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ASSOCIATION BETWEEN VALSALVA AND COUGH LEAK POINT PRESSURES AND PELVIC ORGAN PROLAPSE QUANTIFICATION IN WOMEN WITH STRESS INCONTINENCE
0022-5347/05/1734-1219/0 THE JOURNAL OF UROLOGY® Copyright © 2005 by AMERICAN UROLOGICAL ASSOCIATION
Vol. 173, 1219 –1222, April 2005 Printed in U.S.A.
DOI: 10.1097/01.ju.0000152323.78869.93
ASSOCIATION BETWEEN VALSALVA AND COUGH LEAK POINT PRESSURES AND PELVIC ORGAN PROLAPSE QUANTIFICATION IN WOMEN WITH STRESS INCONTINENCE JERILYN M. LATINI, M. BRIDGET ZIMMERMAN
AND
KARL J. KREDER, JR.*
From the Departments of Urology and Biostatistics, University of Iowa, Iowa City, Iowa
ABSTRACT
Purpose: Women with urodynamically documented stress urinary incontinence (SUI) and urethral hypermobility may have a higher pelvic organ prolapse quantification (POP-Q) stage according to anterior POP-Q measurements. In this study we determined if POP-Q system anterior components representing the urethrovesical junction (anterior wall point Aa/Ba) and/or POP-Q stage has a relationship with leak point pressure testing. Materials and Methods: Of the 1,511 women who underwent video fluoro-urodynamics during 1997 to 2003 at our institution 88 with only evidence of SUI with negative Valsalva leak point pressure and positive cough leak point pressure (CLPP) were selected. Results: Average patient age was 58.6 years (range 32 to 89). Of the 88 women 82 had complete POP-Q examinations available, which revealed stages 0 to III in 21 (25.61%), 20 (24.39%), 40 (48.78%) and 1 (1.22%), respectively. The association between POP-Q stage/components and positive CLPP showed no significant difference in mean positive CLPP among POP-Q stages (p ⫽ 0.178) or components (p ⫽ 0.42 to 0.97). The test for linear trend was not significant (p ⫽ 0.636) for POP-Q stages/components (p ⫽ 0.40 to 0.93). No significant difference in volume at which positive CLPP occurred was observed among POP-Q stages (p ⫽ 0.283) or components (p ⫽ 0.13 to 0.75). The proportion of patients with leakage at 200 cc did not differ significantly among POP-Q stages (p ⫽ 0.119) or components (p ⫽ 0.15 to 0.60). Conclusions: Analysis of women with urodynamic evidence of SUI with negative Valsalva leak point pressure and positive CLPP did not show any significant association with components of the POP-Q system or with POP-Q stages. Findings support that POP-Q measurements should not be interpreted as indicators of urethral hypermobility when evaluating women with SUI. KEY WORDS: urinary incontinence, stress; female; prolapse; urethra; urodynamics
Valsalva leak point pressure (VLPP) or the lowest prompted abdominal pressure that causes leakage of urine in the absence of a detrusor contraction was described more than 20 years ago by McGuire and Woodside.1 VLPP and cough leak point pressure (CLPP) obtained during urodynamics have proved invaluable for evaluating patients with stress urinary incontinence. McGuire et al suggested initially measuring VLPP and then measuring CLPP when VLPP is negative.2 VLPP/CLPP greater than 90 cm H2O3 and video fluorourodynamic evidence of descent of the urethrovesical junction and urine leakage with physical stress with the patient upright in the absence of a detrusor contraction provide evidence for clinically significant urethral hypermobility. Others diagnose urethral hypermobility using the simple, inexpensive cotton swab technique4 to document a change in the urethral axis of more than 30 degrees from baseline during a stress maneuver with the patient supine. In our experience we find that the former is more reliable and clinically useful for evaluating women with urinary incontinence. The pelvic organ prolapse quantification (POP-Q) system has become accepted as a standardized method for staging female pelvic organ prolapse since its introduction in 1996.5 The figure shows the anatomical sites used to quantify pelvic
organ support using the POP-Q system. Anatomical landmarks, measurement recording and POP-Q staging have been described previously.5 The effects of genital organ prolapse on voiding have been documented, including bladder outlet obstruction, occult stress incontinence and detrusor instability.6 POP-Q measurements are obtained with the woman supine. When compared with examination with the woman upright, it misses 25% to 30% of significant genital organ prolapse.7 The POP-Q examination is difficult to perform with the woman standing and to our knowledge it has not been rigorously tested against other examinations for genital organ prolapse or video fluoroscopic imaging of prolapse. As assessed by the cotton swab test, urethral hypermobility test has been shown to correlate with greater degrees of pelvic organ prolapse6, 8 using a modification of the Baden and Walker system.9 Urethral hypermobility did not correlate with abdominal leak point pressures in that study.8 The clinical assessment of urethral sphincter function in women with stress urinary incontinence (SUI) has evolved primarily to use LPP testing to identify women with intrinsic sphincter deficiency (ISD) and/or urethral hypermobility.2, 3 LPP with cough tends to be higher than with the Valsalva maneuver, possibly due to reflex contraction of the pelvic floor.10, 11 The Valsalva maneuver and coughing appear to result in different pelvic floor biomechanical responses.10, 12 During the Valsalva maneuver there is adequate time for pelvic floor and periurethral muscle recruitment and urinary incontinence would most likely not be due to urethral hypermobility, but rather to ISD. Conversely during a cough (200
Submitted for publication July 6, 2004. Study received institutional review board approval. * Correspondence: Department of Urology, University of Iowa, 200 Hawkins Drive, 3 RCP, Iowa City, Iowa 52242-1089 (telephone: 319-356-4525; FAX: 319-356-3900; e-mail: [email protected]). 1219
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LEAK POINT PRESSURE AND PELVIC ORGAN PROLAPSE IN STRESS INCONTINENCE
milliseconds) there is inadequate time for such muscle recruitment. The time delay is too short to involve a neuromuscular reflex13 because the muscles of the female pelvic floor consist of mostly slow twitch fibers.14 Urinary incontinence would most likely be due to urethral hypermobility in this scenario. In select women with negative VLPP, positive CLPP greater than 90 cm H2O, video fluoro-urodynamic evidence of urethral hypermobility and stress urinary incontinence in the absence of a detrusor contraction we determined whether there is an association between LPP testing and the POP-Q examination. Women with urodynamically documented stress urinary incontinence with negative VLPP, positive CLPP and urethral hypermobility may have a higher POP-Q stage, as determined by anterior POP-Q measurements. In this study we determined if POP-Q system anterior components representing the urethrovesical junction (anterior wall point Aa/Ba) and/or POP-Q stage has a relationship with LPP testing in this defined group of women. Secondarily this relationship was evaluated with other POP-Q system components, including cervix/cuff, genital hiatus, perineal body, total vaginal length, posterior wall and posterior fornix.
Aa and Ba, anterior wall. C, cervix/cuff. D, posterior fornix. Ap and Bp, posterior wall. gh, genital hiatus. pb, perineal body. tvl, total vaginal length. Reprinted with permission.5
METHODS
An institutional review board approved retrospective database review identified 1,511 women who presented to the department of urology outpatient clinic at our institution during 1997 and 2003, and underwent evaluation, including multichannel video fluoro-urodynamics. POP-Q examinations with the patient supine were performed during initial clinical evaluation prior to urodynamic study. During multichannel video fluoro-urodynamics performed in a standardized manner by the same experienced urodynamicists at a single urodynamic laboratory with the same equipment VLPP and CLPP were measured with the patient upright position at 200 cc bladder volume and at cystometric capacity. In women with pelvic organ prolapse LPP testing was performed with prolapse unreduced and reduced to obtain the most accurate LPP measurement possible.15 Data are presented for LPPs obtained with prolapse reduced. Intraabdominal pressure (Pabd) was recorded using an 8Fr rectal catheter. The change from baseline Pabd immediately before provocation to Pabd at the time of leakage was recorded. The absence of concomitant detrusor contraction was monitored with a 10Fr dual lumen intravesical catheter. Of the 1,511 women studied 88 (5.8%) with urodynamic evidence of stress urinary incontinence with negative VLPP, positive CLPP greater than 90 cm H2O and video fluorourodynamic evidence of urethral hypermobility were selected for study. Women with urodynamic evidence of stress urinary incontinence with positive VLPP and positive CLPP, and women with urodynamic evidence of detrusor contraction(s) were excluded. Interestingly of the 1,511 women studied none with urodynamically documented stress urinary incontinence had positive VLPP and negative CLPP. Statistical analyses were performed using 1-way ANOVA and the Kruskal-Wallis test. For each analysis patients were grouped according to POP-Q stage (stages 0, I, II, etc) and according to POP-Q score components (Aa, Ba, Ap, Bp, etc). RESULTS
Average patient age was 58.6 years (range 32 to 89). Eight women were nulliparous. Median parity was 3 in 21 patients, followed by 2 in 18. Hysterectomy had been performed in 43 women abdominally in 42 and vaginally in 1. In 36 women a total of 49 prior anti-incontinence procedures had been done, including Contigen (Bard, Covington, Georgia) and Durasphere (Carbon Medical Technologies, Saint Paul, Minnesota) injection in 15 and 1, respectively, anterior colporrhaphy in 4, needle suspension in 19, a Burch procedure in 2 and a pubo-
vaginal sling procedure in 8. Presenting symptoms and signs were frequency in 36 of 88 patients (40.91%), urgency in 44 (50%), stress incontinence in 65 (73.86%), a sense of incomplete emptying in 32 (36.36%), nocturia in 52 (59.09%) and urinary tract infection in 19 (21.59%). Of the 88 women 26 (29.55%) were on hormonal replacement therapy at the time of evaluation. Mean American Urological Association symptom score ⫾ SD was 17 ⫾ 7.49 (range 4 to 32, mode 14). Of the 88 women 82 had complete POP-Q examinations available, which revealed POP-Q stages 0 to III in 21 (25.61%), 20 (24.39%), 40 (48.78%) and 1 (1.22%), respectively. The patient with stage III was not included in statistical analysis. Mean negative VLPP was 88.5 ⫾ 32.1 cm H2O. Mean positive CLPP was 118.6 ⫾ 24.8 cm H2O. Mean cystometric capacity was 356.7 ⫾ 202.0 cc. Association between POP-Q stage/components and positive CLPP. One-way ANOVA was used to test the association between POP-Q stage/components and positive CLPP. This compared the mean CLPP in patients grouped by POP-Q stage 0 to II and by POP-Q components. There was no significant difference in mean CLPP among the 3 POP-Q stage groups (p ⫽ 0.178) or among any POP-Q component groups (p ⫽ 0.42 to 0.97). The test for linear trend, which tests if there is an increasing or decreasing linear trend in mean values with increasing POP-Q stage, was not significant (p ⫽ 0.636). The test for linear trend was also not significant for any POP-Q component group (p ⫽ 0.40 to 0.93). Association between POP-Q stage/components and volume at which positive CLPP occurred. The Kruskal-Wallis test was used to compare the volume at which positive CLPP occurred among the 3 POP-Q stage groups and among POP-Q component groups. No significant difference in volume was observed among the 3 POP-Q stage groups (p ⫽ 0.283) or any POP-Q component group (p ⫽ 0.13 to 0.75). Association between POP-Q stage/components and urine leakage at 200 cc. The proportion of patients with leakage at 200 cc did not differ significantly among the 3 POP-Q stage groups (p ⫽ 0.119) or in any POP-Q component group (p ⫽ 0.15 to 0.60). Association between POP-Q stage/components and negative VLLP. One-way ANOVA was used to test the association between POP-Q stage/components and negative VLPP at 200 cc. This compared mean VLPP in patients grouped by POP-Q stage and by POP-Q components. This showed no significant difference in mean VLPP among the 3 POP-Q stage groups
LEAK POINT PRESSURE AND PELVIC ORGAN PROLAPSE IN STRESS INCONTINENCE
(p ⫽ 0.367) or in any POP-Q component group (p ⫽ 0.24 to 0.79). DISCUSSION
SUI that is caused by the inability of the bladder neck and proximal urethra to function as a competent sphincteric unit and maintain mucosal coaptation during increased intravesical pressure is termed intrinsic sphincter deficiency.16 This is in contrast to SUI caused by hypermobility of the anatomical bladder neck with inferior and rotational descent of the bladder base and urethra (urethrovesical junction). In urethral hypermobility the compromised urethrovesical angle results in a pressure transmission discrepancy between the bladder and urethra, which is enough to overcome resting urethral closure pressure at the moment of increased intraabdominal pressure induced by physical stress. These 2 entities are not mutually exclusive and they may coexist along a spectrum in many women with SUI. In contrast to urethral hypermobility, ISD must be treated with maneuvers that increase urethral coaptation and resistance. Surgical procedures that support the urethrovesical junction and prevent hypermobility but do not compress the urethra are not effective for treating SUI caused by ISD. ISD and urethral hypermobility often coexist but they are independent variables. In women with the 2 entities, as suggested by VLPP/CLPP 60 to 90 cm H2O2, urethral hypermobility has not been shown to be predictive of and it appears not to worsen stress urinary incontinence, ie the presence of ISD may be the more important factor.17 Nevertheless, the presence and degree of urethral hypermobility is important in the clinical evaluation because it is useful for choosing the most appropriate surgical procedure and it is believed to affect surgical outcome.18 Video fluoro-urodynamics and LPP testing characterize the urethrovesical junction and urethral function in women with incontinence for the presence and severity of urethral hypermobility and/or ISD. In a recent study Cogan et al questioned whether the POP-Q examination also assesses urethral hypermobility.8 They found that the cotton swab test straining angle correlates with point Aa of the POP-Q system. However, they observed that the cotton swab test may not add additional information in women with POP-Q stages II to IV prolapse at point Aa because urethral hypermobility is almost always be present in these women. To our knowledge it remains to be determined whether these findings are the result of anterior POP-Q components not truly assessing urethrovesical junction movement or the cotton swab test not accurately assessing clinically significant urethral hypermobility. We retrospectively evaluated this question using LPP testing and video fluoro-urodynamic documentation of SUI and urethral hypermobility in a select cohort of women. In our opinion LPP testing with video fluoro-urodynamics is a more reliable indicator of clinically significant urethral hypermobility with incontinence than the cotton swab test performed with the patient supine. Given our findings, we suspect that VLPP/CLPP testing would not have a significant association with the cotton swab straining angle because it is also obtained with the patient supine. It is reported that ISD does not correlate with the degree of pelvic organ prolapse. We would agree since they are 2 distinct pathophysiological/anatomical processes. However, to our knowledge there has not been a report that details whether a relationship exists between LPP testing in women with SUI due to ISD and the POP-Q examination. The clinical usefulness of leak point pressures and physical examination maneuvers (cotton swab test, POP-Q examination system, etc) must be understood. They address different aspects of the genitourinary system anatomically and functionally. It is not surprising that there are not significant rela-
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tionships among these clinical tools. Used in combination and depending on the clinical presentation each diagnostic maneuver carries its own value. Together they combine to create a cohesive evaluation of the clinical situation, leading to an appropriate treatment algorithm. Urethral hypermobility has been shown to correlate with greater degrees of pelvic organ prolapse6 using the cotton swab test and graded prolapse examination. The cotton swab test and POP-Q examination are performed with the patient supine. This differs from our results using VLPP/CLPP testing, and video fluoro-urodynamic evidence of SUI and urethral hypermobility, which is done with the patient upright. Although we anticipated a relationship between urodynamic parameters and anterior POP-Q measurements, we did not find any statistically significant correlation between POP-Q stage or POP-Q components and positive CLPP, the cystometric volume at which positive CLPP occurred, urine leakage at a cystometric capacity of 200 cc or negative VLPP. This evidence supports that the POP-Q examination does not assess urethral hypermobility, as defined by LPP and video fluoro-urodynamics. Many women do not perform an adequate Valsalva maneuver without coaching and even with coaching they are reluctant to perform it, fearing the passage of flatus, bowel contents and/or urine. Coughing also presents similar concerns but in our experience is often more reliably well performed than the Valsalva maneuver. It is possible that many or all 88 women described herein had negative VLPP because of poor effort or understanding, whereas they more reliably performed an adequate cough. If this were the case, our conclusions are significantly flawed. However, we recommend that when a woman with SUI has negative VLPP and positive CLPP, one should consider whether this LPP pattern is related to patient effort or whether it represents a potentially meaningful urodynamic observation, especially when video fluoro-urodynamics reveal evidence for SUI and hypermobility. Future research evaluating the POP-Q examination and other techniques with the patient upright may provide insight and better clinical tools with which to assess genital organ prolapse, urethral hypermobility and women with SUI. Even when they are performed with the patient upright, they will likely be confounded by patient effort and cooperation as well as by the objective variations that the human body undergoes among different gravitational and physiological positions. Continuing research in physical examination and imaging techniques (3-dimensional magnetic resonance imaging, ultrasound, etc) of the female genitourinary system are ongoing and we await the results of these studies. CONCLUSIONS
Analysis of women with urodynamic evidence of stress urinary incontinence with negative VLPP and positive CLPP did not show any significant association with individual components of the POP-Q system or with POP-Q stage. LPP testing with the patient upright evaluates urethral sphincter function and anatomical mobility, whereas evidence suggests that this is not measured by the POP-Q system. These findings support that POP-Q measurements should not be interpreted as indicators of urethral hypermobility when evaluating women with stress urinary incontinence. REFERENCES
1. McGuire, E. J. and Woodside, J. R.: Diagnostic advantages of fluoroscopic monitoring during urodynamic evaluation. J Urol, 125: 830, 1981 2. McGuire, E. J., Cespedes, R. D. and O’Connell, H. E.: Leak-point pressures. Urol Clin North Am, 23: 253, 1996 3. McGuire, E. J., Fitzpatrick, C. C., Wan, J., Bloom, D., Sanvordenker, J., Ritchey, M. et al: Clinical assessment of
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LEAK POINT PRESSURE AND PELVIC ORGAN PROLAPSE IN STRESS INCONTINENCE
urethral sphincter function. J Urol, 150: 1452, 1993 4. Crystle, C. D., Charme, L. S. and Copeland, W. E.: Q-tip test in stress urinary incontinence. Obstet Gynecol, 38: 313, 1971 5. Bump, R. C., Mattiasson, A., Bo, K., Brubaker, L. P., DeLancey, J. O., Klarskov, P. et al: The standardization of terminology of female pelvic organ prolapse and pelvic floor dysfunction. Am J Obstet Gynecol, 175: 10, 1996 6. Romanzi, L. J., Chaikin, D. C. and Blaivas, J. G.: The effect of genital prolapse on voiding. J Urol, 161: 581, 1999 7. Barber, M. D., Lambers, A., Visco, A. G. and Bump, R. C.: Effect of patient position on clinical evaluation of pelvic organ prolapse. Obstet Gynecol, 96: 18, 2000 8. Cogan, S. L., Weber, A. M. and Hammel, J. P.: Is urethral mobility really being assessed by the pelvic organ prolapse quantification (POP-Q) system? Obstet Gynecol, 99: 473, 2002 9. Baden, W. F. and Walker, T. A.: Physical diagnosis in the evaluation of vaginal relaxation. Clin Obstet Gynecol, 15: 1060, 1972 10. Bump, R. C., Elser, D. M., Theofrastous, J. P. and McClish, D. K.: Valsalva leak point pressures in women with genuine stress incontinence: reproducibility, effect of catheter caliber, and correlations with other measures of urethral resistance. Continence Program for Women Research Group. Am J Obstet Gynecol, 173: 551, 1995
11. Peschers, U. M., Jundt, K. and Dimpfl, T.: Differences between cough and Valsalva leak-point pressure in stress incontinent women. Neurourol Urodyn, 19: 677, 2000 12. Zmrhal, J., Horcicka, L. and Lochman, P.: Dynamic tests of the urethral sphincter closure and pelvic floor function. Zentr Gynakol, 123: 158, 2001 13. Hertogs, K. and Stanton, S. L.: The mechanism of successful colposuspension: a new model. Proceedings of 13th International Continence Society Meeting, Aachen, Prussia, 1983 14. Heit, M., Benson, J. T., Russel, B. and Brubaker, L.: Levator ani muscle in women with genitourinary prolapse: indirect assessment by muscle histopathology. Neurourol Urodyn, 15: 17, 1996 15. Gallentine, M. L. and Cespedes, R. D.: Occult stress urinary incontinence and the effect of vaginal vault prolapse on abdominal leak point pressures. Urology, 57: 40, 2001 16. McGuire, E. J.: Diagnosis and treatment of intrinsic sphincter deficiency. Int J Urol, suppl., 2: 7, 1995 17. Fleischmann, N., Flisser, A. J., Blaivas, J. G. and Panagopoulos, G.: Sphincteric urinary incontinence: relationship of vesical leak point pressure, urethral mobility and severity of incontinence. J Urol, 169: 999, 2003 18. Kreder, K. J. and Austin, J. C.: Treatment of stress urinary incontinence in women with urethral hypermobility and intrinsic sphincter deficiency. J Urol, 156: 1995, 1996
Vol. 173, 1219 –1222, April 2005 Printed in U.S.A.
DOI: 10.1097/01.ju.0000152323.78869.93
ASSOCIATION BETWEEN VALSALVA AND COUGH LEAK POINT PRESSURES AND PELVIC ORGAN PROLAPSE QUANTIFICATION IN WOMEN WITH STRESS INCONTINENCE JERILYN M. LATINI, M. BRIDGET ZIMMERMAN
AND
KARL J. KREDER, JR.*
From the Departments of Urology and Biostatistics, University of Iowa, Iowa City, Iowa
ABSTRACT
Purpose: Women with urodynamically documented stress urinary incontinence (SUI) and urethral hypermobility may have a higher pelvic organ prolapse quantification (POP-Q) stage according to anterior POP-Q measurements. In this study we determined if POP-Q system anterior components representing the urethrovesical junction (anterior wall point Aa/Ba) and/or POP-Q stage has a relationship with leak point pressure testing. Materials and Methods: Of the 1,511 women who underwent video fluoro-urodynamics during 1997 to 2003 at our institution 88 with only evidence of SUI with negative Valsalva leak point pressure and positive cough leak point pressure (CLPP) were selected. Results: Average patient age was 58.6 years (range 32 to 89). Of the 88 women 82 had complete POP-Q examinations available, which revealed stages 0 to III in 21 (25.61%), 20 (24.39%), 40 (48.78%) and 1 (1.22%), respectively. The association between POP-Q stage/components and positive CLPP showed no significant difference in mean positive CLPP among POP-Q stages (p ⫽ 0.178) or components (p ⫽ 0.42 to 0.97). The test for linear trend was not significant (p ⫽ 0.636) for POP-Q stages/components (p ⫽ 0.40 to 0.93). No significant difference in volume at which positive CLPP occurred was observed among POP-Q stages (p ⫽ 0.283) or components (p ⫽ 0.13 to 0.75). The proportion of patients with leakage at 200 cc did not differ significantly among POP-Q stages (p ⫽ 0.119) or components (p ⫽ 0.15 to 0.60). Conclusions: Analysis of women with urodynamic evidence of SUI with negative Valsalva leak point pressure and positive CLPP did not show any significant association with components of the POP-Q system or with POP-Q stages. Findings support that POP-Q measurements should not be interpreted as indicators of urethral hypermobility when evaluating women with SUI. KEY WORDS: urinary incontinence, stress; female; prolapse; urethra; urodynamics
Valsalva leak point pressure (VLPP) or the lowest prompted abdominal pressure that causes leakage of urine in the absence of a detrusor contraction was described more than 20 years ago by McGuire and Woodside.1 VLPP and cough leak point pressure (CLPP) obtained during urodynamics have proved invaluable for evaluating patients with stress urinary incontinence. McGuire et al suggested initially measuring VLPP and then measuring CLPP when VLPP is negative.2 VLPP/CLPP greater than 90 cm H2O3 and video fluorourodynamic evidence of descent of the urethrovesical junction and urine leakage with physical stress with the patient upright in the absence of a detrusor contraction provide evidence for clinically significant urethral hypermobility. Others diagnose urethral hypermobility using the simple, inexpensive cotton swab technique4 to document a change in the urethral axis of more than 30 degrees from baseline during a stress maneuver with the patient supine. In our experience we find that the former is more reliable and clinically useful for evaluating women with urinary incontinence. The pelvic organ prolapse quantification (POP-Q) system has become accepted as a standardized method for staging female pelvic organ prolapse since its introduction in 1996.5 The figure shows the anatomical sites used to quantify pelvic
organ support using the POP-Q system. Anatomical landmarks, measurement recording and POP-Q staging have been described previously.5 The effects of genital organ prolapse on voiding have been documented, including bladder outlet obstruction, occult stress incontinence and detrusor instability.6 POP-Q measurements are obtained with the woman supine. When compared with examination with the woman upright, it misses 25% to 30% of significant genital organ prolapse.7 The POP-Q examination is difficult to perform with the woman standing and to our knowledge it has not been rigorously tested against other examinations for genital organ prolapse or video fluoroscopic imaging of prolapse. As assessed by the cotton swab test, urethral hypermobility test has been shown to correlate with greater degrees of pelvic organ prolapse6, 8 using a modification of the Baden and Walker system.9 Urethral hypermobility did not correlate with abdominal leak point pressures in that study.8 The clinical assessment of urethral sphincter function in women with stress urinary incontinence (SUI) has evolved primarily to use LPP testing to identify women with intrinsic sphincter deficiency (ISD) and/or urethral hypermobility.2, 3 LPP with cough tends to be higher than with the Valsalva maneuver, possibly due to reflex contraction of the pelvic floor.10, 11 The Valsalva maneuver and coughing appear to result in different pelvic floor biomechanical responses.10, 12 During the Valsalva maneuver there is adequate time for pelvic floor and periurethral muscle recruitment and urinary incontinence would most likely not be due to urethral hypermobility, but rather to ISD. Conversely during a cough (200
Submitted for publication July 6, 2004. Study received institutional review board approval. * Correspondence: Department of Urology, University of Iowa, 200 Hawkins Drive, 3 RCP, Iowa City, Iowa 52242-1089 (telephone: 319-356-4525; FAX: 319-356-3900; e-mail: [email protected]). 1219
1220
LEAK POINT PRESSURE AND PELVIC ORGAN PROLAPSE IN STRESS INCONTINENCE
milliseconds) there is inadequate time for such muscle recruitment. The time delay is too short to involve a neuromuscular reflex13 because the muscles of the female pelvic floor consist of mostly slow twitch fibers.14 Urinary incontinence would most likely be due to urethral hypermobility in this scenario. In select women with negative VLPP, positive CLPP greater than 90 cm H2O, video fluoro-urodynamic evidence of urethral hypermobility and stress urinary incontinence in the absence of a detrusor contraction we determined whether there is an association between LPP testing and the POP-Q examination. Women with urodynamically documented stress urinary incontinence with negative VLPP, positive CLPP and urethral hypermobility may have a higher POP-Q stage, as determined by anterior POP-Q measurements. In this study we determined if POP-Q system anterior components representing the urethrovesical junction (anterior wall point Aa/Ba) and/or POP-Q stage has a relationship with LPP testing in this defined group of women. Secondarily this relationship was evaluated with other POP-Q system components, including cervix/cuff, genital hiatus, perineal body, total vaginal length, posterior wall and posterior fornix.
Aa and Ba, anterior wall. C, cervix/cuff. D, posterior fornix. Ap and Bp, posterior wall. gh, genital hiatus. pb, perineal body. tvl, total vaginal length. Reprinted with permission.5
METHODS
An institutional review board approved retrospective database review identified 1,511 women who presented to the department of urology outpatient clinic at our institution during 1997 and 2003, and underwent evaluation, including multichannel video fluoro-urodynamics. POP-Q examinations with the patient supine were performed during initial clinical evaluation prior to urodynamic study. During multichannel video fluoro-urodynamics performed in a standardized manner by the same experienced urodynamicists at a single urodynamic laboratory with the same equipment VLPP and CLPP were measured with the patient upright position at 200 cc bladder volume and at cystometric capacity. In women with pelvic organ prolapse LPP testing was performed with prolapse unreduced and reduced to obtain the most accurate LPP measurement possible.15 Data are presented for LPPs obtained with prolapse reduced. Intraabdominal pressure (Pabd) was recorded using an 8Fr rectal catheter. The change from baseline Pabd immediately before provocation to Pabd at the time of leakage was recorded. The absence of concomitant detrusor contraction was monitored with a 10Fr dual lumen intravesical catheter. Of the 1,511 women studied 88 (5.8%) with urodynamic evidence of stress urinary incontinence with negative VLPP, positive CLPP greater than 90 cm H2O and video fluorourodynamic evidence of urethral hypermobility were selected for study. Women with urodynamic evidence of stress urinary incontinence with positive VLPP and positive CLPP, and women with urodynamic evidence of detrusor contraction(s) were excluded. Interestingly of the 1,511 women studied none with urodynamically documented stress urinary incontinence had positive VLPP and negative CLPP. Statistical analyses were performed using 1-way ANOVA and the Kruskal-Wallis test. For each analysis patients were grouped according to POP-Q stage (stages 0, I, II, etc) and according to POP-Q score components (Aa, Ba, Ap, Bp, etc). RESULTS
Average patient age was 58.6 years (range 32 to 89). Eight women were nulliparous. Median parity was 3 in 21 patients, followed by 2 in 18. Hysterectomy had been performed in 43 women abdominally in 42 and vaginally in 1. In 36 women a total of 49 prior anti-incontinence procedures had been done, including Contigen (Bard, Covington, Georgia) and Durasphere (Carbon Medical Technologies, Saint Paul, Minnesota) injection in 15 and 1, respectively, anterior colporrhaphy in 4, needle suspension in 19, a Burch procedure in 2 and a pubo-
vaginal sling procedure in 8. Presenting symptoms and signs were frequency in 36 of 88 patients (40.91%), urgency in 44 (50%), stress incontinence in 65 (73.86%), a sense of incomplete emptying in 32 (36.36%), nocturia in 52 (59.09%) and urinary tract infection in 19 (21.59%). Of the 88 women 26 (29.55%) were on hormonal replacement therapy at the time of evaluation. Mean American Urological Association symptom score ⫾ SD was 17 ⫾ 7.49 (range 4 to 32, mode 14). Of the 88 women 82 had complete POP-Q examinations available, which revealed POP-Q stages 0 to III in 21 (25.61%), 20 (24.39%), 40 (48.78%) and 1 (1.22%), respectively. The patient with stage III was not included in statistical analysis. Mean negative VLPP was 88.5 ⫾ 32.1 cm H2O. Mean positive CLPP was 118.6 ⫾ 24.8 cm H2O. Mean cystometric capacity was 356.7 ⫾ 202.0 cc. Association between POP-Q stage/components and positive CLPP. One-way ANOVA was used to test the association between POP-Q stage/components and positive CLPP. This compared the mean CLPP in patients grouped by POP-Q stage 0 to II and by POP-Q components. There was no significant difference in mean CLPP among the 3 POP-Q stage groups (p ⫽ 0.178) or among any POP-Q component groups (p ⫽ 0.42 to 0.97). The test for linear trend, which tests if there is an increasing or decreasing linear trend in mean values with increasing POP-Q stage, was not significant (p ⫽ 0.636). The test for linear trend was also not significant for any POP-Q component group (p ⫽ 0.40 to 0.93). Association between POP-Q stage/components and volume at which positive CLPP occurred. The Kruskal-Wallis test was used to compare the volume at which positive CLPP occurred among the 3 POP-Q stage groups and among POP-Q component groups. No significant difference in volume was observed among the 3 POP-Q stage groups (p ⫽ 0.283) or any POP-Q component group (p ⫽ 0.13 to 0.75). Association between POP-Q stage/components and urine leakage at 200 cc. The proportion of patients with leakage at 200 cc did not differ significantly among the 3 POP-Q stage groups (p ⫽ 0.119) or in any POP-Q component group (p ⫽ 0.15 to 0.60). Association between POP-Q stage/components and negative VLLP. One-way ANOVA was used to test the association between POP-Q stage/components and negative VLPP at 200 cc. This compared mean VLPP in patients grouped by POP-Q stage and by POP-Q components. This showed no significant difference in mean VLPP among the 3 POP-Q stage groups
LEAK POINT PRESSURE AND PELVIC ORGAN PROLAPSE IN STRESS INCONTINENCE
(p ⫽ 0.367) or in any POP-Q component group (p ⫽ 0.24 to 0.79). DISCUSSION
SUI that is caused by the inability of the bladder neck and proximal urethra to function as a competent sphincteric unit and maintain mucosal coaptation during increased intravesical pressure is termed intrinsic sphincter deficiency.16 This is in contrast to SUI caused by hypermobility of the anatomical bladder neck with inferior and rotational descent of the bladder base and urethra (urethrovesical junction). In urethral hypermobility the compromised urethrovesical angle results in a pressure transmission discrepancy between the bladder and urethra, which is enough to overcome resting urethral closure pressure at the moment of increased intraabdominal pressure induced by physical stress. These 2 entities are not mutually exclusive and they may coexist along a spectrum in many women with SUI. In contrast to urethral hypermobility, ISD must be treated with maneuvers that increase urethral coaptation and resistance. Surgical procedures that support the urethrovesical junction and prevent hypermobility but do not compress the urethra are not effective for treating SUI caused by ISD. ISD and urethral hypermobility often coexist but they are independent variables. In women with the 2 entities, as suggested by VLPP/CLPP 60 to 90 cm H2O2, urethral hypermobility has not been shown to be predictive of and it appears not to worsen stress urinary incontinence, ie the presence of ISD may be the more important factor.17 Nevertheless, the presence and degree of urethral hypermobility is important in the clinical evaluation because it is useful for choosing the most appropriate surgical procedure and it is believed to affect surgical outcome.18 Video fluoro-urodynamics and LPP testing characterize the urethrovesical junction and urethral function in women with incontinence for the presence and severity of urethral hypermobility and/or ISD. In a recent study Cogan et al questioned whether the POP-Q examination also assesses urethral hypermobility.8 They found that the cotton swab test straining angle correlates with point Aa of the POP-Q system. However, they observed that the cotton swab test may not add additional information in women with POP-Q stages II to IV prolapse at point Aa because urethral hypermobility is almost always be present in these women. To our knowledge it remains to be determined whether these findings are the result of anterior POP-Q components not truly assessing urethrovesical junction movement or the cotton swab test not accurately assessing clinically significant urethral hypermobility. We retrospectively evaluated this question using LPP testing and video fluoro-urodynamic documentation of SUI and urethral hypermobility in a select cohort of women. In our opinion LPP testing with video fluoro-urodynamics is a more reliable indicator of clinically significant urethral hypermobility with incontinence than the cotton swab test performed with the patient supine. Given our findings, we suspect that VLPP/CLPP testing would not have a significant association with the cotton swab straining angle because it is also obtained with the patient supine. It is reported that ISD does not correlate with the degree of pelvic organ prolapse. We would agree since they are 2 distinct pathophysiological/anatomical processes. However, to our knowledge there has not been a report that details whether a relationship exists between LPP testing in women with SUI due to ISD and the POP-Q examination. The clinical usefulness of leak point pressures and physical examination maneuvers (cotton swab test, POP-Q examination system, etc) must be understood. They address different aspects of the genitourinary system anatomically and functionally. It is not surprising that there are not significant rela-
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tionships among these clinical tools. Used in combination and depending on the clinical presentation each diagnostic maneuver carries its own value. Together they combine to create a cohesive evaluation of the clinical situation, leading to an appropriate treatment algorithm. Urethral hypermobility has been shown to correlate with greater degrees of pelvic organ prolapse6 using the cotton swab test and graded prolapse examination. The cotton swab test and POP-Q examination are performed with the patient supine. This differs from our results using VLPP/CLPP testing, and video fluoro-urodynamic evidence of SUI and urethral hypermobility, which is done with the patient upright. Although we anticipated a relationship between urodynamic parameters and anterior POP-Q measurements, we did not find any statistically significant correlation between POP-Q stage or POP-Q components and positive CLPP, the cystometric volume at which positive CLPP occurred, urine leakage at a cystometric capacity of 200 cc or negative VLPP. This evidence supports that the POP-Q examination does not assess urethral hypermobility, as defined by LPP and video fluoro-urodynamics. Many women do not perform an adequate Valsalva maneuver without coaching and even with coaching they are reluctant to perform it, fearing the passage of flatus, bowel contents and/or urine. Coughing also presents similar concerns but in our experience is often more reliably well performed than the Valsalva maneuver. It is possible that many or all 88 women described herein had negative VLPP because of poor effort or understanding, whereas they more reliably performed an adequate cough. If this were the case, our conclusions are significantly flawed. However, we recommend that when a woman with SUI has negative VLPP and positive CLPP, one should consider whether this LPP pattern is related to patient effort or whether it represents a potentially meaningful urodynamic observation, especially when video fluoro-urodynamics reveal evidence for SUI and hypermobility. Future research evaluating the POP-Q examination and other techniques with the patient upright may provide insight and better clinical tools with which to assess genital organ prolapse, urethral hypermobility and women with SUI. Even when they are performed with the patient upright, they will likely be confounded by patient effort and cooperation as well as by the objective variations that the human body undergoes among different gravitational and physiological positions. Continuing research in physical examination and imaging techniques (3-dimensional magnetic resonance imaging, ultrasound, etc) of the female genitourinary system are ongoing and we await the results of these studies. CONCLUSIONS
Analysis of women with urodynamic evidence of stress urinary incontinence with negative VLPP and positive CLPP did not show any significant association with individual components of the POP-Q system or with POP-Q stage. LPP testing with the patient upright evaluates urethral sphincter function and anatomical mobility, whereas evidence suggests that this is not measured by the POP-Q system. These findings support that POP-Q measurements should not be interpreted as indicators of urethral hypermobility when evaluating women with stress urinary incontinence. REFERENCES
1. McGuire, E. J. and Woodside, J. R.: Diagnostic advantages of fluoroscopic monitoring during urodynamic evaluation. J Urol, 125: 830, 1981 2. McGuire, E. J., Cespedes, R. D. and O’Connell, H. E.: Leak-point pressures. Urol Clin North Am, 23: 253, 1996 3. McGuire, E. J., Fitzpatrick, C. C., Wan, J., Bloom, D., Sanvordenker, J., Ritchey, M. et al: Clinical assessment of
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