[Technical solution to a complication caused by intra-arterial catheterization]

Knot formation in the distal segment of an angiographic catheter is not very frequent. Its early recognition, as well as domination of several techniques in order to untie it, may avoid surgery. An unique technique in order to untie a knot in a catheter is described, which consists in using other more rigid catheter with "J" shaped end by contralateral femoral via and under direct fluoroscopic visualization, with image magnifier and fitted TV.