URODYNANIC FEATURES OF FEMALE PATIENTS WITH NON-NEUROGENIC LOWER
URINARY TRACT SYMPTOMS

Hypothesis / aims of study
Both in congenital and in acquired neurogenic lower urinary tract dysfunction (NLUTD), early diagnosis and treatment is
essential as irreversible changes may occur, even if the related neuropathological signs may be normal [1]. This proposition is
certainly the same for those with non-neurogenic LUTD. The functional classification for motor function of detrusor and
sphincter are based on urodynamic and clinical findings, and this system is also suited and recommended to non-neurogenic
LUTD [2]. There were two kinds of causes for obstruction of lower urinary tract: organic and functional origens. As compared
with the organic obstruction, such as benign prostatic hyperplasia, or primary bladder neck obstruction, functional obstruction
and over- or underactivity of detrusor and sphincter is relatively difficult to display. Here female patients with LUTD were
divided as with SUI or without SUI, then their functional states of detrusor and sphincter were categorized. The major aims of
the present study were to explore the prevalences of various functional disorders of detrusor and sphincter in female patients
with LUTD.

Study design, materials and methods
From 2002 to 2012, a total of 7200 patients with LUTD received conventional urodynamic examination in our institution. Among
them, 2195 were female patients with non-neurogenic LUTD. A retrospective study was carried out. The urodynamic
investigations included maximum flow rate (free Qmax), filling cystometrography (CMG), voiding pressure-flow study (PFS),
external anal sphincter electromyography (EAS EMG) and urethral pressure profilometry (UPP) according to previously
described techniques. Methods, definitions and units were employed according to the standards recommended by the ICS
(International Continence Society), except where specifically noted [3]. During CMG and PFS, vesical pressure (Pves) and
abdominal pressure (Pabd), and then detrusor pressure (Pdet=Pves-Pabd) were measured by using a two-lumen 8 French
catheter and a rectal balloon catheter, respectively. EAS EMG was also simultaneously monitored using two needle-guided-wire
electrodes which were inserted at 3 and 9 o’clock of the anus aperture with lateral distance of 0.5 cm. Filling CMG was
performed with a flow rate of 50 to 70 mL/min of saline and the compliance was recorded continuously. The infusion was
stopped to initiate voiding with changing position from supine to sitting when maximum cystometric capacity (MCC) was
reached. The urinary flow rates, Pdet, detrusor contraction fashion and EAS EMG were measured during the voiding phase
when the patient was instructed to void. Finally, the UPP was obtained and the maximum urethral closure pressure (MUCP) and
the functional profile length (FPL) were recorded [3]. The distribution of various functional disorders of detrusor and sphincter
was calculated and measured according to the EAU mode for NLUTD.

RESULT

Methods to define sphincter underactivity by conventional urodynamics were not available, so this disorder was not involved in
our study. Among the population, cases (%) of IDO (idiopathic detrusor overactivity), dysfunctional voiding or sphincter
overactivity and detrusor underactivity (DUA) were 783 (35.7%), 453 (20.7%) and 225 (10.3%) respectively. Underactive
detrusor with normal sphincter was deleted from DUA. The majority cases had normal detrusor and sphincter function (52.4%,
Fig 1), and dysfunctional voiding (Fig 2) is relatively more than in male patients [3]. It was interesting that we observed one case
with 10 years history of urge incontinence had symptoms of dysfunctional voiding, IDO, urge incontinence and bladder outlet
obstruction and she was successfully cured after receiving baclofen 10 mg, 3/d (Fig 3, 4).

Interpretation of results
Apart from bladder neck obstruction in female patients, OAB, dysfunctional voiding and DUA may also result in much trouble
and impact on their life-quality in female patients. According to our observation, when the detrusor initiates its contraction, the
sphincter usually relaxes, whereas just before the flow begins, the sphincter contracts suddenly anomalously in patients with
dysfunctional voiding (Fig 2). This kind of sphincter disorder may be associated with an enforced guarding reflex of the sacral
spinal cord [3].

Concluding message
Among female patients with non-neurogenic LUTD, prevalences of IDO, dysfunctional voiding and DUA were 35.7%, 20.7%
and 10.3% respectively. During preoperational examination for non-neurogenic female patients suggested of bladder neck
obstrucion, other functional abnormality of the detrusor and sphincter should be considered and conventional urodynamic
intervention may be a good option in this case.