[Results of sacral nerve modulation for treatment of overactive bladder]. / Ergebnisse der sakralen Neuromodulation bei Therapie der überaktiven Blase.

Currently, sacral nerve modulation (SNM) is an effective treatment for overactive bladder symptoms which are refractory to anticholinergic or muscarinergic treatment. However, SNM requires the implantation of stimulation electrodes at the sacral nerves and a subcutaneous impulse generator. The SNM procedure can be divided into three phases: the acute phase comprising the implantation of the test stimulation electrodes, the subchronic stimulation phase over a period of 7-14 days during which neurostimulation takes place by means of an external impulse generator, and finally chronic SNM after implantation of the final impulse generator. In 1981 the SNM technique for treatment of bladder dysfunctions was first developed by Tanagho and Schmidt and has since been refined, while the range of indications has been extended continuously. It has been shown that patients with neurogenic bladder dysfunctions are able to gain the greatest benefit from SNM. The long-term results of SNM are very encouraging so far. In addition, a highly innovative and promising technique is the implantation of a miniaturized impulse generator with integrated stimulation electrode at the n. pudendus. However, the outcome of these trials has not fully been capable of living up to the expectations so far.

Urinary bladder volumetry by means of a single retrosymphysically implantable ultrasound unit.

AIMS: Optimal voiding is a crucial issue for patients with neurogenic bladder dysfunctions to prevent long-term damage to the urinary tract. In prior studies, implantable ultrasound (US) sensors have proved an appropriate method of measuring the urinary bladder volume. Their disadvantage is that they tend to dislocate in chronic applications as they are fixed directly onto the bladder wall. In the present study, we describe an implantable US volumetry unit that does not require fixing to the bladder wall and consists of a single receiver-transmitter unit. MATERIALS AND METHODS: Six Göttinger minipigs were anesthetized in ITN; a sensor was stitched behind the symphysis into the periosteum and aligned to the bladder so that an US measurement could take place in ventro-dorsal direction. In steps of 50 ml, the bladder was filled up to 250 ml via a transurethral catheter; after each filling step the volume was measured three times and compared to the instilled volume. RESULTS: On average the measurements with implanted US differed from the actual bladder filling by 77.4% at a bladder filling of 50 ml ("error" messages were included as 0 ml), 3.8% at 100 ml, 3.8% at 150 ml, and 0.3% at 200 ml, and 3.6% at 250 ml. When the empty bladder (= 0 ml) was measured, the US sensor detected no volume in 73% of the cases. CONCLUSIONS: In our animal model, the above-described US system proved tantamount with other external US measuring units and presented a precise and low-artefact system, allowing reliable measuring of the urinary volume with good chances of preserving these positive qualities over time. We expect that clinical application of this system may help to determine the optimal voiding time and thus to avoid bladder over-extension and damage to the urinary tract over time.

[Sacral neuromodulation in treatment of functional disorders of the lower urinary tract. An overview of basic principles, indications, outcomes]. / Sakrale Neuromodulation in der Behandlung von Funktionsstörungen des unteren Harntrakts. Ein Uberblick über Prinzip, Indikationen und Ergebnisse.

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.

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.

Secular increase and geographical differences in hip fracture incidence in Norway.

In 1988 and 1989, 2790 hip fractures were reported from the urban population of Oslo (annual incidence per 10,000 in the age group 50 years and older: women 118.7, men 45.4). For the same period, 385 fractures were reported from the rural population of the county Sogn og Fjordane (annual incidence per 10,000 in the age-group 50 years and older: women 74.6, men 36.7). The hip fracture incidence in Oslo had increased for all sex and age groups above 50 years (except women 50-59 years) in the 10-year period 1978/79 to 1988/89. The incidence of hip fractures in Sogn og Fjordane was only 65% of the incidence in Oslo. These results support previous reports on a secular increase and geographical differences in hip fracture incidence.