Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA; Department of Urology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, PR China.
Department of Urology, University of Pittsburgh, Pittsburgh, PA, USA.
Exp Neurol. 2021 Dec;346:113860. doi: 10.1016/j.expneurol.2021.113860. Epub 2021 Sep 3.
The goal of this study is to induce low-pressure voiding by stimulation and bilateral 1 kHz post-stimulation block of the pudendal nerves. In anesthetized cats, wire hook electrodes were placed on the left and/or right pudendal nerves. Stimulus pulses (30 Hz, 0.2 ms) were applied to one pudendal nerve to induce a reflex bladder contraction and to produce contractions of the external urethral sphincter (EUS). High frequency (1 kHz) biphasic stimulation was applied to block axonal conduction in both pudendal nerves and block EUS activity. In 4 cats, a catheter was inserted into the distal urethra to perfuse and measure the back pressure caused by the EUS contraction. In another 5 cats, a catheter was inserted into the bladder dome and the urethra was left open to allow voiding. The 1 kHz stimulation (30-60 s, 0.5-5 mA) delivered via a wire hook electrode completely blocked pudendal nerve conduction for ≥2 min after terminating the stimulation, i.e., a post-stimulation block. The block gradually disappeared in 6-18 min. The block duration increased with increasing amplitude or duration of the 1 kHz stimulation. Without the 1 kHz block, 30 Hz stimulation alone induced high-pressure (90 cmHO) voiding. When combined with the 1 kHz block, the 30 Hz stimulation induced low-pressure (≤50 cmHO) voiding with a high voiding efficiency (80%). In summary, a minimally invasive surgical approach might be developed to restore voiding function after spinal cord injury by stimulation and block of the pudendal nerves using lead electrodes.
本研究旨在通过刺激和双侧 1 kHz 后刺激阴部神经阻断来诱导低压排尿。在麻醉猫中，将钩状电极放置在左侧和/或右侧阴部神经上。刺激脉冲（30 Hz，0.2 ms）施加到一根阴部神经上，以诱导反射性膀胱收缩，并产生尿道外括约肌（EUS）收缩。高频（1 kHz）双相刺激用于阻断双侧阴部神经的轴突传导并阻断 EUS 活动。在 4 只猫中，将导管插入远端尿道以灌注和测量 EUS 收缩引起的后压。在另外 5 只猫中，将导管插入膀胱穹窿，尿道保持开放以允许排尿。通过钩状电极施加的 1 kHz 刺激（30-60 s，0.5-5 mA）在刺激终止后至少 2 分钟内完全阻断阴部神经传导，即后刺激阻断。阻断在 6-18 分钟内逐渐消失。阻断持续时间随 1 kHz 刺激的幅度或持续时间增加而增加。没有 1 kHz 阻断，单独的 30 Hz 刺激会引起高压（90 cmHO）排尿。当与 1 kHz 阻断结合时，30 Hz 刺激会引起低压（≤50 cmHO）排尿，且排尿效率高（80%）。总之，通过使用导联电极刺激和阻断阴部神经，可能会开发出一种微创手术方法，在脊髓损伤后恢复排尿功能。
