POP means Pelvic Organ Prolapse, where a section of the female genital tract descends to a level below it's normal position. To understand prolapses it is important to remember the anatomical support of the female genital tract.
There are 3 main levels of support:
- Level 1
- There are 2 ligaments that support the cervix and upper third of the vagina, these are the cardinal (aka transverse cervical - extends from cervix to pelvic side wall) and uterosacral (extends from the upper third of the vagina to the sacrum)
- Level 2
- This is the support for the middle third of the vagina, it is made up of the endopelvic fascia (aka endofascial condensation) that runs from the vagina to the pelvic side wall
- Level 3
- This is the support for the lower third of the vagina which is supported by 2 anatomical features, the first is the levator ani and the second is the perineal body (that lies between the vagina and the anus)
Causes of POP
Weakness of any of the support mechanisms detailed above or of the pelvic floor can lead to POP. Remember that half of all women who have given birth have a prolapse in some form, but only a fifth ever come to the attention of medical services. It is important to ask patients about them (sensitively) as women often think that there is nothing you can do or are too embarrassed to bring them up themselves. Treatment can greatly improve QoL (quality of life).
Some of the mechanisms that can lead to POP include:
- Congenital - Disorders of collagen metabolism (e.g. Ehlers Danlos)
- Neurological - e.g. muscular dystrophy, spina bifida
- Pregnancy and Vaginal Delivery - This injures the pelvic floor especially if the baby is large, there is a long second stage of labour or instrumental delivery is needed
- Chronic Increased Abdominal Pressure - e.g. obesity, lung conditions leading to a long term cough, bowel conditions leading to chronic constipation and straining and pelvic masses
- Oestrogen Withdrawal - following the menopause leads to collagenous tissue deterioration
- Pelvic Surgery - These include some of the continence procedures and hysterectomy (increases risk of prolapse - post-hysterectomy patients can develop vaginal vault prolapse)
Types of POP
The different types of prolapse are named according to which part of the anatomy is the problem.
- Urethrocoele (lower anterior vaginal wall involving the urethra)
- Cystocoele (upper anterior vaginal wall involving the bladder)
- Cystourethrocoele (combination of the two above)
- Apical prolapse (uterus, cervix and vaginal prolapse - basically stuff at the apex of the vagina prolapses, in cases where there has been a hysterectomy the vaginal vault can prolapse i.e. the top of the vagina)
- Complete procidentia is a complete eversion of the vagina
- Enterocoele (upper posterior vaginal wall involving the small bowel)
- Rectocoele (lower posterior vaginal wall involving the rectum)
The grade of the POP is based on how much has prolapsed and how far. There are various grading systems:
History and Examination Findings
There may be no symptoms and any that are present may be difficult for the patient to describe (although are often worse at the end of the day or after prolonged standing), they may use phases like "dragging sensation" or "feeling a lump down below". It may present as stress incontinence.
Severe prolapses can ulcerate and bleed, become very painful and interfere with daily life. For example they interfere with continence, defecation and sex.
Examination should be thorough, starting with an abdominal examination to look for any palpable masses. Then gynaecological examination, (bimanual and external genitalia). Examination with a Sims' speculum is used to help visualize the prolapse.
Think about doing an Ultrasound of the abdomen and pelvis. Further investigations will be needed if a pelvic mass is suspected.
This is often the best place to start, unless the prolapse is very severe. Encourage patients to lose weight and stop smoking, make a referral to physiotherapy for pelvic floor exercises.
Pessaries can be very helpful in alleviating symptoms, they act as an artificial replacement for the pelvic floor. There are various different types with the most often used being the ring pessary (shaped like a ring and placed in the vagina). Pessaries are changed every 6–9 months although they may fall out - they are sized to the woman and different sizes may need to be tried to find the right fit.
There are various surgical options available depending on the type of prolapse and the severity, including sacral colpopexy, uterosacral colpopexy, transvaginal mesh, or posterior vaginal wall repair. Bear in mind that hysterectomy may not be the answer, approximately 40% of patients who have hysterectomy present later with a vaginal vault prolapse.
Prolapse is more likely to occur in patients who are:
- Have a chronic cough
- Undertake heavy physical activities.