Combined transarterial and direct puncture approach for embolisation of hepatic artery pseudoaneurysms

A 77-year-old woman with a history of bronchial carcinoid tumour and hypervascular liver metastases, treated with surgical resection (right upper lobectomy) and Lanreotide. During the follow-up new imaging findings of two hepatic artery pseudoaneurysms with fistula to the portal vein were incidentally discovered on CT.

A CT scan and angiography showed multiple hypervascular liver metastases and two pseudoaneurysms arising from the right hepatic artery, one of them with fistulisation to the portal vein (Fig. 1, 2).

Superselective embolisation of segmental branch with fibered microcoils and 1cc of cyanocrylate was performed. Post-embolisation angiography showed complete occlusion of the small pseudoaneurysm and of the portal vein fistula with recanalisation of the large pseudoaneurysm via small collateral branches of another segmental branch, this branch was catheterised and embolised with 500 microns particles. Control angiogram showed persistent filling of the pseudoaneurysm. A second attempt was made to treat the pseudoaneurysm percutaneously under ultrasound and fluoroscopic guidance, the pseudoaneurysm was punctured with a 21-gauge needle, contrast was injected through the needle and we were able to visualise the pseudoaneurysm. A total of 2cc of human thrombin was slowly injected into the pseudoaneurysm controlling the entire procedure with fluoroscopy guidance. Final angiography showed complete occlusion of the pseudoaneurysm (Fig. 3).

Hepatic artery aneurysm incidence is estimated at 0.002%, and approximately 50% of hepatic artery aneurysms are pseudoaneurysms [1].

Pseudoaneurysm formation occurs when there is a breach in the vessel wall with blood leaking through the wall but contained by the adventitia or surrounding soft tissue. Classically pseudoaneurysms arise secondary to blunt or penetrating abdominal trauma, iatrogenic hepatic, biliary or pancreatic procedures, rarely as sequelae to inflammatory pathologies of the same, due to atherosclerosis or intratumoral.

Intratumoural arterial pseudoaneurysm is an uncommon pathologic process, their development is thought to be directly related to vessel injury, vessel erosion, and tumour angiogenesis [2]. In our patient, the pseudoaneurysms appeared to occur de novo, with no previous percutaneous or endovascular treatment for the hypervascular metastases.

Several strategies for treatment of pseudoaneurysms have been described, in our case we performed a successful percutaneous embolisation of a hepatic artery pseudoaneurysm under combined endovascular, ultrasound and fluoroscopic guidance [3, 4, 5].

Compared to surgery, transarterial embolisation of pseudoaneurysms is considered the less invasive method [4, 5] but it is not always technically feasible. This may be due to either difficulties in visualising the anatomy of the arterial feeder, due to mechanical inability to maneuver the catheter to the desired location in the feeder artery or incomplete embolisation due to recanalisation via small collaterals. An alternative or complementary method can be a direct percutaneous puncture approach under ultrasound of fluoroscopic guidance.

Combined angiographic and fluoroscopy-guided percutaneous embolisation of intrahepatic pseudoaneurysms can be considered a feasible and effective treatment approach.

Written informed patient consent for publication has been obtained.