Search PubMed⌕ Search

Biomedical subjects

U Jonas

Publications and source records attributed to U Jonas.

At least 271 records · Page 15Linked to original sources
PubMed1978

Study of threee urethral pressure recording devices: theoretical considerations.

Using a bladder-urethra model, 2 perfusion catheters (open side and open tip) were compared to the balloon catheter. The most accurate results were obtained using the balloon catheter. Based on the law of continuity and Bernouilli's law, the disadvantage of the open side catheter is due to the inconstant diameter of the sum of the side holes. Therefore, the measured pressure is not necessarily identical to the real pressure. The open tip catheter measures the opening pressure and the recorded pressure does not necessarily reflect the pressure at the site of the tip hole. The balloon catheter has elastic and plastic characteristics. Optimum results were obtained only with prestretch of the balloon and with calibration before and after each study. This catheter was the most complicated, but produced the best results and gave rise to the least irritation.

Biomechanical Phenomena↗
PubMed1978

Evaluation of urodynamic studies by computer.

In an attempt to simplify urodynamic evaluation, the data obtained from cystometry, urethral profile and flowmetry were analysed using the ICS recommendations for standardization and terminology. All studies were compiled from check lists feasible for computation. The aim was to establish standards and "typical" changes for the normal bladder and pathological states to enable automatic readout of computed data. The results did, in fact, show "typical" changes but failed to establish standard measurements suitable for completely computed diagnoses.

Adolescent↗
PubMed1978

Late results of bladder stimulation in 11 patients: followup to 4 years.

Direct stimulation of the detrusor muscle offers the best possibility to evacuate the bladder in highly selected patients. During the last 4 years 11 patients have undergone implantation of a bladder pacemaker; followup revealed that 1 patient could void only during stimulation, while 7 patients had reflex evacuation and 3 had no function at all. An exceptional case report is presented.

Adult↗
PubMed1978

Transurethral bladder neck operation in neurogenic bladder.

86 adults with bladder outlet obstruction and neurogenic bladder underwent bladder neck resection or incision to establish effective vesical emptying or damping of detrusor reflex activity. Follow-up examinations revealed a good effect on flow, reflux and hydronephrosis, infection rate and symptoms such as frequency, dysuria, nocturia and urgency. Since 1974, bladder neck incision is preferred; resection remains for selected cases only.

Adolescent↗
PubMed1978

[Conservative-surgical therapy of the neurogenic bladder].

If physical therapy and drugs remain unsuccessful in the treatment of the neurogenic bladder, conservative-operative interventions should be performed prior to urinary diversion. Bladder neck incision, supraselective neurectomy and implantation of a bladder pacemaker in highly selected patients offer a good chance of avoiding diversion. In 64 cases of bladder neck incision, 80% improved or were cured. Experience with the neurectomy in patients with hyperactive detrusor is still limited. The preliminary results, however, proved that this technique should be included in the treatment of neurogenic bladder. 8 of 11 patients in whom a bladder pacemaker was implanted showed voiding following implantation. 7 patients displayed reflex evacuation.

Female↗
PubMed1978

[The continent colon-conduit stoma].

A conduit occlusor is presented consisting of a tube surrounded by foam rubber and covered by a latex membrane, with a polyurethane cap attached to the other end. A valve imbedded in the cap allows voluntary urine drainage. This atraumatic, pneumatic, non-invasive occlusor device was used quite succesfully in 3 volunteers who had had a colon conduit urinary diversion. The device was well-tolerated, leakage was effectively prevented. Further experience, however, will be necessary for final evaluation.

Humans↗
PubMed1978

[Inguinovaginal sling operation in the treatment of female urinary incontinence (author's transl)].

Sling operation have long occupied an established position in the treatment of severe female urinary incontinence and recidivous incontinence. The inguino vaginal sling operation as modified by Narik and Palmrich is described and the operation results for 73 female patients are differentially evaluated. A precise preoperative urodynamic clarification and a previous or simultaneous hysterectomy are prerequisites for satisfactory operation results. In certain instances, this surgical procedure represents a possible method for the restoration of continence even in the case of neurogenic bladder dysfunction.

Female↗
PubMed1977

Membrane catheter: effective for recording pressure in lower urinary tract.

A membrane catheter operating on the principle of pressure transmission across a latex membrane and permitting simultaneous recording of intravesical and urethral pressure is presented. A single and double membrane model are described in detail. Their use for accurate recording of urethral pressure profile and sphincteric activity, and responses to progressive bladder filling at the initiation and during the act of voiding are discussed. This catheter is also useful in neurophysiologic experimental studies as a means to record detrusor and sphinteric responses to various drugs, nerve stimulation, blocking. It is superior to water and gas perfusion catheters.

Humans↗
PubMed1977

Long-term followup of children with colon conduit urinary diversion and ureterosigmoidostomy.

Sixty-four children underwent colon conduit urinary diversion because of a neurogenic bladder owing to myelomeningocele and 39 children required a ureterosigmoidostomy because of bladder exstrophy. The average length of followup was 4.6 years after colon conduit and 5.6 years after ureterosigmoidostomy. Colon conduit diversion was secondary in 3 children and ureterosigmoidostomy was secondary in 5. Of the children with a colon conduit 9.4% and of those with ureterosigmoidostomy 12.8% had postoperative surgical complications. Late surgical complications were encountered after colon conduit in 14.5% and after ureterosigmoidostomy in 20%. Of the children with normal renal function preoperatively 8.3% showed late deterioration after colon conduit and 8.7% after ureterosigmoidostomy. Conversely, only 16.7% with impaired renal function preoperatively did not improve at long-term followup after colon conduit. Of the renoureteral units 91% were normal after colon conduit and 95.2% were normal after ureterosigmoidostomy. The colon conduit halted the preoperative pyelonephritis in 74% of 31 affected kidneys.

Adolescent↗
PubMed1977

[Kidney damage during translumbar aortography treated by selective catheter embolisation (author's transl)].

During a low translumbar aortogram, a kidney was damaged leading to uncontrollable haematuria. The damaged segmental artery was selectively occluded by the injection of butyl-2-cyanoacrylate through a catheter. Bleeding stopped immediately, thereby avoiding a nephrectomy which had been planned. The complications and potential hazards of therapeutic embolisation are discussed.

Aortography↗
PubMed1977

Urodynamic equipment for screening and office use: CO2 cystometry.

A newly available compact urodynamic set-up is presented herein, consisting of a 2-channel CO2 pressure recording unit with flow registration. Flow, bladder and rectal pressure recording are considered the minimal requirements for obtaining sufficient information on functional changes of the lower urinary tract.

Carbon Dioxide↗
PubMed1976

Controlled electrical bladder evacuation via stimulation of the sacral micturition center or direct detrusor stimulation.

Electrical stimulation of the spinal cord and of the detrusor was compared in 5 'acute' dogs. Strong detrusor contraction and rise in intravesical pressure were obtained either way but, with spinal cord stimulation, concomitant rise in urethral resistance prevented micturition. Stimulation with a bladder pacemaker induced detrusor contraction high enough to overcome outflow resistance, thus was more effective in initiating voiding.

Animals↗
PubMed1976

Studies on vesicourethral reflexes. II. Urethral sphincteric responses to spinal cord stimulation.

A bipartite bladder model was developed with and without complete muscular separation in order to isolate and analyze separately sphincteric and detrusor responses. Spinal cord stimulation of the sacral micturition center evoked responses in the detrusor compartment as well as in the urethral sphincteric compartment. The micturition center was easily definable in the spinal cord at a variable point lying in the segment L51/2 to L6 vertebral levels. It was not possible to isolate a separate detrusor center from a sphincteric center. They did overlap-with the sphincteric center extending both above and below the detrusor center. Parameters of stimulation were tested and it was noted that 1 to 3 v, frequency of 10 to 15 cps, and duration of 1 msec gave the optimal responses. Complte muscular separation did not alter sphincteric response to spinal cord stimulation. Nerve-mediated impulses resulted in rise in detrusor pressure and a simultaneous rise in urethral pressure that interfered with proper voiding and hindered bladder emptying. This problem remains to be solved before central spinal cord stimulation for the purpose of controlled bladder evacuation becomes fully effective.

Animals↗
PubMed1976

Voiding pressure as it relates to outlet and/or sphincteric resistance.

Electrically quantitated and controlled detrusor contraction can produce either minimal or excessive rise in intravesical pressure depending upon openness or occlusion of the bladder outlet. Higher rise in intravesical pressure thus does not imply stronger detrusor contraction but should be viewed as a reflection of the outflow resistance mechanism. Possible damaging hydrodynamic effect of sudden partial or complete functional occlusion of the bladder outlet by intermittent or sustained voluntary sphincter activity is illustrated.

Animals↗
PubMed1976

Urodynamic evaluation of a chronically implanted bladder pacemaker.

A "chronic" study of an implantable bladder pacemaker revealed that, although the electrode array did not significantly impair vesical function during the 10 weeks of research, electric stimulation did spread to the voluntary perineal musculature. There was also a drop in bladder response to the same stimulation parameters, probably due to progressive development of fibrous reaction and encasement of electrodes.

Animals↗