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Biomedical subjects

C Seif

Publications and source records attributed to C Seif.

27 records · Page 2Linked to original sources
PubMed2003

[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.

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↗
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↗
PubMed2000

[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.

Animals↗
PubMed1999

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.

Animals↗
PubMed1999

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.

Animals↗
PubMedDate not supplied

Slightly modified technique of the original Essed plication procedure for congenital penile deviation.

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 (LQ) 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: Twenty-six patients with congenital penis deviation were treated for penile deviation by the original Schroeder-Essed plication with inverted sutures (11 patients) and by the described modification (15 patients). In case of modified technique, horizontal and parallel incisions 4 mm to 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 3-0). Mean age was 21.6 years in the first group and 23.2 years in the second group. Average follow-up was 28 months and 13 months, respectively. The preoperative penile deviation angle was > 25 degrees in all patients without difference between the 2 groups. RESULTS: All patients in both groups reported an improvement in their quality of life and full ability to engage in sexual intercourse. Nine patients (88%) in the first group and 14 patients (93%) in the second group were satisfied with the cosmetic result. In contrast, 10 patients (91%) of the first and 13 patients (87%) of the second group complained of penile shorting. Recurrence of deviation was only noticed 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.

Journal Article↗