The role of pudendal nerve damage in the aetiology of genuine stress incontinence in women

Assessment of Kegel pelvic muscle exercise performance after brief verbal instruction

Forty-seven women had urethral pressure profile determinations performed at rest and during a Kegel pelvic muscle contraction, after brief standardized verbal instruction. Twenty-three (49%) had an ideal Kegel effort--a significant increase in the force of urethral closure without an appreciable Valsalva effort. Twelve subjects (25%) displayed a Kegel technique that could potentially promote incontinence. Age, parity, weight, estrogen deprivation, prior continence surgery or hysterectomy, and passive urethral function did not predict a successful effort. We concluded that simple verbal or written instruction does not represent adequate preparation for a patient who is about to start a Kegel exercise program.

Urethral pressure and power generation during coughing and voluntary contraction of the pelvic floor in females with genuine stress incontinence

A probe which permits continuous measurement of the related values of pressure and cross-sectional area in the female urethra was used for a quantitative description of the adjunctive closure forces in terms of pressure and power generation during coughing and squeezing in 30 females with genuine stress incontinence (GSI). Measurements were performed at the bladder neck, midurethrally and distally in the urethra. A statistically significant decrease in power generation was found at the bladder neck and midurethrally during squeezing compared with the values in healthy females. During coughing the power generation was significantly decreased midurethrally and measurement of pressure generation revealed similar results. These findings indicate that the active closure mechanisms at the bladder neck and midurethra are significantly weakened in females with GSI. The results do not support the concept that impaired passive pressure transmission to the urethra is an important pathophysiological factor in GSI.

Pudendal nerve function in women with symptomatic utero-vaginal prolapse

Pelvic floor function has been studied in 27 women with symptomatic utero-vaginal prolapse and 15 age-matched control subjects. There was no evidence in the patients on physiological testing of significant denervation of the pelvic floor muscles, with no significant difference in the maximum resting and squeeze anal pressures, the pudendal nerve terminal motor latency or external anal sphincter fibre density on single fibre electromyography between the groups. However, those patients with a small rectocele (less than 2 cm) had a significantly higher fibre density than the group with a large rectocele (p = 0.03) and the control group (p less than 0.001). Six of eight patients with a small rectocele had increased fibre density compared with 3/19 with a large rectocele (p = 0.006) and 2/15 control subjects (p = 0.006). This was independent of age, obstetric factors and the presence of internal rectal prolapse. These findings suggest that patients with symptomatic utero-vaginal prolapse and small rectoceles have pelvic nerve damage, and development of a large rectocele may provide some protection against perineal descent and pudendal neuropathy, although the number of patients in the small rectocele group was small and confirmation from further similar studies is required.

Treatment of stress urinary incontinence

This review presents reported cure and improvement rates of stress urinary incontinence in women obtained by different treatment modalities. Apart from the urodynamic findings, histological and histochemical changes of the pelvic floor may be clinically relevant to treatment in the future. Long-term cure and improvement rates achieved by non-surgical treatment (physiotherapy, biofeedback, bladder training, electrostimulation) are commented on. These rates range from 40-60% for physiotherapy and electrostimulation but are considerably less after biofeedback and bladder training. Pharmacotherapy is unlikely to offer more than a placebo effect. Studies of a single surgical procedure usually report high cure rates. In making the appropriate choice of operation the best guidelines are the cure rates from comparative or prospective randomized reports. From such studies an abdominal retropubic suspension operation (cure rates after five years 57-78 %) is more likely to help the patient than an anterior colporrhaphy (cure rates 31-70 %) or a transvaginal needle bladder neck suspension (cure rates 39-61 %). In selected patients sling procedures or the use of artificial sphincters may produce excellent results (70-80 %). To estimate the results of different treatments urine loss should be assessed objectively and physical restrictions and hygienic and social implications taken into account. A method of pre- and post-treatment "performance scores" should be developed.

Pelvic floor damage and childbirth: a neurophysiological study

Ninety six nulliparous women were investigated to establish whether childbirth causes damage to the striated muscles and nerve supply of the pelvic floor. The techniques used were concentric needle electromyography (EMG), pudendal nerve conduction tests and assessment of pelvic floor contraction using a perineometer. There was EMG evidence of re-innervation in the pelvic floor muscles after vaginal delivery in 80% of those studied. Women who had a long active second stage of labour and heavier babies showed the most EMG evidence of nerve damage. Forceps delivery and perineal tears did not affect the degree of nerve damage seen. We conclude that vaginal delivery causes partial denervation of the pelvic floor (with consequent re-innervation) in most women having their first baby. In a few this is severe and is associated with urinary and faecal incontinence. For some it is likely to be the first step along a path leading to prolapse and/or stress incontinence.

Evaluating the pelvic floor in obstetric patients

Up to 40% of vaginal deliveries lead to pelvic floor denervation. This has been linked causally with the later occurrence of urinary incontinence, faecal incontinence and vaginal prolapse. Pelvic floor position, anal sphincter pressures and anal electrosensitivity were evaluated in 72 volunteers as simple screening tests for detecting patients who might benefit from neurological assessment. A lower perineum and reduced voluntary sphincter pressures were found antenatally in parous women when compared with nulliparas. The tests were repeated postnatally 24 to 72 hours after delivery. When compared with antenatal readings, the perineum was lower and sphincter pressures were reduced in subjects delivered vaginally. Forty one subjects were reexamined after 6-8 weeks and partial recovery was found. Anal squeeze pressures and pelvic floor position when straining were the results most consistently changed. On the basis of this study it is suggested that 28% of multiparas seen anrenatally and between 25% to 30% of all women who deliver vaginally may be eligible for more detailed neurological study.