Managing Stress Incontinence and Classifying Detrusor Instability

Neurourology; Urinary Incontinence; Female Urology

REVIEWING THE LITERATURE Neurourology • Urinary Incontinence • Female Urology Managing Stress Incontinence and Classifying Detrusor Instability Michael B. Chancellor, MD University of Pittsburgh School of Medicine, Pittsburgh, Pa. [Rev Urol. 1999;1(4):205-206] C linicians are always looking for simpler and surer solutions for managing incontinence. A minimally invasive surgical procedure done under local anesthesia has shown a 90% cure rate for stress incontinence, according to the prospective study reviewed here. As important as the right treatment is the right assessment. What is the value of urodynamic studies in classifying detrusor instability? A British team examined that question. A Multicenter Study of Tension-Free Vaginal Tape (TVT) for Surgical Treatment of Stress Urinary Incontinence Ulmsten U, Falconer C, Johnson P, et al. Int Urogynecol J. 1998;9:210-213. A new surgical technique for managing stress urinary incontinence is gaining popularity and has been championed by urogynecologists in Europe. The procedure, the tension-free vaginal tape (TVT) procedure, can be done under local anesthesia. Urologists with a special interest in female urology should be familiar with the operation. This paper’s lead author is Dr. Ulmsten of the department of obstetrics and gynecology at Uppsala University Hospital in Sweden. The aim of the study was to evaluate the safety and efficacy of the TVT procedure for the surgical management of stress urinary incontinence. A total of 131 women with genuine stress incontinence were included at 6 centers in Sweden. Similar diagnostic workup and operation were prospectively performed on all patients. After surgery, patients were followed for at least 1 year using a standardized protocol for objective and subjective evaluation of the outcome. Mean operation time for the TVT procedure was 28 minutes. As many as 91% of the patients were cured, according to the protocol, and another 7% showed significant improvement. There were 2% failures. The majority of the patients (>90%) were operated on and discharged from the hospital within 24 hours. Only 4 patients needed postoperative catheterization. My first impression was that this procedure seems almost too good to be true. How is TVT performed? For the operation, the patients received a local anesthetic (0.25% prilocaine adrenaline). Two small incisions [length not specified] 5 cm apart were made in the abdominal skin immediately above the superior rim of the pubic bone. A 1.5 cm sagittal incision was made in the anterior vaginal wall, 1 cm proximal to the external urethral meatus. After minimal bilateral paraurethral dissections [not specified], a prolene tape (Ethicon, Somerville, NJ) covered by a plastic sheath was introduced using a 2-component needle instrument (Ethicon). From the vaginal incision, the tip of the delivery needle first perforated the urogenital diaphragm. Within Retzius’ space, the needle tip, immediately behind the pubic bone, was brought up to the abdominal incision. The procedure was repeated on the contralateral side, placing the tape in a U fashion around the midurethra. Cystoscopy was then performed to rule out perforation of the bladder or urethra. The tape was left, without tension, under the midurethra. During final tape adjustment, the patient was asked to cough to check that she had become continent by the procedure. Then the plastic sheath covering the prolene tape was removed and, because of the strong friction created between the tape and the tissue canals, no fixation was necessary. After cutting the abdominal ends of the tape subcutaneously without fixation, the vaginal and abdominal incisions were closed. One advantage of this procedure: Continence can be checked intraoperatively using the cough test without elevation of the urethra, avoiding postoperative retention. Yet the operation is individualized; the tape is adjusted to suit each patient’s tissue requirements. To do this, the procedure must be performed under local anesthesia. Postoperatively, the patient is generally discharged within 24 hours without catheterization. Let’s look at the results of the study. Of the 131 patients, 119 (91%) were cured. The protocol defined cured as >90% improvement in life quality evaluation and <10 g/24 h on pad testing as well as negative stress test on repeated FALL 1999 REVIEWS IN UROLOGY 205 Stress Incontinence continued coughs with the bladder filled with 250 mL. Another 9 patients (7%) were significantly improved. There were 3 patients (2%) deemed failures. The majority of the patients (>90%) were operated on and discharged from the hospital within 24 hours. There were no reports of tape rejection or nonhealing. There was no postoperative catheterization in all but 4 patients. Three patients needed an indwelling catheter for 3 days each. In 1 patient, catheterization was necessary for more than 10 days. Two uncomplicated hematomas and 1 uncomplicated bladder perforation occurred. The authors concluded that the TVT is a safe and effective ambulatory surgical procedure for the management of genuine stress urinary incontinence. Although there are other reports on TVT in the literature, this is the first prospective study of this new and minimally invasive surgical procedure for stress urinary incontinence. The strengths of this important paper are obvious. The surgery is simple, safe, and appears to work! The patient is awake, and the surgeon can decide, with the collaboration of the patient, on how tight the TVT needs to be to cure stress incontinence but not cause obstruction. The potential weaknesses of the TVT and this report are less obvious. The diagnostic criteria the authors used in selecting their patients, as well as the degree of testing performed postoperatively, are not completely clear. We do not know if TVT can work for both urethral hypermobility and intrinsic sphincter deficiency. Furthermore, a long artificial material is required in the perivaginal and retropubic space. We all know the incidence of infection and erosion associated with synthetic slings. Anybody who has had to remove an infected synthetic sling graft would think twice about trying to remove this long sling with high friction and tissue bonding. Further studies are needed to look at the long-term outcome of TVT; results need to be confirmed at other centers in different countries. I believe the concept of a TVT- like ”sling” that we can insert using local anesthesia in an outpatient setting is the future of surgical therapy of stress urinary incontinence. To be able to properly adjust the tension with feedback and not to have to suture or tie down or anchor to bone the sling are highly desirable. Looking into a crystal ball, I see a nonsynthetic, biocompatible material better than the prolene tape used for the TVT. I believe that tissue engineering will be able to develop this “ideal” sling material in the near future. Urodynamic Variables Cannot Be Used to Classify the Severity of Detrusor Instability Wagg A, Bayliss M, Ingham NJ, et al. Br J Urol. 1998;82:499-502. When and how should we do urodynamic studies in patients with symptoms of an overactive bladder? Urologists and 206 REVIEWS IN UROLOGY FALL 1999 other health care providers have known for years that it is OK to manage the symptoms of overactive bladder with anticholinergic drugs or pelvic floor training without first doing a comprehensive urodynamic study. Unfortunately, not all patients improve, and many researchers have searched for the Holy Grail in urodynamics—the 1 or more precious urodynamic parameters that can tell us which patient with an overactive bladder will respond to treatment. A new study by Wagg and associates at University College London, St. Pancras Hospital, in London, United Kingdom, explored the relationship between subjective severity of symptoms of detrusor instability (DI) and urodynamic variables. The key aim of the study was to identify a urodynamic variable that might, by predicting a favorable outcome from treatment, classify the severity of DI. The investigators looked at a cohort of 300 women (mean age, 54 years old) with a urodynamically verified diagnosis of DI. The patients were recruited prospectively for the study. Data on disease symptoms and variables from the diagnostic cystometrogram were collected. All women were then treated with oxybutynin and bladder training, and the outcomes 6 weeks later were compared with initial urodynamic variables. Data on severity of symptoms were compared with initial urodynamic variables to explore any differences in these variables attributable to symptom severity. Of the 300 patients, 290 were treated with oxybutynin and bladder training. At 6 weeks, 82 women had their outcome classified as worse or no change, 218 women had improved. When good or poor outcome was compared with the urodynamic results, there was no significant difference between the groups. Likewise, severity of symptoms did not relate to the values of urodynamic variables. The most important point of this paper is that there is no discrete correlation between the symptom severity of the overactive bladder and simple urodynamic parameters. Therefore, it will not be possible in a woman with an overactive bladder to predict if she will get better from treatment based solely on urodynamic variables. But, it would be quite wrong to conclude that urodynamic studies are not useful for DI. This project was not designed to address this issue. Let’s go back to the first question: When and how should we do urodynamic studies in patients with symptoms of an overactive bladder? Unfortunately, this paper cannot completely answer this important question. This paper does point out the weakness in our symptomatic assessment of DI. We need to develop more sensitive questionnaires to assess subjective bladder dysfunction. Furthermore, we need to carefully correlate all urodynamic parameters, including parameters for stress incontinence, with symptoms of the overactive bladder. The study also gave us encouraging outcomes in over two-thirds of patients with anticholinergic drugs and bladder training for all grades of DI. ■