Technical feasibility of embolizing aneurysms with glue (N-butyl 2-cyanoacrylate): experimental study in rabbits

Abstract

Background and purpose: Liquid embolic agents may have potential as a therapeutic option to reconstruct a defective vessel wall. We evaluated the feasibility of transarterial glue embolization in surgically constructed carotid artery aneurysms.

Methods: Reconstruction of arterial wall defects with use of glue casts was performed in 16 surgically constructed aneurysms of carotid arteries in rabbits. Via the transfemoral route, glue was injected without balloon protection through a microcatheter into the aneurysmal sac with (n = 8) and without (n = 8) a framework of coils. To identify safe and effective methods, four concentrations (28%, 33%, 40%, 50%) of glue-iodized oil mixtures were used in four aneurysms each. Immediate (n = 16) and 2-month follow-up (n = 10) postembolization angiograms were obtained to evaluate the residual aneurysmal sac and the carotid artery patency.

Results: Continuous column injection of glue was possible in all aneurysms, without fragmented migration of the injected glue cast. Catheter sticking or breakage did not occur during catheter retrieval. Glue embolization without a framework of coils (n = 8) resulted in complete obliteration of the aneurysmal sac in five aneurysms and incomplete obliteration with a small residual lumen in three. Two aneurysms resulted in carotid occlusion after catheter removal. A follow-up angiogram (n = 4) showed decreased residual lumen in two aneurysms, no change in the complete aneurysm occlusion in one, and carotid occlusion in one. Glue embolization with a coil framework (n = 8) resulted in complete obliteration of the aneurysmal sac in six aneurysms and incomplete obliteration with a small residual lumen in two. A small amount of spillage occurred in one owing to the improper position of the microcatheter caused by a difficult neck angle to the parent artery. Follow-up angiograms (n = 6) showed decreased residual lumen in one of two aneurysms and no change of the complete occlusion in five of six aneurysms.

Conclusion: Effective glue embolization into the aneurysmal sac is technically feasible. Microcatheter position within the aneurysm, concentration of glue, and direction of the aneurysmal neck angle all must be considered. With a coil framework, glue injection was more complete, without deformity or spillage of the glue from the aneurysm.

Fig 1.

Aneurysm 1. Complete glue embolization of aneurysm without a coil framework. A, After obtaining this preembolization angiogram, 50% glue was injected for 2 minutes and 28 seconds under subtracted, real-time road-map fluoroscopy. B and C, Frozen images of early (B) and late (C) phases show slow enlargement of the cast without fragmentation. D and E, Angiograms obtained immediately after embolization (D) and at 2-month follow-up (E) show no residual lumen in the aneurysm and a patent carotid artery.

Fig 2.

Aneurysm 4. Partially embolized aneurysm without a coil framework. A, After obtaining this preembolization angiogram, 40% glue was injected for 1 minute and 26 seconds under subtracted, real-time road-map fluoroscopy. B–D, Frozen images of the early (B), middle (C), and late (D) phases show leakage of the cast along the wall. E and F, Angiograms obtained immediately after embolization (E) and at 2-month follow-up (F) show persistent occlusion of the carotid artery.

Fig 3.

Aneurysm 16. Complete embolization with a coil framework. A and B, After obtaining the preembolization angiogram (A), an 8 x 20-cm GDC was introduced into the aneurysm to make a coil framework (B) and 28% glue was injected for 2 minutes and 3 seconds under subtracted, real-time road-map fluoroscopy. C and D, Frozen images of the early (C) and late (D) phases. E and F, Angiorams obtained immediately after embolization (E) and at 2-month follow-up (F) reveal persistent obliteration of the aneurysm.

Fig 4.

Aneurysm 9. Partially embolized aneurysm after making a coil framework. A–C, After obtaining a preembolization angiogram (A), an 8 × 20-cm GDC was introduced into the aneurysm to make a coil framework (B) and 50% glue was injected for 1 minute 35 seconds under subtracted, real-time road-map fluoroscopy (C). Glue could not be further injected probably because of the premature cast within the microcatheter. D and E, Angiogram obtained immediately after embolization (D) shows a residual lumen within the aneurysm that appears smaller on the 2-month follow-up angiogram (E).

Fig 5.

Aneurysm 13. Glue spillage during injection after making a coil framework. A–C, After obtaining a preembolization angiogram (A), a 5 × 15-cm GDC was introduced into the aneurysm to make a coil framework (B), and 33% glue was injected for 33 seconds under subtracted, real-time road-map fluoroscopy (C). Note the acute angle of the aneurysmal neck to the parent carotid artery. D and E, Angiogram obtained immediately after embolization (D) shows a filling defect caused by spilled glue, which has been absorbed on the 2-month follow-up angiogram (E).