title: The use of internal stents in chronic ureteral obstruction.
abstract: OBJECTIVE
  Despite the lack of a well delineated definition, chronic ureteral obstruction imposes significant quality of life loss, increased pathological morbidity and risk of mortality as well as substantial economic burden. Ureteral stenting serves as an important therapeutic option to alleviate obstruction. Thus, we assessed the recently published literature on chronic ureteral obstruction; treatment options; types, benefits and shortcomings of current ureteral stents; as well as outcomes and complications of chronic ureteral stenting, with the goal of providing concise management guidelines.
  
  
  METHODS
  A systemic literature review was performed on Embase™, PubMed®, Cochrane Controlled Trials Register and Google Scholar™ on ureteral obstruction and internal ureteral stents. Relevant reviews, original research articles and their cited references were examined, and a synopsis of original data was generated on a clinically oriented basis.
  
  
  RESULTS
  Chronic ureteral obstruction can be classified into compression that is either intrinsic or extrinsic to the ureteral wall, or obstruction that is of a benign or malignant origin. Patients with malignant ureteral obstruction generally have a poor prognosis and are often difficult to treat. The aim of stenting is to adequately drain the upper urinary tracts while minimizing hospitalization and the negative impact on quality of life. Facing the challenge of chronic ureteral obstruction, novel stents with new compositions, materials, coatings and designs have been developed. Metallic stents are emerging as efficacious and financially viable alternatives. Early stent related complications include iatrogenic injury, stent migration or patient discomfort, while late complications include infection, difficulties with stent exchange, hardware malfunction, infection and stent encrustation.
  
  
  CONCLUSIONS
  Stenting in chronic ureteral obstruction is a complex and challenging problem. Much work is being done in this area and many options are being explored.
authors.affiliation: Division of Urology, Southern Illinois University School of Medicine, Springfield, Illinois.
authors.forename: Julia
authors.initials: J
authors.lastname: Fiuk
authors.affiliation: Division of Urology, Department of Surgery and Department of Microbiology and Immunology, Schulich School of Medicine & Dentistry, Western University, London, Ontario, Canada; Department of Urology, West China Hospital, Sichuan University, West China School of Clinical Medicine, Sichuan University, Chengdu, China.
authors.forename: Yige
authors.initials: Y
authors.lastname: Bao
authors.affiliation: Department of Urology, North Manchester General Hospital, Manchester, United Kingdom.
authors.forename: John G
authors.initials: JG
authors.lastname: Calleary
authors.affiliation: Division of Urology, Southern Illinois University School of Medicine, Springfield, Illinois.
authors.forename: Bradley F
authors.initials: BF
authors.lastname: Schwartz
authors.affiliation: Division of Urology, Southern Illinois University School of Medicine, Springfield, Illinois. Electronic address: john.denstedt@sjhc.london.on.ca.
authors.forename: John D
authors.initials: JD
authors.lastname: Denstedt
mesh_terms: D002908:Chronic Disease; D006801:Humans; D011379:Prognosis; D015607:Stents; D016896:Treatment Outcome; D014517:Ureteral Obstruction / Q000209:etiology / Q000601:surgery*
keywords: stents; ureteral obstruction