Computational Modeling of the Female Pelvic Support Structures and Organs to Understand the Mechanism of Pelvic Organ Prolapse: A Review

Abstract

Pelvic organ prolapse (POP) is an abnormality of the female pelvic anatomy due to events, such as multiple child births, menopause, and morbid obesity, which may lead to weakening of the pelvic floor striated muscles and smooth musculo-connective tissues. POP leads to dropping of the pelvic organs, namely, the bladder, uterus, and rectum into the vaginal canal and eventual protrusion, causing vaginal pain, pressure, difficulty emptying the bladder and rectum, and sexual dysfunction. Each year, close to 300,000 POP surgeries are performed in the U.S., out of which more than 60% of patients may face relapse conditions. A closer look into the problem reveals that POP surgery failures may be attributed mainly to the lack of understanding among medical practitioners on the mechanics of prolapse. In the literature, there have been attempts in the engineering community to understand prolapse using phenomenological computational modeling. This paper reviews the development and study of these numerical models, aimed at understanding the mechanics of POP. The various computational challenges related to geometry creation, material modeling, finite-element (FE) modeling, and boundary conditions (BCs) will be discussed and significant future research directions will also be highlighted in this review.

Mechanical Properties of Female Reproductive Organs and Supporting Connective Tissues: A Review of the Current State of Knowledge

“…There are only a few published studies on the development of constitutive models for pelvic floor tissues, and for some organs such as the uterus, no constitutive model has been proposed. This is quite puzzling since, at the same time, there are several computational models of the pelvic floor, as discussed in a recent review by Chanda et al [16]. Often, simplifying assumptions about the tissues, such as linear elasticity and isotropy, are made that may not be accurate.…”

“…Together with histological and microscopy data, the mechanical data can guide the development of constitutive equations for the reproductive organs and supporting connective tissues. These equations can then be implemented into finite element models, and other numerical models, to predict the behavior of the pelvic floor under a variety of mechanical stimuli that emulate both normal and pathological conditions [16].…”

Functional mapping of the pelvic floor and sphincter muscles from high-density surface EMG recordings

“…Many computational pelvic floor models have been developed recently to investigate the biomechanics of incontinence and prolapse [22]. Unfortunately, voluntary contraction of PFM/EAS has not been objectively considered in previously reported pelvic models because of the lack of appropriate techniques which can be used to quantitatively characterize pelvic muscle contractions.…”

A biofidelic computational model of the female pelvic system to understand effect of bladder fill and progressive vaginal tissue stiffening due to prolapse on anterior vaginal wall

“…To date, the mechanics and pathophysiology of AVP are poorly understood among gynecologic surgeons and medical practitioners, which makes it difficult to optimize POP mitigation strategies and surgical planning. There have been few recent attempts to computationally model the female pelvic system and the mechanics of AVP . In 2009, Chen et al developed a computational model of the AVW and associated connective tissue to study the effect of the pelvic floor muscles and connective tissue impairments (obtained from magnetic resonance image (MRI) observations) in AVP.…”