Lower Detrusor Pressure Research Articles

Causes of Failed Urethral Botulinum Toxin A Treatment for Emptying Failure

Urethral injection of botulinum toxin A (BTX-A) can reduce urethral resistance in patients with voiding dysfunction. However, some patients do not benefit from this treatment. It is essential to identify the causes for these failed procedures. A total of 200 patients receiving urethral BTX-A injections for voiding dysfunction refractory to conventional medication during a 5-year period were included in this study. The patients received 50 or 100 U of BTX-A injected into the urethral sphincter. Treatment was considered successful when patients were subjectively satisfied with the outcome and (a) patients with chronic urinary retention resumed spontaneous voiding, (b) patients with a large postvoid residual volume had a reduction in postvoid residual of more than 50%, (c) patients voided with a lower detrusor pressure or lower abdominal pressure to urinate adequately. The therapeutic results and causes of failed treatment were retrospectively analyzed. The overall success rate was 88.5% (177 patients), including 47.5% (95 patients) with an excellent result and 41% (82 patients) with an improved result. The causes of failed treatment in 23 patients were detrusor underactivity with very low abdominal straining pressure in 7, a tight urethral sphincter in 7, bladder neck obstruction in 7, and psychological inhibition of voiding in 2. Transurethral incision of the bladder neck was performed in 7 patients, and all had an improved result. BTX-A urethral treatment failed in 11.5% of patients with voiding dysfunction refractory to medical treatment after one session. Careful investigation of the underlying causes of failed treatment is mandatory to achieve a satisfactory outcome.

Healthy, Middle-Aged, History-Free, Continent Women—Do They Strain to Void?

We evaluated to what extent abdominal straining is used for voiding in an asymptomatic, continent, healthy, middle-aged female population. A total of 32 women (mean age 49 +/- 6 years old) could be prospectively included. Technical investigations consisted of flowmetry, pressure flowmetry with EMG and electrosensation evaluation. Some data were compared with those of stress incontinent women investigated prospectively in the same way. There were 4 women who were excluded from analysis because of abnormal sensory evaluation. The symptom-free participants voided with low detrusor pressure, a high flow rate and no residual. A large segment (42%) used additional abdominal straining to void on cystometry and reported that such straining was their usual habit for voiding at home. Straining was seen as frequent in women with stress incontinence. However, significantly more women with stress incontinence used straining without detrusor contraction. These healthy middle-aged women without a history of pelvic surgery, or symptoms or signs of urological, anorectal or gynecological problems, voided with a mean Pdetmax of 25 cm H(2)O, mean Qmax of 29 ml per second, and the majority without residual. Many of them strained during detrusor contraction and this had not led to the development of signs or symptoms. The way straining is done may make the difference in that during reflex bladder contraction and urethral relaxation, additional straining may have little negative effect. If straining is used to void without the initiation of the micturition reflex, voiding dysfunction and incontinence might develop more easily.

BLADDER NECK SLING FOR TREATMENT OF NEUROGENIC INCONTINENCE IN CHILDREN WITH AUGMENTATION CYSTOPLASTY: LONG-TERM FOLLOWUP

We retrospectively reviewed the outcome and long-term followup (mean 4.16 years) of bladder neck slings for the treatment of neurogenic urinary incontinence in 58 patients (15 males) who also underwent bladder augmentation. A total of 58 patients with neurogenic bladder (43 females and 15 males, median age 11.4 years) underwent a rectus fascial sling procedure as part of the reconstructive efforts for continence between July 1991 and July 2003. Criteria for enhancement of bladder outlet resistance included a detrusor leak point pressure of less than 45 cm H2O, an open bladder neck during bladder filling at low detrusor pressures and clinical evidence of stress incontinence. Followup ranged from 1 year to 10 years, 3 months (mean 4.16 years). A total of 51 patients (88%) obtained good continence results. Five females and 2 males remained incontinent following the sling procedure. Four females underwent a secondary open bladder neck procedure at a mean of 18 months after the initial procedure (artificial urinary sphincter in 2, bladder neck closure in 2). Two male patients (5 and 17 years old) had daily underwear staining or dampness with exercise or transfer. We consider bladder neck slings the procedure of choice for the enhancement of bladder outlet resistance in the majority of patients with neurogenic bladder who need augmentation cystoplasty and whom we do not expect will be capable of voiding spontaneously. In males and females satisfactory long-term continence can be expected with the use of the rectus fascial sling.

Voiding dynamics in women: a comparison of pressure-flow studies between asymptomatic and incontinent women

Objectives. To define the normative values for pressure-flow studies in asymptomatic women and to compare them with the values in women with stress incontinence. Methods. Asymptomatic women between the ages of 30 and 70 years were recruited from the community to undergo urodynamic studies (UDSs). Only women with no or minimal symptoms on the Urogenital Distress Inventory Questionnaire, minimal pelvic organ prolapse, and no previous surgery for incontinence were included. The results of the pressure-flow studies were compared with the values from women evaluated for stress urinary incontinence (SUI) between December 1998 and August 2000. Results. Twenty asymptomatic women (mean age 41.7 years) met the inclusion criteria of the 59 who applied. Their pressure-flow data were compared with that of 40 women with symptoms of pure SUI selected from the 415 who underwent UDSs during this period, 16 of whom were found to have SUI during the UDS. The average maximal flow was 17.2 ± 6.7 mL/s in the control population and 22.0 ± 6.8 mL/s among women with genuine SUI during the UDS ( P = 0.039). The detrusor pressure at the maximal flow averaged 24 ± 10 cm H 2O and 16.0 ± 8.6 cm H 2O for the control and SUI groups, respectively ( P = 0.016). The voided volumes were somewhat higher for the SUI group (330 versus 419 mL, P = 0.041). Conclusions. These findings confirm the normative pressure-flow data in women and suggest that women with stress incontinence void at a lower detrusor pressure. A chronically reduced outlet resistance during bladder filling, which likely contributes to SUI, also appears to affect the voiding phase in stress-incontinent women.

Urethral resistance factor (URA) versus Schäfer's obstruction grade and abrams–griffiths (AG) number in the diagnosis of obstructive benign prostatic hyperplasia

Different methods of analyzing pressure/flow plots to quantify bladder outlet resistance in men with lower urinary tract symptoms (LUTS) due to benign prostatic hyperplasia (BPH) were developed in the past. The aims of this study were to quantify the degree of agreement between the diagnosis of obstruction by the different methods, and to compare the applicability of the different methods in the evaluation of bladder outflow conditions, in a large group of these men. In consecutive men with LUTS basic initial evaluations, recommended diagnostic tests, and urodynamic investigations were performed. From pressure/flow studies, the group-specific resistance factor (URA), Schäfer's obstruction grade, and Abrams–Griffiths (AG) number were estimated. Men with 21 cm H2O≤URA≤29 cm H2O and men with Schäfer's grade equal 2 were classified as equivocal. In conformity with the provisional ICS definition, men with 20≤AG number≤40 were classified as equivocal. In 78% of the 565 included men Schäfer's classification agreed with URA classification. In 82% ICS classification agreed with URA classification. Most agreement (94%) existed between Schäfer's classification and ICS classification. All differences were near the points of intersection of the different boundaries, and a decision whether to perform surgery on a patient is not likely to be influenced by this disagreement. Males with relatively low detrusor pressure at maximum flow and relatively low maximum flow had a high prevalence among those in whom URA and Schäfer's classifications and among those in whom URA and ICS classifications differed. Neurourol. Urodynam. 20:175–185, 2001. © 2001 Wiley-Liss, Inc.

URODYNAMIC FACTORS INFLUENCE THE DURATION OF ESCHERICHIA COLI BACTERIURIA IN DELIBERATELY COLONIZED CASES

Purpose We evaluated the influence of urodynamic factors on the establishment of bacteriuria, after deliberate intravesical inoculation with Escherichia coli. Materials and Methods Nine women and 7 men with recurrent symptomatic urinary tract infections underwent intravesical injection of E. coli 83972. This strain had documented ability to persist in the urinary tract and it lacks expressed virulence factors associated with urinary tract infection. Results Successful long-term colonization (5 months to 3 years) was achieved in 6 of 12 patients with neurogenic bladder disorder, including normal or high bladder capacity, normal or low detrusor pressure and residual urine. Short-term bacteriuria (13 days) occurred in 1 but long-term bacteriuria was not established in the 4 patients with normal lower urinary tract function. Occasionally urine samples from the colonized patients contained other bacterial strains, which cleared spontaneously except for a Klebsiella strain that became established in 2 and subsequently eliminated E. coli 83972. Conclusions E. coli 83972 bacteriuria could only be established in a subset of patients with defective bladder voiding, suggesting that urodynamic defects permit a nonvirulent strain to establish in the urinary tract, but that additional host factors determine if bacteriuria will persist.

Lower urinary changes over time in suprasacral spinal cord injury.

This paper reviews 179 patients (23 females and 156 males) with suprasacral spinal cord injury (SCI) who underwent videourodynamic evaluation to compare maximum detrusor pressure, compliance, and trabeculation with methods of bladder management, years post-injury, and age. The patients were divided into four groups based on mode of bladder management: clean intermittent catheterization (CIC), indwelling catheter (IND), external collector (EC), and voiding (V). Maximum pressure decreased significantly with increasing age for those using EC (P < 0.01) and CIC (P < 0.05). Maximum pressure also decreased significantly with years post-injury for patients on EC (P < 0.01) and was highest the first decade after injury and progressively decreased through the fifth decade. Post-hoc tests indicated more severe trabeculation in patients in the EC group than in either the CIC or IND groups. Age and trabeculation did not correlate in those on EC. We conclude that patients with long-standing suprasacral SCI using EC are more likely to have lower detrusor pressures than are those with less chronic SCI. This finding may reflect the effects of age as well as reduced survival in those using EC with chronically elevated detrusor pressure.

Obstruction Following Anti-Incontinence Procedures: Diagnosis and Treatment with Transvaginal Urethrolysis

We reviewed the charts of 41 patients who underwent transvaginal urethrolysis and resuspension of the bladder neck by the Raz technique for urethral obstruction with or without stress urinary incontinence following anti-incontinence surgery. We sought to evaluate the effectiveness of the procedure as well as to determine any factors that had an effect on the outcome of surgery. Patients were evaluated for obstruction and stress urinary incontinence by history, physical examination, video urodynamics (or multichannel urodynamics plus cystogram and voiding cystourethrography) and cystoscopy. All patients reported normal emptying before the procedure that caused obstruction. Several variables were evaluated for individual predictive values for outcome, including type of surgery causing obstruction, number of previous antiincontinence procedures, urodynamic evidence of obstruction (high pressure, low flow), instability, concomitant stress urinary incontinence and total urinary retention, which were evaluated by the Fisher exact test, and the amount of post-void residual, bladder capacity, maximum detrusor pressure, maximum urinary flow and interval since surgery causing obstruction, which were evaluated by logistic regression analysis.Mean patient age was 59 years (range 26 to 86 years) and mean followup was 21 months. A total of 19 patients (46%) suffered from concurrent stress urinary incontinence, 23 (56%) had urodynamic evidence of obstruction (high pressure/low flow) and 6 (15%) had only radiographic or endoscopic evidence with a deviated or kinked urethra. Postoperatively, 29 patients (71%) voided normally without significant residuals. Eight patients (20%) remain on self-catheterization and 1 has persistent stress urinary incontinence. When individual variables were evaluated to determine the predictive values with respect to outcome of urethrolysis, only the preoperative post-void residual was statistically significant (the greater the post-void residual, the more likely was failure, p = 0.021). The presence or strength of the detrusor contraction preoperatively and pressure-flow analysis did not predict outcome. Of the patients with stress urinary incontinence 15 (79%) were cured and 3 (16%) were significantly improved with rare stress urinary incontinence not requiring protection.Overall, 33 patients (80%) had some benefit from surgery. Patients who emptied normally before an anti-incontinence procedure that causes obstruction or impaired emptying should not be excluded from urethrolysis based on low detrusor pressures or pressure-flow analysis alone. Simultaneous radiographic imaging and endoscopy may help to select certain patients with obstruction.

Transrectal hyperthermia in the management of men with prostatism: an algorithm for therapy.

Transrectal hyperthermia has been proposed as a potential treatment for benign prostatic hyperplasia (BPH). This report presents our initial experience in an ongoing clinical trial to evaluate the safety and efficacy of transrectal thermal therapy (TRTT) for symptomatic BPH. To date, 24 patients (mean age 60.6 years) have undergone TRTT. In all cases the initial investigations included pre-operative symptom score analysis, synchronous video/pressure/flow urodynamic studies and transrectal measurement of both the size of the prostate and the distance between the applicator and the prostatic urethra (AU). Twenty-one patients completed the study (mean follow-up 6.7 months). There was a significant reduction in symptom score (> 50%) in 14 patients and the peak urinary flow rate (Qmax) increased from 5.9 to 12.4 ml/s at 1 month, 12.7 ml/s at 3 months and 13.2 ml/s at 6 months. In 12 patients the decrease in symptom score and the increase in flow rate exceeded 50%. Five of the 6 patients who failed to respond to treatment had prostate volumes > 85 g; 4 had voiding detrusor pressures < 40 cm H2O and 5 had an AU distance > 2.5 cm. These preliminary results suggest that TRTT may be a potential therapeutic alternative in patients with mild to moderate symptoms of prostatism. However, patients with either lower detrusor pressures (< 40 cm H2O) or very large prostates are unlikely to show a beneficial response. We suggest that large prostates may preclude effective temperature distribution and therefore mitigate the potential therapeutic benefit.

Stop‐flow Measurement of Detrusor Contractility in Bladder Outflow Obstruction

Detrusor contractility was evaluated by measuring the increase in isometric pressure during a stop test in 25 men with benign prostatic hyperplasia. Before transurethral prostatic resection (TUR), a low pressure increase (delta P det iso) was associated with a large volume of residual urine. After TUR both the speed and the amplitude of isometric detrusor contractions during the stop test increased. A pre-operative low detrusor pressure increase was correlated with a great improvement in flow rate after TUR. The value of the stop-flow test was limited, however, since improvement in other urodynamic parameters could not be predicted.

Bladder Hypocompliance in the Spinal Cord Injury Population

To determine the incidence and effects of low bladder compliance on the upper urinary tracts in spinal cord injury patients, we evaluated the last 254 patients during a 3-year period who underwent a complete urodynamic study, along with an excretory urogram and/or renal ultrasound. Compliance was determined at 100cc volume. A compliance number of 20 or less was considered low. Of the 254 patients 43 (17 per cent) had low compliant bladders by our definition. Hydronephrosis was present in 56 of the 84 renal units (64 per cent) and reflux was present in 39 (46 per cent). These results are in sharp contrast to the normal compliant group in which 21 per cent of 418 renal units had hydronephrosis and only 6 per cent had reflux. Of the 254 patients over-all 44 had lower motor neuron lesions as determined by no bulbocavernosus reflex as well as a denervated external sphincter; 22 of these 44 patients (50 per cent) had low compliant bladders. Conversely, among the 210 patients with suprasacral lesions only 21 (10 per cent) had low compliant bladders.In conclusion, the development of a low compliant bladder in spinal cord injury patients is not an uncommon event and places the upper urinary tracts at great risk. All attempts must be directed toward maintaining low detrusor pressures, and these patients must have adequate and frequent followup evaluation.