1296 © 2 0 0 4 B J U I N T E R N A T I O N A L | 9 4 , 1 2 9 6 – 1 2 9 9 | doi:10.1111/j.1464-410X.2004.05160.x Original Article PREDICTING THE OUTCOME OF CONTINENCE SURGERY DIGESU et al. Preoperative pressure-flow studies: useful variables to predict the outcome of continence surgery GIUSEPPE ALESSANDRO DIGESU, VIK KHULLAR, LINDA CARDOZO, FARAH SETHNA and STEFANO SALVATORE Department of Urogynaecology, King’s College Hospital, London, UK Accepted for publication 23 July 2004 Burch colposuspension were assessed retrospectively. The AFR, the opening (ODP) and closing detrusor pressure (CDP), DP at maximum flow rate and UPP values were calculated for each woman before surgery. RESULTS The preoperative AFR was significantly higher in women who developed de novo detrusor overactivity after surgery. The women who had persistent USI after colposuspension had significantly lower preoperative ODP and CDP than women who were continent after colposuspension. Other variables were not significantly different between the groups of women. CONCLUSIONS The AFR and ODP appear to be useful preoperative measures to predict the outcome of continence surgery and the emergence of de novo detrusor overactivity. KEYWORDS Burch colposuspension, urinary incontinence, urodynamics, pressure flow studies, uroflowmetry, urethral pressure profilometry, acceleration of flow rate OBJECTIVE To determine whether the acceleration of flow rate (AFR), pressure flow variables and urethral pressure profilometry (UPP) measurements might have a role in evaluating women with urodynamic stress incontinence (USI), to predict the surgical outcome and de novo detrusor overactivity after Burch colposuspension. PATIENTS AND METHODS Women with a urodynamic diagnosis of USI (209) who had a modified INTRODUCTION Urodynamic stress incontinence (USI) is ‘the involuntary leakage of urine, during increased abdominal pressure, in the absence of a detrusor activity and desire to void’ [1]. It is the commonest cause of incontinence in women, detected in 40–60% of those investigated [2]. Urodynamic studies are mandatory for the diagnosis and correct surgical treatment of these patients. The number of treatments for USI increases each year, but Burch colposuspension has traditionally been the ‘reference standard’ surgical technique to which all operations are compared, offering a long-term objective cure in >80% of women [2–4]. However, detrusor overactivity arises de novo in 12–18.5% of patients after surgery [5–7], reducing the surgical cure rate. Therefore, more accurate preoperative diagnosis might aid the clinician in predicting de novo detrusor overactivity, and improve counselling of women about the outcome of surgery. Uroflowmetry, pressure-flow studies and urethral pressure profilometry (UPP) have been proposed as important urodynamic variables in the management of urinary incontinence. Susset et al. [8,9] described the acceleration of flow rate (AFR) as a simple urodynamic variable that reflects the speed of the detrusor contraction and opening of the bladder neck. It is defined as the maximum flow rate divided by the time to reach maximum flow, and is independent of voided volume [10,11]. The detrusor pressure (DP) at urethral opening (ODP, the pressure at which urinary flow commences), and at urethral closure (CDP, the pressure at the end of the urinary flow), give further information about urethral function; ODP and CDP are reproducible with low intra/inter-observer variation [12], and differences in ODP and CDP between women with different diagnoses were reported by Wagg et al. [13]. The aim of the present study was to determine whether AFR, pressure flow variables and UPP measurements have a role in evaluating women with USI, to predict surgical outcomes and de novo detrusor overactivity. PATIENTS AND METHODS Women with LUTS and recruited from a tertiary referral urodynamic clinic between April 1985 and August 1999 were studied retrospectively. On referral, all women were sent a urinary-symptoms questionnaire and a frequency-volume chart to complete before their first appointment. The questionnaire elicited daily fluid intake, day- and night-time urinary frequency, urgency, urge incontinence, stress incontinence, hesitancy, urine flow, UTIs and enuresis. At the first visit a complete history was taken and the women physically examined. All women were investigated with video cysto-urethrography (VCUG) using a standardized protocol. Each woman was asked to attend for urodynamic studies with a comfortably full bladder. After uroflowmetry, taken with the patient voiding in private and recorded by a gravimetric flowmeter, the urinary residual was measured. The bladder was filled, using a 12 F filling catheter, with room temperature, X-ray contrast medium (metrizoate, 100 mg/mL at 100 mL/min). Separate 4.5 F fluid-filled bladder and rectal pressure catheters were used. The filling catheter was removed when the patient developed a strong desire to void, or when 600 mL had been infused into the bladder, whereas the bladder- and rectal-pressure