Long-term changes in urodynamic studies of voiding in the elderly

[Diagnostics of benign prostate syndrome]

The diagnostic work-up of lower urinary tract symptoms (LUTS) in the German guidelines consists of obligatory and optional diagnostic parameters. Recommendations for assessing LUTS include patient history, symptom questionnaires (IPSS international prostate symptoms score), physical examination, urine analysis, prostate-specific antigen, uroflowmetry, ultrasound examination of the urinary bladder, including postvoid residual urine and ultrasound examination of the upper urinary tract. Optional tests are voiding diary, pressure-flow studies, ultrasound measurement of detrusor wall thickness, urethrocystography and urethrocystoscopy. Ultrasound measurement of detrusor wall thickness in particular has a 95 % positive predictive value in diagnosing bladder outlet obstruction. With all diagnostic parameters it is possible to treat LUTS in a risk-adapted manner.

The effect of darifenacin on overactive bladders in female and male rabbits

Our current study utilized a model of bladder instability to compare the effectiveness of darifenacin, a selective m3 muscarinic antagonist, at inhibiting overactive bladder (OAB) dysfunction in both male and female rabbits. Twenty-four male and female NZ white rabbits were used for this experiment. Each rabbit was anesthetized and the carotid artery was cannulated for blood pressure (BP) monitoring and the left femoral artery was cannulated for acetylcholine (Ach) administration. The bladder dome was catheterized for monitoring bladder pressure and for cystometry. A ligature was placed around the urethra just distal to the bladder to induce OAB. After OAB developed, the response to four IV doses of darifenacin (0.003; 0.01; 0.03; 0.09 mg/kg) evaluated for their effects. Darifenacin: (1) was an equally potent inhibitor of the contractile response of both sexes to intra-arterial Ach, (2) had no effects on BP, (3) was a potent inhibitor of the frequency of OAB, but had a significantly less potent effect on the amplitude, and (4) Darifenacin showed a greater potency in the female rabbits than in the males. These studies provide support for the use of darifenacin in the treatment of OAB.

Antimuscarinic drugs in detrusor overactivity and the overactive bladder syndrome: motor or sensory actions?

Antimuscarinic drugs are generally thought to exert their therapeutic action on detrusor overactivity by reducing the ability of the detrusor muscle to contract. We review currently available published data to establish whether there is any evidence to support this contention. Using a PubMed data search, only 14 original articles (including two abstracts) were found that contained cystometric data for both filling and voiding phases and where the actions of antimuscarinic drugs have been reported in detail. These articles were separated into three groups dealing with neuropathic patients (three papers), patients with idiopathic overactive bladder (four papers) and a group whose aetiology was unclear (seven papers). Variables relating to bladder function during the filling phase (time of first desire to void, time to first unstable contraction, and bladder capacity) were identified. Similarly, variables relating to voiding were identified and compared (e.g. maximum detrusor pressure and detrusor pressure at maximum flow rate). The antimuscarinic drugs have a clearly significant effect on sensations of urge, time to first sensation to void, maximum bladder capacity, decrease in voiding frequency and reduction in incontinence episodes. However, only one article (studying neuropaths) reported a significant reduction of the variables associated with detrusor contraction. The remaining four studies (idiopaths/not stated), reported no change in bladder contractility with antimuscarinic drugs. Thus the available data do not support the conclusion that antimuscarinic drugs at doses used in current clinical practice exert their therapeutic action by inhibiting detrusor contractility, but they suggest effects on variables associated with sensation.

Can persisting detrusor hyperreflexia be predicted after transurethral prostatectomy for benign prostatic hypertrophy?

Detrusor hyperreflexia (DH) is frequently found in patients with benign prostatic hypertrophy (BPH) and persists in 30-50% of patients after successful removal of bladder neck obstruction by transurethral prostatectomy (TUR-P) or surgical enucleation of the prostate. It would be beneficial for surgeons to be able to identify patients who are at risk of persistent post-operative urinary irritation symptoms and DH. Twenty-three patients who showed DH pre-operatively were included in this study. Of these 23 patients, four had neurogenic bladder because of previous cerebrovascular disease. The other 19 patients were considered to have DH because of BPH. These 19 patients were classified according to their cystometry chart patterns. Pattern 1 was the continual sporadic onset and offset of DH, pattern 2 was a single episode of DH at a bladder volume of <160 mL, and pattern 3 was a single DH episode at a bladder volume >160 mL. Preoperative single-photon emission computed tomography (SPECT) was performed on 14 patients. Cystometric findings at 3 to 6 months after surgery were compared with the pre-operative findings. Four of the six patients with pattern 2 (67%) and all patients with pattern 3 (100%) showed an absence of DH after surgery. In contrast, all five patients with pattern 1 and all four patients with neurogenic bladder showed persistent DH. Compared with pattern 3 patients, pattern 1 patients more frequently complained of urgency before surgery, and their symptoms and uroflowmetry parameters did not improve afterward. Among 14 patients who had pre-operative SPECT, all eight patients with low cerebral blood flow in the frontal region showed persisting DH. Conversely, all six patients with normal SPECT results showed no DH after surgery. When DH occurs repeatedly (pattern 1) or occurs at a bladder volume of <160 mL (pattern 2), there is a greater risk of post-operative irritation symptoms. Abnormal SPECT findings can also predict the post-operative persistence of DH. Combing these two pre-operative examinations allows us to predict better post-operative DH in patients with BPH.