title: A new biodegradable braided self-expandable PLGA prostatic stent: an experimental study in the rabbit.
abstract: OBJECTIVE
  The biodegradable PLGA (a copolymer of L-lactide and glycolide) urethral stent with a spiral configuration has been used clinically for the prevention of postoperative urinary retention after different types of thermal therapy for benign prostatic hyperplasia. A new braiding pattern for this stent has recently been developed by our group. The aim here was to investigate the in situ degradation and biocompatibility of the new braided stent in the rabbit urethra.
  
  
  METHODS
  PLGA stents with a one-over-one braiding pattern and steel stents served as controls that were inserted into the posterior urethras of 24 male rabbits using a special delivery instrument. The animals were sacrificed after 1 week, 1 month, 2 months, or 4 months, and light microscopy and histologic analyses were performed.
  
  
  RESULTS
  The delivery instrument worked well and cystoscopy was not needed in the insertion process. The braided PLGA stents degraded smoothly in 1 to 2 months. The metallic stents induced more epithelial hyperplasia and epithelial changes than the biodegradable stents at all time points analyzed. These differences increased during follow-up.
  
  
  CONCLUSIONS
  The degradation process was well controlled and the biodegradable stents were more biocompatible than the metallic stents. The new stent can be inserted into the posterior urethra without cystoscopic aid.
authors.affiliation: Department of Urology, Tampere University Hospital and Medical School, University of Tampere, Tampere, Finland. andres.kotsar@pshp.fi
authors.forename: Andres
authors.initials: A
authors.lastname: Kotsar
authors.forename: Taina
authors.initials: T
authors.lastname: Isotalo
authors.forename: Joonas
authors.initials: J
authors.lastname: Mikkonen
authors.forename: Hanne
authors.initials: H
authors.lastname: Juuti
authors.forename: Paula M
authors.initials: PM
authors.lastname: Martikainen
authors.forename: Martti
authors.initials: M
authors.lastname: Talja
authors.forename: Minna
authors.initials: M
authors.lastname: Kellomäki
authors.forename: Pertti
authors.initials: P
authors.lastname: Törmälä
authors.forename: Teuvo L J
authors.initials: TL
authors.lastname: Tammela
mesh_terms: D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials; D004848:Epithelium / Q000473:pathology; D019344:Lactic Acid; D008297:Male; D008422:Materials Testing; D023421:Models, Animal; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011467:Prostate / Q000601:surgery; D011474:Prosthesis Design; D011817:Rabbits; D015607:Stents; D014521:Urethra / Q000473:pathology* / Q000601:surgery*
chemical_list: D001672:Biocompatible Materials; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid