3 Pelvic Organ Prolapse
Introduction, Nonsurgical Management, and Planning of Surgical Repair
Pelvic organ prolapse (POP) is a common condition affecting almost a quarter of the adult female population. However, the mere presence of prolapse of one or more organs or compartments does not necessarily mean that a problem or abnormality exists. As surgeons, we typically think in terms of normal and abnormal anatomy, considering “normal” to be a perfectly supported pelvis. However, various degrees of POP occur with aging, childbearing, and so on. POP may be totally asymptomatic or may create symptoms of prolapse such as heaviness or the feeling of tissue protrusion. These symptoms may or may not be associated with functional derangements, whether they be visceral or sexual. Our current understanding of the correlation between anatomical descent and functional derangements is very poor. Therefore, the decision to intervene surgically to correct POP should be based more on the presence or absence of outright symptoms of prolapse than on a functional derangement that is felt to be due to anatomical descent.
Historically, POP has been classified in terms of organs or structures; for example, cystocele, enterocele, rectocele, and uterine prolapse. Although these terms are descriptive, they are often not accurate in describing POP. In this book the discussion of POP is divided into chapters on anterior vaginal wall prolapse, posterior vaginal wall prolapse, and enterocele and apical prolapse. There is a separate chapter on vaginal hysterectomy for uterovaginal prolapse. Although each compartment is described separately, it is important to remember that most patients with POP have loss of support in more than one compartment. Consequently, the surgeon commonly must use techniques applicable to multiple compartments in repairing POP.
POP is a common worldwide problem, but data are conflicting on whether differences in prevalence exist based on race and culture. Most reports suggest a higher incidence in white and Hispanic women than in black or Asian populations, but no good comparison studies exist.
The multifactorial etiology of POP makes the prevention of its occurrence difficult. Bump and Norton categorized risk factors for the development of POP as predisposing (genetics, race, gender), inciting (pregnancy, delivery, surgery, myopathy, neuropathy), promoting (obesity, smoking, chronic cough, constipation, repetitive occupational or recreational activities), and decompensating (aging, menopause, debilitation, and medications). Physiologically and anatomically, loss of the integrity and the support of the pelvic organs that causes herniation resulting in prolapse of the vaginal compartments singly or in combination.
Most women with POP have a combination of pelvic floor support defects affecting multiple compartments (anterior, apical, and posterior). Very commonly, anterior vaginal wall prolapse that is significant enough to require repair will be accompanied by apical or vault prolapse. In addition, many recurrences after POP repair may in part be due to failure to adequately address support of the vaginal apex during the original procedure.
The apical portion of the vagina is supported by sheetlike extensions of the endopelvic fascia that attach it to the pelvic sidewall and levator ani fascia, referred to as the paracolpium. The paracolpium provides two levels of support. Level I, or upper support, suspends the vagina, attaching it to the pelvic sidewall. Level II, or midvaginal support, which includes the pubocervical fascia, attaches the midvagina more directly to the pelvic walls, including the levator fascia and arcus tendineus fasciae pelvis. Damage to midlevel support usually results in anterior and posterior defects, whereas damage to upper-level support results in apical prolapse, including enterocele and/or vault or uterine prolapse (Fig. 3-1).
Figure 3-1 Level I (suspension) and level II (attachment) support of the vagina. In level I the paracolpium (uterosacral ligaments) suspends the vagina from the lateral pelvic walls. Fibers of level I extend both vertically and posteriorly toward the sacrum. In level II support the vagina is attached to the arcus tendineus fasciae pelvis and superior fascia of the levator ani by condensations of the levator fascia (e.g., endopelvic and pubocervical fascia). In level III support the vaginal wall is attached directly to adjacent structures without intervening paracolpium (i.e., urethra anteriorly, perineal body posteriorly, and levator ani muscles laterally).
(From DeLancey JOL. Anatomic aspects of vaginal eversion after hysterectomy. Am J Obstet Gynecol. 1992;166:1717.)