Decrease In Urethral Pressure Research Articles

Urodynamics in patients with pheochromocytoma: a peri-operative study of 10 cases.

Alpha receptors have been demonstrated in the bladder neck, and urinary retention may be the presenting symptom in an occasional pheochromocytoma patient. This prompted us to define the urodynamic profile in pheochromocytoma patients. Ten patients were studied. Except for 2 patients, all tumors secreted norepinephrine either alone (n = 4) or mixed (n = 4). Urodynamic studies (uroflowmetry, cystometry, profilometry, response to alpha-adrenergic agents) were performed with Urodyn 5000 chain (DANTEC) connected to a water perfused Bohler's catheter. Profilometry was done according to the Brown and Wickham technique. Normal values were those of the International Continence Society. Alpha blocker test was done by intravenous injection of thymoxamine (0.5 mg/kg) and was considered as positive if urethral closure pressure (UCP) decrease was greater than 30% after 10 minutes. Ten patients had a pre-operative study, omitting alpha-blocker test in 1 patient; 5 patients consented a postoperative study. Pre-operatively we could demonstrate: 1) Increased UCP in 8 of 10 patients, regardless of the secretory pattern; 2) Response to alpha-adrenolytic agents in 7 of 9 patients; and postoperatively: 3) Good correlation between a positive alpha-blocker test and a decrease in urethral pressure in 3 of 5 patients. Urodynamics in pheochromocytoma patients show a typical alpha-adrenergic pattern and may explain bladder dysfunction as a presenting symptom.

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Effect of moxisylyte on the lower urinary tracts was studied with the urethral pressure profile (UPP) and balloon method in anesthetized female dogs. In the UPP, moxisylyte produced relaxation in both the proximal and distal urethras. The relaxation effects of prazosin and bunazosin on the distal urethra was weaker than on the proximal urethra. In the balloon method, moxisylyte, prazosin, bunazosin and phentolamine caused a decrease in urethral pressure dose-dependently. The ID25 values of moxisylyte, prazosin, bunazosin and phentolamine were 23.4, 0.43, 0.76 and 33.1 micrograms/kg, respectively. In the balloon method, moxisylyte noncompetitively antagonized phenylephrine induced contraction of the urethra at high doses, whereas prazosin, bunazosin, phentolamine and yohimbine competitively antagonized phenylephrine induced contraction of the urethra. These results suggest that moxisylyte relaxes both the proximal and distal urethras due to alpha 1-adrenoceptor antagonistic and direct urethral smooth muscle relaxant actions. Therefore, moxisylyte is useful for the therapeutic treatment of micturitional disorder.

Urethrometry: Considerations of static, dynamic, and stability characteristics of the female urethra

AbstractMeasurements of resting anterior/posterior urethral pressures and detrusor function are considered with respect to clinical observations made during the physical examination of patients complaining of urinary incontinence. Observations made on a large number of consecutive unselected patients show that the extent of incontinence is much larger than can be determined by the physical examination alone. Urethral profilometry shows that there are statistically significant differences in the anterior and posterior maximum urethral closure pressure between stress‐ and non‐stress‐incontinent patients regardless of age and detrusor function. The measurement of posterior resting urethral closure pressure correlates best with the physical demonstrability of stress incontinence among patients with a stable detrusor function. The age‐related rate of decrease in the maximum resting urethral pressure is approximately the same for both anterior and posterior urethra in the continent patient. Demonstrably incontinent patients show a rate of posterior urethral pressure decrease with age double that of those with no evidence of incontinence on physical examination. The differences between anterior, posterior, and lateral closure pressures are discussed in terms of their correlative anatomical periurethral structures and are graphically represented in a threedimensional perspective schema.The direction of occlusive forces in the proximal healthy female urethra is critically examined at rest and also during dynamic events such as holding and coughing. The results show that compressive forces in the proximal urethra are asymmetrically distributed with respect to the anterior/posterior plane and are symmetrical in the lateral plane. Resting urethral pressure profiles show that the absolute value of the maximum urethral closure pressure is equal in the anterior/posterior and lateral aspects of the urethra. Dynamic measurement at the proximal urethra in controls shows that holding or coughing produces directional closure from posterior to anterior. The directional forces acting at the proximal urethra are observed in the region coincident with the position of the vaginal attachments to the pelvic diaphragm. Based on resting and dynamic urethral pressure measurements, evidence is presented to indicate that the microtip transducer with sensors oriented in the anterior/posterior plane provides a significant advantage in identifying urethral closure mechanisms and has contributed towards localization of anatomical structures involved in the continence mechanisms. Finally, consideration is made of urethral stability and local pressure variations detected in the absence of external periurethral influences possible interplay between the stability of the urethra on the one hand and the detrusor on the other are discussed with particular emphasis on establishing a link between them.

Ambulatory urethro‐cysto‐rectometry: A new technique

AbstractIn some patients complaining of urinary incontinence a leakage is not found during sitting simultaneous urethrocystometry (SUCM). In these patients, who often exhibit marked urethral pressure variations, the closure pressure frequently falls close to zero due to a decrease in the maximum urethral pressure without simultaneous detrusor contraction. In order to see what happens to urethral, bladder, and rectal pressures when these patients leak urine in daily‐life situations, a new ambulatory urethro‐cysto‐rectometric technique (AUCRM) has been developed.Twenty‐six female patients who had urethral pressure variations of 20–100 cm H2O during SUCM were reinvestigated with this new technique.Urinary leakage was found significantly more often during AUCRM than during SUCM (21 patients of 26, vs. 13 of 26; P < 0.05).Twenty‐one of 26 patients complained of the symptom urge incontinence. In these patients urinary leakage was found to be highly significant more often during AUCRM than during SUCM (16 patients of 21, vs. 4 patients of 21; P < 0.001). Leakage was always due to a combination of urethral pressure decrease and detrusor pressure increase, as in normal micturition. The condition unstable urethra was not found.During SUCM 17 patients were found to have sensory and 4 motor urgency. Performing AUCRM in the same patients, 5 were found to have sensory and 16 motor urgency. By the use of AUCRM the condition sensory urgency has been shown to be less frequent than was previously believed.The new technique of AUCRM used in the present study is compared to supine and sitting SUCM, judged to be superior for detection of the leakage mechanism.

Urethral pressure variations in women with and without neurourological symptoms

AbstractSimultaneous urethrocystometry was performed in 93 females without and 174 patients with neurourological symptoms. Both populations were divided into three age groups. The urethral pressure variation (ΔMUP) was calculated as the difference between the highest and the lowest maximum urethral pressure observed during 1 minute. In all age groups, both the highest and the lowest maximum urethral pressure recorded during bladder filling were significantly higher in the normal females than in the patients. There was, however, no significant difference in the degree of ΔMUP between normal females and patients in the different age groups. Typical urethral pressure variation was also observed during physiological bladder filling. Thus, urethral pressure variation in itself is a physiological phenomenon. With less difference between the lowest maximum urethral pressure and the bladder pressure, the possibility of leaking urine is increased. A urethral pressure decrease may therefore cause leakage in a patient but not in a normal female. More than 50% of the normal females had a urethral pressure variation of more than 20 cm H2O. The previous definitions of urethral pressure variations (unstable urethral pressure, urethral instability), which describe the condition as pathologic when the pressure varies more than 10, 15, or 20 cm H2O, can therefore no longer be considered useful.

Effects of autonomic agonists on in vivo female canine urethral motility.

The response of the urethra to intra-arterially administered autonomic agonists was studied in vivo by measuring the motility and pressure changes in female dogs. Phenylephrine produced shortening along the transverse axis with an increase in urethral pressure in a dose-dependent manner. Isoproterenol produced lengthening along the transverse axis with a decrease in urethral pressure. Both acetylcholine and dimethylphenylpiperazinium did not produce consistent patterns in urethral response. It seems that adrenergic drugs act predominantly on the circular muscle layer and cholinergic drugs act equally on both the circular and longitudinal muscle layers.

Sympatholytic effect on striated urethral sphincter. A peripheral or central nervous system effect?

Effects of intravenous administration of sympatholytic drugs on urethral pressure and electromyographic activity from urethral and anal sphincter, were investigated in five normal women. Clonidine (Catapresan), which easily passes the blood brain barrier, resulted in a pronounced decrease in urethral pressure and electromyographic activity from both sphincters. Phentolamine (Regitine), which does not pass the blood brain barrier, also lowered urethral pressure but had no effect on electromyographic activity from the sphincters. Neither drug depressed reflex induced increase in urethral pressure and sphincter activity during bladder filling or during voluntary contraction of the pelvic floor muscles. Phenoxybenzamine administration to one normal female had the same effect as clonidine. It is suggested that part of the clinical effect on voiding disorders seen after treatment with sympatholytic drugs passing the blood brain barrier (e.g. phenoxybenzamine) might be due to an effect on the central part of the striated urethral sphincter innervation.

A Clinical Experience with Dantrolene Sodium for External Urinary Sphincter Hypertonicity in Spinal Cord Injured Patients

Significant bladder residual urine is secondary to pelvic floor skeletal muscle hypertonicity in some spinal cord injury patients with suprasacral or mixed lesions. Fifteen patients with residual urine volumes greater than 150 cc were treated with dantrolene sodium because of its ability to decrease skeletal muscle contractibility. All of the patients had urethral closure pressures greater than 100cm. water.Of the 15 patients 8 benefited from dantrolene sodium therapy and were maintained on external condom urinary drainage. Five of these 8 patients required up to 600mg. dantrolene sodium daily to affect this result. The residual urine volume decreased to less than 100 cc and the post-therapy decrease in urethral pressure averaged 77cm. water (49 per cent). The patients in the failure group (residual urine greater than 150 cc) had an average decrease in urethral pressure of 21cm. water (16 per cent). Detrusor hyporeflexia possibly contributed to the failure rate.In summary, dantrolene sodium seems to be beneficial in some patients with external urinary sphincter hypertonicity. However, it will not supplant external sphincterotomy in the more complete male spinal cord injury patient in whom reflex incontinence is of minimal concern. Dantrolene sodium could be an ideal treatment of patients with incomplete neurologic lesions in whom continence might be preserved. The drug will have to be effective at low doses to obviate the major side effect of over-all muscle weakness.

Initiation of micturition: a study of combined urethrocystometry and urethrocystography in healthy and stress incontinent females.

Six continent and 4 incontinent females were examined by a combined technique of simultaneous urethrocystometry and rapid X-ray-film exposures. The study confirmed that pressure changes occurring in the urethra and bladder at initiation of voiding were not caused by artefacts of the measuring technique. It was found that the continent females initiated micturition mainly by a rapid decrease in urethral pressure followed by an increase in the bladder pressure. The stress incontinent females strained out the urine without initial urethral relaxation. Since the X-ray-technique did not add any new clinical information about micturition in females the pressure recording technique is recommended for routine investigation of micturition in females.

Pubovaginal Sling Procedure for Stress Incontinence

Urinary stress incontinence associated with poor urethral sphincter function and indicated by a urethral pressure of less than 10cm. water was treated in 52 cases with a pubovaginal autogenous fascial sling. No urethral sphincter function could be measured in 7 patients. Of these 52 patients 42 had undergone a previous operation for stress incontinence.The uninhibited detrusor dysfunction that accompanied the stress incontinence in 29 cases ceased after operation in 20 but persisted in 9. Postoperative urethral pressure measurements indicated that while the sling increased urethral pressure it did not cause an obstruction during voiding, since there was a measurable decrease in urethral pressure during a detrusor contraction.Urodynamic determinations were useful in patient selection, in the adjustment of sling tension at operation and in the assessment of reasons for failure. A satisfactory result with good urinary control was obtained in 50 cases and the procedure was a failure in 2.