A Gathering of Urologists and Urogynecologists

29th Annual Meeting of the International Continence Society

MEETING REVIEW A Gathering of Urologists and Urogynecologists Highlights from the 29th Annual Meeting of the International Continence Society, the 2nd Annual Meeting of the International Children’s Continence Society, and the 24th Annual Meeting of the International Urogynecology Association August 23-26, 1999, Denver [Rev Urol. 2000;2(1):11-15] Key words: Incontinence, urinary • Cholinergic antagonists • Muscarinic antagonists • Electric stimulation therapy • Pediatrics U rologists and urogynecologists from around the world, representing three medical societies, held a combined meeting in Denver. The International Continence Society (ICS) comprises mainly urologists. Besides the annual meeting of the American Urological Association, the ICS annual meeting is the most important educational conference for urologists interested in neurourology and female urology. The focus of the meeting was the overactive bladder. The program of the International Children’s Continence Society, a new society with several hundred international members, included state-of-theart lectures on maturation of bladder function during postnatal development and desmopressin treatment of nocturnal enuresis in addition to the 57 abstracts presented. The International Urogynecology Association (IUA) is a well-recognized and established international society. This meeting and the American Urogynecological Society’s annual meeting are the two most important gatherings of urogynecologists. Areas of focus of the IUA’s meeting were risk factors for the development of pelvic floor dysfunction; surgery for incontinence and Reviewed by Michael B. Chancellor, MD, University of Pittsburgh School of Medicine prolapse; diagnosis of pelvic floor dysfunction; and nonsurgical management, such as biofeedback and electrical stimulation. The meeting also included a dozen video presentations with emphasis on MRI diagnosis of pelvic prolapse and surgical pelvic prolapse repair. The leaders of each society deserve congratulations for coming together to exchange the latest research and surgical techniques that truly bridge urology and gynecology. Combined Meeting Stress Urinary Incontinence. The topic of long-term surgical outcomes for the management of stress urinary incontinence was debated on numerous occasions. Several presenters pointed out that there are only a few studies comparing outcomes of surgical therapy with biofeedback and physical therapy. The consensus was that colposuspension achieves continence in about 80% of patients for up to 5 years, that approximately 60% of patients are satisfied with results of surgery, and that the open procedure keeps a significantly greater percentage of patients dry during 3 to 5 years of follow-up compared with the laparoscopic approach. Leak Point Pressure. Another theme of the meeting was the refinement of the leak point pressure (LPP) measurement as a reproducible and reliable clinical instrument. Hofner and associates1 from Hannover, Germany, made a significant contribution to the debate on LPP. They developed an investigator-independent, computeraided means of recording fast signals during cough LPP that is integrated with a recording from a flowmeter. Cough LPP is defined as the corresponding pressure when leakage starts. The cough LPP uses a transrectal catheter to measure the abdominal pressure without the requirement of a transurethral catheter. Overall, there was a strong correlation between cough LPP and leakage at maximum flow, and this parameter correlated with the level of clinical incontinence or number of pads used per 24 hours. This new technique is similar to pressure-flow studies that are the “gold standard” for determining bladder outlet obstruction. This leak-flow technique is minimally invasive and should be reproducible in clinical centers. Pediatric Voiding Dysfunction. The hot topic was biofeedback therapy for challenging patients with voiding dysfunction or non-neuropathic bladdersphincter dysfunction. Vandaele,2 on behalf of a multidisciplinary team from Ghent, Belgium, reported on a WINTER 2000 REVIEWS IN UROLOGY 11 Continence/Urogynecology continued Meeting Mission Statement Incontinence, pelvic pain, benign prostatic hyperplasia, and the many nonspecific, functional disorders of the pelvic organs have become major issues for men and women of all ages. Since the bladder, bowel, and reproductive systems are intimately related in their innervation and their relationship to the pelvic floor, there is a common neurophysiologic basis for pelvic organ dysfunction. These observations, together with the many similarities among problems encountered in children and adults, have led to the gathering of three distinguished societies, representing many of the world’s preeminent leaders, to explore the following objectives: • The time-related impact of childhood disorders on the integrity of pelvic organ symptoms in later life. • The neurophysiologic basis for pelvic organ dysfunction and inflammation. • Epidemiologic and environmental factors that potentially influence the integrity of the pelvic organs. • Refinements in diagnosis and therapy, through a better understanding of overall pelvic physiology. As this millennium comes to a close, we hope this meeting will help set the stage for further breakthroughs in understanding and therapeutic discovery for many of the above conditions that so significantly impact the quality of all our lives. [Richard A. Schmidt, chairman] Take-Home Messages 29th Annual Meeting of the International Continence Society. The important message is the arrival of new pharmacotherapy for the management of the overactive bladder. Within the last 18 months, two new drugs were introduced. Tolterodine and controlled-release oxybutynin are both significantly better tolerated than conventional medications. Public education and pharmaceutical commercials have dramatically increased the public awareness of the overactive bladder and have increased the number of new patients seeking intervention for voiding dysfunction. There will be further exciting developments and research in the next decade. 2nd Annual Meeting of the International Children’s Continence Society. A major topic of discussion was a comparison between the recently introduced desmopressin acetate (DDAVP) tablets and DDAVP nasal spray in the treatment of patients with nocturnal enuresis. The DDAVP tablets are more convenient than nightly nasal sprays. The tablets have also been shown to be bioequivalent when dissolved in solution, chewed, or crushed and mixed with applesauce. This should make the job easier for parents. 24th Annual Meeting of the International Urogynecology Association. Tension-free vaginal tape (TVT) received a great deal of attention. This new and minimally invasive surgical technique has been championed by urogynecologists in Europe. A unique advantage of this procedure is that the surgeon can make sure that continence, based on an intraoperative cough test, has been obtained intraoperatively without any elevation of the urethra, thereby avoiding postoperative retention. To achieve this, local anesthesia is used for the procedure. “voiding school” where a dedicated group of urologists, nephrologists, nurses, physiotherapists, and psychologists were able to help 98 of 108 children with voiding dysfunction. Relapse occurred in 28 children, but ultimately they were re-treated successfully. The results of the combined behavioral and physiotherapy approaches were impressive—but at what cost, because hospitalization of these children was required? Van Gool and associates3 of Utrecht, the Netherlands, presented results of the European Bladder Dysfunction Study (EBDS), a multicenter prospective study comparing treatment plans for neurologically normal children with bladder-sphincter dysfunction. Since 1995, 216 children have been enrolled in the EBDS. The investigators concluded that adding pharmacotherapy or bladder rehabilitation to biofeedback does not significantly improve outcomes. With standard therapy alone, approximately 64% of neurologically normal children with bladder-sphincter dysfunction can be cured. Standard therapy consists of low-dose chemoprophylaxis and management of constipation when indicated, complemented with standardized explanations of detrusor-sphincter dyssynergia and instructions for patients and parents on how to cope with the problem. Standard bladder rehabilitation with biofeedback has urine flow rate/electromyelographic recordings displayed on-line on a personal computer as biofeedback and consists of at least 12 sessions of 3 hours each. Satellite Symposiums There were three satellite symposiums during the week of the combined meetings. The theme was new therapies for the overactive bladder and voiding dysfunction. Tolterodine. A new muscarinic receptor antagonist, tolterodine tartrate (Detrol, Pharmacia & Upjohn) has favorable selectivity for the bladder continued on page 15 12 REVIEWS IN UROLOGY WINTER 2000 Continence/Urogynecology continued from page 12 over salivary glands in cat experiments. Tolterodine was reported at the ICS meeting to be safe and effective in patients with overactive bladder.4 There was a statistically significant difference in the decreased episodes of incontinence and micturition frequency between tolterodine, 2 mg bid, and placebo. Because cardiac toxicity has been a concern with the use of this class of drugs, careful clinical toxicity studies were conducted. These studies showed no evidence of risk of cardiac toxicity from this agent. Tolterodine has been shown to be as effective as oxybutynin in reducing urgency and detrusor instability. However, this drug is better tolerated than immediate-release oxybutynin. Traditionally, up to about 43% of patients taking oxybutynin discontinued the drug because of problems with dry mouth. In a meta-analysis of four multicenter prospective trials of 1,120 patients, moderate to severe dry mouth was reported in 6% of patients receiving placebo, 4% of those taking 1 mg of tolterodine, 17% of those taking 2 mg of tolterodine, and 60% of those receiving oxybutynin. Sacral Nerve Stimulation. For the patient with intractable urgency and urge incontinence in whom other methods of treatment have failed, sacral nerve stimulation (SNS [Interstim, Medtronic, Inc]) is an innovative surgical technique that is minimally invasive and not destructive. If SNS does not work, it causes no permanent damage and does not preclude other modes of therapy.5 Initially, there is a 1-week trial implantation of a temporary stimulation unit. The electrodes are placed through the S3 sacral foramen and attached to a transcutaneous electrical nerve stimulator unit–like pulse generator. Then the patient receives appropriate stimulation. If the trial is successful, a permanent implant is inserted. For more on SNS, see “Sacral Nerve Stimulation for the Management of Main Points • Colposuspension results in continence in about 80% of patients for up to 5 years. • Fast signals recorded during cough leak point pressure can be integrated with flowmeter recording without use of a transurethral catheter. • Combined physiotherapy and behavioral therapy may be helpful for children with voiding dysfunction. • Tolterodine and a controlled-release form of oxybutynin have been added to the armamentarium for patients with overactive bladder. • Sacral nerve stimulation is a minimally invasive surgical technique for patients with intractable urgency and urge incontinence for whom other forms of therapy have failed. Voiding Dysfunction,” page 43. Oxybutynin. Powerful antimuscarinic properties characterize oxybutynin, a tertiary amine that is absorbed well from the gastrointestinal tract, reaching maximum plasma concentrations shortly after ingestion. It is excreted by the kidneys and has a plasma halflife of about 3 hours. The plasma halflife is only slightly increased in elderly patients, and the side effects in the elderly are similar to those in the general population. There is no reported age-specific toxicity. A 24-hour controlled-release form of oxybutynin (Ditropan XL, ALZA Pharmaceuticals) is now available. For patients with overactive bladder who either have received an anticholinergic drug in the past or have never been previously treated, efficacy and effectiveness are similar for both the controlled- and immediate-release oxybutynin. The long-acting preparation reportedly is associated with significantly fewer incidences of moderate or severe dry mouth and a much lower dropout rate. The most intriguing advantage of the controlled-release oxybutynin is its site of absorption.6 Oxybutynin is not only metabolized in the liver but also through oxidation pathways in the stomach and small-intestine wall. Moreover, it appears that it is the metabolite of oxybutynin that accounts for most of the side effects involving the salivary glands. Because the controlled-release oxybutynin delivers the drug at a constant rate for 24 hours, the drug generally passes through the stomach and small intestine within 3 to 5 hours and spends approximately 20 hours in the colon. Therefore, there is significantly less oxybutynin metabolite, reducing the side effects. ■ References 1. Hofner K, Oelke M, Wagner T, et al. Cough leak point pressure (CLPP): development of a new method for routine use and testing of clinical reliability. Neurourol Urodyn. 1999;18:249-250. 2. Vandaele J, Vande Walle J, Hoebeke P, et al. A multidisciplinary therapeutic approach in a ‘voiding school’ for therapy-resistant dysfunctional voiding. Neurourol Urodyn. 1999;18:258-260. 3. van Gool JD, de Jong TPVM, Winkler-Seiinstra P, et al. A comparison of standard therapy, bladder rehabilitation with biofeedback, and pharmacotherapy in children with non-neuropathic bladder sphincter dysfunction. Neurourol Urodyn. 1999;18:261-262. 4. Mitcheson HD, Chancellor MB, Zadra J, Diokno AC, and the Tolterodine Study Group. Flexible dose study with tolterodine in patients with overactive bladder confirms efficacy and safety of tolterodine (Detrol). Neurourol Urodyn. 1999; 18:381-382. 5. Siegel S, Cantanzaro F, Dijkema H, et al. Sacral nerve stimulation for refractory urge incontinence: patient outcomes and quality of life; Improvement in quality of life: sacral nerve stimulation for urinary urgency-frequency. Neurourol Urodyn. 1999;18:373-374. 6. Chancellor MB, Sathyan G, Gupta SK. Effect of ketoconazole on the pharmacokinetics of oxybutynin: comparison between Ditropan XL and conventional oxybutynin. Neurourol Urodyn. 1999; 18:378-379. WINTER 2000 REVIEWS IN UROLOGY 15