The study of voiding in men and women has been handicapped by the lack of a normal reference range covering urinary flow rates over a wide range of voided volumes. Normal volunteers (331 males and 249 females) were studied. Each voided once into a calibrated Dantec Urodyn 1000 mictiograph. On a second occasion 282 men and 46 women voided. The maximum and average urine flow rates of the first voids in both sexes were compared with the respective voided volumes. Nomogram charts, in centile form, for both the maximum and average urine flow rates were constructed using statistical transformations of the data. Males showed a significant decline in both urinary flow rates with age, although there was no statistically significant variation in either urine flow rate with respect to first versus repeated voiding. Females showed no statistically significant variation in either urine flow rate with respect to age, parity or first versus repeated voiding. The maximum and average urine flow rates in both sexes showed an equally strong relationship to voided volume. No artificial restriction of voided volume, e.g. minimum 200 ml, appeared appropriate. These nomograms offer reference ranges for both maximum and average urinary flow rates in both sexes covering a wide range of voided volumes (15-600 ml).

Two hundred and fifty consecutive women referred because of symptoms of lower urinary tract dysfunction underwent a full clinical and urodynamic assessment. Their urine flow rates and residual urine volumes were analyzed. The urine flow rates of the urogynecology patients were found to be significantly less than those of an asymptomatic population. There were significant declines in urine flow rates in the presence of a previous hysterectomy and with increasing grades of prolapse, particularly uterine prolapse, cystocele and enterocele. Unlike the normal female population, there was also deterioration with increasing parity and age, the latter largely due to the increasing incidence of hysterectomy and prolapse with age. The 10th centile of the Liverpool Nomogram for the maximum urine flow rate was found to be the most useful discriminant for a final urodynamic diagnosis of voiding difficulties. Most urogynecology patients have no or small residual urine volumes, 74% <10 ml and 81% <30 ml (vs 95% <30 ml in asymptomatic women). In urogynecology patients residuals were larger where there had been a prior hysterectomy or with grade 2 or higher uterine prolapse, cystocele and enterocele. Mean residual was 14.8 ml (vs 4.8 ml in asymptomatic women). These data indicate a higher incidence of voiding difficulties (abnormally slow urine flow (under 10th centile) and/or abnormally high residual urine volume (over 30 ml) in urogynecology patients, particularly those with higher grades of prolapse and with prior hysterectomy.

To compare the safety and efficacy of the transobturator tape (Monarc) with the retropubic tape (tension-free vaginal tape, TVTR) for the treatment of urodynamic stress incontinence (USI) a prospective, single-blinded, multi-centre randomised clinical controlled trial was undertaken in four urogynaecology units in Australia. One hundred and eighty-seven women with USI were randomly allocated to undergo surgery with either the Monarc sling (n = 80) or TVT (n = 107). Outcome measures were intra-operative complications (especially bladder injury), as well as peri-operative complications, symptomatology, quality of life and urodynamic outcomes. At 3 months, data were available on 140 women, 82 (59%) TVT and 58 (42%) Monarc. The TVT group was significantly more likely to be complicated by bladder injury (7 TVT, 0 Monarc, p < 0.05). Blood loss and operative time were significantly less in the Monarc group, which was 49 mls (31) vs that of the TVT group, which was 64 mls (41) p < 0.05; 18.5 min (6.5) TVT vs 14.6 min (6) Monarc (p < 0.001). The subjective and objective stress incontinence cure rates were 86.6% (71) vs 72.4% (42) p = 0.77 and 79.3 vs 84.5%, p = 0.51 for the TVT and Monarc groups, respectively. Both groups reported similar improvement in incontinence impact and satisfaction with their operation, although return to activity was significantly quicker with the transobturator route (p = 0.029). The transobturator tape appears to be as effective as the retro-pubic tape in the short term, with a reduction in the risk of intra-operative bladder injury, shorter operating time, decreased blood loss, and quicker return to usual activities.

Transvaginal linear array ultrasound is described as a method of measuring bladder volumes in the range 2 to 175 ml, overcoming the limitations of abdominal ultrasound at these smaller (though clinically important) volumes. The mean error over the range 10 to 175 ml was 23%. Statistical analysis of preliminary data obtained by this technique shows that bladder volume in ml can be calculated by the formula: Volume = 5.9 x (height x depth) - 14.6 ml (95% confidence limits = +/- 37 ml)

The case histories of 494 women referred to a urodynamic clinic with the symptom of stress incontinence were studied. None had undergone previous incontinence surgery. In only 12 patients was stress incontinence the sole symptom. In the remainder, symptoms suggestive of detrusor instability were present in 417, of a voiding disorder in 261 and of an inflammatory disorder in 166. The sign of stress incontinence was present in only 168 patients and was not a reliable guide to the diagnosis of genuine stress incontinence. Urodynamic studies were necessary in 488 patients in order to obtain an accurate diagnosis.