Reduction of bladder outlet resistance by selective stimulation of the ventral sacral root using high frequency blockade: A chronic study in spinal cord transected dogs
Reduction of bladder outlet resistance by selective stimulation of the ventral sacral root using high frequency blockade: A chronic study in spinal cord transected dogs
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DOI：
10.1016/s0022-5347(05)66051-x
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发表时间：
2001-08-01
影响因子：
6.6
通讯作者：
Elhilali, MM
中科院分区：
文献类型：
--
作者：
Abdel-Gawad, M;Boyer, S;Elhilali, MM
用途：使用电神经刺激作为神经源性膀胱的治疗是复杂的同时收缩的横纹括约肌。这一结果是由于腹侧骶骨根的组成，其中包含支配尿道外括约肌的躯体纤维和支配逼尿肌的节前副交感神经纤维等。躯体纤维具有比副交感神经纤维更大的口径，并且作为大直径纤维，需要比较小纤维更低的刺激幅度来激活。较小纤维的活化总是伴随着较大纤维的活化。我们研究了慢性应用程序的选择性结合低，高频率电流刺激的腹侧骶神经根膀胱排空和尿道阻力的慢性脊髓（脊髓横断以上的脊髓排尿中心）的雄性狗每天膀胱evaluation.Materials和方法：共14只雄性杂种狗，体重20至25公斤。在T10椎骨处进行了脊髓横切S2腹侧骶神经根包裹有连接到皮下微刺激器的双极电极。每天通过神经刺激进行膀胱排空，并测定排尿量和残余尿量，持续8个月。在1个月的脊髓休克阶段，动物仅用低频电流刺激。随后应用低频刺激和高频阻滞电流组合的选择性参数6个月。在最后一个研究月，再次单独用低频电流刺激动物。每月评估膀胱和尿道压力以及尿道外括约肌和骨盆底肌肉的肌电图。对慢性刺激的神经和外括约肌进行了组织学检测。结果：14只狗中有12只完成了随访研究。在仅应用低频刺激的休克阶段，动物排泄了平均功能性膀胱容量的26%，逼尿肌活动早期恢复。平均逼尿肌压力±平均值的标准误差为76.4 ± 21.6 cm。水，而平均尿道压力为83.6 +/- 16.8 cm。水在应用选择性组合低频和高频刺激期间，7只动物（58%）完全排空膀胱，排尿后残余尿小于平均个体功能性膀胱容量的10%，5只动物（42%）的平均排尿后残余尿小于平均个体膀胱容量的20%。平均逼尿肌压力为73.5 ± 20 cm。水和平均尿道压力为44 +/- 7.3 cm。水外括约肌的平均肌电图活动减少了45.19%。刺激的狗的最后一个月，由低频电流导致平均膀胱容量的33%的平均尿道压力和肌电图activity.Conclusions的增加排尿：这些结果减少外括约肌活动的同时应用高频电流阻滞的躯体纤维和激活的自主神经纤维的膀胱低频刺激是有前途的。
Purpose: The use of electrical neural stimulation as treatment for neurogenic bladder is complicated by simultaneous contraction of the striated sphincter. This result is due to the composition of the ventral sacral roots, which contain somatic fibers innervating the external urethral sphincter and preganglionic parasympathetic fibers innervating the detrusor, among others. The somatic fibers have a larger caliber than the parasympathetic fibers and, as large diameter fibers, need a lower stimulus amplitude for activation than smaller fibers. Activation of the smaller fibers is always accompanied by activation of the larger fibers. We studied the effect of chronic application of selective combined low and high frequency current stimulation of the ventral sacral root on bladder evacuation and urethral resistance in chronically spinalized (spinal cord transected above the spinal micturition center) male dogs for daily bladder evacuation.Materials and Methods: A total of 14 male mongrel dogs weighing 20 to 25 kg. underwent transection of the spinal cord at the T10 vertebra. The S2 ventral sacral root was wrapped with a bipolar electrode connected to a subcutaneous microstimulator. Daily bladder evacuation by neural stimulation with determination of the voided and residual urine volumes was done for 8 months. The animals were stimulated only with low frequency current during the 1-month spinal shock phase. Selective parameters of combined low frequency stimulation and high frequency blockade currents were subsequently applied for 6 months. For the last study month the animals were again stimulated by low frequency current alone. Bladder and urethral pressure as well, as electromyography of the external urethral sphincter and pelvic floor muscles were evaluated monthly. Histopathological testing of the chronically stimulated nerve and external sphincter was performed.Results: Of the 14 dogs 12 completed the followup study. During the shock phase with the application of low frequency only stimulation the animals voided 26% of mean functional bladder capacity with the early return of detrusor activity. Mean detrusor pressure plus or minus standard error of mean was 76.4 +/- 21.6 cm. water, while mean urethral pressure was 83.6 +/- 16.8 cm. water. During the application of selective combined low and high frequency stimulation 7 animals (58%) evacuated the bladder completely with post-void residual urine less than 10% of mean individual functional bladder capacity and 5 (42%) had mean post-void residual urine less than 20% of mean individual bladder capacity. Mean detrusor pressure was 73.5 +/- 20 cm. water and mean urethral pressure was 44 +/- 7.3 cm. water. There was a 45.19% reduction in the mean electromyography activity of the external sphincter. Stimulation of the dogs for the last month by low frequency current resulted in the voiding of 33% of mean bladder capacity with an increase in mean urethral pressure and electromyography activity.Conclusions: These results of reducing external sphincter activity by the simultaneous application of high frequency current blockade of the somatic fibers and activation of the autonomic fibers of the bladder by low frequency stimulation are promising.