Lagunas Amador C, Chen Po-Ju, Ruiz Luis, Jhand Amolak S, Baishya Nystha, Lempka Scott F, Gupta Priyanka, Bruns Tim M
Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA.
Biointerfaces Institute, University of Michigan, Ann Arbor, MI, USA.
Int Urogynecol J. 2025 Aug 13. doi: 10.1007/s00192-025-06238-3.
The relationship between pudendal neuromodulation and patient factors is not well understood. This observational study was aimed at identifying and quantifying physiological, demographic, and stimulation factors that significantly affect external anal sphincter (EAS) recruitment and outcomes in participants receiving pudendal neuromodulation for treatment of lower urinary tract symptoms and pelvic pain.
Participants (N = 16) provided demographic and diagnostic information upon entry to this observational study. EAS activation at different stimulation amplitudes and pulse widths was recorded during lead implantation. Magnetic resonance imaging and computed tomography were used to determine the distance of the electrodes on the implanted lead from the nerve. Linear mixed modeling was used to quantify the impact of each variable on EAS recruitment.
Participant sex, age, and body mass index did not significantly affect EAS recruitment. Participant diagnoses had significant relationships with EAS recruitment, likely because of unbalanced group sizes. A pulse width of 210 µs required less current than 60 µs (p = 0.005) and less charge than 450 µs (p = 0.02) to activate the EAS. Increased electrode-to-nerve distance decreased the magnitude of the EAS response (p = 0.0011), increased the EAS activation threshold (p < 0.001), and was related to reduced bladder symptom improvements.
Of the three tested pulse widths, 210 µs best balances current and charge for EAS recruitment. Minimizing the distance between the electrode and pudendal nerve should be a priority during lead implantation. External sphincter activation threshold and response magnitude could be useful clinical indicators of electrode-to-nerve distance.
阴部神经调节与患者因素之间的关系尚未完全明确。本观察性研究旨在识别和量化生理、人口统计学及刺激因素，这些因素会显著影响接受阴部神经调节治疗下尿路症状和盆腔疼痛的参与者的肛门外括约肌（EAS）募集情况及治疗效果。
16名参与者在进入本观察性研究时提供了人口统计学和诊断信息。在植入电极期间记录不同刺激幅度和脉冲宽度下的EAS激活情况。使用磁共振成像和计算机断层扫描确定植入电极上的电极与神经之间的距离。采用线性混合模型量化每个变量对EAS募集的影响。
参与者的性别、年龄和体重指数对EAS募集无显著影响。参与者的诊断与EAS募集有显著关系，可能是因为组间规模不均衡。激活EAS时，210微秒的脉冲宽度所需电流比60微秒时少（p = 0.005），所需电荷量比450微秒时少（p = 0.02）。电极与神经距离增加会降低EAS反应的幅度（p = 0.0011），提高EAS激活阈值（p < 0.001）且与膀胱症状改善程度降低有关。
在测试的三种脉冲宽度中，210微秒最能平衡激活EAS时的电流和电荷量。在植入电极期间，应优先考虑尽量缩短电极与阴部神经之间的距离。外括约肌激活阈值和反应幅度可能是电极与神经距离的有用临床指标。
