Caudal epidural pulsed radiofrequency
ProcedureThe patient lied in prone position. After cutaneous and subcutaneous anesthesia with 3 ml of 2% lidocaine, a 22- gauge 150-mm RF cannula with 20 mm active tip was advanced through the sacrococcygeal ligament into the caudal epidural space under floroscopic guidence. A few milliliters contrast was injected to observe the expansion of the epidural space. After correct needle placement was confirmed, an electrode was connected to the cannula, and stimulation was conducted with impedance measured between 250 and 350 Ohms A different sensation or feeling such as fullness, impression, tingling, pulling or plethora at the rectal and/or coccygeal region was observed by the patients when 50 Hz was applied with 0,4 to 0,7 V sensory stimulation. No leg muscle contraction was observed with 2 Hz motor stimulation at 2 V. PRF was performed for 600 s at 5 Hz using a 5-ms pulse width at 55 V, avoiding electrode tip temperatures above 42 C.