A new method for uncoiling knots in angiographic tubing

Techniques for uncoiling knots formed in catheters during angiography have been the subject of several previous reports. A new technique for catheter unknotting is presented, based on the use of graded flexibility guidewires. The application of this graded taper method appears particularly pertinent to uncoiling softer, narrow-caliber, adversely looped catheters. Moreover, the mechanisms of knot uncoiling in the previous reports are reassessed and their imprecisions corrected.