Rhonda Walsh

Effect of Escalating Versus Fixed Voltage Treatment on Stone Comminution and Renal Injury During Extracorporeal Shock Wave Lithotripsy: A Prospective Randomized Trial

PURPOSE ESWL is a minimally invasive, efficacious therapy for most renal stones. However, an optimal voltage treatment protocol ensuring effective stone comminution while minimizing tissue injury is not well established. We performed a prospective, randomized trial of the stone-free rate and renoprotective effect of an escalating vs a fixed voltage treatment strategy during ESWL. MATERIALS AND METHODS Between February 2006 and June 2008 we enrolled 45 patients undergoing ESWL for a renal stone in this institutional review board approved trial. A Dornier DoLi 50 lithotriptor was used. Patients were randomized to receive the escalating strategy of 500 shocks at 14k V, 1,000 at 16 kV and 1,000 at 18 kV or the fixed strategy of 2,500 shocks at 18 kV. Abdominal x-ray was done to determine the stone-free rate at 1 month. Voided urine was analyzed for beta2-microglobulin and microalbumin before, immediately after and 1 week after ESWL to evaluate renal damage. RESULTS Median patient age was 48 years. Median stone size was 8 mm. Of patients in the escalating group 81% were stone-free vs 48% in the fixed group (p <0.03). There was a significant difference between microalbumin and beta2-microglobulin 1 week after the procedure (p = 0.046 vs 0.045). There was trend toward a difference in microalbumin and beta2-microglobulin immediately after the procedure (p = 0.17 and 0.25, respectively). CONCLUSIONS This prospective, randomized study shows that an escalating voltage treatment strategy produces better stone comminution than a fixed strategy. The study suggests that there may be a protective effect against damage caused by ESWL with an escalating treatment strategy.

Multicenter Experience with Metallic Ureteral Stents for Malignant and Chronic Benign Ureteral Obstruction

BACKGROUND AND PURPOSE A new coil-based metallic ureteral stent offers greater radial strength with longer indwelling time compared with plastic stents. This multicenter retrospective study reviews the clinical experience with this stent for malignant or benign chronic ureteral obstruction. PATIENTS AND METHODS Patients had stent placement in a retrograde fashion. We analyzed preplacement and postplacement renal imaging to determine degree of hydronephrosis. Stent encrustation was determined by either visual inspection at the time of stent change or plain abdominal radiography. Preoperative and follow-up serum creatinine values were compared for each patient. RESULTS A total of 76 stents in 59 renal units (40 patients) were successfully placed. Creatinine value follow-up on 54 renal units showed 20 (37%) units to have stable, 15 (28%) improved, and 19 (35%) with worsening values. No stent showed encrustation on plain radiography despite it being seen on two during direct visualization. Three stents needed operative removal with either percutaneous nephrolithotomy or cystolitholapaxy. Fifteen of 41 (37%) metallic stents placed because of an obstructed plastic stent also became obstructed. At last follow-up, 6 of 40 patients were kept from nephrostomy tubes because of the metallic stent. CONCLUSIONS Metallic stents are a viable alternative to nephrostomy tubes in patients in whom conventional stents fail because of malignant obstruction, but patients need to be followed closely. Stent encrustation that resulted in retained stents was poorly visualized on plain radiography. Patients still remain at risk for obstruction, urinary tract infections, and lower urinary tract symptoms from the metallic stent.

Prospective Randomized Evaluation of Periureteral Botulinum Toxin Type A Injection for Ureteral Stent Pain Reduction

PURPOSE The use of ureteral stents for ureteral obstruction and after ureteroscopy can result in substantial deterioration in patient quality of life due to pain, frequency and urgency. We postulated that many stent related symptoms may be related to detrusor muscle spasm in and around the intramural ureter, and evaluated the effect of botulinum toxin type A (Botox) in patients with indwelling stents after ureteroscopy. MATERIALS AND METHODS A total of 51 patients between December 2007 and March 2009 were enrolled in an institutional review board approved, prospective, randomized, single-blind study comparing botulinum toxin type A injection at a concentration of 10 U/ml to 3 locations around the ureteral orifice (30) vs no injection after unilateral ureteral stent insertion (21). Pain and urinary symptoms after stent placement were evaluated through the Ureteral Stent Symptom Questionnaire, which was completed on postoperative day 7. In addition, patients were required to maintain a log of narcotic use after stent placement until removal. The Wilcoxon rank sum and Fisher exact tests were used for nonparametric and categorical data, respectively, with p <or=0.05 considered significant. RESULTS No complications or adverse events occurred in this study. There was a significant decrease in the reported postoperative pain score between the botulinum toxin type A and control group at 3.4 vs 6.0 (p = 0.02). Postoperative narcotic use was also significantly less in the botulinum toxin type A group at 7.7 pills during an average of 2.7 days vs 24.7 in an average of 7.0 days in control patients (p = 0.03). With respect to postoperative lower urinary tract symptoms there was no significant difference between cohorts using the individual index scores within the Ureteral Stent Symptom Questionnaire. Stent related emergency room visits were reported by 1 patient treated in the botulinum toxin type A group vs 2 in the control group. CONCLUSIONS Periureteral botulinum toxin type A injection improves ureteral stent tolerability by significantly decreasing postoperative pain and narcotic requirements. Improvement in irritative symptoms was not observed.

Pilot Study of Alteplase (Tissue Plasminogen Activator) for Treatment of Urinary Clot Retention in an In Vitro Model

INTRODUCTION The management of urinary clot retention and hematuria involves manual irrigation with sterile water or normal saline via a Foley catheter followed by continuous bladder irrigation. Irrigation may become difficult because of the formation of dense blood clots. Tissue plasminogen activator (t-PA/Alteplase) may be a useful pharmacological agent to improve the efficacy of manual irrigation of large, dense clots. The goal of the current study was to compare t-PA to sterile water for clot irrigation in an in vitro model. MATERIALS AND METHODS In vitro models of clot retention were created using 500-cc urinary leg bags each filled with 80 cc of unpreserved whole blood from a healthy volunteer. Each model was incubated at 25 degrees C for 24 hours to allow clot formation. Four models each with 25 mL solution of t-PA at concentrations of 2, 1, 0.5, and 0.25 mg/mL were evaluated and compared to a control (25 mL sterile water). Models were instilled with solution (t-PA or control) and incubated for 30 minutes at 37 degrees C, and then irrigated with sterile water via 18F Foley by a blinded investigator. Three separate experiments were conducted, and statistical analysis was performed comparing various irrigation parameters. RESULTS Clot evacuation with 25 mL of t-PA at a concentration of 2 mg/mL (50 mg) was significantly easier (p = 0.05) and faster (p < 0.05) than the sterile water control. The mean time for clot evacuation in this model was 2.7 minutes for t-PA solution 2 mg/mL versus 7.3 minutes for the control (p < 0.05). Compared to the control, irrigation with t-PA solution 2 mg/mL also required less irrigant (180 mL vs. 500 mL) (p < 0.05) for complete evacuation. There was a similar trend in efficacy for the lower doses of t-PA, but this was not statistically significant. CONCLUSION In this in vitro study, a single 25 mL instillation of t-PA solution 2 mg/mL is significantly better than sterile water alone for clot evacuation. In vivo animal studies are pending.

Percutaneous renal surgery: use of flexible nephroscopy and treatment of infundibular stenoses.

Abstract Percutaneous nephrolithotomy is now the gold standard for treatment of large renal stones. In this article, we describe the indications for use of antegrade flexible nephroscopy during percutaneous nephrolithotomy, as well as for treatment of infundibular stenosis. We also discuss various new technologies to help in these endeavors, including digital cystoscopes and ureteroscopes and our preferred baskets, as well as our particular techniques for improving stone-free rates. The treatment of infundibular stenosis through percutaneous access is also reviewed.

Male Readjustable Sling (MRS) System for Postprostatectomy Incontinence: Experiences of 2 Centers

OBJECTIVE To evaluate the outcomes of Male Readjustable Sling (MRS) in patients with postprostatectomy incontinence at 2 unrelated centers and to determine preoperative factors relevant to the outcome. MATERIALS AND METHODS From January 2007 to January 2014, a total of 64 men with urinary incontinence following radical prostatectomy were treated with MRS at 2 centers. Patients were evaluated based on medical history, daily pad usage, urodynamics, and cystoscopy. The clinical outcome was evaluated according to daily pad usage and questionnaires. Success was defined according to reductions in the number of pads used per day after surgery, and factors related to surgical outcome were investigated. RESULTS The median age of the patients was 70 years (range: 53-84), and the mean follow-up duration was 46.0 ± 19.47 months (range: 12-89). During follow-up, readjustment of the sling was required 1.9 times on average. Daily pad usage decreased significantly from 3.42 ± 2.00 to 0.84 ± 1.20 (P <.001), and the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form score improved (18.65 ± 2.61 to 10.55 ± 6.21, P <.001) without deterioration of voiding symptoms at the last follow-up. MRS was successful in 46 of 64 patients (71.9%). Of the 18 patients who experienced surgical failure, 12 patients required secondary artificial urethral sphincter implantation. The number of daily used pads (odds ratio 1.414) and a history of pelvic irradiation (odds ratio 8.400) were potential risk factors for surgical failure. CONCLUSION According to our midterm follow-up data, MRS is an effective and a safe treatment option for radiation-naïve patients with a mild degree of postprostatectomy incontinence.