Experimental and clinical studies on artificial bladder reflex arc after spinal cord injury / 中华显微外科杂志

ABSTRACT

Objective To establish an artificial reflex arc to reinnervate the nerropathic bladder and restore bladder function after spinal cord injury. It involves a somatic reflex are with a modified efferent branch which passes the somatic motor impulses to the bladder and initiate autonomic bladder detrusor contraction. Methods This is achieved by intradural microanastomosis of the right L5 ventral root to S2 ventral root in canines. After a-conal regeneration,the pateller ligament-spinal cord center-bladder new artificial bladder reflex pathway was extablished. The early and final function of the reflex are was observed by electrophysiological experiments, bladder pressure tests and detrusor electromyograms (EMG)' Surgical operation of bilateral intradural microanastomosis of the L5 ventral roots to the S2 ventral roots was done in a 20 years old male patient with upper thoracispinal paraplegia. Results Single stmuli (115 mV, 1. 0 ms) of the right L, dorsal root resulted in evoked potentials recorded from the right S2 ventral root distal to the anastomosized site in all 6 canines. In 4 canines 6 months postoperation and 48 hours after spinal cord was transected, bladder contraction was very quickly initiated by trains of stimuli (l 000 mV, 10 Hz, 2 s) of the right L5 dorsal root and bladder pressures increased rapidly to average 65% of normal compared to controls' Bladder contraction induced by knocking the right pateller ligament increased to average 51 % of controls througt the new reflex arc. In 2 canines 18 months postoperation,bladder pressures increased by the same stimuli to average 84% of controls and to average 62% of controls by knocking the pateller ligament. Stimuli (3. 8 mA, 1' 0 Hz) of the right L5 dorsal root and femoral nerve resulted in EMG recorded from the detrusor in 2 canines 18 months postoperation. The patient achieved controllable micturition by calcaneus tendon-spinal cord center-bladder new artificial bladder reflex pathway at 14 months postoperation. Micturition was very quickly initiated by passive dorsalflexion of either lateral ankle joint,and the results of bladder function was excellent at postoperation. Conclusion The somatic motor a-cons can regenerate into the parasympathetic endoneurial tubes of autonomic nerve. Using the survived somatic reflex under the horizon of spinal cord injury to reconstruct the bladder autonomic reflex arc by intradural microanasto- mosis of ventral root is successful in the first patient and have a potential of clinical application.