Postvoid residual urine in the evaluation of men with benign prostatic hyperplasia

Traditionally, the measurement of postvoid residual urinary volume (PVR) has played a prominent role in the evaluation of men with symptoms suggestive of benign prostatic hyperplasia (BPH). This article reviews current opinions about the cause of PVR, methods and accuracy of measurement, correlations between PVR and symptoms as well as physiologic measures of BPH and the role of PVR determination in the evaluation of BPH patients. Community-based data obtained on PVR in men aged between 55 and 74 years in the city of Rotterdam (The Netherlands) are reported

Sacral (S3) segmental nerve stimulation as a treatment for urge incontinence in patients with detrusor instability: Results of chronic electrical stimulation using an implantable neural prosthesis

Most patients with urge incontinence and idiopathic detrusor instability are initially treated conservatively with bladder retraining, pelvic floor exercises and biofeedback, while in the majority this regimen will be supplemented with anticholinergic drugs. The urinary incontinence guideline panel has summarized the literature on results achieved with various drugs for urge incontinence, and found that oxybutynin and terodiline appeared to be the most effective.[1] Subjective cure rates of up to 44 percent over placebo and decreased urinary incontinence rates in up to 56 percent over placebo were achieved with these drugs.[1] Interestingly, no changes in urodynamic parameters were found in well designed drug trials despite symptomatic improvement.2 and 3 Fortunately, many patients seem to be satisfied with a less than optimal result. Patients who do not achieve an acceptable condition remain a therapeutic problem and alternative procedures, with variable success rates, such as bladder transection, transvesical phenol injection of the pelvic plexus, augmentation ileocystoplasty and even urinary diversion, are being advocated.[4] Unilateral sacral segmental nerve stimulation by a permanent foramen S3 electrode (neuromodulation) offers a nondestructive alternative for those whose condition is refractory to conservative measures. The aim of this treatment modality is to achieve detrusor inhibition by chronic electrical stimulation of afferent somatic sacral nerve fibers via an implanted electrode coupled to a subcutaneously placed pulse generator. The ratio of this treatment modality is based on the existence of spinal inhibitory systems that are capable of interrupting a detrusor contraction. Inhibition can be achieved by electrical stimulation of afferent anorectal branches of the pelvic nerve, afferent sensory fibers in the pudendal nerve and muscle afferents from the limbs.5, 6 and 7 Most of these branches and fibers reach the spinal cord via the dorsal roots of the sacral nerves. Of the sacral nerve roots the S3 root is the most practical for use in chronic electrical stimulation.[8] We evaluate the effectiveness of this treatment modality in patients with urge incontinence due to bladder instability

Treatment of benign prostatic hyperplasia by transurethral ultrasound- guided laser-induced prostatectomy (TULIP): Effects on urodynamic parameters and symptoms

Objectives This prospective study was undertaken to evaluate the effects oftransurethral ultrasound-guided laser-induced prostatectomy (TULIP) on urodynamic, symptomatic, and prostate volume parameters as well as serum prostate-specific antigen. Methods The TULIP procedure was performed in 33 patients with benign prostatic hyperplasia with a mean age of 66 years. Patients were evaluated by pressure—flow studies, prostate volume measurement by transrectal ultrasound, and the American Urological Association (AUA) symptom score. Results At 3-month follow-up, laser prostatectomy has resulted in an increased maximum flow rate from 6.6±0.5 to 11.2±0.6 mL/s and in an objectively proven relief of the urodynamic obstruction, as is evident by a decrease of the average value of the urethral resistance parameter URA and the detrusor pressure at maximum flow rate from 38.3 ± 2.7 to 21.3 ± 1.3 cm water and from 62.7 ±4 to 38.9 ± 2.1 cm water, respectively. Symptomatic improvement is evident from a decrease in the AUA symptom score from 20.4 at baseline to 8.8 at 6-month follow-up. Although the total symptom score did not change significantly between 6 months and 1 year follow-up, the score of the symptom “weak stream” was significantly higher again at 12 months follow-up. Conclusions The TULIP procedure is a urodynamically and symptomatically effectivetreatment. Conclusions about the durability of this treatment modality should be made with reser

Estimation of the lag time between detrusor pressure- and flow rate- signals

In a urodynamic measurement setup there is a considerable spatial separation between the uroflowmeter and the location where the detrusor pressure is measured. Therefore, a “time shift” (or lag time correction) has to be applied to one of these signals in order to align related samples in studies where pressure and flow rate are considered simultaneously (e.g., assessment of bladder contractility or bladder outlet resistance). Currently, a heuristic value for this time shift of 0.8 s is applied. In this article, we present a method to estimate the lag time directly from the measurements. Using this method we have found, amongst others, that the mean lag time in our clinic is 0.6 s for males, 0.4 s for females voiding in sitting position, and 1.1 s for females voiding in standing position using a special receptacle in video urodynamics. Furthermore, we found that sphincter/urethral activity during voiding (which causes a drop in flow rate and an accompanying increase in detrusor pressure) is associated (on average) with shorter lag times than straining (when a positive pressure rise accompanies an increase in flow rate). Additionally strong evidence is provided that lag time correction is not a major source of error in urodynamics

Contractility of the guinea pig bladder measured in situ and in vitro

To study the relative importance of neurogenic factors in detrusor contractility and to relate a total bladder in vitro contractility model to a previously described bladder wall strip model, active intravesical pressure values were compared in situ and in vitro in eight male guinea pigs. In situ, the active pressure was measured in spontaneous isometric and nonisometric micturition contractions. In vitro, the active pressure was measured in isometric contractions of the same bladders, developed in response to optimal electrical stimulation. The volume dependence of the active pressure generated by the bladder was measured in vitro in order to relate bladder capacity to the volume where the generated force is maximal and to determine the optimal volume at which to study detrusor contractility. The results indicated that in normal micturition the detrusor muscle was not fully stimulated: active pressure in isometric contractions in vivo was about 60% of the pressure values attained in vitro at the same bladder volume. Most micturitions occurred at a volume where the active pressure generated in vitro was about 80% of the maximal pressure. The active pressure-bladder volume relationship complied with the sliding filament-cross bridge theory. In whole bladder preparations act

Natural history of benign prostatic hyperplasia: Appropriate case definition and estimation of its prevalence in the community

There is no consensus about a case definition of benign prostatic hyperplasia (BPH). In the present study, BPH prevalence rates were determined using various case definitions based on a combination of clinical parameters used to describe the properties of BPH: symptoms of prostatism, prostate volume increase, and bladder outflow obstruction. The aim of this study—in a community-based population of 502 men (55–74 years of age) without prostate cancer—was to determine the relative impact on prevalence rates of the inclusion of these different parameters (and of different cutoff values for these parameters) in a case definition of BPH. There is agreement that age is the dominant determinant of BPH. However, of 28 different case definitions that were formulated only eight gave a statistically significant increase in the prevalence of BPH with age. The highest overall prevalence of 19% (95% confidence interval [CI], 15–23%) occurred using the definition that combines a prostate volume >30 cm3 and an International Prostate Symptom Score (IPSS) >7. The lowest prevalence rate of 4.3% (95% CI, 2-6%) occurred using the definition that combines a prostate volume >30 cm3, an IPSS >7, a maximum flow rate 50 mL Thus, prevalence rates depend very much on the parameters used in a case definition. Follow-up will establish which men will eventually request a workup and treatment for BPH and will help determine the best clinical definition of BPH