title: Application of paclitaxel-eluting metal mesh stents within the pig ureter: an experimental study.
abstract: OBJECTIVE
  The purpose of the present study is to compare the standard bare metal stents (BMS) with the Paclitaxel-Drug Eluting Stent (DES) in the ureter of a pig model.
  
  
  METHODS
  We report on an experimental study with ten female pigs weighing between 25 and 30 kg. The stents were randomly placed in either the right or left ureter in each of 10 study animals, for a total of 20 stented ureters. Ten ureters were stented with an R-Stent (Orbus Medical Technologies, Hoevelaken Netherlands), and ten with a Paclitaxel-Eluting Coronary Stent (Boston Scientific, Natick, MA, USA). Patency was measured by radiograph of the nephrostomy tract, intravenous urography and virtual endoscopy at 24 hours and 21 days after the initial procedure, respectively.
  
  
  RESULTS
  Free flow of urine through the stents into the bladder was documented in all stented ureters 24 hours after stent insertion by radiograph of the nephrostomy tract. At the 21 day follow-up examination, 5 R-Stents were found to be completely occluded and two partially stenosed, whereas no occluded stent was detected in the Paclitaxel-DES group. Pathology examination of the stents at 21 days follow-up showed that the obstructed R-Stents generated severe inflammation with metaplasia of the urothelium. The Paclitaxel-Eluting MS generated a mild inflammatory response within the ureteral lumen at the site of the stent, without hindering ureteral patency. R-stents proved to develop more hyperplasia compared to the Paclitaxel-Eluting MS.
  
  
  CONCLUSIONS
  Paclitaxel-DES, when compared with the standard R- Stent BMS, generated less inflammation and/or hyperplasia of the surrounding tissues, thus maintaining ureteral patency. Long-term animal trials are required to further validate our results.
authors.affiliation: Department of Urology, University of Patras, School of Medicine, Patras, Greece. Liatsikos@yahoo.com
authors.forename: Evangelos N
authors.initials: EN
authors.lastname: Liatsikos
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Karnabatidis
authors.forename: George C
authors.initials: GC
authors.lastname: Kagadis
authors.forename: Kostantinos
authors.initials: K
authors.lastname: Rokkas
authors.forename: Costas
authors.initials: C
authors.lastname: Constantinides
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Christeas
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Flaris
authors.forename: Theodore
authors.initials: T
authors.lastname: Voudoukis
authors.forename: Chrisoula D
authors.initials: CD
authors.lastname: Scopa
authors.forename: Petros
authors.initials: P
authors.lastname: Perimenis
authors.forename: Kriton S
authors.initials: KS
authors.lastname: Filos
authors.forename: George C
authors.initials: GC
authors.lastname: Nikiforidis
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Stolzenburg
authors.forename: Dimitrios
authors.initials: D
authors.lastname: Siablis
mesh_terms: D000818:Animals; D005260:Female; D009403:Nephrostomy, Percutaneous; D017239:Paclitaxel; D011859:Radiography; D013193:Stainless Steel; D015607:Stents / Q000009:adverse effects; D034421:Sus scrofa; D014513:Ureter / Q000000981:diagnostic imaging / Q000473:pathology; D014517:Ureteral Obstruction / Q000000981:diagnostic imaging / Q000628:therapy
chemical_list: D013193:Stainless Steel; D017239:Paclitaxel