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P Alken

Publications and source records attributed to P Alken.

At least 55 records · Page 3Linked to original sources
PubMed2003

Rotoresect for bloodless transurethral resection of the prostate: a 4-year follow-up.

OBJECTIVE: To report the results and long-term follow-up of transurethral resection of the prostate (TURP) with a new resection device, the Rotoresect (Karl Storz, Tuttlingen, Germany). PATIENTS AND METHODS: Most endoscopic resection techniques for benign prostatic tissue aim for high ablation rates and minimal bleeding. Available resection electrodes are effective, but cause high blood loss (loop electrode), or less bleeding but poorer ablation rates (electrovaporization). To resolve these conflicts the Rotoresect was developed in 1995; it consists of a specially designed rotating resection electrode, driven by a micromotor, and a high-frequency current to enable simultaneous coagulation, vaporization and mechanical tissue removal during resection. To date, 84 patients with benign prostatic hyperplasia have had their prostate resected with this device (mean prostate size 46.0, sd 18.4 mL) and have been assessed for up to 4 years. RESULTS: During resection there was very little bleeding, with no significant changes in haemoglobin or sodium levels. The mean (sd) duration of catheterization was 1.4 (1.1) days; the urinary peak flow rate was improved from 9.7 (3.2) to 24.2 (8.23) mL/s and the residual urine volume reduced from 187.3 (109.6) to 22.7 (19.5) mL. The International Prostate Symptom Score and quality-of-life index were both improved, from 24.0 (7.5) to 4.1 (2.7), and 4.2 (3.2) to 0.8 (0.9), respectively. Overall the results were stable during the 4 years of follow-up. CONCLUSION: The Rotoresect combines the advantages of standard resection (high ablation rate) by actively rotating the resection electrode, and the haemostatic effect of electrovaporization (minimal blood loss) by simultaneous tissue coagulation and vaporization.

Aged↗
PubMed2003

Improved sacral neuromodulation in the treatment of the hyperactive detrusor: signal modification in an animal model.

OBJECTIVE: To investigate different stimulation signals for the peripheral nerve evaluation test (PNE, carried out before implanting a sacral neuromodulator for functional voiding dysfunction) in an animal model and to determine their efficacy, as up to 80% of patients do not respond to the PNE test. MATERIALS AND METHODS: PNE foramen electrodes were placed in the S3 of 12 anaesthetized Göttingen minipigs. First, detrusor instabilities were induced by the intravesical instillation of formalin. A 10-min stimulation phase with both a quasi-trapezoidal (QT) signal and a rectangular signal followed. An interval of 30 min elapsed between the series of stimulations. The attained bladder 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 a control group. RESULTS: After formalin instillation, the mean (sd) number of involuntary detrusor contractions was 3.5 (0.8)/min and the sum of amplitudes 7.2 (1.1) cmH2O/min. Subsequent NaCl instillation and QT-stimulation reduced the contractions to 0.3 (0.3)/min and the sum of amplitudes to 0.8 (0.4) cmH2O/min. Stimulation with a rectangular signal, as used in the PNE test, followed after an interval of 10 min, giving 1.1 (0.1) contractions/min and a sum of amplitudes of 5.1 (2.4) cmH2O/min. Within the control group there was no significant reduction. CONCLUSIONS: These results show that QT-stimulation suppresses uncontrollable detrusor contractions in the minipig more effectively than the conventional rectangular stimulation presently applied in sacral neuromodulation.

Animals↗
PubMed2003

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.

Female↗
PubMed2003

[Penile fractures: controversy of surgical vs. conservative treatment].

This paper reviews the current status of information on diagnostic and therapeutic management of penile fractures, focusing on the controversy between surgical vs. conservative treatment of this uncommon injury. Penile fracture, commonly defined as a rupture of the tunica albuginea and corpus cavernosum, is a serious urological disorder demanding surgical management. The diagnostic procedure classically consists of history taking, physical examination and urinary status. Determination of the extent of severity and location of the rupture in the tunica albuginea takes foremost priority and requires additional imaging procedures, such as ultrasound or cavernosography, which will impart enough diagnostic information for the correct choice of treatment. In some cases, the urethra is injured as well. Immediate surgical repair offers complete recovery for patients with penile fracture in most cases, even in the presence of urethral injury. Although penile fracture is easily recognized and can therefore be classified as a "first-look diagnosis", therapy remains controversial to date. The correct therapeutical approach is a vital factor in management, as the associated significant morbidity can result in complete loss of erectile function, painful erections or penis deviation. Early surgical treatment is strongly recommended because of the excellent results, shorter hospitalization, less morbidity and an early return to sexual activity.

Anti-Bacterial Agents↗
PubMed2003

[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.

Adult↗
PubMed2003

[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.

Aged↗
PubMed2003

[Quality of life after surgical correction of penile deviation with the Schroeder-Essed plication].

PURPOSE: For the correction of congenital and acquired penile deviations, there are two established operative methods: the Nesbit procedure and the Schroeder-Essed technique. However, which operative method is optimal with respect to the specific underlying pathology, is still controversial. The aim of the study was to evaluate patient satisfaction retrospectively after modified Essed-Schroeder plication using quality of life questionnaires. MATERIAL AND METHODS: Between June 1997 and June 2000, 59 patients underwent Essed-Schroeder at our institution for correction of a penile deviation. Mean patient age was 40 years (18 - 71) and mean follow-up 30 months (19 - 36). A standardised questionnaire was sent to all patients. Of these, the questionnaires completed by 50 patients could be assessed as valid. RESULTS: Of these 50 patients, 22 suffered from a congenital penis deviation, 28 from Peyronie's disease. The percentage of patients who were able to perform sexual intercourse pre- and postoperatively was 62 % and 90 %, respectively. The proportion of patients who felt hampered during intercourse was reduced from 68 % to 48 %. Frequency of pain occurring during intercourse was diminished by half. Sixty percent of the patients would choose to have the same operation again, while 22 % were dissatisfied with the results. None of the patients showed complete erectile dysfunction after the operation. Seventy-four percent of the patients observed a decrease in penile length. CONCLUSIONS: In patients with Peyronie's disease, the Schroeder-Essed technique with tunica plicature leds to significant improvement in relatively few cases. Alternative methods, such as the Nesbit corporoplasty, appear to be superior in these patients. In cases of congenital penile deviation, however, where the aim is cosmetic correction under maximum protection of erectile function, the Schroeder-Essed tunica plicature has shown good results with regard to penile function and quality of life.

Adolescent↗
PubMed2003

[Cystinuria - Cystine Stones: Recommendations for Diagnosis, Therapy and Follow-up].

Cystinuria, an autosomal-recessive disorder, is the cause of 1 - 2 % of all kidney stones observed in adults and about 10 % of those observed in infants. Despite increasing understanding of underlying pathomechanisms, patients still form recurrent stones and have to undergo repeated interventions with increasing risk of renal insufficiency. Dietary and medical metaphylaxis may lower the frequency of recurrent stones but are often not practiced. Regular follow-up examinations and optimal therapy significantly enlarge stone-free intervals. This review offers an overview of the underlying pathogenetic mechanisms as well as guidance for diagnosis, monitoring, metaphylaxis and therapy of cystinuria following the recommendations of the Deutsche Gesellschaft für Urologie (DGU) and the European Association of Urology (EAU).

Adult↗
PubMed2003

[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.

Adult↗
PubMed2003

[A New Ex-Vivo 3D Bladder Matrix Model for Standardised Evaluation of Urothelial Transfection Methods].

PURPOSE: Gene therapy strategies are a promising new alternative option in the treatment of cancer diseases and great effort is dedicated to the development of new gene transfer methods. At present, in vitro cell culture experiments or in vivo animal trials are the only available alternatives in the search for new gene transfer methods. We attempted to develop and evaluate a new 3D matrix model as a step between in vitro experiments and animal trials. MATERIALS AND METHODS: We generated a convenient model with an agarose gel as a basis for small intestinal submucosa or a polyethylene membrane. The produced model consisting of human smooth muscle cells and human bladder carcinoma cells was transfected with a modified standard Lipofectamine trade mark 2000 transfection procedure and visualised by fluorescence microscopy after cryo-sectioning. RESULTS: With the help of this new technique it is possible to generate three dimensional tissues consisting of different types of cells in which the cells are adherent on the polyethylene and the SIS-membrane during the entire treatment. The resulting model was successfully transfected with the pEGFP-N1 plasmid. CONCLUSIONS: This new three dimensional model allows the standardised evaluation of new transfection methods on multilayered ex-vivo generated tissues consisting of different cells.

Cell Line, Tumor↗
PubMed2003

[Minimally-invasive therapy of urinary stones].

Open surgery was the standard therapy for urinary calculi up to about 30 years ago. This changed upon introduction of extracorporeal shockwave lithotripsy (ESWL) in 1980, a procedure that is now the primary therapy for 70 % of the patients in western countries. Simultaneously, endourological procedures like ureterorenoscopy (URS) and percutaneous nephrolithotripsy (PCNL) have been improved, and now, modern small diameter and highly efficient instruments offer an ideal alternative to shockwave lithotripsy. Today, minimally-invasive stone treatment has replaced open stone surgery almost completely. This article introduces ESWL, URS and PCNL and discusses indications, outcomes and limitations.

Follow-Up Studies↗
PubMed2003

[Metachronous testicular tumor of an extragonadal germ cell tumor].

INTRODUCTION: Approximately 5 - 7 % of germ cell tumors are of extragonadal origin. Biology and genetics are unclear, especially when the primary location is in the retroperitoneum. Chemotherapy is the initial treatment of choice for extragonadal germ cell tumors (EGGCTs), followed by surgical resection of the residual tumor mass. A primary testicular tumor must be ruled out by sonographic investigation and biopsy. The rate of metachronous testicular cancer in men with primary EGGCT is largely unknown. CASE REPORT: We present the first patient in the literature who developed a metachronous testicular cancer 10 months after primary occurrence of EGGCT in the retroperitoneum. CONCLUSIONS: This case report emphasizes the importance of follow-up examinations of patients with primary EGGCTs. They should include careful sonographic investigation of the testis in order to detect metachronous testicular cancer early. Suspicious findings require open surgery biopsy. Intraoperative histopathology can be false-negative for cancer detection, as an immunohistochemical examination is not available.

Adult↗
PubMed2003

[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.

Adult↗
PubMed2003

Recommendations for the treatment of localized prostate cancer by permanent interstitial brachytherapy.

The increasing use of interstitial brachytherapy for the treatment of prostate cancer has made it necessary to discuss and establish guidelines for the application of this treatment modality. A group of experts representing the four professional and scientific societies of urologic surgeons and radiation oncologists in Germany was formed by the German Society of Urology (Deutsche Gesellschaft für Urologie, DGU), the Association of German Urologists (Berufsverband der Deutschen Urologen e.V., BDU), the German Society for Radiation Oncology (Deutsche Gesellschaft für Radioonkologie, DEGRO) and the Association of German Radiotherapists (Berufsverband der Deutschen Strahlentherapeuten, BVDSt). This group has formulated a consensus statement consisting of recommendations and guidelines for the indications, planning, implementation and follow-up of permanent interstitial brachytherapy by seed implantation for the treatment of localized prostate cancer. These recommendations also define the responsibilities of the two medical disciplines involved in the use of this interdisciplinary treatment.

Aged↗
PubMed2002

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.

Animals↗
PubMed2002

[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.

Electric Stimulation Therapy↗
PubMed2002

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.

Adult↗