Vesicoureteral Reflux

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 Vesicoureteral Reflux continued scintigraphy was performed in all cases before the presence of UTI. Of the 31 patients (24 boys and 7 girls), reflux was bilateral in 23. Six patients underwent surgery for increasing creatinine level, poor bladder emptying, and a family desire for surgery in their child with bilateral grade IV VUR after 3 years of follow-up. These patients were excluded from the resolution rate analysis. The current study reports on 25 patients (44 renal units), including 9 patients who were lost to follow-up during the initial report period. Of the 25 patients who were followed conservatively, 19 (16 boys and 3 girls) had bilateral reflux and 6 had unilateral reflux. Grade I VUR was present in 3 units (7%), 100% of which resolved. Grade II VUR was present in 9 units (20%), 77% of which resolved. Grade III VUR was present in 15 units Overall, neonatal reflux resolved or improved in 76% of the units. (34%); it resolved in 53% and improved in 13% of the units. Grade IV VUR was detected in 7 units (16%); it resolved in 28% and improved in 14% of the units. Grade V VUR was present in 10 units (23%); it resolved in 40% and improved in 30% of the units. Mean follow-up was 48 months (range, 14-80 months; median, 44 months). Minimum follow-up of the other health outcomes was 4 years. Breakthrough urinary tract infections occurred in 4 patients with grade IV or V VUR within the first 20 months of follow-up; they did not correlate to circumcision status. At 4 years, 24 of 26 patients had no further infections. One patient with bilateral grade IV VUR is currently undergoing biofeedback therapy for dysfunctional voiding. The other patient underwent surgery. Dysfunctional voiding developed in 4 male and 1 female patient with VUR. The boys were all infrequent voiders with constipation. All had grade III to V VUR and global atrophy of 1 renal unit with no further deterioration. The girl required behavior modification and anticholinergic therapy, which subsequently resolved her grade II VUR. Follow-up renal scans in the entire group showed decreased function in only 2 units (34% to 19% and 45% to 17%) but no new scarring. There was no interval renal 100 VOL. 6 NO. 2 2004 REVIEWS IN UROLOGY growth noted on subsequent ultrasound examinations in these patients. One of the 2 patients had bilateral grade IV reflux, whereas the other had only grade II. There was no obvious explanation for the decrease in renal function. All other units in the study showed normal renal growth, and all patients had normal somatic growth. No hypertension was detected. Overall, outcome health measures did not differ in the 6 children in the surgical group versus the group of 25 children managed medically. Reflux resolved in 13 patients (52%) and improved in 6 patients (24%). The rates of resolution for grades I to V reflux were 100%, 77%, 53%, 28%, and 40%, respectively. The rates of improvement for grades III to V reflux were 13%, 14%, and 50%, respectively. Of the 6 patients who had no improvement, 4 were the boys with dysfunctional voiding; the other 2 had high-grade reflux, grades IV and V, which were downgraded to grades III and IV, respectively. At 4 years of follow-up, no patient had grade V VUR. This study provides a unique long-term assessment of the natural history of neonatal reflux associated with prenatal hydronephrosis. Although the study population was not large, results show that low grades of reflux resolve spontaneously and that dysfunctional voiding contributes to the nonresolution of reflux, especially high-grade reflux. Expectant management resulted in a 28% reflux-related complication rate. Overall, neonatal reflux resolved or improved in 76% of the units. More important, high-grade reflux resolved or improved in 59% during the 4-year study period, and most patients had no adverse health outcomes. In fact, the authors note that, of the patients with highgrade reflux, 4 experienced complete resolution and 3 had considerable improvement, bringing them into the range of the “standard” patient studied in the International Reflux Study, who could be expected to have spontaneous resolution. Had surgery been initially offered, it would have been unnecessary. Expectant management is always worrisome, especially during the first year of life, when infants are at great risk for UTI. This, however, is not the time when most pediatric urologists would choose to intervene surgically, because of the small size of the bladder. These data are useful in providing some statistical information to parents of newborns with high-grade reflux to allay some of the concerns about health care outcomes in this special population of children.