 patients with 21 AVFs undergoing embolization after SRS. We retrospectively analyzed the angioarchitecture of the CAVM to identify AVFs, morphologic change and outcomes of AVFs after SRS and embolisation.

RESULTS

Eight AVFs were in the periphery of CAVMs, the other 13 were in a central location. Eighteen of 21 AVFs remained constant in morphology after SRS, while three feeders of AVFs were associated with radiation arteritis. The causes of failure to identify AVFs before SRS were overlooked (n = 7) or there was superimposition with feeders, nidus and/or venous drains of CAVMs (n = 14). Total fistula occlusion was achieved in all 21 AVFs; residual CAVMs was totally obliterated by embolisation and/or additional SRS in 12 patients. One patient had a small procedure-related intracerebral hemorrhage. Mean follow-up period was 26 months.

CONCLUSIONS

Early detection of AVF components of CAVMs prior to SRS may be difficult, particularly those in a central location. However, most AVFs became evident and showed consistency in angiographic morphology after obliteration of the majority nidus parts of CAVMs. Endovascular embolisation is effective in managing these AVF components.

Coils and Onyx Embolization of Traumatic Carotid-Cavernous Fistula Caused by an Intradural Internal Carotid Artery Pseudoaneurysm

A rare case of traumatic carotid-cavernous fistula caused by an intradural internal carotid artery pseudoaneurysm arising from the intradural internal carotid artery is described. The presentation was similar to that of carotid-cavernous fistulae, with ocular pain, chemosis and proptosis being the common symptoms. The patient was successfully treated by transarterial coil and Onyx-34 embolization. A 40-year-old man presented with severe injury, including multiple fractures of ribs, clavicle scapula and blind left eye. He gradually recovered and was discharged after intensive treatment in a local hospital. But about 70 days after discharge, his left eye became gradually chemotic and he felt a pulsatile bruit in his left ear. A CT scan and DSA confirmed a large intradural pseudoaneurysm and the associated carotid-cavernous fistula. Angiography revealed a fistula between the intradural aneurysm and the cavernous sinus. The origin of the aneurysm was above the posterior communicating artery. The aneurysm was successfully obliterated with detachable coils and Onyx-34 with the protection of a Hyperglide balloon. Subsequent studies demonstrated no flow through the fistula and good opacification of the ipsilateral internal cerebral artery system. Intradural pseudoaneurysm associated with carotid-cavernous fistula is a rare sequel of trauma. It may be treated successfully with the use of transarterial coil and Onyx embolization.