title: The resonance® metallic ureteric stent in the treatment of chronic ureteric obstruction: a safety and efficacy analysis from a contemporary clinical series.
abstract: BACKGROUND
  We evaluate the efficacy and safety of metallic ureteric stenting using the Cook Resonance® stent in the treatment of chronic ureteric obstruction of benign and malignant aetiology. Published experience of using this stent in this context is limited. We add to the body of literature on this topic.
  
  
  METHODS
  All patients who had a Resonance® metallic stent inserted between April 2009 and November 2014 in our institution were identified from a prospectively maintained stent-database. Primary outcome was relief of ureteric obstruction, defined by successful clinical and radiological treatment of hydronephrosis/hydroureter. Secondary outcome measures included operative time, radiological exposure, total stent dwell time (defined as the cumulative time in months for which a Resonance® metallic stent was in situ), and early and late complications.
  
  
  RESULTS
  Twenty-one patients underwent 52 stent insertion episodes (SIE). Median age was 58 years (range 39-90). Stent insertion resulted in successful treatment of hydronephrosis/hydroureter in 96% (2 SIE resulted in failure to relieve ureteric obstruction). Median operative time was 21 min (range 12-90) Median radiation exposure was 815.3 cGy/cm2 (range 192.9-5366.3). Median stent dwell time was 19.5 months (range 6-52) in non-malignant and 12 months (range 2-48) in malignant ureteric obstruction. One stent migrated proximally during insertion and had to be retrieved using an antegrade approach. 5 patients re-admitted with haematuria: all resolved without intervention or blood transfusion. 3 episodes of post-operative urinary infection were recorded; all were successfully treated with oral antibiotics.
  
  
  CONCLUSIONS
  Metallic ureteric stenting using the Resonance® stent is safe and effective for treating ureteric obstruction from both malignant and benign causes. The success rate in our series is 96%.
authors.affiliation: Department of Urology, Wrexham Maelor Hospital, Croesnewydd Rd, Wrexham, LL13 7TD, Wales. chigsypatel@doctors.org.uk.
authors.forename: C
authors.identifier: http://orcid.org/0000-0002-6877-3363
authors.initials: C
authors.lastname: Patel
authors.affiliation: Department of Urology, Wrexham Maelor Hospital, Croesnewydd Rd, Wrexham, LL13 7TD, Wales.
authors.forename: D
authors.initials: D
authors.lastname: Loughran
authors.affiliation: Department of Urology, Wrexham Maelor Hospital, Croesnewydd Rd, Wrexham, LL13 7TD, Wales.
authors.forename: R
authors.initials: R
authors.lastname: Jones
authors.affiliation: Department of Urology, Wrexham Maelor Hospital, Croesnewydd Rd, Wrexham, LL13 7TD, Wales.
authors.forename: M
authors.initials: M
authors.lastname: Abdulmajed
authors.affiliation: Department of Urology, Wrexham Maelor Hospital, Croesnewydd Rd, Wrexham, LL13 7TD, Wales.|North Wales and North West Urological Research Centre, Croesnewydd Rd, Wrexham, LL13 7TD, Wales.
authors.forename: I
authors.initials: I
authors.lastname: Shergill
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D005260:Female; D006801:Humans; D008297:Male; D008670:Metals; D008875:Middle Aged; D019919:Prosthesis Implantation / Q000295:instrumentation*; D062165:Receptors, Artificial; D015607:Stents; D016896:Treatment Outcome; D014513:Ureter; D014517:Ureteral Obstruction / Q000209:etiology / Q000601:surgery*
chemical_list: D008670:Metals; D062165:Receptors, Artificial