Optimal voiding is a crucial issue for patients with neurogenic bladder dysfunctions to prevent long‐term damage to the urinary tract. In prior studies, implantable ultrasound (US) sensors have proved an appropriate method of measuring the urinary bladder volume. Their disadvantage is that they tend to dislocate in chronic applications as they are fixed directly onto the bladder wall. In the present study, we describe an implantable US volumetry unit that does not require fixing to the bladder wall and consists of a single receiver‐transmitter unit.

Aims: Patients with spinal cord injury often present with dysfunction of urinary bladder and urethral sphincter. One treatment option is sacral rhizotomy and sacral anterior root stimulation with the Finetech Brindley stimulator. However, a major disadvantage is the lack of selective stimulation, resulting in simultaneous contraction of sphincter and bladder followed by unphysiological micturition. This study investigated the possibility of selective bladder stimulation by using a Brindley electrode. Method: In 11 male anaesthetized foxhounds, a complete posterior rhizotomy was perormed. The anterior S2 roots were stimulated with different quasi-trapezoidal (QT) pulses (pulse length range, 600-1,400 musec; stimulation current, 0.1-2.0 mA; frequency, 20 Hz) by using a tripolar Brindley electrode. Sphincter and bladder pressures were measured urodynamically. Results: All 11 animals showed a maximal reduction of the highest sphincter pressure over 80%, and in 6 of 11 trials, the sphincter pressure was inhibited completely (100%). With stimulations at maximal sphincter blockade, the average achievable bladder pressure was 33.48 cm H2O higher than the average sphincter pressure, and in three cases, a strong micturition was observed Selective blockade of the sphincter was possible by applying QT pulses. The bladders remained uninfluenced by this blockade and kept their excitability at any time. Conclusion:This study shows that selective bladder stimulation with little or no coactivation of the sphincter is possible. A physiological micturition can be achieved by using a tripolar Brindley electrode. Introduction of this stimulation technique into clinical practice should not face major difficulties, considering that the device is an established electrode. (C) 2002 Wiley-Liss, Inc.

Purpose: The objective was to investigate the influence of two anticholinergics, propiverine and tolterodine, on bladder contraction in a standardized in vivo model taking neurogenic innervation into account. In addition, standardized salivary flow measurements enabled the evaluation of hyposalivation, the most predominant anticholinergic side effect. Furthermore, the detrusor electromyogram (EMG) was evaluated.Materials and Methods: 10 male mini pigs were anaesthesized. The carotic artery was cannulated for blood pressure control and the jugular vein for administration of propiverine 0.4 mg/kg b.w. and L(+) tolterodine 0.06 mg/kg b.w. For stimulation-induced salivary flow measurements, both lingual nerves were exposed and a cuff electrode placed around the nerves. After exposure of the bladder, 2 electrodes were implanted under the serosa of the bladder dome to record the detrusor EMG and a cystostomy was performed to assess cystometrographic measurements. A bilateral ureterocutaneostomy was performed in order to maintain a constant bladder volume during the trial. The urethra was then ligated to initiate isovolumetric bladder contraction during sacral anterior root stimulation (SARS).Results: In all experiments, reproducible intravesical pressure values (pves) and salivary flow rates were elicited for each animal during electrostimulation before administration of the drug. Bladder pressure: After administration of propiverine, the neurostimulation-induced rise in pves dropped to 64% of the initial value. After administration of tolterodine, pves declined to 60%. Salivation: After propiverine, salivary flow dropped to 61%. inhibition of salivary flow under tolterodine was about 56%. Similar results were obtained in detrusor EMG recordings. Both propiverine and tolterodine increased the heart rate temporarily by a median of 18%. No change in ECG recordings was noted after administration of the test substances.Conclusions: The in vivo model presented herein allows comparative studies of pharmacological effects on bladder function. Both drugs have similar effects on bladder inhibition in mini pigs. Hyposalivation was comparable in both drugs.

such cases although the risk of infection is very low the consequence is devastating, and this is the justification for prophylaxis. Antibiotic prophylaxis is also appropriate where the risk of infection is high, for example, during colonic surgery where there is contamination with bowel organisms. These established uses help improve operative morbidity and mortality but only in the context of good surgical technique and proper theatre discipline. For clean elective operations the standard measures to prevent perioperative infection remain paramount. These are:

Purpose: Many neurological diseases are associated with bladder sensibility disorders. The aim of this study was to develop, in animal experiments, a diagnostic tool to improve the objective assessment of bladder afferences. Materials and Methods: Evolted potentials were registered by bladder afference stimulation in 6 foxhounds during electrical stimulation of the bladder wall, the complete sacral root and the C- and A delta-fibres and, in 6 rabbits, during repeated bladder filling. Furthermore, the influence of afferent stimulation by bladder filling and electrical sacral root stimulation on EEG-frequencies was investigated. Results: Evoked potentials during electrical bladder wall stimulation or repeated bladder filling showed maximal cerebral responses:after a latency of 2500-6500 ms after beginning stimulation. Stimulation of the complete sacral root resulted in maximal responses up to 800 ms and smaller responses up to 3500 ms. During selective stimulation of C- and A delta-fibres, the response up to 800ms was clearly reduced whereas the response up to 3500 ms remained unchanged. Before afferent stimulation, the EEG-frequency analysis showed frequencies between 2 and 4Hz. During stimulation,these frequencies (2 - 4 Hz) were reduced and frequencies > 8 Hz were observed. After stimulation, the frequencies returned to the values bt fore stimulation. Conclusions: We conclude that the registration of evoked potentials with latencies of > 6500 ms and selective afferent stimulation in necessary for the evaluation of bladder afferences and that the activation of bladder afferences results in reversible and reproducible changes in EEG-activity representing an increased vigilance.

Objective: Urinary retention and micturition disorders after overdistension are clinically well-known complications of subvesical obstruction. We attempted to evaluate whether bladder overdistension influences bladder response and whether overdistension supports detrusor decompensation. Methods: Following lumbal laminectomy in 9 male foxhounds, the sacral anterior roots S2 and S3 were placed into a modified Brindley electrode for reproducible and controlled detrusor activation. The bladder was filled in stages of 50 ml from 0 to 700 ml, corresponding to an overdistension. At each volume, the bladder response during sacral anterior root stimulation was registered. After overdistension, the bladder was refilled stepwise from 0 to 300 ml and stimulated. Results: In all dogs, the bladder response was influenced by the intravesical volume. The maximum pressure (mean 69.1 cm H2O) was observed at mean volume of 100 ml. During overdistension, a significant reduction in bladder response of more than 80% was seen. After overdistension, a significant reduction in intravesical pressure of 19.0% was observed. In 2 cases, reduction in bladder response was more than 50% after a single overdistension. Conclusions: We conclude that motoric bladder function is influenced during and after overdistension. A single bladder overdistension can support acute and long-lasting detrusor decompensation. In order to protect motoric bladder function, bladder overdistension must be prevented.

Purpose: Children with persistent voiding problems, urinary incontinence and/or recurrent urinary tract infections are often difficult to treat. Abnormal behavior during micturition, i.e. detrusor/sphincter dyscoordination, is a frequent cause. Nowadays, biofeedback training is the most suitable therapy.Material and Methods: 45/268 (16.8%) incontinent children (31 girls and 14 boys) aged 4 to 19 years (mean 8.4 years) with detrusor-sphinkter dyscoordination underwent routine diagnostic procedures. Dyscoordination was confirmed by repeated flow-EMG and urodynamic evaluation. Urodynamically, an unstable bladder was revealed in 19/45 children. 29 children had a history of recurrent urinary tract infection, and vesicoureteral reflux was determined in 11/29. All children underwent a behavior therapy with special biofeedback training: sphincter relaxation is practiced in front of a monitor. Optical feedback reflects relaxation and contraction control. Residual urine volume assessed subsequently and the results reviewed after each micturition.Results: Poor compliance by 3 children made biofeedback training impossible. 8 children absolved further biofeedback training at home with the Myotrainer 2000. Good results were achieved in 38/42 children (90.5%) after a 2-5 days period of intensive biofeedbacle training. These children displayed a normal voiding pattern or an at least 50% improvement of enuretic episodes. The success rate dropped to 76.2% during the followup period. During a follow-up of 3 - 39 months (mean 18.55 months), 6 children with recurrent dyscoordination were sucessfully treated on an outpatient basis (Myotrainer 2000).Conclusion: Our results demonstrate that biofeedbacle training can successfully rectify detrusor-sphincter dyscoordination and effectively enable a normal voiding pattern.

To elucidate smooth muscle activity of the urinary bladder, we utilized an optimized animal model and a specially developed, computer-aided data acquisition and analysis system for bioelectrical signals. Twenty-five Wistar rats were pharmacologically paralyzed and artificially respirated. The urinary bladder was exposed by a suprapubic midabdominal incision, and both ureters were ligated to prevent physiological filling of the bladder. The bladder was initially emptied by slight manual pressure and was then filled via a transurethral catheter in 0.1-ml steps to a maximum of 0.45 ml with physiological saline. A custom-made, gold-plated needle electrode was tangentially guided by a micromanipulator to the smooth muscle of the bladder dome, and the recordings commenced. Furthermore, smooth muscle EMG recordings of the bladder were performed after pharmaco-stimulation of the detrusor with carbachol. Initial results demonstrate that, with the animal model presented here, it is possible to record reproducible and almost artifact-free smooth muscle activity from the urinary bladder. All experiments displayed a stochastic distribution of similar electrical events, increasing in appearance and amplitude with increased bladder volume and after pharmacostimulation with carbachol. Two-dimensional power spectrum analysis revealed a main signal frequency below 1 Hz.

Bei Patienten mit suprasakraler Querschnittläsion und spastischer Blase wird die sakrale Deafferentation in Kombination mit der Implantation eines Vorderwurzelstimulators nach Brindley seit mehreren Jahren erfolgreich zur funktionellen Wiedererlangung der Blasenfunktion eingesetzt. Ein Nachteil des verwendeten Stimulators ist jedoch seine fehlende Selektivität in bezug auf die Stimulation der Blase, da es zu einer simultanen Kontraktion des Harnröhrensphinkters kommt, was eine den physiologischen Verhältnissen nahekommende Miktion verhindert. In früheren tierexperimentellen Studien konnte mittels Anodenblocktechnik und unter Verwendung von tripolaren Manschettenelektroden eine weitgehend selektive Blasenstimulation ohne bzw. mit nur geringfügiger Miterregung des Harnröhrenschließmuskels erzielt werden. In der vorliegenden Studie ließ sich mit dieser Stimulationstechnik eine solche selektive Stimulation der Blase erstmals unter Verwendung einer modifizierten Brindley-Elektrode im Tierversuch erfolgreich durchführen. Sollen sich die von uns gewonnenen Ergebnisse beim Menschen reproduzieren lassen, so müßte eine klinische Einführung dieser neuartigen Stimulationstechnik relativ einfach zu realisieren sein, da eine bereits langjährig erprobte Elektrode verwendet werden könnte.

The influence of intravesical volume on bladder response during sacral anterior root stimulation (SARS) was investigated in animal experiments. Following lumbal laminectomy in 9 male foxhounds, bilateral placement of the sacral anterior roots S2 and S3 into a modified Brindley electrode was performed. The bladder was filled in 50 ml steps in the first series up to 700 ml and in the second series up to 300 ml. At these different intravesical volumes, the bladder was stimulated by sacral neurostimulation and intravesical pressure was measured and registered. In all dogs, intravesical pressure during stimulation was influenced by the intravesical volume. Maximum increase in intravesical pressure (69.1 cm H2O) was observed at an average intravesical volume of 100 ml. With increasing intravesical volume after this maximum, the increased pressure slowly dropped down to 11.2 cm H2O at 700 ml. After overdistension, an average reduction in intravesical pressure of 19% in relation to the initial pressure was observed. Therefore, overdistension should be prevented in patients with disturbed bladder function because of the reduction in bladder response during and after overdistension.

A prospective, urodynamic study was carried out with the newly-developed VIVA(R) urethral plug. A total of 32 females suffering from stress or recurrent stress incontinence participated in the study and follow-up. All patients underwent urodynamic assessment, including urethral pressure profile, urethrocystoscopy, and a standardized pad-weighing test which was repeated at intervals of 1 and 6 months. Regular urine analysis and symptom score evaluation, as well as further urodynamic assessment were included in the follow-up after 6 months. Urodynamic evaluation after 4 weeks revealed an improvement of maximum bladder capacity and a distinct shift in involuntary urine loss to greater filling volumes of 218 ml-309 ml at 6 months. The pad-weighing test also revealed that in 16 of the 32 patients (50%) urine loss had decreased significantly and 12 patients remained dry. In all 9 Women developed urinary tract infection which was successfully treated with antibiotics under continual use of the plug. In conclusion, the good preliminary results achieved confirm that the VIVA(R) urethral plug offers a promising alternative in the treatment of female stress incontinence. After 3 months, 86% proclaimed the VIVA(R) urethral plug to be (very) satisfactory.