Identification of the anterior psoas sheath as a landmark for lumbar sympathetic block.

This clinical report demonstrates that identification of the psoas muscle via contrast media injection under fluoroscopy and the subsequent tenting and puncture of the psoas fascia with a 6-inch 22-gauge needle is a definite aid in the correct placement of the needle for lumbar sympathetic block. In ten patients in whom this technique was used, the needle position was subsequently proven to be correctly placed in all cases. The authors conclude that this method is a valuable adjunct in fluoroscopy-guided lumbar sympathetic block.