OBJECTIVETo investigate the therapeutic mechanism of point 8L54-through-point ST2S acupuncture with elongate needles in treating urinary retention after spinal cord injury.

METHODSThirty-five healthy Japanese rabbits (weight 2.5 +/- 0.25 kg, 3 months old, male or female), used as experimental subjects, were divided into 4 groups involving blank group, model group, acupuncture group, elongate needles group (5 rabbits in blank group, 10 rabbits in each of the other group 10). Modified Allen's method was used to cause spinal cord injury model for the model group, the acupuncture group and the elongate needles group, the blank group was only sham surgery. Immediately after spinal cord injury model,the elongated needle group was given the bilateral acupoints of the elongated needle penetration needling and electric stimulation, electrical stimulation 15 mm stimulation frequency of 20 to 40 times/mm, intensity 1.5 to 3 V the acupuncture group immediately was given ordinary electric needle acupuncture, given other disposals as the elongated needle group; model group was not given electric needle acupuncture, waiting 15 minutes, started to detect and record the observed indicator as the elongated needle group; the blank group was only sham surgery. The following indicators including the Tarlov score ,urinary bladder pressure point, the threshold urination, voided volume, were observed in the first day and the fifth day after surgery.

RESULTSThree groups of animals which modeled were urinary retention after operation. Compared to 1 d, Tarlov score of model group, acupuncture group and elongate needles group significantly improved at postoperative 5 d (P < 0.05). Compared with acupuncture group, the Tarlov score of elongate needles group had no significant difference at postoperative 5 d (P > 0.05). Compared with model group, values of urinary bladder pressure point decreased with varying degrees in the acupuncture group and elongate needles group at postoperative 5 d (P < 0.05); relative to the acupuncture group, the point of the bladder voiding pressure in the elongate needles group decreased more significantly at postoperative 5 d (P < 0.05); compared with model group, micturition threshold of acupuncture group and elongate needles group had been significantly improved at the fifth day after surgery (P < 0.05); relative to the acupuncture group, the improvement is more obvious in the elongate needles group. Compared with model group, voided volume of acupuncture group and elongate needles group had increased significantly at the fifth day after surgery (P < 0.05); relative to the acupuncture group, the increment is more evident in the elongate needles group (P < 0.05).

CONCLUSIONTo treat urinary retention after spinal cord injury, the method, which was point-through-point acupuncture with elongate needles in the "Zhibian" and "Shuidao", was better than general acupuncture method. The therapeutic mechanism may be related to stimulate peripheral nerve of bladder, and to rectify the dysfunction between detrusor and sphincter.