title: Rate of dislodgment of ureteral stents when using an extraction string after endoscopic urological surgery.
abstract: OBJECTIVE
  Ureteral stents are manufactured with an extraction string tethered to the distal end, which facilitates removal after urological surgery. However, the string may allow for stent dislodgment. We report the stent dislodgment rate in a multi-institutional series.
  
  
  METHODS
  We retrospectively reviewed the records of ureteroscopy cases at 3 academic endourology practices. Demographic and operative data were obtained as well as string use and stent dislodgment data. Categorical variables were assessed with the Fisher exact test and the Student t-test was used to assess continuous variables.
  
  
  RESULTS
  Of the 512 cases a string was used in 98 (19.1%) comprising 41 females (41.8%) and 57 males (58.2%). The stent was dislodged in 10 women and 3 men. No dislodgment occurred when a string was not used. When stratified by gender, 5.3% of men and 24.4% of women with a string experienced stent dislodgment (p = 0.013). Women were more than fourfold more likely to experience stent dislodgment than men (RR 4.6, 95% CI 1.36-15.8, p = 0.01).
  
  
  CONCLUSIONS
  Almost 15% of patients in whom a stent is placed with a string sustain stent dislodgment and most of these patients will be women. We recommend considering the risks of dislodgment in each patient who undergoes ureteroscopy with stent placement and considering string removal if the surgeon believes that dislodgment could result in adverse events such as severe colic or obstruction.
authors.affiliation: Brigham and Women's Hospital, Boston, Massachusetts; Beth Israel Deaconess Medical Center, Boston, Massachusetts. Electronic address: aalthaus@partners.org.
authors.forename: Adam B
authors.initials: AB
authors.lastname: Althaus
authors.affiliation: Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.affiliation: Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
authors.forename: Erik
authors.initials: E
authors.lastname: Pattison
authors.affiliation: Massachusetts General Hospital, Boston, Massachusetts.
authors.forename: Brian
authors.initials: B
authors.lastname: Eisner
authors.affiliation: Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
authors.forename: Vernon
authors.initials: V
authors.lastname: Pais
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, Massachusetts.
authors.forename: Peter
authors.initials: P
authors.lastname: Steinberg
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D015607:Stents; D014513:Ureter / Q000601:surgery*; D018666:Ureteroscopy
keywords: nephrolithiasis; postoperative complications; stent; ureter; ureteroscopy