[A fluoroscopic analysis of the catheters abnormally placed in the epidural space]

In order to know how the catheters are placed abnormally in the epidural space, we inserted the epidural catheters under fluoroscopy. The catheter was placed straightly upward when the epidural puncture was done in the center of epidural space. When the puncture site was nearly close to the side wall of epidural space, we could not insert catheter at all. When the tip of the needle was near the side wall and the inserting catheter slipped upward, catheter was placed straight. When the catheter wedged at the side wall, it made loop and curled or kinked. We thought that the cause of abnormal location of the catheters in epidural space is the right angle between the wall of the epidural space and the direction of catheter.