Superselective Coaxial Microballoon-Occluded Coil Embolization for Vascular Disorders: A Preliminary Report

Feasibility of the Glue-in-Plug Technique Using a Novel Liquid Embolic Material in a Swine Model

PURPOSE

To evaluate the feasibility of the glue-in-plug (GIP) technique using n-butyl-2-cyanoacrylate‒Lipiodol (NL)-iopamidol (NLI) for short-segment embolization in swine.

MATERIALS AND METHODS

The renal arteries, left external iliac artery, subclavian arteries, and common carotid arteries were each embolized in 4 swine using the GIP technique under general anesthesia. First, a type I Amplatzer vascular plug (AVP) (1-2 times the target vessel diameter) was deployed in the target artery. Next, the AVP was filled with NL mixture prepared at a ratio of 1:2 (NL12) (n = 11) or with NLI mixture prepared at a ratio of 2:3:1 (NLI231) (n = 11). Angiography was performed before, immediately after, and 1 hour after embolization to assess embolization and migration of the embolic materials. The embolized arteries were also evaluated histopathologically.

RESULTS

The migration distance of the embolic material beyond the plug tip was significantly shorter in the NLI231 group than in the NL12 group immediately after embolization (6.5 mm ± 4.5 vs 1.0 mm ± 1.8, P = .0024) and 1 hour after embolization (8.4 mm ± 5.6 vs 1.0 mm ± 1.8, P = .0013). Angiography revealed no sign of recanalization of the target vessels in any artery in either group. Mild inflammatory cell infiltration was observed around the arterial wall at the embolization site in all arteries in both groups.

CONCLUSIONS

The GIP technique using NLI231 may be a feasible procedure for short-segment embolization based on these short-term results.

Transcatheter arterial embolization for unruptured renal angiomyolipoma using a 1.8-Fr tip microballoon catheter with a mixture of ethanol and Lipiodol

Background

To evaluate the efficacy and safety of transcatheter arterial embolization for renal angiomyolipoma using a 1.8-French tip microballoon catheter and a mixture of ethanol and Lipiodol.

Methods

Seven consecutive patients with total of eight angiomyolipomas underwent this procedure between June 2014 and June 2017. A 1.8-French tip microballoon catheter was advanced to the feeding artery of the angiomyolipoma, and transcatheter arterial embolization was performed with a mixture of ethanol and Lipiodol under microballoon inflation. We retrospectively evaluated the characteristics of angiomyolipomas, technical success rate, clinical success rate, renal function, and adverse events. Technical success and clinical success were defined as complete embolization of all feeding arteries and reduction of tumor size, respectively.

Results

The median size of the angiomyolipomas was 46 mm (range, 40–64 mm). Transcatheter arterial embolization was successful in all eight angiomyolipomas. The median volume of the mixture of ethanol and Lipiodol was 6.0 ml (range, 2.0–14 ml). The median ratio of ethanol to Lipiodol was 71% (range, 71–75%). All eight angiomyolipomas shrank with a median shrinkage rate of 34% in diameter (range, 9–63%) and 77% in volume (range, 48–94%). The median follow-up period was 13 months (range, 9–54 months). Clinical success was achieved in all cases. Serum creatinine concentrations and the pre- and post-procedural estimated glomerular filtration rates did not change notably, and there were no major complications.

Conclusion

Transcatheter arterial embolization for renal angiomyolipoma using a 1.8-French tip microballoon catheter with a mixture of ethanol and Lipiodol is effective and safe.

Treatment of Periorbital and Palpebral Arteriovenous Malformations

Objectives: To clarify clinically challenging palpebral arteriovenous malformations (AVMs) and to propose a novel therapeutic modality, we developed a multi-disciplinary approach for the management of AVMs with ulcer. Approach: First, the central retinal artery was secured with embolization by the transophthalmic arterial, a terminal branch of the internal carotid artery (ICA), and then, the branches of the external carotid artery (ECA) were embolized to cause a response in the AVM vasculature followed by sclerotherapy and surgery. Results: Over a 3-year follow-up of palpebral and periorbital AVMs in four females and one male 20 to 50 years of age with a mean age of 38 years, complete remission of the lesions were seen with no major complication, such as blindness, ptosis, or cerebral infarction, with functionally sound and esthetically acceptable results, with no recurrence or worsening even with one case of ulceration postembolization. Innovation: Planned treatment of palpebral and periorbital AVMs, which have been often left untreated because of their complex vasculature and a risk of total blindness due to occlusion of the central retinal artery. A "wait-and-watch" approach is frequently taken. It is important to secure the periphery to the bifurcation of the central retinal artery of the ICA, and then, embolization through the ECA results in complete remission of the lesion, followed by sclerotherapy and surgery, which are successful both in terms of function and esthetics. Conclusion: First, securing the central retinal artery leads to safer and complete resolution of palpebral and periorbital AVMs; wounding or therapeutic complications such as skin necrosis may be seen, but this approach results in complete remission in 3 years with no major complications.