Abdominal and Pelvic Aneurysms and Pseudoaneurysms: Imaging Review with Clinical, Radiologic, and Treatment Correlation

Abnormally enlarged visceral arteries in the abdomen and pelvis must be recognized radiologically because early treatment can improve the quality of life and prevent life-threatening complications. These lesions, typically classified as aneurysms and pseudoaneurysms, are being detected more frequently with increased utilization of imaging and have various causes (eg, atherosclerosis, trauma, infection) and complications that may be identified radiologically. Ultrasonography, computed tomography, and magnetic resonance imaging often enable detection of visceral vascular lesions, but angiography is important for further diagnosis and treatment. Endovascular treatment is often the first-line therapy. Endovascular intervention or open surgical repair is necessary for all visceral pseudoaneurysms and is likely indicated for visceral aneurysms 2 cm or more in diameter. Endovascular exclusion of flow can be achieved with coils, stents, and injectable liquids. Techniques include embolization ("sandwich" or "sac-packing" technique), exclusion of flow with luminal stents, and stent-assisted coil embolization. Management often depends on the location and technical feasibility of endovascular repair. Embolization is usually preferred for aneurysms or pseudoaneurysms within solid organs, and the sandwich technique is often used when collateral flow is present. Covered stent placement may be preferred to preserve the parent artery when main visceral vessels are being treated. It is usually tailored to lesion location, and a cure can often be effected while preserving end-organ arterial flow. Posttreatment follow-up is usually based on treatment location, modality accuracy, and potential consequences of treatment failure. Follow-up imaging may help identify vessel recanalization, unintended thrombosis of an artery or end organ, or sequelae of nontarget embolization. Retreatment is usually warranted if the clinical risks for which embolization was performed are still present.