title: An unusual case of intrarenal coiled and ruptured guidewire.
abstract: OBJECTIVE
  To the best of our knowledge there are only 3 reports of fractured guidewires inside the pelvicalyceal system, successfully removed with endourology techniques, and this is the first one presenting a tightly coiled intraparenchymal section.
  
  
  METHODS
  A 59-year-old woman was hospitalized for surgical treatment of a right kidney of reduced size. Past history revealed pyelolithotomy for a staghorn stone 14 months earlier at another Institution with subsequent ureteral obstruction, one failed attempt at ureteral double-J catheter insertion and one failed attempt at percutaneous nephrostomy placement 5 months postoperatively. Another nephrostomy was placed, but left indwelling briefly. CT scan demonstrated a small-size kidney with residual stone fragments and presence of a "device" in the lower pole. The tapered distal extremity of an hydrophilic guidewire, with a tightly coiled central section wedged in the renal tissue was found inside the nephrectomy specimen.
  
  
  RESULTS
  While the Radiologist who read the CT scan hypothesized that the "device" was a fragment of double-J ureteral stent or nephrostomy catheter, it consisted of the hydrophilic extremity of a guidewire, broken during a previous attempt at nephrostomy placement. Perirenal fibrosis and inappropriate angle between the needle and the lower calyx are the likely causes of guidewire coiling during its advancement and subsequent rupture during withdrawal.
  
  
  CONCLUSIONS
  Urologists must be aware that, although percutaneous nephrostomy has a very high technical success rate, unusual complications like guidewire fracture may occur, and that modern imaging techniques can provide an accurate picture of this condition.
authors.affiliation: Section of Urology, Department of Translational Research, University of Pisa. francy_manassero@hotmail.com.
authors.forename: Francesca
authors.initials: F
authors.lastname: Manassero
authors.forename: Simona
authors.initials: S
authors.lastname: Ortori
authors.forename: Cristina
authors.initials: C
authors.lastname: Gabellieri
authors.forename: Michela
authors.initials: M
authors.lastname: Gabelloni
authors.forename: Cesare
authors.initials: C
authors.lastname: Selli
mesh_terms: D020878:Device Removal; D003937:Diagnosis, Differential; D005260:Female; D005547:Foreign Bodies / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery; D006801:Humans; D008875:Middle Aged; D009392:Nephrectomy; D009403:Nephrostomy, Percutaneous / Q000009:adverse effects*; D011859:Radiography; D012307:Risk Factors; D015607:Stents / Q000009:adverse effects*; D016896:Treatment Outcome; D014517:Ureteral Obstruction / Q000628:therapy