[Experimental study on the artificial bladder reflex arc established in therapy of flaccid bladder after spinal cored...

To establish the artificial bladder reflex arc by the normal body reflex pathway above the horizon of spinal cord injury to reinnervate the flaccid bladder and restore bladder micturition function.

An intradural microanastomosis was performed on the L6 ventral root to the S2 ventral root. After axonal regeneration,the "patellar ligament-spinal cord center-bladder" reflex pathway was reestablished. A long-term function of the reflex arc was observed in the nerve electrophysiological experiment, detrusor electromyography experiment, and urodynamic testing 8 months after anastomosis.

Trains of the stimuli (200 microV, 5 ms) in the left L6 dorsal root and the nerve at the anastomosized site resulted in motor evoked potential from the distal to the anastomosized site before and after the spinal cord was destroyed horizontally between S1 and S4 segment levels in 2 Beagle dogs. The figure and amplitude of the evoked potential were similar to those of the control and general stability which showed a noninterventional wave. The urodynamic test revealed a rapid increase of the bladder pressure and a minor increase in the abdominal pressure. This showed that the bladder detrusor mainly resulted in the pressure increase. The bladder pressure increased to 60% of the normal on average compared with the controls when resulted in the left L6 dorsal root and the nerve anastomosized site were stimulated.

The long-term observation by the nerve electrophysiological experiment, detrusor electromyography experiment, and urodynamic test indicate that the new artificial reflex arc can be established successfully. The somatic motor axons can regenerate into the parasympathetic endoneurial tubes of the autonomic nerve.