Shaker H S, Tu L M, Robin S, Arabi K, Hassouna M, Sawan M, Elhilali M M
Urology Research Laboratory, Royal Victoria Hospital, McGill University, Montreal, Quebec, Canada.
J Urol. 1998 Sep;160(3 Pt 1):901-7. doi: 10.1016/S0022-5347(01)62830-1.
Detrusor-sphincter dyssynergia is a main problem in supra-sacral spinal cord injured patients. The problem of high pressure voiding is also encountered in most electrically induced micturition because of the mixed somatic and autonomic fiber components of the ventral sacral root. We studied the effect of selective high-frequency blockade at the sacral nerve root in an acute spinalized canine model to prevent the deleterious consequences associated with the elevated bladder outlet resistance. A new functional electrical stimulation system which can generate one signal composed of two independent adjustable current waveforms delivered via a single bipolar electrode was used in 11 dogs. The selectivity resulted from the inhibition of the sphincteric somatic innervation by a high frequency pulse while the low frequency stimuli activated the bladder autonomic fibers. Bladder and urethral pressure as well as electromyograms of external urethral sphincter were recorded to determine whether selective high-frequency blockade occurred. Our experiments showed that we were able to achieve selective blockade of the external urethral sphincter during the simultaneous detrusor stimulation, thus obtaining a more physiologic voiding.
逼尿肌-括约肌协同失调是骶上脊髓损伤患者的一个主要问题。由于骶前神经根中存在混合的躯体和自主神经纤维成分，大多数电诱导排尿也会遇到高压排尿问题。我们在急性脊髓损伤犬模型中研究了骶神经根选择性高频阻滞的效果，以防止与膀胱出口阻力升高相关的有害后果。一种新的功能性电刺激系统被用于11只犬，该系统可以通过单个双极电极产生由两个独立可调电流波形组成的一个信号。这种选择性源于高频脉冲对括约肌躯体神经支配的抑制，而低频刺激则激活膀胱自主神经纤维。记录膀胱和尿道压力以及尿道外括约肌的肌电图，以确定是否发生了选择性高频阻滞。我们的实验表明，在同时进行逼尿肌刺激时，我们能够实现对尿道外括约肌的选择性阻滞，从而获得更生理性的排尿。
