Inferior phrenic artery: anatomy, variations, pathologic conditions, and interventional management.

The inferior phrenic artery (IPA) is the most common source of extra-hepatic collateral blood supply for hepatocellular carcinoma (HCC) and frequently supplies HCCs located in the bare area of the liver. Other pathologic conditions including hemoptysis, diaphragmatic or hepatic bleeding due to trauma or surgery, and bleeding caused by gastroesophageal problems (eg, Mallory-Weiss tear or gastroesophageal cancer) may be related to the IPA. Over a 4-year period, the authors performed 383 interventional procedures related to the IPA. The right and left IPAs originate with almost equal frequency from the aorta and celiac axis and with lesser frequency from the renal arteries. Various other sites of origin-such as the left gastric, hepatic, superior mesenteric, spermatic, and adrenal arteries-are also seen. Radiologists must be familiar with the normal spectrum of IPA anatomy so that detection and adequate interventional management can be achieved when pathologic conditions related to the IPA are present.