Selective activation of the sacral anterior roots for induction of bladder voiding
Selective activation of the sacral anterior roots for induction of bladder voiding
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DOI：
10.1002/nau.20184
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发表时间：
2006-01-01
影响因子：
2
通讯作者：
Mortimer, JT
中科院分区：
文献类型：
--
作者：
Bhadra, N;Gr端newald, V;Mortimer, JT
目的：探讨选择性激活骶前根小直径轴突在电诱导膀胱排尿中的作用。材料和方法：在5只成年犬上进行急性实验。用三极电极植入双侧骶内根S2和S3。记录来自膀胱、近端尿路和外括约肌的压力。探测器和流量计监测流体流动。行完整的骶骨背根切断术。比较了两种类型的脉冲串在20赫兹的效果：准梯形脉冲(500微秒，500微秒指数衰减)和间断矩形脉冲(100微秒，2看开/2看关)。切断神经根前，应用矩形脉冲串(100微秒)激活所有纤维。实验设计为区组随机化，断根前后。结果：准梯形脉冲表现为括约肌激活受阻，平均最小电流为1.37 mA。所有脉搏类型的平均膀胱压均高于括约肌基础闭合压。近端尿路的压力模式与膀胱压力密切相关。在背根切断前，刺激引起括约肌压力增加，上升时间较慢。切断神经根后，选择性激活时括约肌压力随膀胱压力变化，准梯形刺激时排尿，矩形刺激间歇期排尿。结论：选择性脊神经前根激活联合脊神经后根切断术可为神经功能障碍患者提供一种可行的持续低压排尿方法。
Aim: We investigated the efficacy of selective activation of the smaller diameter axons in the sacral anterior roots for electrically induced bladder voiding. Materials and Methods: Acute experiments were conducted in five adult dogs. The interior sacral roots S2 and S3 were implanted bilaterally with tripolar electrodes. Pressures were recorded from the bladder and from the proximal Urethra and the external urethral sphincter. A detector and flow meter monitored fluid flow. A complete sacral dorsal rhizotomy was carried out. The effects of two types of pulse trains at 20 Hz were compared; quasitrapezoidal pulses (500 mu sec with 500 mu sec exponential decay) and interrupted rectangular (100 mu sec, 2 see on/2 see off). Before rhizotomy, rectangular pulse trains (100 mu sec) to activate all fibers were also applied. The experimental design was block randomized before and after rhizotomy. Results: Quasitrapezoidal pulses showed block of sphincter activation with average minimum current for maximum suppression of 1.37 mA. All pulse types evoked average bladder pressures above the basal sphincter closure pressure. The pressure patterns in the proximal urethra closely followed the bladder pressures. Before dorsal rhizotomy, stimulation evoked a superadded increase in sphincter pressures with slow rise time. After rhizotomy, the sphincter pressure patterns followed the bladder pressures during selective activation and voiding occurred during stimulation with quasitrapezoidal trains and in between bursts with interrupted rectangular stimulation. Conclusions: Selective activation of sacral ventral roots combined with dorsal rhizotomy may provide a viable means of low-pressure continuous voiding in neurological impairment.