EUS-guided Embolization of the Visceral Artery Aneurysm

Overview

Visceral Artery Aneurysm (VAA) refers to a localized or diffuse dilation or bulging of the arterial wall in the arteries supplying the gastrointestinal tract, liver, spleen, and pancreas (celiac trunk, superior mesenteric artery, inferior mesenteric artery, and their branches), caused by various pathological conditions or injuries. Among these, splenic artery aneurysms (60%) and hepatic artery aneurysms (20%) are the most common. Similar to cerebral aneurysms and aortic aneurysms, visceral artery aneurysms are a serious vascular disease that threatens human life, with an incidence of 0.2% to 2.0% in the population, second only to abdominal aortic aneurysms and iliac artery aneurysms. The main etiologies include atherosclerosis, degeneration of the arterial media, infection, fibromuscular dysplasia, congenital abnormalities, trauma, and arteritis. The incidence of visceral artery aneurysms ranges from 0.01% to 0.20%. Although the incidence is relatively low, the rupture rate can be as high as 25%, often leading to hemorrhagic shock or even death. The treatment of VAA primarily includes open surgical procedures such as aneurysm resection and vascular reconstruction, as well as endovascular interventions such as aneurysm embolization and covered stent graft placement. Endovascular embolization is the first-line treatment for VAA. This procedure involves puncturing the femoral artery using the Seldinger technique, advancing a microcatheter near the affected vessel, injecting high-pressure iodinated contrast to visualize the lesion, and then superselecting into the aneurysm or adjacent vessels to embolize the aneurysm or its outflow tract using coils or tissue adhesive. However, X-ray-guided treatment is relatively expensive and involves complex steps. Additionally, for small aneurysms, aneurysms with narrow necks, tortuous vessels, or patients allergic to iodine, surgical resection of VAA may be the only option. Surgical procedures are associated with significant trauma, high costs, and multiple complications. Endoscopic Ultrasound (EUS) involves an ultrasound probe attached to the tip of an endoscope, allowing imaging and fine-needle aspiration of the pancreas, gastrointestinal tract, posterior mediastinum, and retroperitoneum. Linear EUS can also identify abdominal vessels and blood flow signals via color Doppler. Therefore, after localizing the VAA with EUS, a fine-needle aspiration needle is advanced into the aneurysm. Through the needle tract, a 0.035-inch or 0.018-inch coil is deployed, and tissue adhesive is injected under direct visualization until the aneurysm is completely embolized (Figure 1). This technique has been reported in international literature.