Research progress on pelvic nerve in pelvic organ prolapse and stress urinary incontinence: Systematic review
Authors: Shen Zhuowei , Jia Yuanyuan , Wang Shiyan , Gao Lei , Wang Jiaqi , Wu Xiaotong , Wang Qing , Li Yaqin , Zheng Shiwen , Zhang Yue , Sun Xiuli , Wang Jianliu 
Published: April 2024

Background: Pelvic floor dysfunction (PFD), mainly including
stress urinary incontinence (SUI) and pelvic organ prolapse (POP), is
escalating at an alarming rate globally, bringing a significant economic
burden. The incapacity of nerves and muscles to regenerate following
damage incurred during vaginal delivery potentially stands as a pivotal
mechanism contributing to PFD. Objectives: While a consensus on
the precise role and mechanism of the pelvic nerve in the pathogenesis
of PFD remains elusive, numerous studies have delved into the
relationship between PFD and the pelvic nerve. The analysis aims to
elucidate the intricate workings of pelvic nerves in the context of
these conditions, encompassing their mechanisms of action, the design of
animal models, assessment methods, and the trajectory of research, and
provides a foundation and inspiration for future neuro-centric
investigations into PFD. Search Strategy: To encompass all
potentially pertinent articles, four independent investigators conducted
a thorough search on both PubMed and CNKI, with the last search executed
on January 20, 2024. The retrieval process amalgamated all pertinent
Medical Subject Headings (MeSH) terms. Selection Criteria:
Records excluded Review, Book, etc.; retrieved; full text found; SUI and
POP; assessment methods related pelvic nerve. Data Collection
and Analysis: Five independent investigators extracted a range of data
from each study using a standardized data-collecting form: article,
title, first author, publication year, experimental groups, evaluation
time, evaluation method, conclusions. All relevant data is contained
within the 61 included articles. Main Results: This systematic
review includes a total of 61 articles, including 32 animal or cell
research, 12 human tissue research, and 17 clinical research. The
vaginal dilation (VD) model, utilizing a 3ml balloon to expand the
vagina for 4 hours and the pudendal nerve transection (PNT) model,
achieved through the bilateral crushing of pudendal nerves, and the
assessment of neurological damage in women tissue samples are currently
well-established. Various electrical stimulation treatments, including
Sacral neuromodulation, Electroacupuncture, Transcutaneous Mechanical
Nerve Stimulation (TMNS), Electrical stimulation of pudendal nerve
(EPNS), targeting the pelvic nerve have also been proven effective.
Conclusions: The animal model related to POP and SUI are
currently well-established, which have significantly different stress
areas within the pelvic floor structure with human. Consequently, the
findings derived from all animal models should be applied to human
subjects with careful consideration. The precise mechanism of pelvic
nerves in POP remains elusive based on existing research, however,
relevant literature research generally believes that the pathogenesis of
POP and SUI is closely related to the pelvic nerve. This highlighting a
direction that demands additional endeavors and potentially necessitates
further relevant experimental studies for validation.