Endovascular Treatment of Visceral Artery Pseudoaneurysms with Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs)

Abstract

Background and Objectives: Treatment of visceral artery pseudoaneurysms (VAPs) is always indicated regardless of their diameters, as their risk of rupture is significantly higher than that of visceral artery aneurysms. The invasiveness of surgery and its associated complications have led to a shift in favor of radiological interventions as the initial treatment of choice. However, there are still some unanswered questions on endovascular treatment of VAPs regarding the optimal endovascular technique and the efficacy and safety outcomes. The purpose of this multicenter study was to retrospectively evaluate the effectiveness and safety of endovascular treatment of visceral pseudoaneurysms using Ethylene-Vinyl Alcohol (EVOH) Copolymer-Based Non-Adhesive Liquid Embolic Agents (NALEAs). Materials and Methods: Consecutive patients who underwent endovascular embolization with EVOH-based NALEAs for visceral artery pseudoaneurysms between January 2018 and June 2023 were retrospectively evaluated. Results: 38 embolizations were performed. Technical success was achieved in all patients. The clinical success rate was high (92.1% overall), with no significant differences between ruptured and unruptured VAPs (p = 0.679). Seven patients (18.4%) experienced procedure-related complications, related to one case of non-target embolization, four splenic abscesses due to end-organ infarction, and two femoral pseudoaneurysms. The rates of procedure-related complications, end-organ infarction, and vascular access-site complications did not significantly differ between ruptured and unruptured VAPs (p > 0.05). Conclusions: Both ruptured and unruptured visceral pseudoaneurysms can be effectively and safely treated with NALEA-based endovascular embolization. We suggest considering the use of NALEAs, particularly in specific clinical cases that highlight their advantages, including patients with coagulopathy, fragile vessels, and embolization targets that are located at a considerable distance from the microcatheter tip and are otherwise difficult to reach.

Keywords: Ethylene-Vinyl Alcohol; Onyx; embolic agents; embolization; endovascular treatment; non-adhesive liquid embolic agents; percutaneous; pseudoaneurysm; transcatheter arterial embolization; visceral pseudoaneurysms.

Figure 1

Flowchart of the selection of VAP cases treated with EVOH copolymer-based NALEAs. Abbreviations: VAP, Visceral Artery Pseudoaneurysm; NALEA: Non-Adhesive Liquid Embolic Agents; EVOH: Ethylene-Vinyl Alcohol.

Figure 2

In Figure (A), Computed Tomography angiography reveals spontaneous retroperitoneal bleeding attributed to a ruptured pseudoaneurysm (indicated by the arrow) originating from a renal tumor. Figure (B) shows digital subtraction angiography, which confirms the presence of a ruptured pseudoaneurysm arising from a feeding artery of the tumor (white arrowhead). Lastly, Figure (C) displays digital subtraction angiography, illustrating the successful embolization achieved using an Ethylene-Vinyl Alcohol copolymer cast (indicated by the black arrowhead). (From Minici et al. doi: 10.3390/medicina59040710, by MDPI, Basel, Switzerland, licensed under CC BY 4.0).

Figure 3

Ruptured Hepatocellular Carcinoma (HCC) within the hepatic parenchyma is depicted in the images. In the contrast-enhanced Computed Tomography, arterial phase, there is evidence of a 1 cm pseudoaneurysm within an HCC nodule (A). On the Magnetic Resonance Imaging (MRI) T1 Fast Field Echo In-Phase sequence, hyperintense material (blood) is observed within a large HCC nodule of the right lobe (B). Gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI in the arterial phase confirms the presence of an intranodular contrast blush (C). Superselective digital subtraction angiography of the S7 hepatic artery branch shows contrast leakage into the ruptured HCC (D). Successful embolization of the HCC nodule (indicated by the arrow) and the parent artery (indicated by the arrowhead) was achieved using Ethylene-Vinyl Alcohol (EVOH) copolymer (E,F). (From Minici et al. doi: 10.3390/medicina59040710, by MDPI, Basel, Switzerland, licensed under CC BY 4.0).

Figure 4

A young woman with a history of non-steroidal anti-inflammatory drug (NSAID) overuse experienced a sudden onset of hematemesis. During endoscopy, duodenal bleeding was observed but proved unresponsive to treatment. Advanced imaging techniques, including axial Computed Tomography scans (A) and multiplanar reconstruction (MPR) coronal reconstruction (B), revealed the presence of a pseudoaneurysm in the gastroduodenal artery. The celiac trunk was subsequently catheterized, confirming the presence of the pseudoaneurysm (arrow) close to the clip previously placed by the endoscopist at the site of bleeding (C). To address the condition, a superselective catheterization of the gastroduodenal artery was performed using a dimethyl sulfoxide (DMSO)-compatible microcatheter, followed by effective embolization using Ethylene-Vinyl Alcohol (EVOH) copolymer (D). The completion angiography confirmed the successful embolization, with the EVOH copolymer cast distributed along the gastroduodenal artery, ensuring no unintended embolizations to non-target areas (E).