Urethral pressure measurement--problems and clinical value

Preoperative urethral parameters at rest and objective cure following laparoscopic colposuspension

INTRODUCTION AND HYPOTHESIS

The aim of this study is to investigate associations between preoperative resting urethral parameters and objective outcome of laparoscopic colposuspension.

METHODS

Data from 219 stress incontinent women who underwent laparoscopic colposuspension, with leakage at standardized pad test repeated after surgery, were collected. Associations between objective cure and preoperative maximum urethral closure pressure, functional urethral length, and continence area were analyzed using receiving operator characteristics curves. The level for 75% cure for each parameter was identified.

RESULTS

All parameters were positively associated with cure. Continence area showed the strongest association. No cut-off values for prediction of failure were found. Women having levels equal or higher than the "75% cure level" for all urethral parameters had a cure rate of 88% compared with 55% for women with all parameters lower than this level.

CONCLUSIONS

A combination of the urethral parameters may be useful for identifying patients with excellent chance for cure after colposuspension. Further studies are needed on continence area.

A telehealth architecture for networked embedded systems: a case study in in vivo health monitoring

The improvement in processor performance through continuous breakthroughs in transistor technology has resulted in the proliferation of lightweight embedded systems. Advances in wireless technology and embedded systems have enabled remote healthcare and telemedicine. While medical examinations could previously extract only localized symptoms through snapshots, now continuous monitoring can discretely analyze how a patient's lifestyle affects his/her physiological conditions and if additional symptoms occur under various stimuli. We demonstrate how medical applications in particular benefit from a hierarchical networking scheme that will improve the quantity and quality of ubiquitous data collection. Our Telehealth networking infrastructure provides flexibility in terms of functionality and the type of applications that it supports. We specifically present a case study that demonstrates the effectiveness of our networked embedded infrastructure in an in vivo pressure application. Experimental results of the in vivo system demonstrate how it can wirelessly transmit pressure readings measuring from 0 to 1.5 lbf/in (2) with an accuracy of 0.02 lbf/in (2). The challenges in biocompatible packaging, transducer drift, power management, and in vivo signal transmission are also discussed. This research brings researchers a step closer to continuous, real-time systemic monitoring that will allow one to analyze the dynamic human physiology.

Urethral pressure response patterns induced by squeeze in continent and incontinent women

Our aim was to compare the urethral pressure response pattern to pelvic floor muscle contractions in 20-27 years old, nulliparous continent women (n = 31) to that of continent (n = 28) and formerly untreated incontinent (n = 59) (53-63 years old) women. These women underwent urethral pressure measurements during rest and repeated pelvic muscle contractions. The response to the contractions was graded 0-4. The young continent women showed a mean urethral pressure response of 2.8, the middle-aged continent women 2.2 (NS vs young continent), and the incontinent women 1.5 (p < 0.05 vs middle-aged continent, p < 0.001 vs young continent). Urethral pressures during rest were significantly higher in the younger women than in both groups of middle-aged women. The decreased ability to increase urethral pressure on demand seen in middle-aged incontinent women compared to continent women of the same age as well as young women seems to be a consequence of a neuromuscular disorder rather than of age.

Fortentwickelte Konzepte zur weiblichen (In-)Kontinenz

The integral theory postulates that defect ligaments and fascias, which impair the supporting function of the vaginal wall, can cause stress urinary incontinence as well as urgency and voiding dysfunction. The anatomical and pathophysiologic basis for these dysfunctions are presented. Voiding dysfunctions can be treated by the substitution of defect structures using the principle of "restoration of structure leads to restoration of function". Essential elements of this therapeutic algorithm are suburethral vaginal slings (retropubic or transobturatoric), further a posterior sling, which runs through the fossa ischiorectalis and suspends the vaginal vault near the sacrospinal ligaments, thus reconstructing defect uterosacral ligaments. In cystoceles, lateral and medial defects can be restored by ventral meshes, which are fixed at the arcus tendineus fasciae pelvis by lateral transobturatoric slings. The use of polypropylene slings and meshes is well-founded because they are well tolerated in the tissues and through the development of scar tissue lead to neoligaments with long-lasting therapeutic effects.

Urodynamic study of women in urinary retention treated with sacral neuromodulation

PURPOSE

We investigated the action of sacral neuromodulation in restoring voiding function in women with urinary retention attributable to sphincter overactivity (Fowler's syndrome).

MATERIALS AND METHODS

We recruited women within retention who were able to void following neuromodulation by temporary test stimulation or a permanent implant. Urethral pressure profiles, cystometry and sphincter electromyography were performed before and after neuromodulation.

RESULTS

A total of 30 women 19 to 52 years old were recruited, including 21 with a permanent implant and 9 undergoing temporary stimulation. Mean maximum urethral closure pressure was elevated compared to expected pressure and it did not change significantly after neuromodulation. The electromyographic abnormality persisted during neuromodulation and voiding was often done with an interrupted flow. There was a slight increase in detrusor contractility.

CONCLUSIONS

This evidence suggests that neuromodulation does not restore voiding in these patients by a direct relaxant effect on the sphincter. The modest increase in detrusor pressure appears to be sufficient to overcome the resistance of the overactive sphincter.

Urethral pressure changes in response to squeeze: a population-based study in healthy and incontinent 53- to 63-year-old women

OBJECTIVE

The purpose of this study was to investigate the urethral pressure pattern during short squeezes in incontinent and healthy women before and after pelvic floor exercise and to correlate the findings with vaginal measurements.

STUDY DESIGN

Sixty women with urinary incontinence and 28 healthy control subjects all aged 53 to 63 years were subject to urethral pressure measurements and vaginal palpation, pressure and surface electromyography measurements. Measurements were repeated after 4 months of pelvic floor exercise in the incontinent group.

RESULTS

The appearance of the urethral pressure curve during a squeeze on a semiquantitative scale from 0 to 4, in the healthy group, was 2.2+/-0.3 and, in the incontinent group, was 1.5+/-0.2 (P<.0 5), rising to 2.2+/-0.2 after pelvic floor exercise (P<.01). The semiquantitative grading correlated with vaginal measurements.

CONCLUSION

The increase of the urethral pressure in response to short squeeze is reduced significantly in incontinent women compared with healthy women of the same age and parity. A normalization was seen after pelvic floor exercise in the incontinent group.

Bladder and urethral responses to pelvic nerve stimulation in the pig

OBJECTIVE

The aim of our study of the pig was to investigate the responses of smooth muscle of the bladder and the urethral sphincter to preganglionic parasympathetic stimulation, and to assess the effect on the lower urinary tract of IV administration of alpha,beta-methylene-ATP.

MATERIALS AND METHODS

In seven anaesthetised female pigs, the responses to repeated 20 s pelvic nerve stimulations before and after IV administration of 0.02 mg/kg alpha-beta-methylene-ATP, and the responses to the drug itself, were recorded in the bladder and the urethra separately.

RESULTS

In the urethral high-pressure zone, pre-stimulation pressure was a mean of 61+/-11 cmH2O. During pelvic nerve stimulation, urethral pressure declined by 48+/-9 cmH2O, while the bladder pressure increased to 30+/-18 cmH2O. The rate of pressure changes during the first 3 s of stimulation (initiation of voiding) was larger in the urethra than in the bladder (urethral pressure decrease: 13.0+/-3.1 cmH2O/s, bladder pressure increase: 3.2+/-2.5 cmH2O/s). Administration of alpha,beta-methylene-ATP was followed by a significant but temporary enlargement in the bladder response to pelvic nerve stimulation to 36+/-20 cmH2O, p = 0.028, n = 7, but no change in urethral response.

CONCLUSIONS

At least 80% of the urethral pre-stimulation pressure was exerted by the smooth muscle. The synergic activation of the detrusor and the urethral smooth muscle in response to preganglionic parasympathetic nerve stimulation was controlled by the peripheral nerves or by the neuromuscular transmission. Administration of alpha,beta-methylene-ATP increased the bladder response to pelvic nerve stimulation without changing the urethral response.