Complications of phlebography: a randomised comparison between an ionic and a non-ionic contrast medium.

A high frequency of thrombotic complications of phlebography with conventional ionic contrast media has recently been reported by several writers. A switch to expensive non-ionic media has been recommended. Such a switch would undoubtedly place great restrictions on the use of this valuable procedure. In this prospective study two types of contrast media were compared. Only patients undergoing phlebography prior to operation for varicose veins and with no history of thrombotic disease were included. Post-phlebographic observations were made by microscopy of surgically removed vein specimens and by plethysmography. No significant difference emerged between the two groups of patients as regards thrombotic complications. A disadvantage of ionic media is their higher rate of immediate side-effects, such as pain. These effects, however, are clinically less important than the thrombotic complications, and they can be reduced by good phlebographic technique. In the authors' opinion, phlebography with ionic media remains justifiable, provided that the examination time is short and the dose and concentration of contrast medium are low.