Multichannel urodynamics: ambulatory versus standard urodynamics.

Standard urodynamics in the office setting has been the mainstay of urodynamic evaluation. Ambulatory urodynamics has previously been viewed as a research tool only. This article summarizes new studies on ambulatory urodynamics that highlight its potentially more practical and clinical use.

Stress urinary incontinence at rest.

We retrospectively identified 37 cases in which urinary incontinence occurred at rest during urodynamic testing in the absence of a coincident detrusor contraction or urethral relaxation. This phenomenon, genuine stress incontinence at rest, was observed during 9.6% of multichannel cystometrograms performed at our institution. The observed urine loss occurred at bladder volumes between 145 ml and 800 ml. Loss occurred with bladder overdistension (overflow incontinence) in only 3 subjects (8%). Decreased bladder compliance was observed in 11 (30%) and decreased outlet resistance was demonstrated in 24 (65%). Our findings suggest that genuine stress incontinence at rest is relatively common in a referred population of incontinent women. This phenomenon is associated with impaired urethral function and/or decreased bladder compliance.

The relationship of body mass index to intra-abdominal pressure as measured by multichannel cystometry.

The aim of the study was to identify the possible relationship between body mass index and intra-abdominal pressure as measured by multichannel cystometry. A retrospective chart review of patients presenting for urodynamic evaluation between January 1995 and March 1996 was carried out. Variables identified included weight, height, intra-abdominal pressure and intravesical pressure as recorded on multi-channel cystometrogram at first sensation in the absence of detrusor activity. Body mass index was defined as weight in kilograms divided by height in square meters. Intra-abdominal pressure was measured intravaginally except in those cases of complete procidentia or severe prolapse, where it was measured transrectally. Adequate data were available on 136 patients. The mean age was 60.6 years (range 30-91); mean body mass index was 27.7 kg/m2 (range 12.7-47.7); and mean intra-abdominal pressure was 27.5 cmH2O (range 9.0-48.0). A strong association between intra-abdominal pressure and body mass index was demonstrated, with a Pearson coefficient correlation value of 0.76 (P<0.0001). Strong correlation was still demonstrated when those patients who had had the intra-abdominal pressure measured transrectally were separated out, thus eliminating any possible confounding factors between measurements of intra-abdominal pressure measured transvaginally versus transrectally. In addition a strong correlation between intravesical pressure and body mass index was also demonstrated, with a Pearson coefficient correlation value of 0.71 (P<0.0001). Of the 136 patients, 65 (47.8%) were ultimately diagnosed as having genuine stress urinary incontinence (GSUI), 35 (25.7%) with GSUI and a low-pressure urethra (maximum urethral closure pressure of less than 20 cmH2O), and 18 (13.2%) with detrusor instability. The remaining 13.2% had severe prolapse. Our data demonstrate a significant correlation between body mass index and intra-abdominal pressure. These findings suggest that obesity may stress the pelvic floor secondary to chronic state of increased pressure, and may represent a mechanism which supports the widely held belief that obesity is a common factor in the development and recurrence of GSUI.

Banked human fascia lata for the suburethral sling procedure: a preliminary report.

OBJECTIVE: To report our initial experience with allogenic (human cadaver donor) fascia lata for the suburethral sling procedure. METHODS: Allogenic fascia lata for the suburethral sling procedure has been used in our practice since July 1994. Fascial grafts were obtained from licensed tissue banks. Women who underwent this procedure were followed prospectively to determine the incidence of perioperative complications, the incidence of local wound complications at the sling insertion site, and the subjective and objective cure rates. RESULTS: Sixteen women underwent the suburethral sling procedure with allogenic fascia. Fourteen had genuine stress urinary incontinence and two required replacement of a previously placed synthetic graft because of chronic infection. Follow-up ranged from 6 months to 1 year. No patient developed sinus tract formation or persistent granulation tissue. Two of 16 patients (12%) developed abdominal wound infections, which resolved with local care. The mean duration of postoperative bladder drainage was 29 days. One patient continued to require intermittent catheterization at 187 days. Among the 14 women with preoperative genuine stress incontinence, the subjective cure rate was 86% and the objective cure rate was 79%. The two patients who required replacement of a chronically infected synthetic graft remained subjectively continent. CONCLUSIONS: These preliminary data suggest that allogenic fascia lata is an acceptable material for the suburethral sling procedure. This material may be considered as an alternative to autologous fascia, which must be harvested from the patient intraoperatively, and to synthetic materials, which have been associated with local complications in up to 40% of cases.

Protecting the pelvic floor: obstetric management to prevent incontinence and pelvic organ prolapse.

OBJECTIVES: To review the literature regarding the effects of childbirth on the muscles, nerves, and connective tissue of the pelvic floor, review the evidence to support an association between childbirth and anal incontinence, urinary incontinence, and pelvic organ prolapse; and present recommendations for the prevention of these sequelae. DATA SOURCES: Sources were identified from a MEDLINE search of English-language articles published from 1984 to 1995. Additional sources were identified from references cited in relevant research articles. METHODS OF STUDY SELECTION: We studied articles on the following topics: anatomy of the pelvic floor association of childbirth with neuromuscular injury, biomechanical and morphologic alterations in muscle function, and connective tissue structure and function; the long-term effects of childbirth on continence and pelvic organ support; and the effects of obstetric interventions on the pelvic floor. TABULATION, INTEGRATION, AND RESULTS: Articles were reviewed and summarized. An overview of the structure and function of the pelvic floor was developed to provide a context for subsequent data. Childbirth was found to be associated with a variety of muscular and neuromuscular injuries of the pelvic floor that are linked to the development of anal incontinence, urinary incontinence, and pelvic organ prolapse. Risk factors for pelvic floor injury include forceps delivery, episiotomy, prolonged second-stage of labor, and increased fetal size. Cesarean delivery appears to be protective, especially if the patient does not labor before delivery. CONCLUSION: The pelvic floor plays an important role in continence and pelvic organ support. Obstetricians may be able to reduce pelvic floor injuries by minimizing forceps deliveries and episiotomies, by allowing passive descent in the second stage, and by selectively recommending elective cesarean delivery.

Postoperative catheterization, urinary retention, and permanent voiding dysfunction after polytetrafluroethylene suburethral sling placement.

OBJECTIVE: To determine the incidence of permanent voiding dysfunction after polytetrafluoroethylene suburethral sling placement, and to assess the effect of voiding mechanism and uroflowmetry on the duration of postoperative catheterization. METHODS: Between January 1986 and April 1991, 108 patients underwent suburethral sling procedures to treat genuine stress incontinence. Medical records were reviewed to collect urodynamic and catheterization data. One year or longer after surgery, 98 women completed a telephone interview evaluating incontinence, self-catheterization, and voiding symptoms. RESULTS: The mean duration of postoperative cathtrerization was 10.7 weeks. There was no significant relationship between preoperative uroflow indices and the duration of catheterization. The presence of a preoperative detrusor contraction was associated with a shorter mean duration of postoperative catheterization (6.1 versus 14.8 weeks, P = .07) and a lower risk of sling removal for retention (7 versus 33%, P = .04). Eight patients continued self-catheterization. Fourteen patients reported other micturition problems: three used the Credé maneuver or double voided to facilitate emptying and 11 were unable to urinate when seated upright. There was no correlation between the duration of catheterization and ongoing voiding dysfunction. Among nine women who underwent further surgery to treat postoperative urinary retention, three continue to catheterize, one performs Credé, and one urinates standing. CONCLUSIONS: Polytetrafluoroethylene suburethral sling placement commonly produces permanent voiding difficulty. Patients who void without a detrusor contraction are at increased risk for prolonged postoperative catheterization. Sling removal does not ensure resolution of urinary retention and may be no better than leaving the sling in place.

Intrasubject variability of the pressure-transmission ratio in patients with genuine stress incontinence.

The aim of the study was to determine the intrasubject variability of the pressure-transmission ratio (PTR) with various cough intensities in subjects with genuine stress incontinence. Thirty-six patients with genuine stress incontinence underwent multichannel urodynamics and had a series of pressure-transmission ratios (PTRs) determined with the urethral transducer placed at the point of the maximal closure pressure. Patients were asked to cough with increasing intensities and three to four different cough-induced PTRs were recorded for each subject. The data were analysed using regression analysis, repeated measures analysis of variance and comparison of variance. The PTRs showed a high degree of variability within subjects. The mean within subject standard deviation was 18.5%. The effect of parity, maximal urethral closure pressure and age were insignificant on the variability. Cough intensities of greater than 90 cmH2O have a lesser degree of variability. The mean PTR across all cough intensities was fairly constant in the 82%-87% range. It was concluded that the PTR in an individual has a high degree of variability independent of cough intensity, and cannot be relied upon as a diagnostic measure in subjects with genuine stress incontinence. However, the PTR for the population as a whole was consistent across all cough intensities.

The effect of patient position on proximal urethral mobility.

OBJECTIVE: To determine the effect of patient position on the mobility of the urethrovesical junction. METHODS: Q-tip tests in the supine and standing positions were performed on forty-six consecutive female patients with a variety of urogynecologic complaints. Wilcoxon signed-rank test and McNemar test were used to compare urethral mobility in the supine and standing positions. RESULTS: Both the maximum straining Q-tip angle and the difference between the resting and straining angles were significantly greater in the supine position than in the standing position (P < .01). Thirty-four subjects had a positive Q-tip test in the supine position (defined as a maximal straining angle of at least 30 degrees), but only 24 (71%) of these women had a positive Q-tip test in the standing position. CONCLUSION: Patient position has a significant effect on mobility of the urethrovesical junction, in that the female urethra is more mobile in the supine than in the standing position. Because the selection of a surgical procedure for a woman with genuine stress incontinence depends in part on the presence or absence of urethral hypermobility, this observation has important implications for the evaluation of women with genuine stress incontinence.

Evaluation of current urodynamic testing methods in the diagnosis of genuine stress incontinence.

OBJECTIVE: To determine the sensitivity and specificity of several urodynamic testing methods in the diagnosis of genuine stress urinary incontinence (GSI). METHODS: One hundred eight consecutive patients were evaluated prospectively by history and physical examination, cough stress test, and single and multichannel urodynamics. Sensitivities and specificities in detecting genuine stress incontinence were calculated for: a positive cough stress test with a negative cystometrogram, equalization throughout a cough urethral pressure profile, a positive stress leak-point pressure determination, observed urine loss with cough during multichannel urodynamics, and a pressure transmission ratio of less than 90% for each third of the urethra. RESULTS: Sixty-five patients (60%) were found to have GSI. Observed urine loss with cough during multichannel studies was 91% sensitive and 100% specific. A positive stress leak-point pressure determination had a 78% sensitivity and was 100% specific. A positive cough stress test with a negative cystometrogram was 77% sensitive and 100% specific. Pressure equalization throughout the length of the urethra during a cough urethral pressure profile was 49% sensitive and 98% specific. A pressure transmission ratio of less than 90% in the distal, middle, and proximal urethra had sensitivities and specificities of 54 and 79%, 51 and 65%, and 45 and 58%, respectively. A pressure transmission ratio of less than 90% along the entire length of the urethra was 22% sensitive and 93% specific. CONCLUSION: Observed urine loss with cough during multichannel urodynamics was the best examination for diagnosing GSI in our population.

Long-term clinical and urodynamic evaluation of the polytetrafluoroethylene suburethral sling for treatment of genuine stress incontinence.

OBJECTIVE: To assess long-term clinical and urodynamic outcomes of suburethral sling procedures using polytetrafluoroethylene grafts. METHODS: Between January 1986 and May 1991, 108 women underwent suburethral sling placement to treat genuine stress incontinence. At least 1 year after surgery, 62 women participated in a telephone interview about surgical outcome and completed a follow-up urodynamic evaluation. RESULTS: Seventy-three percent of patients reported stress incontinence cure and 61% were objectively cured. Neither low urethral closure pressure nor a history of multiple prior anti-incontinence procedures, singly or in combination, adversely affected outcome. Postoperative maximum urethral closure pressure and functional urethral length were significantly greater in patients who were cured of their incontinence than in those whose surgery failed. Patients who were cured had higher amplitude detrusor contractions during micturition and greater post-void residual urine than those who were not cured. Thirty-three percent of patients with urodynamically stable bladders preoperatively developed detrusor instability after surgery. Detrusor instability remitted after surgery in half of the patients who had this condition preoperatively. Postoperative wound complications developed in 40% of patients who underwent sling placement, and 22% of the grafts were eventually removed. CONCLUSION: Polytetrafluoroethylene suburethral sling placement is an effective treatment for stress incontinence and low urethral pressure. Urodynamic data suggest that urethral obstruction is responsible for surgical cure. Patients should be warned of the high complication rate for this suburethral sling procedure and that graft removal may be necessary.

Pelvic floor electrical stimulation in the treatment of genuine stress incontinence: a multicenter, placebo-controlled trial.

OBJECTIVE: Our purpose was to determine the efficacy of transvaginal electrical stimulation in treating genuine stress incontinence. STUDY DESIGN: This was a multicenter, prospective, randomized, double-blind, placebo-controlled 15-week trial comparing the use of an active pelvic floor stimulator with a sham device. Thirty-five women used an active unit and 17 control subjects used sham devices. Weekly and daily voiding diaries were recorded throughout the trial. Urodynamic testing, including pad test and subtracted cystometry, was done before and at the end of device use. Pelvic muscle strength was measured at baseline and at the end of the trial. Patients scored their symptoms on visual analog scales and completed quality-of-life questionnaires before and after therapy. RESULTS: Significant improvements from baseline were found in patients using active devices but not in controls. Comparisons of changes from baseline between active-device and control patients showed that active-device patients had significantly greater improvement in weekly (p = 0.009) and daily (p = 0.04) leakage episodes, pad testing (p = 0.005), and vaginal muscle strength (p = 0.02) when compared with control subjects. Significantly greater improvement was also found for both visual analog scores of urinary incontinence (p = 0.007) and stress incontinence (p = 0.02), as well as for subjective reporting of frequency of urine loss (p = 0.002), and urine loss with sneezing, coughing, or laughing (p = 0.02), when compared with controls. Pad testing showed that stress incontinence was improved by at least 50% in 62% of patients using an active device compared with only 19% of patients using sham devices (p = 0.01). Voiding diaries showed at least 50% improvement in 48% of active-device patients compared with 13% of women using the sham device (p = 0.02). No irreversible adverse effects were noted in either group. CONCLUSIONS: Transvaginal pelvic floor electrical stimulation was found to be a safe and effective therapy for genuine stress incontinence.

Urogynecology and pelvic reconstructive surgery: office preoperative evaluation of the incontinent female.

Successful research outcomes in the treatment of genuine stress incontinence depend upon correct preoperative urodynamic evaluation. These procedures and how they are used for diagnosis and the selection of the correct surgical procedure are discussed.

A comparison of stress leak-point pressure and maximal urethral closure pressure in patients with genuine stress incontinence.

OBJECTIVE: To determine the correlation between the maximal urethral closure pressure and the stress leak-point pressure in patients with genuine stress incontinence, and to define a critical stress leak-point pressure value to detect patients with a low-pressure urethra, as defined by a maximal urethral closure pressure less than 20 cm H2O. METHODS: Fifty-nine patients with genuine stress incontinence were evaluated prospectively with multichannel urodynamics. Maximal urethral closure pressures and stress leak-point pressures were determined and correlated. Several stress leak-point pressure values were evaluated by contingency tables to detect a critical level for detecting a low-pressure urethra. RESULTS: There is a statistically significant relationship (P < .0001) between the stress leak-point pressure and the maximal urethral closure pressure. However, a correlation coefficient of 0.56 demonstrates poor clinical relationship. A stress leak-point pressure less than or equal to 45 cm H2O was found to be 80% sensitive and 90% specific in diagnosing a low-pressure urethra. A stress leak-point pressure less than or equal to 60 cm H2O was 90% sensitive and 64% specific in detecting a low-pressure urethra. CONCLUSIONS: The stress leak-point pressure has poor clinical correlation to the maximal urethral closure pressure. A stress leak-point pressure less than or equal to 45 cm H2O has adequate sensitivity and specificity to diagnose a low-pressure urethra. A value less than or equal to 60 cm H2O would be an appropriate cutoff level to screen for those patients at risk of having a low-pressure urethra in need of further evaluation.

Predicting intrinsic urethral sphincter dysfunction in women with stress urinary incontinence.

OBJECTIVE: To determine whether specific clinical characteristics can be used to identify women with stress urinary incontinence due to intrinsic urethral sphincter dysfunction without the aid of urodynamic testing. METHODS: A retrospective analysis was performed of 263 consecutive patients who underwent complete urodynamic evaluation for complaints of urinary leakage. Intrinsic sphincter dysfunction was defined as a maximum urethral closure pressure of 20 cm H2O or less in the sitting position at maximum cystometric capacity. Women with sphincter dysfunction were then compared to the group with normal pressure (greater than 20 cm H2O) using t test, chi 2, and logistic regression analyses for 13 clinical indices, endoscopic appearance of the proximal urethra, and eight urodynamic criteria. RESULTS: The group with intrinsic sphincter dysfunction totaled 132 women (50.2%). Univariate analysis revealed that women in this group were older and were more likely to have undergone a hysterectomy and at least one anti-incontinence procedure compared to the women with normal urethral pressure. However, multivariate analysis revealed that age greater than 50 years was the only independent variable that could predict the presence of intrinsic sphincter dysfunction in women with stress incontinence (odds ratio 1.6, 95% confidence interval 1.2-2.2). The two groups were similar in all other preoperative clinical characteristics. CONCLUSIONS: The only preoperative clinical index that predicted the presence of intrinsic urethral sphincter dysfunction, as defined by low urethral closure pressure, was age over 50 years. In view of previous studies reporting a higher rate of surgical failure in women with low urethral pressure, urodynamic testing should be considered in surgical candidates over age 50 to allow adequate preoperative counseling.

Evaluation of pressure transmission ratios in women with genuine stress incontinence and low urethral pressure: a comparative study.

OBJECTIVE: To determine whether women with genuine stress incontinence and low urethral closure pressure (20 cm H2O or lower) had more severely impaired pressure transmission to the urethra than women with stress incontinence and normal urethral pressures. METHODS: Seventy-six women who underwent multichannel urodynamic testing were included for comparative analysis. They were classified into the following groups: genuine stress incontinence with low urethral pressure (N = 20), genuine stress incontinence without low urethral pressure (N = 32), and continent controls (N = 24). Urodynamic indices and pressure transmission ratios were calculated from static and stress urethral pressure profiles, respectively. Multiple demographic cofactors, urethral mobility, and previous surgeries were correlated for associations with urodynamic results. RESULTS: Women with stress incontinence and low urethral pressure were significantly older (57.6 years, P < .0071). There were no differences with regard to urethral mobility and previous surgeries. Mean maximum urethral closure pressure and the distance from the proximal margin of the urethra to the point of maximum urethral closure pressure were statistically less in women with low urethral pressure. There were no differences in pressure transmission ratios between any of the study groups. CONCLUSION: Because there are no differences in pressure transmission ratios between women with genuine stress incontinence with and without low urethral closure pressure, the higher risk for surgical failure with low urethral pressure appears to result from another pathophysiologic process.

The role of patient history in the diagnosis of urinary incontinence.

OBJECTIVE: To assess the clinical usefulness and validity of patient history in the diagnosis of genuine stress incontinence and detrusor overactivity. DATA SOURCES: A literature search was performed for publications addressing the clinical evaluation of urinary incontinence between 1975-1992. METHODS OF STUDY SELECTION: Nineteen of 29 articles during this period reported data in such a manner as to allow statistical comparison of patient history to the diagnosis based on urodynamic evaluation. DATA EXTRACTION AND SYNTHESIS: Each article was assessed for the following information: inclusion and exclusion criteria, method of obtaining patient history, clinical evaluation, and diagnostic criteria. Patients in each article were classified according to their history and urodynamic diagnosis. Sensitivity, specificity, and predictive values were calculated for each article, as well as for the combined data from all articles. Combined data from all 19 articles produced a total of 3092 and 2950 patients evaluated for genuine stress incontinence and detrusor overactivity, respectively. A clinical history consistent with stress incontinence, when compared to a urodynamically based diagnosis, showed a sensitivity of 0.906, a specificity of 0.511, a positive predictive value of 0.749, and a negative predictive value of 0.771. A comparison of clinical history suggestive of an overactive detrusor and urodynamic evidence of spontaneous bladder activity revealed a sensitivity of 0.735, specificity of 0.552, positive predictive value of 0.561, and negative predictive value of 0.728. CONCLUSION: Patient history alone is not an accurate tool in the diagnosis of genuine stress incontinence or detrusor overactivity, and should not be the sole determinant of diagnosis or treatment.

Suprapubic needle cystoscopy: a new technique to detect iatrogenic injuries to the lower urinary tract.

Latrogenic injury to the lower urinary tract, specifically the ureter and bladder, is a potential risk of any pelvic surgery. According to the available literature, the incidence of injury to the ureter ranges from 0.5-2.5% for routine pelvic operarions. In actuality, the incidence of ureteral injury during pelvic surgery may even be higher, as many cases are not reported, not detected or are asymptomatic. Injury to the bladder during pelvic surgery most commonly occurs in the form of inadverant laceration or placement of sutures through the bladder wall. Previous pelvic surgery, including Cesearean section, hysterectomy and bladder suspension procedures, and gynecologic conditions such as malignancy, endometriosis and pelvic inflammatory disease increase the risk for bladder trauma.