BACKGROUND: The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo. OBJECTIVE: The current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction. DESIGN, SETTING, AND PARTICIPANTS: In total, 50 patients with extrinsic malignant obstruction (n=25), benign ureteral obstruction (n=18), and previously obstructed mesh metal stents (n=7) were prospectively evaluated. INTERVENTION: All patients were treated by Resonance stent insertion. Twenty stents were inserted in antegrade fashion, and the remaining stents were inserted in a retrograde approach. No patient dropped out of the study. The follow-up evaluation included biochemical and imaging modalities. MEASUREMENTS: We evaluated the technical success rate, stricture patency rate, complications, and the presence and type of encrustation. RESULTS AND LIMITATIONS: The technical success rate of transversal and stenting of the strictures was 100%. In 19 patients, balloon dilatation was performed prior to stenting. The mean follow-up period was 8.5 mo. The stricture patency rate in patients with extrinsic malignant ureteral obstruction was 100% and in patients with benign ureteral obstruction 44%. Failure of Resonance stents in all cases of obstructed metal stents was observed shortly after the procedure (2-12 d). In nine cases, stent exchange was demanding. Encrustation was present in 12 out of 54 stents. CONCLUSIONS: The Resonance stent provides safe and sufficient management of malignant extrinsic ureteral obstruction. Resonance stent use in benign disease needs further evaluation, considering the untoward results of the present study. 2009 European Association of Urology. Published by Elsevier B.V. All rights reserved.
BACKGROUND: The Resonance metallic ureteral stent (Cook Medical, Bloomington, Indiana, USA) has been introduced for the management of extrinsic-etiology ureteral obstruction for time periods up to 12 mo. OBJECTIVE: The current study aims to determine short- and medium-term effectiveness of the Resonance stent in malignant and benign ureteral obstruction. DESIGN, SETTING, AND PARTICIPANTS: In total, 50 patients with extrinsic malignant obstruction (n=25), benign ureteral obstruction (n=18), and previously obstructed mesh metal stents (n=7) were prospectively evaluated. INTERVENTION: All patients were treated by Resonance stent insertion. Twenty stents were inserted in antegrade fashion, and the remaining stents were inserted in a retrograde approach. No patient dropped out of the study. The follow-up evaluation included biochemical and imaging modalities. MEASUREMENTS: We evaluated the technical success rate, stricture patency rate, complications, and the presence and type of encrustation. RESULTS AND LIMITATIONS: The technical success rate of transversal and stenting of the strictures was 100%. In 19 patients, balloon dilatation was performed prior to stenting. The mean follow-up period was 8.5 mo. The stricture patency rate in patients with extrinsic malignant ureteral obstruction was 100% and in patients with benign ureteral obstruction 44%. Failure of Resonance stents in all cases of obstructed metal stents was observed shortly after the procedure (2-12 d). In nine cases, stent exchange was demanding. Encrustation was present in 12 out of 54 stents. CONCLUSIONS: The Resonance stent provides safe and sufficient management of malignant extrinsic ureteral obstruction. Resonance stent use in benign disease needs further evaluation, considering the untoward results of the present study. 2009 European Association of Urology. Published by Elsevier B.V. All rights reserved.