[Use of synthetic slings and mesh implants in the treatment of female stress urinary incontinence and prolapse : Statement of the Working Group on Urological Functional Diagnostics and Female Urology of the Academy of the German Society of Urology]

Due to a safety alert issued by the US Food and Drug Administration (FDA) in 2011 for transvaginal mesh implants to treat female prolapse as a result of numerous reports of complications such as infection, chronic pain, dyspareunia, vaginal erosion, shrinkage and erosion into other organs nearly all industrial products have been withdrawn from the market in the meantime. The United Kingdom, Australia, and New Zealand extended warnings and prohibitions even on the implantation of midurethral slings (TVT, TOT). In view of these current international controversies regarding the use of implanted materials for the treatment of stress incontinence and prolapse and the lack of clear guidelines for the use of biomaterials, the opinion of the Working Group on Urological Functional Diagnostics and Female Urology should provide clarity. The Opinion is based on the SCENIHR Report of the "European Commission's Scientific Committee on Emerging and Newly Identified Health Risks", the "Consensus Statement of the European Urology Association and the European Urogynaecological Association on the Use of Implanted Materials for Treating Pelvic Organ Prolapse and Stress Urinary Incontinence" and in compliance with relevant EAU and national guidelines and the opinion of the Association for Urogynaecology and Plastic Pelvic Floor Reconstruction (AGUB eV). In addition, recommendations are given for the future handling of implants of slings and meshes for the treatment of stress incontinence and prolapse from a urologic viewpoint.

Technological status of reactor coolant pumps in generation III+ pressurized nuclear reactors

KSB has been developing and producing pumps for thermal power plants for nearly 90 years. Consequently, KSB also started to develop and manufacture pumps for all kinds of nuclear power plants from the very beginning of the civil use of nuclear energy. This is especially true for reactor coolant pumps for pressurized water reactors. For the generation of advanced evolutionary reactors (Generation III+ reactors), KSB developed an advanced shaft seal system which is also able to fulfill the requirements of station blackout conditions. The tests in the KSB test rigs, which were successfully completed in December 2015, proved the full functionality of the new design. For generation III+ passive plant reactors KSB developed a new reactor coolant pump type called RUV, which is based on the experience of classic reactor coolant pumps and reactor internal pumps. It is a very compact, hermetically sealed vertical pump-motor unit with a wet winding motor. A full scale prototype successfully passed the 1st stage qualification test program in October 2015.

[Indication for urodynamic testing]

BACKGROUND

The aim of urodynamic testing is to obtain objective information regarding urinary bladder storage and voiding function. Basic investigations provide information of the underlying incontinence form. Depending on the individual situation and findings, further urodynamic investigations are helpful or indicated. Prior to conservative therapy, a routine urodynamic investigation is not indicated.

OBJECTIVES

Due to limited evidence of preoperative urodynamic investigations on postoperative results, the urodynamic results may be helpful when considering various treatment options.

RESULTS

Urodynamic investigations should be performed preoperatively, especially in case of overactive bladder symptoms, prior incontinence surgery, or disordered bladder emptying. The assessment of urethral function should be considered in the urodynamic investigation of stress urinary incontinence. In patients with pelvic prolapse, urodynamic investigations should be performed during prolapse reposition.

[Suburethral tension-free vaginal tape or transobturator tape. When should which procedure be recommended?]

The introduction of tension-free vaginal tapes has led to a complete change of surgical therapy in female urinary stress incontinence. Different materials are used. In many departments, the classic TVT procedure with retropubic placement of the tape has been replaced by transobturator procedures. The current discussion involving transobturator tapes focuses on the question of whether the inside-out technique or the outside-in technique leads to significantly different results. Current state of the art is that all techniques are almost comparable concerning treatment success and complications. Depending on possible pretreatments or concomitant diseases that result in a higher risk for complications, the decision for one technique can be taken individually for each patient. In patients suffering from recurrent stress urinary incontinence after implantation of a tension-free tape, the retropubic implantation of a TVT seems to be superior to a transobturator tape.

[Stress incontinence in women. Is there still an indication to perform the Burch colposuspension and the fascial sling procedure?]

Open Burch colposuspension has been the gold standard for many years in therapy for stress urinary incontinence and still has a major position in this field by virtue of its excellent long-term results. Tension-free transvaginal tapes nowadays also achieve the same success rates and replace the Burch operation due to less invasiveness of the procedure (1). Burch colposuspension is still used in cases of recurrence and as a combination procedure for stress urinary incontinence and vaginal prolapse. The laparoscopic Burch procedure has been increasingly performed in recent years.Fascial sling procedures are used primarily for recurrence of female stress urinary incontinence and intrinsic sphincter deficiency. The treatment principle is based on repositioning both the urethra when it has descended and the bladder neck as well as increasing the reduced outlet resistance. This approach is still employed today to treat stress urinary incontinence in women.

[The role of perineal ultrasound compared to lateral cysturethrogram in urogynecological evaluations]

PURPOSE

The aim of this study was to evaluate prospectively whether perineal ultrasound is comparable to the lateral cysturethrogram in the evaluation of incontinent women.

PATIENTS AND METHODS

Following urodynamic investigations, a lateral cysturethrogram and perineal ultrasound (5 MHz probe, bladder filling 300 mL) were performed in 98 incontinent women. In women with detrusor overactivity and consecutively reduced bladder capacity, ultrasound was performed at maximum capacity. To evaluate differences between perineal ultrasound and the cysturethrogram, the difference between bladder neck and lower border of symphysis and the retrovesicle angle beta were determined at rest and during the Valsalva manoeuvre.

RESULTS

Using perineal ultrasound, the differences between bladder neck and symphysis could be determined at rest and during the Valsalva manoeuvre in all patients. The determination of the retrovesical angle beta was possible in all patients at rest and in 89 of the 98 women during the Valsalva manoeuvre. The lateral cysturethrogram enabled the determination of difference between bladder neck and symphysis and the retrovesicle angle beta at rest in 81 of 98 women. During the Valsalva manoeuvre, the difference between bladder neck and symphysis and retrovesicle angle beta could be determined in 72 of the 98 women. In the 26 remaining women, the determination was impossible due to severe adiposity or cystoceles of the second or third degree.

CONCLUSIONS

Perineal ultrasound provides comparable data to the lateral cysturethrogram. In patients with adiposity, perineal ultrasound seems to be superior. Within the routine evaluation of women suffering from incontinence, the lateral cysturethrogram can be replaced by perineal ultrasound without any limitations of the diagnostic value.

Neue Verfahren zur operativen Therapie der postoperativen Belastungsinkontinenz beim Mann

The impact of minimally invasive techniques for the treatment of postoperative male incontinence has significantly improved in recent years. These techniques are based on the continuous increase in urethral resistance. This resistance can be readjusted with balloons placed paraurethrally or with readjustable suburethral slings. The success rates depend on the preoperative degree of incontinence. With bulking agents that are transurethrally injected into the submucosa of the sphincter, continence rates between 12 and 90% can be seen. Severe complications are rare. The impact of the studies is often limited due to a short follow-up. After implantation of adjustable balloons that are placed paraurethrally close to the bladder neck, continence rates up to 70% can be seen. The overall improvement of incontinence is observed in up to 90% of the treated patients. Complications such as balloon migration or mechanical disorders can cause operative revision. Suburethral sling systems are available as bone-anchored slings or as readjustable slings. Continence can be seen in up to 90% of the patients postoperatively. Severe complications such as sling erosion or sling infection are rare. In cases of mild and moderate incontinence, these minimally invasive techniques are good alternatives to the fascial sling or alloplastic sphincter implantation. To improve the evaluation and to compare these techniques with the conventional methods, further investigations with a longer follow-up are necessary.

Relaxant effects of beta-adrenergic agonists on porcine and human detrusor muscle

AIM

Relaxant effects of different beta-adrenoceptor agonists on porcine and human detrusor were examined. Thus, the beta-adrenoceptor subtype mainly responsible for relaxation in the detrusor muscle of pigs was characterized. Additionally, different effects of several beta-agonists in both species were shown.

METHODS

Experiments were performed on muscle strips of porcine and human detrusor suspended in a tissue bath. The relaxant effects of the non-selective beta-agonist isoprenaline, the selective beta2-agonists procaterol, salbutamol and the selective beta3-agonists BRL 37344, CL 316 243 and CGP 12177 on potassium-induced contraction were investigated. The inhibitory effect of different substances on the maximum contraction and the rank order of potency for endogenous catecholamines was determined in pigs. Furthermore, concentration-relaxation curves were performed for pigs and humans.

RESULTS

Pigs: In the pre-treatment experiments isoprenaline and procaterol showed similar effects. The concentration-response experiments showed that the maximum relaxation induced by procaterol and salbutamol was more than 90%, not significantly different from isoprenaline, whereas the maximum relaxations of CL 316 243, BRL 37344 and CGP 12177 amounted to 68, 70 or 30%, respectively. Rank order of potencies was isoprenaline > or = adrenaline > noradrenaline. Humans: Isoprenaline, procaterol, salbutamol and CL 316 243 showed a maximum relaxation of 80, 41, 24 and 35% and pD2 values of 6.24, 5.65, 5.48 and 5.55, respectively.

CONCLUSION

Beta2-receptors play a main functional role in mediating relaxation of porcine detrusor. Selective beta2- and beta3-agonists similarly relax the human detrusor. Effects were smaller compared with the pig.

Wolfgang Amadeus Mozart

The death of Wolfgang Amadeus Mozart was mysterious from the very first day, and cause of wildest speculation and adventurous assertions. Over the last 100 years, medical science has investigated the physical sufferings and the mysterious death of Mozart with increasing intensity. By means of letters from his father Leopold, his sister "Nannerl", himself and reports from his physicians and contemporaries, we would like to create a medical pathography. The rumour that Mozart was poisoned appeared soon after his early death at the age of 35 on December 5th 1791, and was kept up persistently. Accused were the physician van Swieten, Mozart's freemason's loge and the royal band master Salieri. Mozart, however, died due to chronic kidney disease and ultimately due to uraemia. Once the renal damage has reached a certain point, a minimum of additional stress leads to decompensation. This catastrophe occurs typically within the fourth decade of life. When listening to Mozart's music, we should remember that this apparently happy person was actually a premature adult robbed of his childhood, whose short life was an endless chain of indisposition, over fatigue, misery, concern and illness.

Assisted procreation in cases of hepatitis B, hepatitis C or human immunodeficiency virus infection of the male partner

Guidelines for assisted procreation impose a special responsibility upon physicians for the health of the expected child because of their active role in inducing pregnancy. Therefore, careful clinical evaluation of both partners has to precede every application of these methods. Risks for the mother's health or the development of the child count as a relative contraindication for a treatment. To balance these relative contraindications, the existing risk factors have to be recognized through screening examination. If a chronic infection occurs in the male partner, prevention for the female partner is theoretically possible by using a condom. As this inhibits a pregnancy, at least in cases of human immunodeficiency virus and hepatitis C virus infections, realization of a pregnancy requires assisted procreation. The main question in these cases is whether infectious particles can be eliminated by sperm processing to ensure the safe treatment of the healthy female partner.

[Pelvic pain--definitions, diagnosis and therapeutic options]

Depending on the location, bladder, urethral, penile and prostate pain syndromes are distinguished. In addition to the investigation of urine and ejaculate with the aim of detecting an infection, clinical examination, uroflowmetry are employed and, where indicated, imaging techniques to exclude cancer disease. Chronic pelvic pain is a non-cancer-related pain persisting for more than six months. In the absence of an underlying treatable disease, appropriate pain therapy can be initiated with antiphlogistic analgesics, COX 2 inhibitors or opioids. Depending on the clinical presentation, further therapeutic options or such non-drug measures as bladder training, dietetic measures or surgery may be applied in addition.

[Urodynamic findings in patients with infantile cerebral palsy]

OBJECTIVE

Aim of study was to evaluate the urodynamic findings in patients with infantile cerebral palsy.

MATERIAL AND METHODS

In 29 patients (aged 3-53), a videourodynamic investigation was performed after evaluation of urological anamnesis, clinical assessment and sonographic determination of residual urine. The patients were divided into group 1 (23 symptomatic patients aged 5 years and older with recurrent urinary tract infection, pollakiuria or urinary incontinence) and group 2 (6 asymptomatic patients).

RESULTS

In group 1, 21/23 patients (91%) had reduced compliance (0.6 - 16.4 ml/cmH(2)O) and 16/23 patients (70%) increased leak point pressure (> 40 cmH(2)O). In all 23 patients, detrusor instability and detrusor sphincter dyssynergia (during voiding) was found. Fluoroscopy showed bladder trabeculation or diverticula in 14 patients (61%) and 2nd-3rd degree vesicoureterorenal reflux in 2 patients (9%). In group 2, 2/6 patients (33%) had reduced compliance (0.7 and 5.8 ml/cmH(2)O) and 4/6 (67%) increased leak point pressure (> 40 cmH(2)O). In 5/6 patients (83%), detrusor instability and detrusor sphincter dyssynergia was seen. Fluoroscopy showed bladder trabeculation in 3 patients (50%), whereas no reflux was observed. Only one of the 29 patients (3 %) showed no pathological videourodynamic or anamnestic findings.

CONCLUSIONS

We conclude that videourodynamic assessment should be performed in all patients with infantile cerebral palsy. The decision should not be based on clinical symptoms such as pollakiuria, recurrent urinary tract infection or urinary incontinence.

[Tunica plication with horizontal incisions of the tunica albuginea in the treatment of congenital penile deviations]

PURPOSE

The Schroeder-Essed plication procedure is a standard technique for the correction of penile curvature. In a retrospective analysis we compared functional results and quality of life of the original technique with inverted sutures as described by Schroeder-Essed and our slight modification consisting of horizontal incisions into the tunica albuginea.

MATERIALS AND METHODS

A total of 26 patients with congenital penile deviation were treated, 11 by the original Schroeder-Essed plication with inverted sutures and 15 using the described modification. In the modified technique, horizontal and parallel incisions 4 mm - 6 mm apart and about 8 mm - 10 mm long were made through the tunica albuginea. The outer edges of the incisions were then approximated with permanent inverted sutures (Gore-Tex(R) 3-0). Mean age was 21.6 years in the first group and 23.2 years in the second group. The preoperative penile deviation angle was > 25 degrees in all patients without differention between the two groups.

RESULTS

All patients in both groups reported improvement in their quality of life and full ability to engage in sexual intercourse. A total of 9 patients (88 %) in the first group and 14 patients (93 %) in the second group were satisfied with the cosmetic result, although 10 patients (91 %) in the first and 13 patients (87 %) in the second group complained of penile shortening. Recurrence of deviation was only observed in 2-males in the first group (18 %).

CONCLUSIONS

Our results indicate that this simple modification of the Schroeder-Essed plication offers good functional and cosmetic results. Most patients were satisfied with the penile angle correction results.

Sakrale Neuromodulation in der Behandlung von Funktionsst�rungen des unteren Harntrakts

Over the last few years, sacral neuromodulation has become an established treatment option for dysfunctions of the lower urinary tract. It fills the gap that used to exist between conservative therapy and costly invasive methods such as urinary drainage via a deactivated bowel segment. Initially, the clinical value of sacral neuromodulation was controversial even among neurourologists. This was mainly due to a lack of understanding of the physiological processes, uncertain diagnostics, the design of the hardware, and a surgical topography relatively unknown to the urologist. In the meantime, however, sacral neuromodulation has become a standard part of clinical routine with respect to the treatment of dysfunctions of the lower urinary tract, and it is regularly employed in various urological institutions across Europe and the USA. This form of treatment, which is the final straw for patients who believed themselves-after many frustrated therapy attempts-to be "hopeless cases," can now also successfully be employed as an ambulatory measure. The latest data from our hospital, as well as contributions presented at the last DGU Congress in Wiesbaden, indicate that patients with neurogenic urinary retention are the most likely to profit from this treatment option.

Bladder wall tension during physiological voiding and in patients with an unstable detrusor or bladder outlet obstruction

OBJECTIVE

To develop and evaluate a new clinical method for measuring bladder wall tension (BWT) on detrusor contraction during physiological voiding and under pathological conditions, as in experimental trials during subvesical obstruction the ability to generate pressure increases, whereas the contractile force per cross-sectional area of detrusor muscle decreases.

PATIENTS AND METHODS

In all, 24 patients were divided into three equal groups: group 1 (mean age 58, sd 8.6 years) comprised men with bladder outlet obstruction in accordance with the Abrams-Griffiths nomogram; group 2 (four men and four women, 56, sd 7.2 years) had detrusor instability; and group 3 (54, sd 9.6 years) had normal bladder emptying. BWT, as the detrusor force per cross-sectional area of bladder tissue (in N/cm2), was calculated after a urodynamic evaluation and ultrasonographic estimate of bladder wall thickness.

RESULTS

In all patients it was possible to measure BWT; the mean (sd) maximum BWT in group 1 was 9.8 (3.9) N/cm2, in group 2 during bladder instability was 11.7 (2.6) N/cm2 and in group 3 was 2.8 (0.5) N/cm2.

CONCLUSIONS

Estimating BWT in humans is possible by combining a urodynamic evaluation with an ultrasonographic estimate of bladder wall thickness. Further clinical research should elucidate the clinical relevance of BWT under comparable conditions.

[Established and new urological therapeutic options in the management of prostate carcinoma]

The surgical and medical management of carcinoma of the prostate is a central issue in urology. Radical prostatectomy is the standard procedure in the curative therapy of locally confined carcinoma of the prostate. Recently, alternative minimally invasive options such as brachytherapy and the still experimental focused ultrasound and cryotherapy have gained in interest. Further palliative schemes such as hormonal ablation and chemotherapy have become established in the management of locally advanced and generalized carcinoma or elderly patients. It was our objective to give an account of these established and new urological therapy options in the management of carcinoma of the prostate.

[Clinical Results of PNE Tests in 70 Patients with Different Bladder Dysfunctions]

PURPOSE

Prior to implantation of a sacral neuromodulator we carried out PNE tests (peripheral nerve evaluation test) with bilateral test stimulation to establish which patients might profit from this kind of therapy. In contrast to the original unilateral technique used by Tanagho and Schmidt, we performed bilateral PNE test stimulation. Moreover, we analysed the diagnostic characteristics of those patients who had positive PNE test results and could thus receive a chronic sacral neuromodulator.

MATERIALS AND METHODS

We performed bilateral PNE test stimulation in 70 patients (mean age: 53.6 yrs; 41 with retention symptoms and 29 with a hyperactive detrusor) over a minimum of 3 days. Retrospectively, we analysed the distribution of diagnostic characteristics (retention vs. overactive bladder and neurogenic vs. idiopathic) in the implant recipients.

RESULTS

All patients received bilateral PNE test stimulation, during which the stimulation amplitudes were adjusted individually for each side. 8 patients were treated with the original PNE-electrode (model 0 041 830 - 002, Medtronic Inc., USA) without success. Of the remaining 62 patients, who were treated with an improved electrode, the PNE test was successful in 32 cases (51.6 %). Twenty-seven of these patients suffered from a neurogenic bladder dysfunction, and, in 5 cases, the causes were idiopathic.

CONCLUSIONS

Bilateral PNE-test stimulation and the use of advanced PNE electrodes (model 3057, Medtronic Inc., USA) led to a positive PNE result in 51.6 % of the tested patients. Of these, the group with neurogenic bladder dysfunctions showed the highest response rate. Compared with the success rates in the multicenter study, we were able to increase the overall PNE response rate significantly. For this reason, we prefer a bilateral PNE-test with side-specific stimulation.

[Sacral neuromodulation in patients with nonobstructive, chronic urinary retention: relevance of the carbachol test and influence of associated nerve lession]

OBJECTIVE

Aim of this study was to evaluate whether the carbachol test and the nerve lesions responsible for bladder dysfunction possess predictive value in patients with chronic urinary retention who undergo temporary sacral neuromodulation (PNE test).

MATERIAL AND METHODS

In 1999 and 2000, PNE tests were performed in 24 patients with chronic urinary retention and acontractile detrusor previously assessed by urodynamics. In 18 patients, a carbachol test was performed during urodynamics. The diagnosis related to the acontractile detrusor was additionally assessed and compared to the successful outcome of the PNE test.

RESULTS

The PNE test was successful in 8 of the 24 patients (33.3 %). The bladder was completely emptied during the PNE test in 3 of the 10 patients with negative carbachol test and in 3 of the 8 patients with positive carbachol test. The highest success rate (80 %) was observed in patients after hysterectomy, whereas after lumbosacral pulposal prolapse or with a CNS tumor, it was only 20 - 33.3 %.

CONCLUSIONS

We conclude that sacral neuromodulation is an effective treatment option in patients with nonobstructive urinary retention. The carbachol test does not possess any definitive predictive value with respect to the success rate of sacral neuromodulation in patients with chronic urinary retention. The success rate more likely depends on the localisation of the nerve lesion. PNE tests should be performed in all patients with therapy resistent nonobstructive urinary retention, as no other predictive factors exist.

Stimulation signal modification in a porcine model for suppression of unstable detrusor contractions

OBJECTIVES

To investigate, in an experimental study, the efficacy of a different stimulation signal in a porcine model to suppress formalin-induced unstable detrusor contractions. The current mode of stimulation in peripheral nerve evaluation tests and sacral neuromodulation is based on rectangular signal shapes. Published reports, however, have revealed that up to 80% of patients do not respond to peripheral nerve evaluation stimulation.

METHODS

After placement of electrodes at S3 in 12 anesthetized Göttinger minipigs, unstable contractions were induced by intravesical instillation of formalin. Ten-minute stimulation phases with a quasi-trapezoidal signal and a rectangular signal followed. An interval of 30 minutes elapsed between the two series of stimulations. The pressure values were registered on a urodynamic unit and evaluated as contractions and amplitudes per minute. Six minipigs were treated in the same way but were not stimulated and served as the control group.

RESULTS

After formalin instillation, the average number of involuntary detrusor contractions was 3.5/min (+/- 0.8) and the sum of amplitudes was 7.2/min (+/- 1.1). Subsequent NaCl instillation and quasi-trapezoidal stimulation reduced the contractions to 0.3/min (+/- 0.3) and the sum of amplitudes to 0.8/min (+/- 0.4). A contraction rate of 1.1/min (+/- 0.1) and a sum of amplitudes of 5.1/min (+/- 2.4) were recorded under stimulation with a rectangular signal. In the control group, no significant reduction was recorded.

CONCLUSIONS

The acquired data demonstrate that quasi-trapezoidal stimulation suppresses unstable detrusor contractions in the minipig more effectively than does conventional rectangular stimulation as presently applied in sacral neuromodulation.

Selective block of urethral sphincter contraction using a modified Brindley electrode in sacral anterior root stimulation of the dog

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.

METHODS

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 microsec; 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 H(2)O 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.

CONCLUSIONS

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.

[Bladder wall tension with physiological bladder emptying in patients with detrusor hyperactivity and infravesical obstruction]

PURPOSE

The range of maximum bladder smooth muscle tension in the published literature varies between 1.3 and 59 N/cm (2) depending on the experimental setup. Based on own animal trials, we attempted to determine bladder wall tension during detrusor contraction in physiological and obstructed voiding and during detrusor instabilities in our patient collective.

MATERIALS AND METHODS

In 24 patients (mean age 56 +/- 8.4 years), bladder wall tension as detrusor force per cross sectional area of bladder tissue [in N/cm (2)] was calculated following urodynamic evaluation and ultrasound determination of bladder wall thickness. The patients were divided into 3 groups with 8 patients per group as follows: group I: patients with bladder outlet obstruction in accordance with the Abrams-Griffiths nomogramme; group II: patients with detrusor instabilities; group III: patients with normal bladder emptying.

RESULTS

Maximum bladder wall tension in group I was 9.8 +/- 3.9 N/cm (2). During bladder instabilities (group II), maximum bladder wall tension was 11.7 +/- 2.6 N/cm (2). Maximum bladder wall tension was 2.8 +/- 0.5 N/cm (2) in group III, which was significantly lower (p < 0.05, Mann-Whitney U-Test) than that of groups I and II.

CONCLUSIONS

We conclude that bladder wall tension is distinctly lower in patients with normal voiding than in those with obstructed micturition or detrusor instabilities. Furthermore, our results suggest that the detrusor is not fully activated during normal voiding and is thus capable of compensating for to a greater stress situation with more effective contractions.

[Long-term follow-up of interstitial laser coagulation in the treatment of benign prostatic hyperplasia]

INTRODUCTION

Besides standard open or transurethreal adenoma resection, less morbid interstitial laser coagulation (ILC) is an alternative therapeutical option that could reduce lower urinary tract symptoms, especially in high-risk patients. Although short-term results indicate effectiveness, reliable long-term statistics are still lacking. Therefore, to assess long-term satisfaction and overall success rate, we re-evaluated patients with a mean follow-up of 7 years after laser treatment.

METHODS

A total of 72 patients had been included in our ILC programme between 1993 and 1995. Mean age was 74 years. About 45 % of the patients had since died of other causes. In all, 23 patients were evaluated by telephone questionnaire, International Prostate Symptom Score (IPSS), Quality of Life (QoL), second surgical interventions or medical therapy. Our patient group was treated with interstitial Nd:YAG laser coagulation (mediLas fibertom). A perineal (34 %), transurethral (23 %) or combined (43 %) approach was chosen, depending on the preoperative volume of the prostate (range 40 - 100 ml; mean 59.3 ml).

RESULTS

68.4 % of the patients were satisfied with their current urological situation. Mean IPSS was 8.8 vs. 18.8 preoperatively mean QoL 1.5 vs. 3.3. 15.8 % had undergone conventional transurethral prostatic resection in the interim; one patient uses a urine catheter. 15.8 % receive medical treatment for lower urinary tract symptoms.

CONCLUSIONS

Although the results of standard TUR or open surgery imply higher success, the long-term results of ILC demonstrate effectiveness. Further follow-up studies on a larger number of patients are advisable. The low morbidity of ILC makes this procedure an interesting alternative option in the treatment of high risk patients.

Alterations of cortical electrical activity in patients with sacral neuromodulator

OBJECTIVES

Sacral neuromodulation represents chronic stimulation of the sacral (S3) nerve. So far, the mode of action and neuro-anatomical basis is unclear. Sacral reflex mechanisms as well as pontine or cortical centers of modulation have been postulated. Our aim was to evaluate possible alterations in electroencephalogram (EEG) activity as an indicator of a supraspinally mediated mechanism of sacral neuromodulation.

MATERIALS AND METHODS

We analyzed serial EEGs (apparatus: Kölner Vitaport System) using electrodes placed at Fz, Cz, Cz' and Pz in 10 patients. Subsequently, the sacral (S3) nerve was stimulated by means of an impulse generator (Medtronic, Interstim 3023) using an on-off paradigm with a 1.5s "on" interval followed by a 10s stimulation break. Raw data were analyzed using both Matlab 4.0 software and a specially developed averaging routine.

RESULTS

All patients demonstrated a cortical potential complex following sacral root stimulation with an early electronegative component at 50 ms with a mean amplitude of 23 microV followed by a late potential component with a mean latency of 253 ms and a mean amplitude of 5 microV, both with a maximum at Cz, corresponding to the post-central gyrus. This finding occurred irrespective of patient's reports of actually feeling the neuromodulator being switched on and off.

CONCLUSION

In neuromodulation responders, both short and long latency cortical potentials can be reproduced with a maximum at the sensory cortical area. Although these potentials are similar to cognitively mediated "event-related potentials", they are clearly distinct from any subjective sensory or even painful response since several patients of this series have not been able to feel any neuromodulator action. Therefore, this pilot study indicates a supraspinally mediated site of modulation, most probably in sensory cortex areas.

Intracavernous administration of SIN-1+VIP in an in vivo rabbit model for erectile function

In accordance with the data reporting the identification of nitric oxide synthase (NOS) and vasoactive intestinal polypeptide (VIP) positive nerve fibres in the trabecular meshwork of the corpus cavernosum, we suggest that nitric oxide (NO) and VIP may serve complementary physiological roles in penile erection. Therefore SIN-1 and VIP were administered alone and in combination in an in vivo rabbit model. All rabbits revealed basal pressure values of 5-8 cm H2O intracavernously. In the rabbits intracavernously (i.c.) injected with SIN-1 alone and VIP alone, no adequate erectile responses were observed. Whereas, in the group intracavernously injected with the combination of SIN-1+VIP, erectile responses with mean maximal intracavernous pressure (max. ICP) 52.8 (+/-13.2) cm H2O were noted. These pressure elevations do not statistically diverge (P>0.05) than the ones obtained in the control group administered i.c. injections of the combination of papaverine/phentolamine (mean max. ICP 51 (+/-14.73) cm H2O). Referring to our results, we conclude that the combined use of SIN-1+VIP could play an important role in the physiological treatment of erectile dysfunction.

[Chronic sacral bilateral neuromodulation. Using a minimal invasive implantation technique in patients with disorders of bladder function]

The implantable neuromodulation system described by Tanagho and Schmidt enables unilateral sacral nerve stimulation. Reports have been made on sacral neuromodulation failures of up to 50% in patients undergoing this procedure. We chose the bilateral electrode implantation and a minimal invasive laminectomy to ensure a more effective modulation and better placement and fixation of the electrodes. After successful assessment using a peripheral nerve evaluation test, 20 patients (14 with detrusor instability, 6 with hypocontractile detrusor) underwent minimally invasive laminectomy and bilateral electrode placement. In the patients with detrusor instability, the incontinence episodes were reduced from 7.2 to 1 per day and the bladder capacity improved from 198 to 352 ml. In patients with hypocontractile detrusor, the initial residual urine level of 450 ml dropped to 108 ml. Maximum detrusor pressure during micturition rose from 12 cmH2O initially to 34 cmH2O. The average follow up period was 17.5 months. There was no sign of deterioration in the modulation effect in any of the patients. Bilateral electrode implantation and the new sacral approach allow optimal neuromodulation in patients with bladder dysfunction. Laminectomy enables optimum electrode placement and fixation with minimal trauma.

Combined evaluation of detrusor pressure and bladder wall thickness as a parameter for the assessment of detrusor function: an experimental in vivo study

PURPOSE

We developed a new method for assessing detrusor function, including active detrusor pressure in relation to bladder wall thickness. This parameter should enable the determination of bladder wall tension, defined as detrusor force per cross-sectional area of bladder tissue.

MATERIAL AND METHODS

In acute studies in 8 male foxhounds sacral anterior roots S2 to S3 were placed into a modified Brindley electrode. The bladder was stimulated at different intravesical volumes with bladder filling in 50 ml. stages up to 700 ml. and intravesical pressure was measured and registered. The volume of bladder tissue was determined following cystectomy. Bladder tissue volume and bladder wall thickness were correlated with intravesical pressure during stimulation, resulting in the determination of detrusor force per cross-sectional area in N./cm.2 bladder tissue.

RESULTS

The curve of the intravesical pressure rise during stimulation between 0 and 700 ml. showed a rapid incline with a maximum mean of 70.8 cm. water at 100 ml., followed by a slow decline. The bladder wall tension curve had an approximately symmetrical course with a slow incline, a maximum mean of 10.15 N./cm.2 at 350 ml. and a subsequent slow decline.

CONCLUSIONS

The different curves of intravesical pressure and bladder wall tension show that these parameters are not identical. Combining detrusor pressure with bladder wall thickness enables further information on detrusor function to be obtained. Therefore, the clinical assessment of bladder wall tension may become a promising supplement to standard diagnostic methods with predictive value in patients with disturbed micturition.

Therapeutic administration of an endothelin-A receptor antagonist after acute ischemic renal failure dose-dependently improves recovery of renal function

Endothelin (ET) is known to reduce glomerular filtration rate and renal blood flow and is a possible mediator of acute renal failure (ARF). We recently demonstrated that the administration of a very high dose of the ET(A)-receptor antagonist LU 135252 (LU) accelerates recovery from postischemic acute renal failure by an improvement of renal perfusion in a rat model. The aim of this study was to investigate whether this effect of LU is dose dependent. ARF was induced in rats by clamping both renal arteries. Serum creatinine was measured and endogenous creatinine clearance and fractional sodium excretion were calculated up to 4 days after acute ischemia. Rats were treated either with the selective ET(A)-receptor antagonist LU or with vehicle only after reperfusion. LU in doses of 0.5, 1, or 5 mg/kg per day was infused via a femoral vein using an osmotic minipump. Serum creatinine was increased approximately eightfold after induction of ARF. Creatinine clearance decreased from 4.35 +/- 0.26 ml/min before acute renal failure to 0.15 +/- 0.02, 0.54 +/- 0.1, and 1.49 +/- 0.19 ml/min on days 1, 2, and 4 after ischemia (p < 0.05). Fractional sodium excretion increased from baseline 0.77 +/- 0.05% to 7.5 +/- 1.21 % on day 1 and 8.53 +/- 1.34% on day 2 (p < 0.05). Treatment with LU improved kidney function dose relatedly. There was no significant change in creatinine clearance, but compared with controls, with doses of 0.5 mg/kg per day and 1 mg/kg per day (0.28 +/- 0.1, 0.88 +/- 0.22, and 1.93 +/- 0.24 ml/min on days 1, 2, and 4), we noted a significant increase under 5 mg/kg per day (day 1: 0.62 +/- 0.17 ml/min; day 2: 1.38 +/- 0.26 ml/min; and day 4: 2.45 +/- 0.21 ml/min; p < 0.05). Fractional sodium excretion decreased dose-relatedly to a maximally 2.48 +/- 0.58% on day 1 and 2.25 +/- 0.71 % on day 2 after treatment with the highest dose when compared with untreated control rats (p < 0.05). Our data support the hypothesis that ET plays a major role in ARF. It can be concluded from these results that recovery from ischemic ARF is significantly and dose-dependently enhanced by treatment with a selective ET(A)-receptor antagonist.

Highlights on the latest developments in neurourology - diagnostic technology

Improved appreciation of detrusor malfunction within the complex pathology of lower urinary tract syndrome has led to increased interest in detrusor muscle disorders and possible detrusor myopathies. The rapid development of alternative methods and new pharmacological agents for the treatment of lower urinary tract dysfunction initiate subtle differential diagnosis of the underlying pathology. Research activities related to bladder physiology, neurophysiology and neuropharmacology have increased in the last 10 years. Primarily a purely basic scientific field, neurourology now commences to become a clinically highly significant and useful research domain. This article offers insight into the latest developments in the diagnostic techniques of this exciting field. One of these is smooth muscle EMG of the urinary bladder that aims at distinguishing between signal pattern changes and subsequent evaluation of the different functional and electrophysiological states of smooth muscle cells in various pathologies or in pharmacological tests during urodynamic investigation. A second innovative method in geriatric patients is the measurement of the sensory input to the brain due to bladder distention. The reported techniques are two new examples of lower urinary tract evaluation that contribute to knowledge on the physiology and pathophysiology of the urinary bladder.

Smooth muscle electromyography of the urinary bladder

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.

Smooth muscle fatigue due to repeated urinary bladder neurostimulation: an in vivo study

The presented study investigates the influence of different pause lengths between two consecutive stimulations of the S3 roots on intravesical pressure during bladder neurostimulation. In eight male foxhounds (aged 7-18 months), laminectomy and placement of a modified Brindley electrode were performed. In four series with different pause lengths between two consecutive stimulations (1, 3, 5, and 15 min), the maximum intravesical pressure was measured during stimulation. The changes in intravesical pressure were registered in these four series, each series with six stimulations. A 15-min interval elapsed before the commencement of each series. In the series with a pause length of 15 min, the consecutive stimulations did not result in significant changes in maximum intravesical pressure. In the 5-min series, a significant decrease in intravesical pressure was not observed after the third stimulation. In the 3-min series, a significant decrease was seen at almost every stimulation (average decrease of 3.8% per stimulation) and in the 1-min series, a significant decrease was also observed at almost every stimulation (average decrease of 5.9% per stimulation). The results of repeated bladder neurostimulation demonstrate that the maximum intravesical pressure is dependent on the pause length between two consecutive stimulations. The detrusor muscle showed reversible and short-lived signs of fatigue. This implies the importance of a minimum 5-min interval between two subsequent stimulations. A pause length <5 min leads to a falsification of the results and thus to lower validity of the investigation.

[Volumetry of the urinary bladder with implantable ultrasound sensors]

Experimental studies revealed that the contractile response of the urinary bladder to sacral anterior root stimulation depends on the actual bladder volume. Furthermore, no clinical relevant technique is available for continuous monitoring of the bladder wall distension respectively bladder volume in paraplegic patients. The presented study investigates the reliability of especially developed implantable ultrasound sensors as a sensoric system for continuous monitoring of the bladder volume. In six anaesthesized pigs two ultrasound sensors, one transmitter and one receiver, were implanted on the bladder wall at different locations (latero-lateral, dorsal-ventral, rostral-caudal). After closing the abdominal wall, the bladder was filled in 50 ml steps up to 250 ml. After each filling step the running time of the ultrasound signal was measured. In all experiments reproducible results and a high correlation of the measured running times with bladder volume were observed. The latero-lateral configuration of the sensors seemed to be most confidential. The presented study indicates that bladder volumetry with implantable ultrasound sensors is possible with minimal technical prerequisites. This promising technique for continuous bladder volumetry could play an important role in the development of an intelligent and autoadaptive neurostimulator of the urinary bladder in paraplegic patients.

Restoration of bladder function in spastic neuropathic bladder using sacral deafferentation and different techniques of neurostimulation

PURPOSE

Conventional sacral anterior root stimulation (SARS) results in simultaneous activation of both the detrusor muscle and the external urethral sphincter. We evaluated the possibilities of different neurostimulation techniques to overcome stimulation induced detrusor-sphincter-dyssynergia and to achieve a physiological voiding.

MATERIAL AND METHODS

The literature was reviewed on different techniques of sacral anterior root stimulation of the bladder and the significance of posterior rhizotomy in patients with supraconal spinal cord injury suffering from the loss of voluntary bladder control, detrusor hyperreflexia and sphincter spasm.

RESULTS

The achievement of selective detrusor activation would improve current sacral neurostimulation of the bladder, including the principle of "poststimulus voiding". This is possible with the application of selective neurostimulation in techniques of anodal block, high frequency block, depolarizing prepulses and cold block. Nowadays, sacral deafferentation is a standard therapy in combination with neurostimulation of the bladder because in conclusion advantages of complete rhizotomy predominate.

CONCLUSIONS

The combination of sacral anterior root stimulation and sacral deafferentation is a successful procedure for restoration of bladder function in patients with supraconal spinal cord injury. Anodal block technique and cryotechnique are excellent methods for selective bladder activation to avoid detrusor-sphincter-dyssynergia and thus improve stimulation induced voiding.

Tailored laminectomy: a new technique for neuromodulator implantation

PURPOSE

Neuromodulation of sacral roots is an alternative mode of therapy for patients with urge incontinence or detrusor hypocontractility. We investigated the effects of sacral (S3) nerve stimulation in patients using a new surgical approach for sacral neuromodulator implantation. Modification of the implantation method with sacral laminectomy and bilateral electrode placement led to distinct improvement of stimulation, positioning and dislocation. We developed tailored laminectomy for bilateral neuromodulator electrode implantation to minimize surgical trauma.

MATERIALS AND METHODS

Tailored laminectomy was performed in 6 patients with urge incontinence and 3 with a hypocontractile detrusor. After making a 10 cm. longitudinal skin incision we exposed the spinous processes of S2 and S3. Instead of complete 2-level laminectomy, only 2 oval laminectomy holes were made with a high speed ball drill. An electrode fixation hole was drilled at the edge of the laminectomy window and the wire was fixed with nonabsorbable suture material.

RESULTS

In patients with idiopathic urge incontinence (followup 12.5 months, range 7 to 18) the number of leaks decreased from 7.2 to 0 daily and functional bladder capacity increased from 298 to 352 ml. In patients with a hypocontractile detrusor (followup 10.5 months, range 6 to 20) detrusor pressure increased during voiding from 12 to 34 cm. water and post-void residual decreased from 350 to 58 ml. Average surgery time was 2 hours 15 minutes. In 1 case a seroma developed near the impulse generator.

CONCLUSIONS

Tailored laminectomy is a fast, minimally invasive and reliable technique for neuromodulator implantation.

Recording the evoked canine detrusor electromyogram

With increasing interest in detrusor disorders and possible detrusor myopathies, a method for recording the detrusor electromyogram (detrusor-EMG) would probably greatly assist the diagnosis of various bladder dysfunctions. Therefore, we investigated the electromyographic activity of the detrusor during sacral root stimulation and during spontaneous bladder contractions in six anesthetized dogs. In all experiments, a high correlation of detrusor-EMG recordings with bladder contraction was observed. Analysis in the time domain and power spectrum analysis revealed the most clear correlation of detrusor-EMG with intravesical pressure rise in a frequency band above 3 Hz. The spike duration was 100 to 250 ms with an amplitude of 100 to 500 microV. Low-frequency activity below 1 Hz was mainly presumed to be artifacts due to fluid movement under the electrode. Our trials indicate that smooth muscle EMG recordings from the detrusor smooth musculature are possible. The exact physiological relevance of the signal in the sub-Hertz domain (<1 Hz) is still uncertain. The presented animal model allows the pathophysiologic investigation of various pathologies of bladder dysfunction and detrusor myopathies. Neurourol. Urodynam. 18:687-695, 1999.

Effects of acute urinary bladder overdistension on bladder response during sacral neurostimulation

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 H(2)O) 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.

Sacral anterior root stimulation and cryotechnique: A new option for selective urethral sphincter block and reversible deafferentation in the future?

A possible application of cryotechnique might be a selective block of nerve fiber activity during sacral anterior root stimulation to achieve selective block of urethral sphincter and reversible deafferentation. In 13 foxhounds, electrical stimulation of sacral anterior roots S2 was performed while the accompanying spinal nerves were simultaneously cooled down from +25 degrees C in a stepwise fashion until a block of urethral sphincter activity was observed. The effects of cold block on the urethral sphincter and bladder were monitored by urodynamic investigation. In 2 additional dogs sacral posterior roots S2 were cooled down to +3 degrees C while accompanying anterior and posterior roots were stimulated distal to the cryothermode. Compound action potentials (APs) were registered proximal to the cryothermode before, during and after cooling and recovery time of cold blocked nerves was evaluated. Complete cold block of the urethral sphincter during spinal nerve cooling was achieved in all cases. Block temperature averaged +12 degrees C. Detrusor pressure was a mean 5,2 cm water. Recovery time was on average 5 min. The cold block was always reversible. In both dogs of the second series the compound action potentials disappeared nearly completely at +3 degrees C. Three min after the end of the cooling period the appearance of the compound action potentials was back to normal. In this study, cryotechnique proved to be effective for selective and reversible block of nerve fibers during sacral anterior root stimulation. In functional electrical stimulation this technique may lead to an improvement of quality of life in para- or tetraplegic patients resulting in optimization of voiding, standing, walking and grasping and does so without the necessity of surgical dorsal root rhizotomy.

Extradural cold block for selective neurostimulation of the bladder: development of a new technique

PURPOSE

Cryotechnique for selective block of the urethral sphincter and simultaneous activation of the bladder was developed to achieve physiological micturition during sacral anterior root stimulation (SARS).

MATERIALS AND METHODS

In ten foxhounds SARS of S2 was carried out while extradurally both spinal nerves S2 were cooled down from positive 25C in a stepwise fashion until a sphincter block was observed. Subsequently, SARS of S2 was performed while the pudendal nerves were cooled down from + 15C. The effects of spinal and pudendal nerve cold block on the urethral sphincter and bladder during SARS and the recovery time were monitored by urodynamic investigation.

RESULTS

A complete cold block of the urethral sphincter during spinal nerve cooling was achieved in all cases. During pudendal nerve cooling, the sphincter was completely blocked in two, and incompletely blocked in four dogs. Cold block temperature of the spinal nerves averaged +11.7C and of the pudendal nerves +6.2C. During SARS and spinal nerve cooling, an increase in intravesical pressure up to 13 cm. water was recognized, and recovery time was on average 6.6 minutes. Intravesical pressure remained unchanged during pudendal nerve cooling, with recovery time being less than 1 minute. The cold block was always reversible.

CONCLUSIONS

Cryotechnique is an excellent method for selective and reversible block of the urethral sphincter during SARS to avoid detrusor-sphincter-dyssynergia. The application of cryotechnique in functional electrical stimulation leads to an improvement of quality of life in para- or tetraplegic patients because of selective nerve stimulation with optimization of micturition, standing, walking and grasping and does so without the necessity of surgical dorsal root rhizotomy.

Sacral anterior root stimulation and posterior rhizotomy in spastic neuropathic bladder

The combination of sacral anterior root stimulation (SARS) and posterior rhizotomy is a successful procedure for the restoration of bladder function after supraconal spinal cord injury. Today, complete posterior rhizotomy has become part of the standard therapy. Conventional SARS leads to simultaneous activation of both the detrusor muscle and the external urethral sphincter. We evaluated the possibilities of different neurostimulation techniques to overcome stimulation-induced detrusor-sphincter-dyssynergia and to achieve physiological voiding. Selective detrusor activation improves current sacral neurostimulation of the bladder, including the “poststimulus voiding” principle. Selec-tive neurostimulation is possible in the following techniques: anodal block, high-frequency block, depolarizing prepulses, sinusoidal pulses and cryoblock. The anodal block technique and cryotechnique are excellent methods for selective bladder activation to avoid detrusor-sphinc-ter-dyssynergia and thus improve stimulation-induced voiding. Our experience has shown that future modern selective bladder neurostimulation systems will be based on either the anodal block technique or the cryotechnique.