Urinary incontinence in community-dwelling women: Clinical, urodynamic, and severity characteristics j. A. Fantl, MD,j. F. Wyman, MD, D. K. McClish, MD, and R. C. Bump, MD Richmond, Virginia Descriptive data on 145 community-dwelling older women with urinary incontinence are presented. Assessment included history, physical and functional examinations, and urodynamic and severity evaluations. Patients were 67 ± 8 years old, mentally and functionally intact, predominantly white, and of middle-to-upper socioeconomic strata. Specific urodynamic criteria were used to establish the diagnosis of sphincteric incompetence and detrusor instability. Fifteen (10%) did not fulfill either criteria, 90 (62%) had sphincteric incompetence, 17 (12%) had detrusor instability, and 23 (16%) had both. Detrusor and urethral function variables showed some impairment in all patients. Impairment was least in subjects without demonstrable diagnosis and worst in those with both disorders (p < 0.01). The findings suggest that detrusor and urethral functions are impaired in all incontinent women and that the degree of impairment varies. The impairment seems worse when both urodynamic diagnoses are demonstrable. The data support the pathophysiologic association of urethral and detrusor dysfunctions. (AM J OBSTET GVNECOL 1990; 162:946-52.)
Key words: Urinary incontinence, urodynamics, severity of incontinence
Urinary incontinence affects approximately 37% of older women living in the community; 20% to 25% of cases may be classified as severe.' In nursing homes, the prevalence seems to exceed 50%.2 Lack of urinary control not only has significant psychologic and social impact, but also influences survival.' Conservative estimates in the United States indicate annual costs in excess of 6 billion dollars in managing urinary incontinence.' Although recent advances in standardization of nomenclature and assessment techniques have been significant, further improvements in diagnostic characterization and management strategies are needed." To characterize patients with urinary incontinence, we studied 145 incontinent women living in the community and entering a clinical trial of behavioral treatment. Our purpose is to describe the patients with regard to their specific clinical and urodynamic characteristics and the objective severity of their condition.
From the Continence Program for Women, Department of Obstetrics and Gynecology, Virginia Commonwealth University, Medical College of Virginia. Supported by Grant No. AG05170 from the National Institutes of Health, National Institute on Aging, National Center on Nursing Research. Presented at the Eighth Annual Meeting of the American Gynecological and Obstetrical Society, Hot Springs, Virginia, September 7-9,1989. Reprint requests: J. Andrew Fantl, MD, CPW-Department of Obstetrics and Gynecology, Box 34, MCV Station, Richmond, VA 23298.
946
Material and methods The study population consisted of 145 women entering a clinical trial of behavioral management for urinary incontinence. Inclusion criteria included age 55 years or older, independent resident in the community, ambulatory status, mental intactness (Mini-Mental State score ~23),6 and at least one episode of urinary incontinence per week. Exclusion criteria included persistent urinary tract infection, reversible cause of incontinence (i.e., fecal impaction, direct drug ~ffect), metabolic decompensation, inability for self- or assisted toiletting, outlet obstruction, genitourinary fistula, urethral diverticulum, and permanent catheterization. The initial assessment consisted of a demographic and functional characterization, comprehensive history, physical examination, urinalysis, and serum chemistry tests. Data on symptoms were obtained by interview following a structured questionnaire. The history also included duration of the incontinence, previous treatment of the condition, use of pads for perineal protection, and a review of drug use. Functional status was assessed by the Older Americans Resources and Services' Activities of Daily Living Scale. Diurnal and nocturnal micturition frequencies were determined by a I-week urinary diary.7 More than 8 micturitions a day constituted diurnal frequency and more than one micturition a night constituted nocturnal frequency." The pelvic examination incorporated the specific determination of both anterior and posterior vaginal descensus during maximal bearing-down effort. Descent was categorized as second degree or greater when the
Urinary incontinence in community-dwelling women
Volume 162 Number 4
Table I. Symptoms and pelvic examination results (N
=
No SI or DI (n = 15) (%)
Symptom Stress incontinence Urge incontinence Diurnal frequency Nocturnal frequency Pelvic examination Anterior vaginal wall descensus Rectocele 2: 2 Enterocele Levator ani tone Bulbocavernosus reflex
2:
2
947
145) SI
(n
=
90) (%)
(n
DI 17) (%)
=
SI (n
+
DI
= 23) (%)
80 80 60 53
91 52 46 48
38 88 63 56
57 64 48 65
27 20 13 100 73
26 20 3 88 72
18 24 6 53 82
13 22 17 78 70
S1, Sphincteric incompetence; D1, detrusor instability.
specific segment of the vagina descended further than the mid-vaginal plane. Urethral axial mobility was determined in the supine position by comparing the axis at rest to that during a maximal bearing-down effort. A specially designed goniometer and metallic swab were used. The minimal measure unit was 5 degrees. 9 The detrusor function filling phase was assessed through retrograde subtracted provocative cystometry with room temperature saline solution at a medium infusion rate (50 mL/min). Intravesical and intraabdominal trans rectal pressures were measured with an 8-F microtip transducer catheter. Electronic subtraction of intraabdominal from intravesical pressure allowed simultaneous monitoring of true detrusor pressure. Cystometric variables were measured while the patient was supine and consisted of residual urine, first sensation to void, maximal cystometric capacity, volume from the first sensation to void to maximal cystometric capacity, and compliance. Gravitational and auditory provocative maneuvers to determine detrusor stability included positional changes (supine to erect), forceful coughing, heel bouncing, and listening to running water. Detrusor instability was diagnosed urodynamically when bladder contractions occurring during cystometry could not be voluntarily suppressed. lO The bladder volume at which the initial detrusor contraction occurred and the amplitude of the strongest contraction were measured and recorded. Urethral function was assessed with passive and dynamic urethral profilometry as described by Asmussen and Ulmstead II and standardized by Anderson et al. 12 An 8-F microtip transducer catheter with two sensors (6 cm apart) was pulled through the urethra at a rate of 1 mm/sec. The vesical (distal) sensor remained in the bladder, while the urethral (proximal) sensor traversed the urethra in the 9 o'clock position. Continuous simultaneous electronic subtraction of the intravesical pressure from the urethral pressure provided the ure-
thral closing pressure. All measurements were done at maximal cystometric capacity and with the patient supine. Passive urethral profilometry was performed with the patient at rest and measurements included functional urethral length and maximal urethral closing pressure. Dynamic urethral profilometry was undertaken as the patient was asked to cough forcefully while the urethral sensor traversed the urethra. The test was judged positive when zero closing pressure was reached with each cough throughout the entire functional urethrallength. 9 Fluid loss was directly visualized with the bladder at maximum cystometric capacity in both the supine and erect positions. Urethral incompetence was diagnosed when a spurt of fluid was observed to exit the external meatus at the peak of a maximal cough effort. 9 The presence of positive dynamic profilometry or a direct visualization test fulfilled the urodynamic criteria for urethral sphincteric incompetence. The severity of the incontinence was determined by monitoring the number of incontinent episodes using the 1week urinary diary 7 and the quantity of fluid lost during a controlled laboratory-based perineal pad weighing test. 13 Subjects were classified into four groups according to their urodynamic characteristics. The no sphincteric incompetence or detrusor instability group consisted of subjects who did not fulfill the diagnostic criteria for either dysfunction. Subjects in the sphincteric incompetence group fulfilled only the criteria for urethral sphincteric incompetence. Subjects in the detrusor instability group fulfilled only the criteria for detrusor instability. Subjects in the last group demonstrated urodynamic evidence of both sphincteric incompetence and detrusor instability. Statistical analysis. Means and standard deviations were calculated for continuous variables and percentages for categoric variables. Analysis of age and the duration of urinary incontinence used one-factor anal-
948
Fantl at al.
April 1990 Am J Obstet Gynecol
Table II. Cystometry and passive urethral profilometry (N = 23) No SI or DI (n
Cystometry Residual urine (ml) First sensation to void (ml) Maximal cystometric capacity (ml)* Maximal cystometric capacity - first sensation to void (ml)* Compliance (mllcm H 2O)* Mean bladder volume triggering detrusor contractions (ml)t Mean amplitude of detrusor contractions (cm/H 2O) Passive urethral profilometry Functional urethral length (mm)* Maximal urethral closure pressure.(cm H 2O)* Urethral axial mobility (degrees)*
= 15)
SI
(n
= 90)
Dl
(n
=
17)
SI (n
+
DI
= 23)
6 ± 14 239 ± 135 404 ± 124
8 ± 19 191 ± 95 351 ± III
13 ± 16 197 ± 125 306 ± 112
7± 18 191 ± 102 275 ± 125
165 ± 108
160 ± 108
110 ± 103
84 ± 94
186 ± 143
182 ± 121
N/A
137 ± 92 276 ± 118
99 ± 88 161 ± 87
N/A
N/A
27 ± 17
32 ± 9
28 ± 4
25 ± 7
27 ± 7
22 ± 8
44 ± 18
29 ± 15
31 ± 13
19 ± 10
26 ± 17
21 ± 14
22 ± 14
13 ± 13
N/A
SI, Sphincteric incompetence; DI, detrusor instability.
For cystometry volumes, compliance, and passive urethral profilometry, regression analysis was done to test for trends across groups. For cystometry volumes and compliance, the diagnostic groups were coded 0 = no sphincteric incompetence or detrusor instability, 1 = sphincteric incompetence, 2 = detrusor instability, and 3 = sphincteric incompetence + detrusor instability. For data on passive urethral profilometry, the diagnostic groups were coded 0 = no detrusor instability or sphincteric incompetence, 1 = detrusor instability, 2 = sphincteric incompetence, and 3 = sphincteric incompetence + detrusor instability. Two sample t-tests determined differences between volumes triggering detrusor contractions and their amplitudes. *P < 0.01; tp < 0.001. Trends and differences remain when controlling for age.
ysis of variance to compare means among the four diagnostic groups. Significant differences among groups prompted pairwise comparisons at the alpha = 0.05 level using Tukey's standardized range test. Chi-square tests were used to compare among groups the proportions of subjects using drugs, perineal protective pads, those women having had previous incontinence treatments, and those having positive urethral function diagnostic tests. Regression analysis was used to test the hypothesis that detrusor function and quantity of fluid lost worsened from subjects without demonstrable dysfunction, to those with only sphincteric dysfunction, to those with only detrusor dysfunction, and finally to those with both. A similar analysis tested the hypothesis that urethral function and frequency of incontinence worsened from those subjects showing no demonstrable dysfunction, to those with pure detrusor dysfunction, to those with sphincteric dysfunction, and finally to those with both. The volume at which detrusor contractions occurred and their amplitude were compared between subjects with detrusor instability and with sphincteric incompetence + detrusor instability using a two-sample I-test. All analyses were reevaluated, incorporating age as an independent factor, to determine
if the observed effect remained after controlling for age.
Results Demographically, 93% of the patients were white, 57% had an undergraduate college degree or more education, and 58% had an annual income in excess of $20,000. Mean age, parity, and weight were 67 ± 8 years, 3 ± 1.7 births, and 158 ± 29 pounds. All patients were considered functionally intact. Fifteen (10%) did not fulfill the urodynamic diagnostic criteria for either sphincter incompetence or detrusor instability. Ninety (62%) showed only sphincteric incompetence during urodynamic assessment. Seventeen (12%) had only detrusor instability, and 23 (16%) had both sphincteric incompetence and detrusor instability. Between groups, a significant difference (p < 0.05) was found only in age. Subjects in the sphincteric incompetence + detrusor instability group were older (73 ± 9 years) than those in the group with neither sphincteric incompetence or detrusor instability (67 ± 7 years), the sphincteric incompetence group (65 ± 8 years), and the detrusor instability group (69 ± 11 years). The mean duration of the symptoms of urinary in-
Urinary incontinence in community-dwelling women
Volume 162 Number 4
Table III. Severity by frequency of incontinent episodes and quantity of fluid loss (N No SI or DI (n = 15)
Frequency of incontinence episodes (no'!wk)* Quantity of fluid lost (gm)*
8 ± 6
4 ± 10
=
949
145)
+
SI (n =90)
DI (n =/7)
SI (n
22 ± 21 22 ± 54
14 ± 10 65 ± 84
25 ± 19 91 ± 101
DI
= 25)
SI, Sphincteric incompetence; DI, detrusor instability.
Regression analysis was done to test for trends across groups. For the frequency of incontinence episodes, the diagnostic groups were coded 0 = no sphincteric incompetence or detrusor instability, 1 = detrusor instability, 2 = sphincteric incompetence, 3 = sphincteric incompetence + detrusor instability. For the quantity of fluid loss, the code was 0 = no sphincteric incompetence or detrusor instability, 1 = sphincteric incompetence, 2 = detrusor instability, and 3 = sphincteric incompetence + detrusor instability. *p 0.1). In four subjects with combined dysfunction, dynamic urethral profilometry was technically not satisfactory because of severe detrusor instability stimulated by coughing. One direct visualization test was not performed satisfactorily in a subject with sphincteric incompetence alone because extreme obesity did not allow proper visualization. Urethral sphincteric function variables were also analyzed for trends. Functional urethral length, maximal urethral closure pressure, and mobility of the urethral axis showed the largest values in the group lacking urodynamic diagnosis, decreasing to smaller values in the group with evidence of both urodynamic diagnoses (p < 0.01). The severity of incontinence as determined by the number of incontinence episodes reported in a weekly diary and by quantitating fluid loss is presented in Table III. Incontinent episodes were most frequent in subjects with both diagnoses and less in those without demonstrable dysfunction. Those subjects with pure sphincteric incompetence lost urine more frequently than those with only detrusor instability (p < 0.01). The quantity of the fluid lost was, again, greater for patients with both dysfunctions and least for those without any demonstrable abnormality. Subjects with only an unstable detrusor lost more fluid than those with only sphincteric incompetence (p < 0.01).
950
Fantl et al.
Comment
The descriptive data presented provide the opportunity to review and correlate specific characteristics of community-dwelling women with urinary incontinence. The study population consisted of predominantly white, educated women of middle to upper socioeconomic strata. Such demographic selection may have resulted, at least in part, from the media-based recruitment strategies and/or the behavioral nature of the treatment protocol. The inclusion/ exclusion criteria limited the study to older, mentally intact, and functionally able subjects who clinically resembled those incontinent patients most commonly seen in medical practice. The distribution of subjects among diagnostic groups is mostly in line with that observed by other investigators. s. 14 Review of lower urinary tract symptoms within each group confirms that these occur within each diagnostic category and are not specific, but are sensitive.s. 15. 16 All subjects demonstrated some degree of detrusor dysfunction during filling cystometry. Patients without demonstrable urodynamic diagnosis had volumes of maximal cystometric capacity and first sensation to void smaller than the average volumes observed in normal continent womenY A significant deterioration of these volumes occurs among groups. Subjects in both the detrusor instability and the sphincteric incompetence + detrusor instability groups demonstrated involuntary detrusor contractions, but these occurred at significantly lower volumes in patients with dual dysfunction. Similar observations can be made regarding urethral function. Subjects without demonstrable abnormality have urethral closure pressures and functional urethral lengths somewhat reduced when compared with normative data. 17 In addition, these variables worsen in subjects with pure instability and continue to do so in women with pure sphincteric dysfunction and dual pathology. A progressive deterioration of both detrusor and urethral functions becomes most severe when both dysfunctions are demonstrable. The severity of the incontinence also reveals a worsening trend from subjects without demonstrable urodynamic abnormality to those having evidence of both dysfunctions. However, when measured by the number of incontinent episodes, subjects with pure sphincter dysfunction reveal increased severity compared with those with pure detrusor instability. The reverse is seen when the measure is the quantity of fluid lost. These observations are probably best explained by the mechanism by which the incontinence occurs. In sphincteric dysfunction, the episode is triggered by exertions that result in intermittent sporadic sphincteric failures. Frequency will therefore depend on the number and degree of exertions and the extent of the sphincteric in-
April 1990 Am J Obstet Gynecol
competence. In detrusor dysfunction, the frequency is likely to depend primarily on the bladder reaching critical volumes. This mechanism is likely to occur less frequently and induce larger volumes of fluid loss than episodes occurring as a result of pure sphincteric failure. Patients in the four diagnostic groups described complained of involuntary urine loss at least once a week. This condition led the patients to seek help within a clinical trial that used a behavioral intervention as a treatment. Fifteen (10%) of these patients did not fulfill any of the established urodynamic criteria and, the specific mechanism of their incontinence remains unknown. Lack of a urodynamic diagnosis in a symptomatic patient is likely due to reduced sensitivity of the diagnostic protocol. These include issues of urodynamic technique, diagnostic criteria, and restrictions in reproducing conditions of normal daily activities within a laboratory environment. The urodynamic and severity data of this group indicate that they represent women with a lesser degree of dysfunction, and their physiopathologic mechanism most likely would be demonstrated if diagnostic restrictions were overcome. Ninety (62%) of women had only urethral incompetence and 12% had only detrusor instability. Cystometric volumes in women with pure urethral incompetence were smaller than those in women without demonstrable pathology. In addition, these values are smaller than available data on continent subjects. 17 Although not confirmatory, these observations seem to indicate that in this group, detrusor filling function is not as "normal" as usually thought. Seventeen (12%) of the women had only detrusor instability. Variables of urethral function in this group were reduced when compared with those with no demonstrable urodynamic diagnosis and with continent subjects of similar age. 17 However, these were less compromised than in patients with pure sphincter incompetence. These data lead to the perception, again, that in women with pure instability, urethral function also departs from "normality." Finally, 23 (16%) of women fulfilled both diagnostic criteria. Variables of both detrusor and urethral function were compromised more in this group than in any other. Filling volumes are smaller and involuntary contractions occur sooner. Urethral closure pressures and functional length are reduced and the urethral axis is less mobile than in any other diagnostic group. From a clinical viewpoint they therefore represent a unique group. The presence of detrusor contractions at smaller volumes and low urethral closure pressures with poor axial mobility imposes specific management dilemmas. The observations we present are descriptive. However, they seem to support the hypotheses that (1) some
Volume 162 Number 4
degree of detrusor and urethral dysfunction is present in all symptomatic patients, and (2) the degree of dysfunction varies and is less in subjects with no demonstrable urodynamic diagnosis and greater in those with both dysfunctions. A causal relationship between urethral and detrusor dysfunctions has been postulated in women l8 and men. 19 Our observations seem to substantiate such a hypothesis. The specific correlation between these dysfunctions, and whether such an association is present in all incontinent subjects, remains to be answered by future research. Considerable debate exists as to the appropriateness of therapeutic plans, particularly in subjects without demonstrable urodynamic diagnosis and those with both dysfunctions. 20 We hope that the observations presented here, as well as those resulting from future investigations, will lead to rational solutions to these elusive problems. REFERENCES
1. Diokno AC, Brock BM, Brown D. Prevalence of urinary incontinence and other urologic symptoms in the noninstitutionalized patient. J Urol 1986; 136: 1022. 2. Ouslander JC, Kane RL, Abrass lB. Urinary incontinence in elderly nursing home patients. JAMA 1982;248: 1194. 3. Donaldson LJ,Jagger C. Survival and functional capacity: a three-year follow-up of the elderly population in hospitals and homes. J Epidemiol Comm Health 1983;37: 176. 4. Hu T. The economic impact of urinary incontinence. Clin Geriatr Med 1986;2:672. 5. National Institutes of Health Consensus Development Conference Statement. Bethesda, Md: National Institutes of Health, 1988;7(5). 6. Folstein MF, Folstein SE, McHugh PRo Mini-mental state-a practical method of grading cognitive state of patients for the clinician . .I Psychiatr Res 1975;12:198. 7. Wyman JF, Choi SC, Harkins SW, Wilson MS, Fantl JA. The urinary diary in evaluation of incontinent women: a test-retest analysis. Obstet GynecoI1988;71:812. 8. Hilton P, Stanton SL. Algorithmic method for assessing urinary incontinence in elderly women. Br Med .I 1981;282:940. 9. FantlJA, Hurt WG, Bump RC. Urethral axis and sphincteric function. AM.I OBSTET GYNECOL 1986;155:554. 10. Bates CP, Bradley NE, Glen ES, et al. Fourth report on standardization of terminology of lower urinary tract function. Br J Urol 1981;53:333. 11. Asmussen M, Ulmstead U. Simultanous urethrocystometry and urethral pressure profile measurements with a new technique. Acta Obstet Gynecol Scand 1975;5:385. 12. Anderson RS, Shepard AM, Feneley RCL. Microtransducer urethral profile methodology variations caused by transducer orientation. J Urol 1983; 130:727. 13. Fantl JA, Harkins SW, Wyman .IF, et al. Fluid loss quantitation test in women with urinary incontinence: a testretest analysis. Obstet Gynecol 1987;70:739. 14. Quigley GJ, Harper AC. The epidemiology of urethral vesical dysfunction in the female patient. AM .I OBSTET GYNECOL 1985; 151 :220. 15. Cardozo LD, Stanton SL. Genuine stress incontinence and detrusor instability-a review of 200 patients. Br J Obstet Gynaecol 1980;87: 184. 16. Sunshine TJ, Glowacki GA. Clinical correlation of urodynamic testing in patients with urinary incontinence. J Gynecol Surg 1989;5:93.
Urinary incontinence in community-dwelling women
951
17. Sorensen S. Urodynamic investigation and their reproducibility in healthy postmenopausal females. Scand J Urol Nephrol 1988; 114(suppl):42. 18. Awad SA, McGinnis RH. Factors that influence the incidence of detrusor instability in women. J Urol 1983; 130: 114. 19. Hindmarsh JR, Gosling PT, Deane AM. Bladder instability. Is the primary defect in the urethra? Br J Urol 1983;55:648. 20. McGuire E. Bladder instability and stress incontinence. Neurourol Urodyn 1988;7:563.
Editors' note: This manuscript was revised after these discussions were presented. Discussion DR. R. PETER BECK, Edmonton, Alberta, Canada. Dr. FantI and his associates have reported an interesting study of 145 women who gave a history of urinary incontinence that was essentially stress and/ or urge incontinence. They identified four subgroups. One group of 15 women gave a history of urinary incontinence but had no demonstrable urodynamic evidence of sphincteric incompetence or detrusor instability. I would suspect that most, if not all, of these patients had detrusor instability, a condition subject to spontaneous exacerbations and remissions. Either these patients were in remission at the time of testing or urodynamic testing did not identify existing detrusor instability. Another group of 90 women demonstrated evidence of sphincteric incompetence as either visualized urine loss or pressure equalization between the urethra and the bladder synchronous with cough. In this group, 7 women demonstrated pressure equalization but no demonstrable urine loss with cough, and another 22 women demonstrated urine loss but no urodynamic evidence of pressure equalization synchronous with cough. These findings are paradoxic because if pressure equalizes between the urethra and the bladder, the woman should lose urine synchronous with cough, and vice versa. I believe three explanations exist for these paradoxic findings. Although the microtip transducer these authors used is very popular in North America, in my opinion it is not as accurate in performing urethral profilometry as the balloon catheter system first described by Enhorning. I would stress that, throughout the study, the investigators used standard accepted procedure devised by those urodynamic units using the microtip transducer technique. My comments regarding technique do not in any way reflect on Dr. FantI and his group, but relate to the microtip transducer technique itself. A second reason for the paradoxic results is that visually identifying urine loss with and only with cough can be extremely difficult, especially if the patient coughs in a "stuttered" fashion. I do not think one can diagnose sphincteric incompetence solely on the basis of visualized urine loss synchronous with cough. On the other hand, I very strongly believe the type and timing of loss relative to stress (especially the timing) are very important in the overall assessment. A third explanation for the paradox is that women in this
952
Fantl et al.
study were tested for urine loss with cough in the standing and supine positions, but underwent urethral profilometry only in the supine position. This is standard procedure for those units using the microtip transducer technique because of real technical difficulties in performing standing urethral profilometry using the microtip transducer. Thus some patients may have lost urine only in the standing position, but urethral profilometry was not performed in that position. Postural change has a very significant effect on urethral profilometry results. A real advantage ofthe balloon catheter technique is that standing urethral profilometry can be easily done. We make this a part of our routine. A third group of 17 patients demonstrated evidence of detrusor instability. The only criticism I have is that no mention has been made of how many patients in the detrusor instability group and in the mixed incontinence group lost urine with and after, or after cough (i.e., incontinence with stress other than loss synchronous with cough). These data, in relation to the detrusor instability group, would have been interesting to compare with the 38% incidence of stress incontinence, by history, in these women and other urodynamic findings that were present. The fourth group of 23 women had a mix of sphincteric incompetence and detrusor instability. Two women demonstrated pressure equalization and no urine loss with cough and another woman demonstrated the reverse findings. Explanations for these paradoxic findings were discussed in relation to the sphincteric incompetence group. This group of 23 patients showed the lowest incidence of significant anterior wall descensus, the least urethral axial mobility, but the highest incidence of enterocele formation. Did this group have a higher incidence of surgery affecting the anterior vaginal wall, especially Burch-type procedures? Most of the data presented in relation to sphincteric incompetence and detrusor instability have been previously documented. However, to my knowledge no one has documented as extensively and carefully the various urodynamic findings in mixed sphincteric incompetence and detrusor instability as the Fantl group.
April 1990 Am J Obstet Gynecol
Their findings may better our understanding of how to manage these patients. Patients with mixed incontinence, in general, have the most severe symptoms (greater volumetric loss and more frequent loss) and the worst urethral and detrusor function when compared with the other two incontinent groups. It is therefore little wonder that this patient is most difficult to treat, as often a mix of medical and surgical therapy is required. The other significant generalization that can be made from this study is that one must always remember that the urethra and bladder are a functional unit. When there is detrusor instability, there are often significant changes in urethral function. Also, when there is urethral sphincteric incompetence, there are often significant changes in detrusor function. Patients with mixed incontinence, therefore, often represent a type of fullblown urethral and detrusor dysfunction. I believe this study from the Medical College of Virginia will make a significant contribution to our understanding of the urethrovesical unit. DR. LEO J. DUNN, Richmond, Virginia. The new catheter technique that Dr. Fantl is working on might answer some of the questions that have been asked today. DR. FANTL (Closing). Thank you very much, Dr. Beck, for your comments. As you know, I have always enjoyed your friendship and respected your work. I have learned tremendously from it. Your comments are definitely very welcome and they are very appropriate. My perception of the so-called "paradoxical observations" with regard to urethral function tests relate to their specificity and sensitivity. The reason to use two tests was to improve on sensitivity, inasmuch as both tests are reasonably specific, but modestly to poorly sensitive. I agree with you that the microtip transducer catheter has its shortcomings, and I think the technology to study this small sphincter still is way behind. Dr. Dunn mentioned the fact that we are working at trying to improve those techniques. However, as it stands now, we must know just how these state-of-the-art techniques perform.
Key words: Urinary incontinence, urodynamics, severity of incontinence
Urinary incontinence affects approximately 37% of older women living in the community; 20% to 25% of cases may be classified as severe.' In nursing homes, the prevalence seems to exceed 50%.2 Lack of urinary control not only has significant psychologic and social impact, but also influences survival.' Conservative estimates in the United States indicate annual costs in excess of 6 billion dollars in managing urinary incontinence.' Although recent advances in standardization of nomenclature and assessment techniques have been significant, further improvements in diagnostic characterization and management strategies are needed." To characterize patients with urinary incontinence, we studied 145 incontinent women living in the community and entering a clinical trial of behavioral treatment. Our purpose is to describe the patients with regard to their specific clinical and urodynamic characteristics and the objective severity of their condition.
From the Continence Program for Women, Department of Obstetrics and Gynecology, Virginia Commonwealth University, Medical College of Virginia. Supported by Grant No. AG05170 from the National Institutes of Health, National Institute on Aging, National Center on Nursing Research. Presented at the Eighth Annual Meeting of the American Gynecological and Obstetrical Society, Hot Springs, Virginia, September 7-9,1989. Reprint requests: J. Andrew Fantl, MD, CPW-Department of Obstetrics and Gynecology, Box 34, MCV Station, Richmond, VA 23298.
946
Material and methods The study population consisted of 145 women entering a clinical trial of behavioral management for urinary incontinence. Inclusion criteria included age 55 years or older, independent resident in the community, ambulatory status, mental intactness (Mini-Mental State score ~23),6 and at least one episode of urinary incontinence per week. Exclusion criteria included persistent urinary tract infection, reversible cause of incontinence (i.e., fecal impaction, direct drug ~ffect), metabolic decompensation, inability for self- or assisted toiletting, outlet obstruction, genitourinary fistula, urethral diverticulum, and permanent catheterization. The initial assessment consisted of a demographic and functional characterization, comprehensive history, physical examination, urinalysis, and serum chemistry tests. Data on symptoms were obtained by interview following a structured questionnaire. The history also included duration of the incontinence, previous treatment of the condition, use of pads for perineal protection, and a review of drug use. Functional status was assessed by the Older Americans Resources and Services' Activities of Daily Living Scale. Diurnal and nocturnal micturition frequencies were determined by a I-week urinary diary.7 More than 8 micturitions a day constituted diurnal frequency and more than one micturition a night constituted nocturnal frequency." The pelvic examination incorporated the specific determination of both anterior and posterior vaginal descensus during maximal bearing-down effort. Descent was categorized as second degree or greater when the
Urinary incontinence in community-dwelling women
Volume 162 Number 4
Table I. Symptoms and pelvic examination results (N
=
No SI or DI (n = 15) (%)
Symptom Stress incontinence Urge incontinence Diurnal frequency Nocturnal frequency Pelvic examination Anterior vaginal wall descensus Rectocele 2: 2 Enterocele Levator ani tone Bulbocavernosus reflex
2:
2
947
145) SI
(n
=
90) (%)
(n
DI 17) (%)
=
SI (n
+
DI
= 23) (%)
80 80 60 53
91 52 46 48
38 88 63 56
57 64 48 65
27 20 13 100 73
26 20 3 88 72
18 24 6 53 82
13 22 17 78 70
S1, Sphincteric incompetence; D1, detrusor instability.
specific segment of the vagina descended further than the mid-vaginal plane. Urethral axial mobility was determined in the supine position by comparing the axis at rest to that during a maximal bearing-down effort. A specially designed goniometer and metallic swab were used. The minimal measure unit was 5 degrees. 9 The detrusor function filling phase was assessed through retrograde subtracted provocative cystometry with room temperature saline solution at a medium infusion rate (50 mL/min). Intravesical and intraabdominal trans rectal pressures were measured with an 8-F microtip transducer catheter. Electronic subtraction of intraabdominal from intravesical pressure allowed simultaneous monitoring of true detrusor pressure. Cystometric variables were measured while the patient was supine and consisted of residual urine, first sensation to void, maximal cystometric capacity, volume from the first sensation to void to maximal cystometric capacity, and compliance. Gravitational and auditory provocative maneuvers to determine detrusor stability included positional changes (supine to erect), forceful coughing, heel bouncing, and listening to running water. Detrusor instability was diagnosed urodynamically when bladder contractions occurring during cystometry could not be voluntarily suppressed. lO The bladder volume at which the initial detrusor contraction occurred and the amplitude of the strongest contraction were measured and recorded. Urethral function was assessed with passive and dynamic urethral profilometry as described by Asmussen and Ulmstead II and standardized by Anderson et al. 12 An 8-F microtip transducer catheter with two sensors (6 cm apart) was pulled through the urethra at a rate of 1 mm/sec. The vesical (distal) sensor remained in the bladder, while the urethral (proximal) sensor traversed the urethra in the 9 o'clock position. Continuous simultaneous electronic subtraction of the intravesical pressure from the urethral pressure provided the ure-
thral closing pressure. All measurements were done at maximal cystometric capacity and with the patient supine. Passive urethral profilometry was performed with the patient at rest and measurements included functional urethral length and maximal urethral closing pressure. Dynamic urethral profilometry was undertaken as the patient was asked to cough forcefully while the urethral sensor traversed the urethra. The test was judged positive when zero closing pressure was reached with each cough throughout the entire functional urethrallength. 9 Fluid loss was directly visualized with the bladder at maximum cystometric capacity in both the supine and erect positions. Urethral incompetence was diagnosed when a spurt of fluid was observed to exit the external meatus at the peak of a maximal cough effort. 9 The presence of positive dynamic profilometry or a direct visualization test fulfilled the urodynamic criteria for urethral sphincteric incompetence. The severity of the incontinence was determined by monitoring the number of incontinent episodes using the 1week urinary diary 7 and the quantity of fluid lost during a controlled laboratory-based perineal pad weighing test. 13 Subjects were classified into four groups according to their urodynamic characteristics. The no sphincteric incompetence or detrusor instability group consisted of subjects who did not fulfill the diagnostic criteria for either dysfunction. Subjects in the sphincteric incompetence group fulfilled only the criteria for urethral sphincteric incompetence. Subjects in the detrusor instability group fulfilled only the criteria for detrusor instability. Subjects in the last group demonstrated urodynamic evidence of both sphincteric incompetence and detrusor instability. Statistical analysis. Means and standard deviations were calculated for continuous variables and percentages for categoric variables. Analysis of age and the duration of urinary incontinence used one-factor anal-
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Table II. Cystometry and passive urethral profilometry (N = 23) No SI or DI (n
Cystometry Residual urine (ml) First sensation to void (ml) Maximal cystometric capacity (ml)* Maximal cystometric capacity - first sensation to void (ml)* Compliance (mllcm H 2O)* Mean bladder volume triggering detrusor contractions (ml)t Mean amplitude of detrusor contractions (cm/H 2O) Passive urethral profilometry Functional urethral length (mm)* Maximal urethral closure pressure.(cm H 2O)* Urethral axial mobility (degrees)*
= 15)
SI
(n
= 90)
Dl
(n
=
17)
SI (n
+
DI
= 23)
6 ± 14 239 ± 135 404 ± 124
8 ± 19 191 ± 95 351 ± III
13 ± 16 197 ± 125 306 ± 112
7± 18 191 ± 102 275 ± 125
165 ± 108
160 ± 108
110 ± 103
84 ± 94
186 ± 143
182 ± 121
N/A
137 ± 92 276 ± 118
99 ± 88 161 ± 87
N/A
N/A
27 ± 17
32 ± 9
28 ± 4
25 ± 7
27 ± 7
22 ± 8
44 ± 18
29 ± 15
31 ± 13
19 ± 10
26 ± 17
21 ± 14
22 ± 14
13 ± 13
N/A
SI, Sphincteric incompetence; DI, detrusor instability.
For cystometry volumes, compliance, and passive urethral profilometry, regression analysis was done to test for trends across groups. For cystometry volumes and compliance, the diagnostic groups were coded 0 = no sphincteric incompetence or detrusor instability, 1 = sphincteric incompetence, 2 = detrusor instability, and 3 = sphincteric incompetence + detrusor instability. For data on passive urethral profilometry, the diagnostic groups were coded 0 = no detrusor instability or sphincteric incompetence, 1 = detrusor instability, 2 = sphincteric incompetence, and 3 = sphincteric incompetence + detrusor instability. Two sample t-tests determined differences between volumes triggering detrusor contractions and their amplitudes. *P < 0.01; tp < 0.001. Trends and differences remain when controlling for age.
ysis of variance to compare means among the four diagnostic groups. Significant differences among groups prompted pairwise comparisons at the alpha = 0.05 level using Tukey's standardized range test. Chi-square tests were used to compare among groups the proportions of subjects using drugs, perineal protective pads, those women having had previous incontinence treatments, and those having positive urethral function diagnostic tests. Regression analysis was used to test the hypothesis that detrusor function and quantity of fluid lost worsened from subjects without demonstrable dysfunction, to those with only sphincteric dysfunction, to those with only detrusor dysfunction, and finally to those with both. A similar analysis tested the hypothesis that urethral function and frequency of incontinence worsened from those subjects showing no demonstrable dysfunction, to those with pure detrusor dysfunction, to those with sphincteric dysfunction, and finally to those with both. The volume at which detrusor contractions occurred and their amplitude were compared between subjects with detrusor instability and with sphincteric incompetence + detrusor instability using a two-sample I-test. All analyses were reevaluated, incorporating age as an independent factor, to determine
if the observed effect remained after controlling for age.
Results Demographically, 93% of the patients were white, 57% had an undergraduate college degree or more education, and 58% had an annual income in excess of $20,000. Mean age, parity, and weight were 67 ± 8 years, 3 ± 1.7 births, and 158 ± 29 pounds. All patients were considered functionally intact. Fifteen (10%) did not fulfill the urodynamic diagnostic criteria for either sphincter incompetence or detrusor instability. Ninety (62%) showed only sphincteric incompetence during urodynamic assessment. Seventeen (12%) had only detrusor instability, and 23 (16%) had both sphincteric incompetence and detrusor instability. Between groups, a significant difference (p < 0.05) was found only in age. Subjects in the sphincteric incompetence + detrusor instability group were older (73 ± 9 years) than those in the group with neither sphincteric incompetence or detrusor instability (67 ± 7 years), the sphincteric incompetence group (65 ± 8 years), and the detrusor instability group (69 ± 11 years). The mean duration of the symptoms of urinary in-
Urinary incontinence in community-dwelling women
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Table III. Severity by frequency of incontinent episodes and quantity of fluid loss (N No SI or DI (n = 15)
Frequency of incontinence episodes (no'!wk)* Quantity of fluid lost (gm)*
8 ± 6
4 ± 10
=
949
145)
+
SI (n =90)
DI (n =/7)
SI (n
22 ± 21 22 ± 54
14 ± 10 65 ± 84
25 ± 19 91 ± 101
DI
= 25)
SI, Sphincteric incompetence; DI, detrusor instability.
Regression analysis was done to test for trends across groups. For the frequency of incontinence episodes, the diagnostic groups were coded 0 = no sphincteric incompetence or detrusor instability, 1 = detrusor instability, 2 = sphincteric incompetence, 3 = sphincteric incompetence + detrusor instability. For the quantity of fluid loss, the code was 0 = no sphincteric incompetence or detrusor instability, 1 = sphincteric incompetence, 2 = detrusor instability, and 3 = sphincteric incompetence + detrusor instability. *p 0.1). In four subjects with combined dysfunction, dynamic urethral profilometry was technically not satisfactory because of severe detrusor instability stimulated by coughing. One direct visualization test was not performed satisfactorily in a subject with sphincteric incompetence alone because extreme obesity did not allow proper visualization. Urethral sphincteric function variables were also analyzed for trends. Functional urethral length, maximal urethral closure pressure, and mobility of the urethral axis showed the largest values in the group lacking urodynamic diagnosis, decreasing to smaller values in the group with evidence of both urodynamic diagnoses (p < 0.01). The severity of incontinence as determined by the number of incontinence episodes reported in a weekly diary and by quantitating fluid loss is presented in Table III. Incontinent episodes were most frequent in subjects with both diagnoses and less in those without demonstrable dysfunction. Those subjects with pure sphincteric incompetence lost urine more frequently than those with only detrusor instability (p < 0.01). The quantity of the fluid lost was, again, greater for patients with both dysfunctions and least for those without any demonstrable abnormality. Subjects with only an unstable detrusor lost more fluid than those with only sphincteric incompetence (p < 0.01).
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Comment
The descriptive data presented provide the opportunity to review and correlate specific characteristics of community-dwelling women with urinary incontinence. The study population consisted of predominantly white, educated women of middle to upper socioeconomic strata. Such demographic selection may have resulted, at least in part, from the media-based recruitment strategies and/or the behavioral nature of the treatment protocol. The inclusion/ exclusion criteria limited the study to older, mentally intact, and functionally able subjects who clinically resembled those incontinent patients most commonly seen in medical practice. The distribution of subjects among diagnostic groups is mostly in line with that observed by other investigators. s. 14 Review of lower urinary tract symptoms within each group confirms that these occur within each diagnostic category and are not specific, but are sensitive.s. 15. 16 All subjects demonstrated some degree of detrusor dysfunction during filling cystometry. Patients without demonstrable urodynamic diagnosis had volumes of maximal cystometric capacity and first sensation to void smaller than the average volumes observed in normal continent womenY A significant deterioration of these volumes occurs among groups. Subjects in both the detrusor instability and the sphincteric incompetence + detrusor instability groups demonstrated involuntary detrusor contractions, but these occurred at significantly lower volumes in patients with dual dysfunction. Similar observations can be made regarding urethral function. Subjects without demonstrable abnormality have urethral closure pressures and functional urethral lengths somewhat reduced when compared with normative data. 17 In addition, these variables worsen in subjects with pure instability and continue to do so in women with pure sphincteric dysfunction and dual pathology. A progressive deterioration of both detrusor and urethral functions becomes most severe when both dysfunctions are demonstrable. The severity of the incontinence also reveals a worsening trend from subjects without demonstrable urodynamic abnormality to those having evidence of both dysfunctions. However, when measured by the number of incontinent episodes, subjects with pure sphincter dysfunction reveal increased severity compared with those with pure detrusor instability. The reverse is seen when the measure is the quantity of fluid lost. These observations are probably best explained by the mechanism by which the incontinence occurs. In sphincteric dysfunction, the episode is triggered by exertions that result in intermittent sporadic sphincteric failures. Frequency will therefore depend on the number and degree of exertions and the extent of the sphincteric in-
April 1990 Am J Obstet Gynecol
competence. In detrusor dysfunction, the frequency is likely to depend primarily on the bladder reaching critical volumes. This mechanism is likely to occur less frequently and induce larger volumes of fluid loss than episodes occurring as a result of pure sphincteric failure. Patients in the four diagnostic groups described complained of involuntary urine loss at least once a week. This condition led the patients to seek help within a clinical trial that used a behavioral intervention as a treatment. Fifteen (10%) of these patients did not fulfill any of the established urodynamic criteria and, the specific mechanism of their incontinence remains unknown. Lack of a urodynamic diagnosis in a symptomatic patient is likely due to reduced sensitivity of the diagnostic protocol. These include issues of urodynamic technique, diagnostic criteria, and restrictions in reproducing conditions of normal daily activities within a laboratory environment. The urodynamic and severity data of this group indicate that they represent women with a lesser degree of dysfunction, and their physiopathologic mechanism most likely would be demonstrated if diagnostic restrictions were overcome. Ninety (62%) of women had only urethral incompetence and 12% had only detrusor instability. Cystometric volumes in women with pure urethral incompetence were smaller than those in women without demonstrable pathology. In addition, these values are smaller than available data on continent subjects. 17 Although not confirmatory, these observations seem to indicate that in this group, detrusor filling function is not as "normal" as usually thought. Seventeen (12%) of the women had only detrusor instability. Variables of urethral function in this group were reduced when compared with those with no demonstrable urodynamic diagnosis and with continent subjects of similar age. 17 However, these were less compromised than in patients with pure sphincter incompetence. These data lead to the perception, again, that in women with pure instability, urethral function also departs from "normality." Finally, 23 (16%) of women fulfilled both diagnostic criteria. Variables of both detrusor and urethral function were compromised more in this group than in any other. Filling volumes are smaller and involuntary contractions occur sooner. Urethral closure pressures and functional length are reduced and the urethral axis is less mobile than in any other diagnostic group. From a clinical viewpoint they therefore represent a unique group. The presence of detrusor contractions at smaller volumes and low urethral closure pressures with poor axial mobility imposes specific management dilemmas. The observations we present are descriptive. However, they seem to support the hypotheses that (1) some
Volume 162 Number 4
degree of detrusor and urethral dysfunction is present in all symptomatic patients, and (2) the degree of dysfunction varies and is less in subjects with no demonstrable urodynamic diagnosis and greater in those with both dysfunctions. A causal relationship between urethral and detrusor dysfunctions has been postulated in women l8 and men. 19 Our observations seem to substantiate such a hypothesis. The specific correlation between these dysfunctions, and whether such an association is present in all incontinent subjects, remains to be answered by future research. Considerable debate exists as to the appropriateness of therapeutic plans, particularly in subjects without demonstrable urodynamic diagnosis and those with both dysfunctions. 20 We hope that the observations presented here, as well as those resulting from future investigations, will lead to rational solutions to these elusive problems. REFERENCES
1. Diokno AC, Brock BM, Brown D. Prevalence of urinary incontinence and other urologic symptoms in the noninstitutionalized patient. J Urol 1986; 136: 1022. 2. Ouslander JC, Kane RL, Abrass lB. Urinary incontinence in elderly nursing home patients. JAMA 1982;248: 1194. 3. Donaldson LJ,Jagger C. Survival and functional capacity: a three-year follow-up of the elderly population in hospitals and homes. J Epidemiol Comm Health 1983;37: 176. 4. Hu T. The economic impact of urinary incontinence. Clin Geriatr Med 1986;2:672. 5. National Institutes of Health Consensus Development Conference Statement. Bethesda, Md: National Institutes of Health, 1988;7(5). 6. Folstein MF, Folstein SE, McHugh PRo Mini-mental state-a practical method of grading cognitive state of patients for the clinician . .I Psychiatr Res 1975;12:198. 7. Wyman JF, Choi SC, Harkins SW, Wilson MS, Fantl JA. The urinary diary in evaluation of incontinent women: a test-retest analysis. Obstet GynecoI1988;71:812. 8. Hilton P, Stanton SL. Algorithmic method for assessing urinary incontinence in elderly women. Br Med .I 1981;282:940. 9. FantlJA, Hurt WG, Bump RC. Urethral axis and sphincteric function. AM.I OBSTET GYNECOL 1986;155:554. 10. Bates CP, Bradley NE, Glen ES, et al. Fourth report on standardization of terminology of lower urinary tract function. Br J Urol 1981;53:333. 11. Asmussen M, Ulmstead U. Simultanous urethrocystometry and urethral pressure profile measurements with a new technique. Acta Obstet Gynecol Scand 1975;5:385. 12. Anderson RS, Shepard AM, Feneley RCL. Microtransducer urethral profile methodology variations caused by transducer orientation. J Urol 1983; 130:727. 13. Fantl JA, Harkins SW, Wyman .IF, et al. Fluid loss quantitation test in women with urinary incontinence: a testretest analysis. Obstet Gynecol 1987;70:739. 14. Quigley GJ, Harper AC. The epidemiology of urethral vesical dysfunction in the female patient. AM .I OBSTET GYNECOL 1985; 151 :220. 15. Cardozo LD, Stanton SL. Genuine stress incontinence and detrusor instability-a review of 200 patients. Br J Obstet Gynaecol 1980;87: 184. 16. Sunshine TJ, Glowacki GA. Clinical correlation of urodynamic testing in patients with urinary incontinence. J Gynecol Surg 1989;5:93.
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17. Sorensen S. Urodynamic investigation and their reproducibility in healthy postmenopausal females. Scand J Urol Nephrol 1988; 114(suppl):42. 18. Awad SA, McGinnis RH. Factors that influence the incidence of detrusor instability in women. J Urol 1983; 130: 114. 19. Hindmarsh JR, Gosling PT, Deane AM. Bladder instability. Is the primary defect in the urethra? Br J Urol 1983;55:648. 20. McGuire E. Bladder instability and stress incontinence. Neurourol Urodyn 1988;7:563.
Editors' note: This manuscript was revised after these discussions were presented. Discussion DR. R. PETER BECK, Edmonton, Alberta, Canada. Dr. FantI and his associates have reported an interesting study of 145 women who gave a history of urinary incontinence that was essentially stress and/ or urge incontinence. They identified four subgroups. One group of 15 women gave a history of urinary incontinence but had no demonstrable urodynamic evidence of sphincteric incompetence or detrusor instability. I would suspect that most, if not all, of these patients had detrusor instability, a condition subject to spontaneous exacerbations and remissions. Either these patients were in remission at the time of testing or urodynamic testing did not identify existing detrusor instability. Another group of 90 women demonstrated evidence of sphincteric incompetence as either visualized urine loss or pressure equalization between the urethra and the bladder synchronous with cough. In this group, 7 women demonstrated pressure equalization but no demonstrable urine loss with cough, and another 22 women demonstrated urine loss but no urodynamic evidence of pressure equalization synchronous with cough. These findings are paradoxic because if pressure equalizes between the urethra and the bladder, the woman should lose urine synchronous with cough, and vice versa. I believe three explanations exist for these paradoxic findings. Although the microtip transducer these authors used is very popular in North America, in my opinion it is not as accurate in performing urethral profilometry as the balloon catheter system first described by Enhorning. I would stress that, throughout the study, the investigators used standard accepted procedure devised by those urodynamic units using the microtip transducer technique. My comments regarding technique do not in any way reflect on Dr. FantI and his group, but relate to the microtip transducer technique itself. A second reason for the paradoxic results is that visually identifying urine loss with and only with cough can be extremely difficult, especially if the patient coughs in a "stuttered" fashion. I do not think one can diagnose sphincteric incompetence solely on the basis of visualized urine loss synchronous with cough. On the other hand, I very strongly believe the type and timing of loss relative to stress (especially the timing) are very important in the overall assessment. A third explanation for the paradox is that women in this
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study were tested for urine loss with cough in the standing and supine positions, but underwent urethral profilometry only in the supine position. This is standard procedure for those units using the microtip transducer technique because of real technical difficulties in performing standing urethral profilometry using the microtip transducer. Thus some patients may have lost urine only in the standing position, but urethral profilometry was not performed in that position. Postural change has a very significant effect on urethral profilometry results. A real advantage ofthe balloon catheter technique is that standing urethral profilometry can be easily done. We make this a part of our routine. A third group of 17 patients demonstrated evidence of detrusor instability. The only criticism I have is that no mention has been made of how many patients in the detrusor instability group and in the mixed incontinence group lost urine with and after, or after cough (i.e., incontinence with stress other than loss synchronous with cough). These data, in relation to the detrusor instability group, would have been interesting to compare with the 38% incidence of stress incontinence, by history, in these women and other urodynamic findings that were present. The fourth group of 23 women had a mix of sphincteric incompetence and detrusor instability. Two women demonstrated pressure equalization and no urine loss with cough and another woman demonstrated the reverse findings. Explanations for these paradoxic findings were discussed in relation to the sphincteric incompetence group. This group of 23 patients showed the lowest incidence of significant anterior wall descensus, the least urethral axial mobility, but the highest incidence of enterocele formation. Did this group have a higher incidence of surgery affecting the anterior vaginal wall, especially Burch-type procedures? Most of the data presented in relation to sphincteric incompetence and detrusor instability have been previously documented. However, to my knowledge no one has documented as extensively and carefully the various urodynamic findings in mixed sphincteric incompetence and detrusor instability as the Fantl group.
April 1990 Am J Obstet Gynecol
Their findings may better our understanding of how to manage these patients. Patients with mixed incontinence, in general, have the most severe symptoms (greater volumetric loss and more frequent loss) and the worst urethral and detrusor function when compared with the other two incontinent groups. It is therefore little wonder that this patient is most difficult to treat, as often a mix of medical and surgical therapy is required. The other significant generalization that can be made from this study is that one must always remember that the urethra and bladder are a functional unit. When there is detrusor instability, there are often significant changes in urethral function. Also, when there is urethral sphincteric incompetence, there are often significant changes in detrusor function. Patients with mixed incontinence, therefore, often represent a type of fullblown urethral and detrusor dysfunction. I believe this study from the Medical College of Virginia will make a significant contribution to our understanding of the urethrovesical unit. DR. LEO J. DUNN, Richmond, Virginia. The new catheter technique that Dr. Fantl is working on might answer some of the questions that have been asked today. DR. FANTL (Closing). Thank you very much, Dr. Beck, for your comments. As you know, I have always enjoyed your friendship and respected your work. I have learned tremendously from it. Your comments are definitely very welcome and they are very appropriate. My perception of the so-called "paradoxical observations" with regard to urethral function tests relate to their specificity and sensitivity. The reason to use two tests was to improve on sensitivity, inasmuch as both tests are reasonably specific, but modestly to poorly sensitive. I agree with you that the microtip transducer catheter has its shortcomings, and I think the technology to study this small sphincter still is way behind. Dr. Dunn mentioned the fact that we are working at trying to improve those techniques. However, as it stands now, we must know just how these state-of-the-art techniques perform.
