Search PubMed⌕ Search

Biomedical subjects

Michael Müntener

Publications and source records attributed to Michael Müntener.

8 recordsLinked to original sources

Systemic nitric oxide augmentation leads to a rapid decrease of the bladder outlet resistance in healthy men.

OBJECTIVE: We examined the immediate effect of a systemic nitric oxide augmentation on the bladder outlet resistance in healthy men. METHODS: Eleven healthy male volunteers with a mean age of 25.5 yr were included in the study. They were prepared for a standard urodynamic study, and a baseline pressure-flow study was obtained. The subjects were then given 20 mg isosorbide dinitrate sublingually, and after refilling their bladder a second pressure-flow study was done after 20 min. The pressure-flow studies were then compared in regard to the average flow rate, the average detrusor pressure during micturition, and the detrusor pressure at maximum flow rate. RESULTS: One of the subjects was unable to void and had to be excluded from the study. In the remaining 10 men, the mean average flow rate increased from 16.7 ml/s before to 20.2 ml/s after the intake of the NO donor (P=0.013). Concomitantly, the average detrusor pressure during micturition decreased from a mean of 57 to 52 cm H2O (P=0.004) and the mean detrusor pressure at maximum flow rate decreased from 60 to 52 cm H2O (P=0.013). CONCLUSIONS: Systemic NO augmentation can lower the functional bladder outlet resistance very rapidly in men. Our results support the concept that the NO-cGMP pathway may be a promising target for medical treatment of lower urinary tract symptoms.

Administration, Sublingual↗

Peri-operative morbidity and changes in symptom scores after transurethral prostatectomy in Switzerland: results of an independent assessment of outcome.

OBJECTIVES: To assess, in a prospective study, the contemporary outcome of transurethral resection of the prostate (TURP) in patients with benign prostatic hyperplasia (BPH) in Switzerland, by evaluating peri-operative morbidity and changes in lower urinary tract symptoms (LUTS). PATIENTS AND METHODS: Between January 2000 and January 2005, 11 hospitals in Switzerland participated in the study. The hospitals were required to inform Verein Outcome (VO), an independent institution specialising in outcome measurements in the Swiss healthcare system, about patients with BPH who were scheduled for TURP. Later, the hospitals provided data on peri-operative complications in these patients. The patients' Danish Prostate Symptom Score (DAN-PSS) was obtained by VO before and 4 months after TURP (via mailed questionnaires). RESULTS: Data on peri-operative complications from 1014 patients were included in this analysis. The mean (range) age of the patients was 69 (43-91) years. The most common complication after TURP was urinary retention, in 4.5% of the patients; the overall peri-operative complication rate was 9%. In all, 468 patients returned questionnaires both before and after TURP. The mean total DAN-PSS before and 4 months after surgery was 25.2 and 6.2, respectively (P < 0.001). CONCLUSIONS: The results of this prospective multicentre study showed that the current peri-operative morbidity of TURP is lower than that reported from older large-scale trials. The independent assessment of symptom scores confirms that TURP is highly effective in alleviating bothersome LUTS due to BPH.

Adult↗

Systemic augmentation of nitric oxide: is there an immediate effect on the urinary flow rate in healthy men?

INTRODUCTION: Nitric oxide (NO) is an important neurotransmitter in the lower urinary tract. Data from experimental studies in animals and humans suggest that NO donors like isosorbide dinitrate could be used to lower the infravesical resistance. Despite the potentially significant clinical benefit of such an effect, it has hardly been studied in vivo in men. We investigated the immediate effect of isosorbide dinitrate on the urinary flow rate and the functional bladder capacity in healthy young men. PATIENTS AND METHODS: A free urinary flow was measured in 20 healthy male volunteers on two consecutive micturitions. 15-25 min prior to the second micturition, 10 mg of the NO donor isosorbide dinitrate was administered sublingually. RESULTS: We found no significant difference between baseline measurement and the micturition after NO administration with regard to the totally voided volume, the maximal or the average flow rate as well as the flow rate corrected for the voided volume. CONCLUSION: Systemic augmentation of NO does not produce a relevant immediate effect on the urinary flow rate or the functional bladder capacity in healthy men.

Adult↗

Local anesthesia for transurethral manipulations: is a transrectal periprostatic nerve block effective?

Periprostatic nerve block has been reported to be an effective form of anesthesia for prostatic surgery. Recent studies have shown the simplicity and the efficacy of a transrectal approach for periprostatic nerve block. The goal of our study was to evaluate the effect of a transrectal periprostatic nerve block on the discomfort associated with rigid cystoscopy. A total of 73 patients underwent cystoscopy. Group 1 (n = 39) received a transrectal periprostatic lidocaine infiltration prior to the cystoscopy. Group 2 (n = 34) underwent cystoscopy alone. The pain that patients experienced during cystoscopy was assessed on a visual analog scale. The patients in the two groups were very similar in regard to age and size of the prostate. The mean pain score was 3.4 in group 1 and 3.9 in group 2. This difference was not statistically significant. We conclude that nerve block does not seem to reduce the pain associated with transurethral manipulations.

Aged↗

Bilateral perirenal lymphangioma: a conservative approach.

The lymphangioma is a well-recognized benign tumor most frequently encountered in infancy and childhood. The kidneys are rarely involved. Despite its benign nature, most of the patients were treated by partial or radical nephrectomy. We describe a case of bilateral perirenal lymphangioma in a 33-year-old man for whom we chose a conservative approach.

Adult↗

The effect of nitric oxide on the resting tone and the contractile behaviour of the external urethral sphincter: a functional urodynamic study in healthy humans.

AIMS: This functional urodynamic study assessed the effect of the nitric oxide donor isosorbide dinitrate on the external urethral sphincter and hypothesised first that nitric oxide could lower the resting sphincter pressure, second that nitric oxide could influence the sphincter contractility during magnetic stimulation, and third that nitric oxide could induce a faster external urethral sphincter fatigue during continuous magnetic stimulation. METHODS: Eight healthy males gave their written informed consent and were included. A 2-channel microtip pressure transducer catheter was inserted into the urethra measuring the bladder and the external urethral sphincter pressure. Magnetic stimulation of the sacral roots was performed to evoke reproducible contractions of the external urethral sphincter. The baseline protocol included six single pulse stimulations and three stimulations 10sec in duration each for two frequencies 5Hz and 50Hz with intensities at the motor threshold of the pelvic floor. Then the subjects received 10 mg of isosorbide nitrate sublingually and the protocol was repeated 5min, 20min, 40min and 60min after drug administration. RESULTS: The sublingual administration of isosorbide dinitrate could significantly reduce the resting pressure of the external urethral sphincter for at least one hour. The maximal contractile strength measured as the maximal urethral pressure during single pulse and continuous magnetic stimulation of the sacral roots also decreased significantly. Nitric oxide did not induce a significantly faster fatigue of the external urethral sphincter during continuous magnetic stimulation of the sacral roots. CONCLUSIONS: This study shows a functionally relevant effect of nitric oxide on the resting tone and the contractile behaviour of the human external urethral sphincter in vivo while the fatigue properties did not changed significantly. Nitric oxide donors could offer a new pharmacological approach to treat urinary retention due to overactive or non-relaxing external urethral sphincter.

Adult↗

Oral nitric oxide donors: a new pharmacological approach to detrusor-sphincter dyssynergia in spinal cord injured patients?

PURPOSE: Detrusor-sphincter dyssynergia is a common cause of bladder outlet obstruction in spinal cord injured patients and leads to poor bladder emptying and high bladder pressures, which if left untreated might cause renal failure. In this study, we tested the recently published hypothesis that oral administration of a nitric oxide donor could be a new pharmacological approach to treat detrusor-sphincter dyssynergia in humans with spinal cord injury. METHODS: 12 male spinal cord injured patients presenting with neurogenic detrusor overactivity and detrusor-sphincter dyssynergia were studied. 6 performed clean intermittent catheterisation and 6 used suprapubic tapping for bladder emptying. During cystometry the bladder was filled until the first overactive bladder contraction accompanied by detrusor-sphincter dyssynergia occurred while bladder and external urethral sphincter pressures were continuously recorded. Then the bladder was emptied and the patients received 10 mg of isosorbide dinitrate sublingually. Resting pressures were recorded and cystometry was repeated starting 15 min after drug administration. Maximal and mean values for bladder and external urethral sphincter pressures were calculated in both fillings and statistically compared by analysis of variance for repeated measurements (level of significance p < 0.05). RESULTS: Nitric oxide significantly reduced external urethral sphincter pressures at rest (p < 0.05) and during dyssynergic contraction (p < 0.05) while bladder pressures at rest and during contraction as well as the reflex volume remained unchanged. In the patients who used suprapubic tapping for bladder emptying the mean post triggering residual volume was significantly reduced (p < 0.05). CONCLUSIONS: Oral administration of nitric oxide donors significantly reduced bladder outlet obstruction due to detrusor-sphincter dyssynergia suggesting a role for nitric oxide in inhibitory neurotransmission to the urethral sphincter. This new approach could offer a potential pharmacological option to treat detrusor-sphincter dyssynergia in spinal cord injured patients.

Administration, Oral↗