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Low pressure voiding induced by a novel implantable pudendal nerve stimulator
Author(s) -
Cai Haotian,
Morgan Tara,
Pace Natalie,
Shen Bing,
Wang Jicheng,
Roppolo James R.,
Horlen Kyle,
Khanwilkar Pratap,
Groat William C.,
Tai Changfeng
Publication year - 2019
Publication title -
neurourology and urodynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 90
eISSN - 1520-6777
pISSN - 0733-2467
DOI - 10.1002/nau.23994
Subject(s) - medicine , pudendal nerve , cuff , urethra , anesthesia , catheter , urinary bladder , surgery
Aim To validate the functionality of an implantable pudendal nerve stimulator under development for Food and Drug Administration approval to restore bladder function after spinal cord injury. Methods In nine cats under anesthesia, two tripolar cuff electrodes were implanted bilaterally on the pudendal nerves and one bipolar cuff electrode was implanted on the right pudendal nerve central to the tripolar cuff electrode. The pudendal nerve stimulator was implanted subcutaneously on the left lower back along the lumbosacral spine and connected to the cuff electrodes. In five cats, a double lumen catheter was inserted into the bladder through the urethra to infuse saline and measure bladder pressure and another catheter was inserted into the distal urethra to perfuse and measure the back pressure caused by urethral contraction. In four cats, a bladder catheter was inserted into the bladder dome and the urethra was left open so that voiding could occur without urethral outlet obstruction. Results The implantable pudendal nerve stimulator was controlled wirelessly and successfully provided the required stimulation waveforms to different cuff electrodes. Pudendal nerve stimulation (PNS) at 5 Hz increased bladder capacity to about 200% of control capacity. PNS at 20 to 30 Hz induced large (80‐100 cmH 2 O) bladder contractions under isovolumetric conditions. When combined with ipsilateral or bilateral pudendal nerve block induced by 6 to 10 kHz stimulation, PNS at 20 to 30 Hz elicited low pressure (<40 cmH 2 O) efficient (70%) voiding. Conclusions The implantable stimulator generated the required stimulation waveforms and successfully induced low pressure efficient voiding in anesthetized cats.