Genital prolapse

Introduction

Uterovaginal prolapse is described as the descent of one or more of the pelvic organs (urethra, bladder, uterus, Pouch of Douglas (POD) and rectum) into the vagina. While prolapse of a single organ independently can happen, typically more than one organ will be involved. This is because all of the organs which can prolapse (with the exception of the POD) are attached either directly or indirectly to the pelvic floor musculature. Of women who have had children, 30% will develop prolapse. The lifetime risk of requiring surgery for prolapse is around 11%.

Aetiology

The aetiology of genital prolapse is pelvic floor muscle weakness. Other contributing factors are listed in Box 16.1. In addition, obesity, chronic cough and constipation, which all raise intra-abdominal pressure, can aggravate the condition.

Box 16.1

Factors predisposing to genital prolapse

Childbirth

Menopause

Congenital

Suprapubic surgery for urinary incontinence

Genetic

Childbirth

Childbirth results in trauma to the pelvic floor and loss of tissue support to the female pelvic organs. While direct trauma can happen at the time of vaginal delivery, the biggest problem in the long term is pudendal nerve damage, which causes a gradual weakening of the fascia and neuromuscular tissue of the pelvic floor. A prolonged labour, in particular a prolonged second stage and a large baby are the biggest risk factors. The pudendal nerve is crushed against the bony pelvis during labour and the longer the patient is in labour, the worse the damage is likely to be. This explains why prolapse seldom happens immediately after childbirth but rather many years later. The same aetiology is responsible for stress urinary incontinence, which demonstrates the same time scale. While the aetiological problem starts in labour, some of the factors mentioned below, along with obesity, are typically the triggers for the development of symptomatic prolapse.

Menopause

The menopausal state, characterized by oestrogen deficiency and loss of connective tissue strength, is a causative factor in the development of prolapse.

Congenital

Congenital weakness and neurological deficiency of the tissues account for prolapse in a small proportion of women. Rarely, children may be born with prolapse or they may develop significant prolapse during childhood. There may also be anatomical variants that may make certain women more susceptible to prolapse in later life.

Gynaecological surgery

Although surgery is often used to treat prolapse, it may be responsible for a small number of cases. Suprapubic surgical procedures for urinary incontinence (e.g. Burch colposuspension – see History box) alter the anatomy such that the bladder neck is approximated behind the symphysis pubis. This increases gravitational effects on the pouch of Douglas, prolapse of which leads to enterocele. Prolapse of the vaginal vault is a not uncommon long-term consequence of a hysterectomy.

History

John Burch (1900–1977), from Nashville, followed his father into gynaecology and developed the Burch colposuspension peroperatively, when he was unable to suspend the bladder neck from the retropubic periosteum (the usual operation of the time).

Genetic

Genetic factors have been implicated in the development of prolapse. It is uncommon, for example, in the African population, possibly related in some way to the different collagen content of tissues.

Classification

The classification of prolapse, and the main symptoms, are summarized in Table 16.1.

Table 16.1

Types of genital prolapse

Original position of organs	Prolapse	Symptoms^a
Anterior	Urethrocele Cystocele	Stress urinary incontinence Poor bladder emptying, residual urine, frequency and urinary infection
Central	Cervix/uterus (1st-, 2nd-, 3rd-degree and procidentia) and vaginal vault	Bleeding and/or discharge from ulceration in association with procidentia Backache
Posterior	Enterocele (POD) Rectocele	Pressure, backache Difficulty in bowel emptying

^a In addition to the general symptoms of discomfort, dragging, the feeling of a ‘lump’, and, rarely, coital problems.

Urethrocele

A urethrocele is descent of the part of the anterior vaginal wall which is fused to the urethra. This is approximately the first 3–4 cm of the anterior wall superior to the urethral meatus. Any descent of this tissue may alter the urethrovesical angle and disrupt the continence mechanism, predisposing to stress urinary incontinence (SUI).