**1. Introduction**

The human being is the only mammal capable of walking and simultaneously maintaining an upright position. This fact, greatly affected by the law of gravity, implies somewhat unfavorable repercussions for the pelvic region that must support the weight of the abdominal organs. Therefore, throughout evolution, fundamental modifications have emerged in the pelvic skeleton, and in the surrounding muscles and ligaments, to offset the negative effect of the law of gravity. A prime example of the aforementioned adverse effects of the standing position are pelvic organ prolapses (POP).

The prevalence of this pathology is clearly on the rise: it is estimated that the number of women with pelvic organ prolapse will rise from 3.3 million women in 2010 to 4.9 million in 2050. Pelvic floor dysfunction is considered to be underdiagnosed,

affecting 50% of women, although only 10–20% will seek assistance [1]. More than 60% of the patients affected by this condition present more than one pathology as the pelvic floor organs constitute a functional and organic unit [2]. It is estimated that a woman's risk of undergoing surgery related with POP during her life varies from 6.3 to 19%, with 30% requiring one or more surgical interventions due to recurrence [3]. Some authors have reported re-intervention rates for recurrence after primary reconstructive surgery of between 43 and 58% [4].

The anatomical support of the pelvic viscera is provided mainly by the levator ani and the connective tissue junctions of the pelvic organs: vaginal support arises from the connective tissue junctions between the vagina and the pelvic lateral wall, the vaginal wall and levator ani muscles [5].

In 1994, Delancey had already introduced the concept of the division of the support of the pelvic connective tissue in three levels (I-III) that represent apical, mid-vaginal and distal support, respectively. The upper portion of the paracolpium (Level I) consists of a lamina from which the vagina is suspended attaching it to the pelvic wall, and is responsible for suspending the apex of the vagina after hysterectomy. In the middle third of the vagina, the paracolpium joins the vagina laterally to the tendinous arch and the fascia of the elevator ani muscles (Level II). This stretches the vagina transversally between the bladder and the rectum. The structural layer that supports the bladder (pubocervical fascia) is made up of the anterior vaginal region and its attachment through the endopelvic fascia to the pelvic wall. Similarly, the posterior vaginal wall and endopelvic fascia (rectovaginal fascia) form the containing layer that prevents protrusion of the rectum toward its anterior surface. The lower third of the vagina (Level III) fuses with the perineal membrane, levator ani muscle, and the perineal body. Defects in the mid-level vaginal base (pubocervical and rectovaginal fascia) result in cystocele and rectocele, while the loss of upper suspensory fibers of the paracolpium and parametrium are responsible for the development of vaginal and uterine prolapse, and these defects of combined form [6].

During examination, the prolapse of the anterior compartment is the most frequently reported site of prolapse and it is diagnosed twice as frequently as the defects of the posterior compartment, and three times more common than apical prolapse [7]. After hysterectomy, 6–12% of women will develop a prolapse of the vaginal vault [8] and in two thirds, multi-compartmental prolapse will be present.

The etiology of POP is believed to be multi-factorial with contributions from both environmental and genetic risk factors. The environmental factors that contribute to POP include vaginal delivery and newborn weight, chronic increases in intra-abdominal pressure, obesity, advanced age and estrogen deficiency [9].

Not all prolapses are clinically symptomatic, and finding mild asymptomatic prolapses during pelvic floor examination is common. If symptoms are present, the most frequent complaints include a sensation of pressure, a lump or protrusion and with evidence upon physical examination of a second degree or greater anterior and / or posterior and / or central vaginal wall prolapse. Ellerkmann et al. found that in 237 women evaluated for POP, 73% reported urinary incontinence, 86% urinary urgency and / or frequency, 34–62% voiding dysfunction and 31% fecal incontinence [10]. Evaluation of a patient with vaginal prolapse requires a comprehensive review of the full spectrum of pelvic floor symptoms and an assessment of how these symptoms affect her quality of life.
