Urethral Stents

Prostate Cancer continued primary end point was the prevalence of prostate cancer during the study period. Approximately 15 months before its anticipated completion, the data and safety monitoring committee recommended early termination of the PCPT because the study objectives had been met and the conclusions were extremely unlikely to change with additional diagnoses of prostate cancer. The rate of diagnosis of prostate cancer or end-ofstudy biopsy was significantly lower in the finasteride group than in the placebo group (59.6% vs 63.0%; P < .001). The results, based on the 86.3% of men (9060) who had completed the 7-year study, revealed that prostate cancer was detected in 803 (18.4%) of 4368 subjects in the finasteride group and 1147 (24.4%) of 4692 in the placebo group, a relative risk reduction of 24.8% (95% confidence interval, 18.6%-30.6%; P < .001). However, tumors of Gleason scores 7 through 10 were more common in the finasteride group than in the placebo group (280 [37%] of 757 tumors vs 237 [22.2%] of 1068 tumors [P < .001] or 6.4% vs 5.1% [P < .005] of the 4368 and 4692 men in the finasteride and placebo groups included in the final analysis, respectively). Sexual side effects were significantly (P < .001) more common (though not unexpected) in the finasteride group compared with the placebo group: reduced ejaculate volume (60.4% vs 47.3%), erectile dysfunction (67.4% vs 61.5%), loss of libido (65.4% vs 59.6%), and gynecomastia (4.5% vs 2.8%). Conversely, urinary symptoms were significantly (P < .001) more common in the placebo group: increased urinary frequency or urgency (15.6% vs 12.9%), urinary incontinence (2.2% vs 1.9%), and urinary retention (6.3% vs 4.2%). The authors concluded that finasteride prevents or delays the appearance of prostate cancer. However, they also stated that this possible benefit and a reduced risk of urinary problems must be weighed against sexual side effects and the increased risk of high-grade prostate cancer at presentation. Despite the slight bias toward more men in the finasteride group than in the placebo group receiving an end-of-study biopsy (3820 [40.4%] of 9459 vs 3652 [38.8%] of 9423), demonstrating more cancers being detected in the placebo group than in the finasteride group (576 [15.1%] of 3820 vs 368 [10.1%] of 3652), this study revealed that finasteride exhibits chemopreventative properties. However, finasteride was associated with a significantly (P < .001) greater risk of harboring higher Gleason score disease and an increased incidence of sexual side effects compared with placebo. Men who present with symptoms of BPH should continue to be considered for finasteride therapy and be counseled on the associated risks. In addition, doubling of the serum PSA values for men receiving finasteride has been questioned. A total of 222 subjects who received a recommendation for biopsy would not have received this recommendation 98 VOL. 6 NO. 2 2004 REVIEWS IN UROLOGY if doubling, instead of a factor of 2.3, of the PSA value was used. Sixty-nine of these subjects accepted the recommendation, and prostate cancer was detected in 17. If doubling of the PSA value been used, only 2% of the cancer cases in the finasteride group would have been missed. Therefore, when evaluating the true serum PSA levels in men receiving finasteride, we should consider multiplying the values by at least 2. References 1. 2. 3. 4. 5. 6. Coffey DS, Walsh PC. Clinical and experimental studies of benign prostatic hyperplasia. Urol Clin North Am. 1990;17:461-475. Gormley GJ, Stoner E, Bruskewitz RC, et al. The effect of finasteride in men with benign prostatic hyperplasia. N Engl J Med. 1992;327:1185-1191. Silver RI, Wiley EL, Thigpen AE, et al. Cell type specific expression of steroid 5-reductase 2. J Urol. 1994;152:438-442. Vermeulen A, Giagulli VA, De Schepper P, et al. Hormonal effects of an orally active 4-azasteroid inhibitor of 5 alpha-reductase in humans. Prostate. 1989;14:45-53. Bologna M, Muzi P, Biordi L, et al. Antiandrogens and 5-alpha reductase inhibition of the proliferation rate in PC3 and DU145 human prostate cancer cell lines. Curr Ther Res. 1992;51:799-813. Lamb JC, Levy MA, Johnson RK, Isaacs JT. Response of rat and human prostatic cancers to the novel 5-alpha-reductase inhibitor, SK&F 105657. Prostate. 1992;21:15-34. Urethral Stents Overview of Biodegradable Urethral Stents Reviewed by Hiroshi Azuma, MD, Michael B. Chancellor, MD Department of Urology, University of Pittsburgh School of Medicine, Pittsburgh, PA [Rev Urol. 2004;6(2):98-99] © 2004 MedReviews, LLC Biodegradable Urethral Stents Tammela TL, Talja M. BJU Int. 2003;92:843-850. ver the past decade, the development and deployment of a biodegradable urethral stent has gradually gained academic acceptance. The polymers of hydroxyl acids have good biocompatibility properties, and it is possible to make stents with different expansion rates and degradation times. For certain urologic conditions, there is an intrinsic advantage to the use of a bioabsorption device, because it eliminates the need for a second operation for stent removal. In this article, Tammela and Talja O Vesicoureteral Reflux review the current state of biodegradable urethral stents and consider future possibilities. Intraprostatic placement of spiral stents has been confirmed to prevent urinary retention due to edema in the prostate after minimally invasive therapy for benign prostatic hyperplasia (BPH). Biodegradable urethral stents also allow voiding in men with acute retention due to BPH while the size of the prostate is being reduced by 5--reductase inhibitor therapy. In the prostatic urethra, the stents are not covered by the epithelium and are not bioabsorbed but rather biodegraded into fragments that are washed out with urine. However, Although the results of the use of bioabsorbable spiral stents for the treatment of recurrent stricture are encouraging, there are still too many failures. in strictures of the anterior urethra, biodegradable stents, when inserted immediately after optical urethrotomy, are mostly covered by epithelium. These stents are bioabsorbed (except in cases in which the stent suddenly collapses at the time of the bioabsorption and the fragments of the stent perforate through the mucosa into the lumen, where they may partly obstruct the urethral lumen). Although the results of the use of bioabsorbable spiral stents for the treatment of recurrent stricture are encouraging, there are still too many failures. An important reason for this appears to be the excessive urethral scarring and periurethral fibrosis present in patients with chronic recurrent urethral strictures. A bioabsorbable spiral stent cannot prevent the scar from shrinking. It is possible that better patient selection may improve results. Although the biodegradable stent offers a new and convenient option to avoid an indwelling catheter in procedures that cause edema and postoperative urinary retention, costs may be a limiting factor. In addition, irritative symptoms are common to all patients with permanent or temporary urethral stents. To minimize the effects of degradation and sudden collapse in the terminal phase of bioabsorption, new configurations of bioabsorbable urethral stents should be developed and compared with the other permanent stents available. Recently, the design properties of urethral stents in particular have been the subject of keen investigation. The newest design of biodegradable urethral stents is the helical mesh stent, and preliminary experimental and clinical data will soon be available. Because a bioabsorbable stent cannot prevent the recurrence of urethral stricture after urethrotomy, in the most difficult cases, it would be necessary to devel- op bioactive biodegradable stents that could modulate the formation of the scar tissue. Controlled studies are needed to compare bioabsorbable stents with other forms of therapy for the treatment of urethral strictures. Studies to discover the ideal materials, shape, size, and coating materials are needed. Nevertheless, the use of biomaterials in general urologic care is likely and will provide new therapeutic methods to urologists in the near future. Vesicoureteral Reflux Expectant Management in Neonatal Reflux Reviewed by Ellen Shapiro, MD, FACS, FAAP Department of Urology, New York University School of Medicine, New York, NY [Rev Urol. 2004;6(2):99-100] © 2004 MedReviews, LLC Natural History of Neonatal Reflux Associated With Prenatal Hydronephrosis: Long-Term Results of a Prospective Study Upadhyay J, McLorie GA, Bolduc S, et al. J Urol. 2003;169:1837-1841. here is a paucity of long-term data on outcomes in patients with prenatal diagnoses of hydronephrosis who are found to have vesicoureteral reflux (VUR). The investigators from the Hospital for Sick Children at the University of Toronto provide 4-year follow-up data from their expectantly managed cohort and review the specific health issues, including urinary tract infection (UTI), renal growth and function, somatic growth, hypertension, and dysfunctional voiding patterns. This center has previously reported on 17 patients (28 units) at 20 months of follow-up. Those 17 patients, who were treated nonoperatively, showed a 50% rate of improvement (defined as 2 or greater grades on 1 side) in grades III to V VUR by 16 months. Resolution rates in this group were 32%, 18%, and 30% for grades III, IV, and V, respectively. Between 1993 and 1998, 31 (12%) of 260 neonates with prenatal hydronephrosis were found to have reflux and received prophylaxis with trimethoprim. Baseline nuclear T VOL. 6 NO. 2 2004 REVIEWS IN UROLOGY 99