How important is localization of the bleeding site before angiography?
Preangiographic localization of the GI bleeding site is extremely helpful.
A visceral arteriogram involves evaluation of the celiac, superior mesenteric, and inferior mesenteric arteries; selective catheterization of these vessels and the multiple angiographic projections needed when looking for a bleeding site can make this a tedious and time-consuming procedure, requiring large contrast volumes.
Localization of a bleeding vessel or even distinguishing an upper from a lower GI source is helpful, can guide the interventionalist in choosing which vessel should be studied first, and can shorten the procedure.