Uterovaginal displacements, damage and prolapse

Published on 10/03/2015 by admin

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Chapter 38 Uterovaginal displacements, damage and prolapse

UTERINE DISPLACEMENTS

The uterus is an organ that normally pivots about an axis formed by the cardinal ligaments at the level of the internal cervical os. In 90% of women the uterus is anteflexed and anteverted, lying on the urinary bladder and moving backwards as the bladder fills. In 10% of women the uterus is retroflexed and may be retroverted (Fig. 38.1). This is a developmental occurrence. The uterus is mobile and can be moved by inserting a finger in the posterior vaginal fornix. In spite of anecdotal statements, a mobile retroverted uterus is not a cause of infertility, abortion or backache.

Acquired uterine retroversion may occur, but is less common. It is associated with endometriosis of the uterosacral ligaments or the cul-de-sac; with adhesions resulting from pelvic inflammatory disease; or caused by a tumour in front of the uterus pushing it backwards.

UTEROVAGINAL DAMAGE AND INJURIES

Injury to the vulvovaginal area may occur, for example if a girl or woman falls astride some object or is kicked. The vagina may be damaged or a haematoma may form in the vulva (Fig. 38.3). Injury may also occur if a young girl or a postmenopausal woman is sexually assaulted.

During the first sexual intercourse, the hymen is stretched and torn and a small amount of bleeding results; very occasionally more severe bleeding occurs if a large blood vessel is damaged.

Injury resulting from childbirth is discussed on page 81. Occasionally a vaginal tear is not sutured immediately, and the woman attends a medical practitioner some time later. On inspection the vaginal entrance is seen to gape and the perineal muscles are separated (Fig. 38.4). The woman may complain that water enters her vagina when she bathes, or that vaginal flatus occurs.

Vaginal burns may occur following a very hot vaginal douche, or the deliberate insertion of a caustic agent, such as rock salt, to procure an abortion or, in a few cultures, following tightening of the vagina after childbirth to make sexual intercourse more satisfying to the man.

Cervical damage may occur during rough cervical dilatation. The laceration is usually small, but may extend from one or other lateral angle of the external cervical os. This may cause marked bleeding. Cervical damage may also occur during childbirth and is discussed on pages 81, 82.

UTEROVAGINAL PROLAPSE

Uterovaginal prolapse is defined as a descent of the uterus or vagina. A vaginal prolapse may occur independently of any uterine descent, but a prolapsed uterus always carries some part of the upper vagina with it.

To understand how uterovaginal prolapse occurs some knowledge about the supports of the uterus is required. The uterus is supported in the midpelvis by three structures. These are:

The transcervical (cardinal) ligaments, which stretch from each pelvic wall and attach to the uterus at the level of the supravaginal cervix. They are not ligaments in the true sense as they are composed of a felted mass of collagenous connective tissue through which blood vessels pass to supply the uterus and bladder (Fig. 38.6). The cardinal ligaments act as the middle support of the uterus and their function can be explained in terms of chicken wire. If the strain is not too great the ligaments have considerable tensile strength, but if the strain is increased or the ligaments are damaged, they stretch (Fig. 38.7). Posteriorly, on each side, condensations of the tissue form the uterosacral ligament.

Acting in conjunction, these supports prevent uterine prolapse (Fig. 38.8). However, this state of affairs may be altered if the supports are stretched during childbirth. This may occur if the woman tries to expel the fetus before the cervix is fully dilated, strains for a long time in the second stage of labour, or if undue force is used to expel the placenta. In these circumstances the cardinal ligament may be stretched, making a uterine prolapse more likely. In consequence, prolapse is more common in women who have had several children and are obese.

Uterovaginal prolapse is more common in the later reproductive years and after the menopause. In most cases it is due to damage to the supporting tissues and pudendal nerve damage occurring during childbirth, but is not apparent until the tissues atrophy in middle age when, deprived of oestrogen, the collagen tissue of the ligaments diminishes and the vaginal muscle becomes weaker, permitting the prolapse to occur. An additional cause may be chronic constipation leading to straining.

A further way in which prolapse occurs in a very few nulliparous women is through the supporting tissues failing to develop properly.

Degrees of uterine prolapse

For descriptive purposes uterovaginal prolapse is divided into three degrees of increasing severity (Fig. 38.9). In each of these the cervix elongates and may become congested or oedematous. When the cervix protrudes from the vagina, as in the third degree of prolapse, the cervical epithelium becomes dry and its superficial layers are keratinized.

With better obstetric care the frequency of uterovaginal prolapse is diminishing and severe cases are not so often seen.

Treatment

Treatment depends on the age of the woman, her desire to have further children, and the degree of the prolapse. Younger women with mild degrees of symptomless prolapse can delay treatment until the prolapse worsens or the menopause is reached. They should be taught pelvic floor exercises (see p. 311), which alone may control the symptoms. It is preferable not to treat a prolapse surgically if the woman wishes to have a further child, as the delivery must then be by caesarean section to avoid damage to the repair. If the woman has a cystocele, a midstream urine sample should be taken to exclude bacteriuria. If the urine is sterile, surgery is not required unless the woman desires it. She should be checked periodically.

If the prolapse is marked and is causing symptoms, surgery can be recommended. There are two choices, which should be discussed with the woman. The first is vaginal hysterectomy and vaginal repair. The second is the Manchester operation, which involves shortening the cervix and the cardinal ligaments and plicating them in front of the shortened cervix (to keep the uterus anteverted), and then performing a vaginal repair. If urinary incontinence is present it should be treated.

Elderly women should be given oestrogen for 4–6 weeks before the operation to improve the quality of the vaginal tissues. Old frail women, or women who decline an operation, may choose to have a polythene ring pessary introduced into the vagina. The size chosen should prevent descent of the vaginal walls or the uterus and be comfortable. The woman should have the pessary removed at intervals for cleaning and then replaced.

The treatment of a cystocele or a rectocele consists of repairing the vagina by excising a triangular piece of the anterior or posterior vaginal wall, depending on whether a cystocele or a rectocele is present, pushing the bladder or rectum proximally, and suturing the supporting muscles beneath it and then rejoining the cut edges of the vagina.