Introduction

If the body was divided into specialties by physiological rather than anatomical boundaries, there would be no need for an explanation of urogynaecology. As it is, this specialty represents an interface between gynaecologist and urologist. Physiological events or disease affecting gynaecological organs invariably affect the urinary tract, as they will also sometimes affect the adjacent alimentary system.

It is increasingly recognized that colorectal surgeons have an important role in the management of pelvic floor disorders. The studies of Snooks et al (1984a,b) and Sultan et al (1993) show the traumatic effects of vaginal delivery on the pelvic floor and anal sphincters. Wall and de Lancey (1991) succinctly summarized the need for a holistic approach involving gynaecologists, urologists and colorectal surgeons in the management of pelvic floor disorders.

Following the introduction of subspecialization by the American College of Obstetricians and Gynecologists, the Royal College of Obstetricians and Gynaecologists considered and then recommended subspecialization in 1982. Four subspecialties were created, among them urogynaecology. This comprised the following disorders: congenital anomalies, incontinence, voiding difficulties, urinary fistulae, bladder neuropathy, genital prolapse, urgency and frequency, and urinary tract infection. By common consent, all ‘supravesical’ conditions and neoplasia arising anywhere in the urinary tract belong to the realm of urology.

To these might now be added disordered bowel motility, descending perineum and rectal prolapse, anal sphincter injuries, rectovaginal fistula, perineal hernia, and faecal and flatal incontinence.

Terminology

As in any developing branch of medicine and science, old terms and definitions have become inadequate. To provide a common language for both clinician and researcher, the International Continence Society’s (1973) Standardization Committee drew up standards of terminology of lower urinary tract function.

Nine reports have now been published, as follows.

The term ‘stress incontinence’ was coined by Sir Eardley Holland in 1928 and meant the loss of urine during physical effort. It came to be used not only as a symptom and sign, but also as a diagnostic term. As the pathophysiology of urinary incontinence became more clearly understood, it was apparent that the term ‘stress incontinence’ was ambiguous as it could be applied to a symptom, a sign and a diagnosis; indeed, the symptoms and sign of stress incontinence can be found in most types of incontinence.

Nowadays, the term ‘stress incontinence’ is retained for the symptom of involuntary loss of urine on physical exertion and the sign of urine loss from the urethra immediately on increase in abdominal pressure. The term ‘genuine stress incontinence’ was proposed by the International Continence Society in 1976 (Bates et al 1976) to mean the condition of involuntary loss of urine when ‘the intravesical pressure exceeds the maximum urethral pressure in the absence of a detrusor contraction’. This condition has a number of synonyms: urethral sphincter incompetence, stress urinary incontinence and anatomical stress incontinence. The authors prefer the term ‘urethral sphincter incompetence’ because this accurately describes the pathophysiology of this condition.

In a similar way, the term ‘dyssynergic detrusor dysfunction’ was introduced by Hodgkinson et al in 1963 and other synonyms followed: urge incontinence, uninhibited bladder, bladder instability/unstable bladder and, more recently, overactive bladder. In 1979, the International Continence Society defined an unstable bladder as one ‘shown objectively to contract, spontaneously or on provocation during the filling phase, while the patient is attempting to inhibit micturition. Unstable contractions may be asymptomatic and do not necessarily imply a neurological disorder.’ The contractions are phasic. Another term, ‘low compliance’, is used to mean a gradual increase in detrusor pressure without a subsequent decrease during bladder filling. The term ‘neurogenic detruser overactivity’ is used for phasic uninhibited contractions when there is objective evidence of a relevant neurological disorder. Terms to be avoided include ‘hypertonic’, ‘spastic’ and ‘automatic’.

Classification

Incontinence

Urinary incontinence forms the major proportion of urogynaecology. It is defined by the International Continence Society as ‘an involuntary loss of urine which is objectively demonstrable and a social or hygienic problem’.

Incontinence is considered to be involuntary; for two categories of patients, further explanation is needed. In a child under 3 years of age, control of continence has not yet developed; however, careful observation shows that the normal child is dry between involuntary voids, whereas the incontinent child is wet the whole time. On the other hand, the mentally frail or elderly demented patient may be incontinent because she has lost her social consciousness and appreciation of the need to be dry.

The social isolation caused by incontinence is demonstrated by 25% of patients delaying for more than 5 years before seeking advice, owing to embarrassment (Norton et al 1988). Ostracism and rejection by relatives may lead to an elderly patient being institutionalized solely because of incontinence; paradoxically, some allegedly ‘caring’ institutions will not accept an elderly patient if she is incontinent.

It is now accepted that incontinence should be objectively demonstrable using urodynamic studies, which will define the cause and detect other conditions such as voiding disorders and overactive bladder.

The hygienic aspect of incontinence occupies some 25% of nursing time in hospitals. Unless managed, urinary odour is offensive to both patient and relatives alike.

Incontinence may be divided into urethral and extraurethral conditions (Figure 49.1).

Figure 49.1 Classification of incontinence.

Urethral conditions

Urethral sphincter incompetence (urodynamic stress incontinence)

This is the most common urethral condition, has several causes and can present from childhood (see Chapter 52). The original classification of type 1, 2 and 3 is facile. It is realistic to acknowledge that whilst only some patients have ‘urethral hypermobility’, all will have some degree of sphincter incompetence, otherwise they would not leak. Type 3 is gross incontinence with a maximum urethral closure pressure below 20 cmH₂O (more usefully termed ‘intrinsic sphincter defect’). Conventional bladder neck elevating surgery or even midurethral support surgery is unlikely to succeed in type 3 patients; what is required is something to restore urethral pressure, such as an artificial urinary sphincter. For the vast majority (i.e. old type 1 and 2), either a bladder neck elevating procedure, such as a colposuspension or sling, or a midurethral support procedure, such as a tension-free vaginal tape procedure, will likely suffice. The latter has shown that lack of midurethral support is a significant cause of sphincter incompetence.

Overactive bladder (see Chapter 53)

Depending on its cause, this may be subdivided into neuropathic or idiopathic. Some patients with overactive bladder and a competent sphincter mechanism may remain dry. If, however, there is coexistent sphincteric incompetence (‘mixed incontinence’), the patient may complain of stress incontinence and urge incontinence.

Urinary retention and overflow (see Chapter 54)

This may be acute or chronic; the former is usually sudden in onset and painful. There may be an obvious cause, such as an impacted pelvic mass. Chronic retention, on the other hand, is often painless, insidious and frequently undetected, so errors in diagnosis are often made. It occurs more commonly in the elderly as a result of neuropathy (e.g. peripheral diabetic neuropathy or stenosis of the lumbar spinal canal).

Congenital disorders

Epispadias is usually detected during childhood, but occasionally it is not diagnosed until adult life.

Miscellaneous

These causes include urethral diverticulum, urinary tract infection (temporary and most common in the elderly), faecal impaction, drugs (such as α-adrenergic blocking agents) and functional disorders. These are rare; the patient should be fully investigated and all the above causes excluded before this diagnosis is made. The loss of social awareness of the need to be continent is usually associated with dementia or a space-occupying lesion of the frontal cortex.

Extraurethral conditions

These may be divided into congenital and acquired. Extraurethral conditions may be distinguished from urethral conditions by the symptom of continuous incontinence. The congenital disorders include ectopic ureter and bladder exstrophy. Acquired conditions include urinary fistulae, which in the Western world are largely iatrogenic, the majority occurring after abdominal hysterectomy for benign conditions (see Chapter 57). Other causes include pelvic carcinoma and its attendant surgery or radiotherapy. In the developing world, obstetrical causes such as obstructed labour with an impacted vertex are more common. If the fistula is small, skill and patience are required to detect it.

Conclusion

This classification is an introduction to urogynaecology and the ensuing chapters will provide more detail. For more specialized reading, a list of selected books is given after the references.