Neurointervention.  2023 Nov;18(3):190-194. 10.5469/neuroint.2023.00185.

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

• Ioku T
• Ohshima T
• Yokota M
• Matsuo N
• Miyachi S

• KMID: 2547281
• DOI: http://doi.org/10.5469/neuroint.2023.00185

Abstract

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.

Keyword

Complications; Dural arteriovenous fistula; Embolization; Onyx

Figure

• 

  Fig. 1. (A) Preoperative angiography. Anterior–posterior view of right external carotid angiography showing the dural arteriovenous fistula (DAVF). (B) Preoperative angiography. Lateral view of right external carotid angiography showing the DAVF. (C, D) Angiography during Onyx injection before migrating into the venous side (C: anterior–posterior view, D: lateral view). The white arrows indicate the Scepter balloon catheter (Terumo) in the right occipital artery. The black arrows indicate the Shouryu balloon catheter (Kaneka) in the transverse sinus. (E, F) Angiography during Onyx injection just after the migration into the venous side (E: anterior-posterior view, F: lateral view). The black arrowheads indicate a hairball-like structure in the right jugular vein. (G) A hairball-like foreign body seen in the jugular vein on fluoroscopic imaging (black arrowheads). (H) The foreign body (black arrowhead) was retrieved by clamping with a goose-neck snare and a 4-Fr diagnostic catheter (white arrow). (I) Photograph of the retrieved foreign body. (J) Postoperative angiography. Anterior–posterior view of the right external carotid angiography. (K) Postoperative angiography. Lateral view of right external carotid angiography showing that shunt reduction was achieved. (L) Onyx cast and coils placed in the transverse sigmoid sinus. R, right side; A, anterior direction.

• 

  Fig. 2. Photograph of the in vitro experiment. (A) Onyx was injected using a 27-gauge needle into water. (B) The Onyx was precipitated in a thread-like manner and accumulated as a hair-ball-like structure.

Reference

1. Mounayer C, Hammami N, Piotin M, Spelle L, Benndorf G, Kessler I, et al. Nidal embolization of brain arteriovenous malformations using Onyx in 94 patients. AJNR Am J Neuroradiol. 2007; 28:518–523.

2. Nogueira RG, Dabus G, Rabinov JD, Eskey CJ, Ogilvy CS, Hirsch JA, et al. Preliminary experience with onyx embolization for the treatment of intracranial dural arteriovenous fistulas. AJNR Am J Neuroradiol. 2008; 29:91–97.

3. Wang H, Lv X, Jiang C, Li Y, Wu Z, Xu K. Onyx migration in the endovascular management of intracranial dural arteriovenous fistulas. Interv Neuroradiol. 2009; 15:301–308.

4. Piechowiak E, Zibold F, Dobrocky T, Mosimann PJ, Bervini D, Raabe A, et al. Endovascular treatment of dural arteriovenous fistulas of the transverse and sigmoid sinuses using transarterial balloon-assisted embolization combined with transvenous balloon protection of the venous sinus. AJNR Am J Neuroradiol. 2017; 38:1984–1989.

5. Ohshima T, Yokota M, Ogura K, Koiwai M, Matsuo N, Miyachi S. Usefulness of a curved multiple reconstruction image for transarterial intravenous coil embolization of a dural arteriovenous fistula of the sphenobasal vein: a case report. NMC Case Rep J. 2022; 9:43–47.