title: Evaluation of zotarolimus-eluting metal stent in animal ureters.
abstract: OBJECTIVE
  Drug-eluting stents proved to minimize neointimal hyperplasia in coronary vessels. Hyperplastic reaction is the most common unwelcome event related to the use of metal mesh stents in the ureter. We evaluated the effect of zotarolimus-eluting stent (ZES) Endeavor Resolute in the porcine and rabbit ureter.
  
  
  METHODS
  A ZES and a bare metal stent (BMS) were inserted in each ureter of 10 pigs and 6 rabbits. The insertion was performed by the retrograde approach. CT was used for the evaluation of porcine ureters while intraoperative intravenous urography (IVU) was used for rabbit ureters. The follow-up included CT or IVU every week for the following 4 weeks for pigs and 8 weeks for rabbits. Renal scintigraphies were performed before stent insertion and during the third week in all animals. Optical coherence tomography (OCT) has been used for the evaluation of the luminal and intraluminal condition of the ureters with stents. Histopathologic examination of the these ureters embedded in glycol-methacrylate was performed.
  
  
  RESULTS
  Hyperplastic reaction was present in both stent types. BMSs in seven porcine ureters were completely obstructed while porcine ureters with ZES stents had hyperplastic tissue that did not result in obstruction. Two rabbit ureters with BMS stents were occluded while no ZES was associated with ureteral obstruction. The function of the seven porcine renal units and the two rabbit units with obstructed ureters with stents was compromised. The OCT revealed increased hyperplastic reaction in the ureters with BMS stents in comparison with those with ZESs. Although, hyperplastic reaction was present in all cases, pathologic examination revealed significantly more hyperplastic reaction in BMSs.
  
  
  CONCLUSIONS
  ZESs in the pig and rabbit ureter were not related to hyperplastic reaction resulting in stent occlusion. These stents were related to significantly lower hyperplastic reaction in comparison with BMSs while inflammation rates were similar for both stent types.
authors: Department of Urology, University of Patras, Patras, Greece.
authors: Panagiotis
authors: P
authors: Kallidonis
authors: Panagiotis
authors: P
authors: Kitrou
authors: Dimitrios
authors: D
authors: Karnabatidis
authors: Iason
authors: I
authors: Kyriazis
authors: Christina
authors: C
authors: Kalogeropoulou
authors: Athanasios
authors: A
authors: Tsamandas
authors: Dimitrios J
authors: DJ
authors: Apostolopoulos
authors: Theofanis
authors: T
authors: Vrettos
authors: Despoina
authors: D
authors: Liourdi
authors: Stavros
authors: S
authors: Spiliopoulos
authors: Abdulrahman
authors: A
authors: Al-Aown
authors: Chrisoula D
authors: CD
authors: Scopa
authors: Evangelos
authors: E
authors: Liatsikos
mesh_terms: D000818:Animals; D054855:Drug-Eluting Stents / Q000009:adverse effects; D005260:Female; D006965:Hyperplasia; D007249:Inflammation / Q000473:pathology; D007668:Kidney / Q000000981:diagnostic imaging / Q000187:drug effects / Q000473:pathology; D008670:Metals / Q000009:adverse effects; D019919:Prosthesis Implantation; D011817:Rabbits; D011877:Radionuclide Imaging; D020123:Sirolimus / Q000031:analogs & derivatives* / Q000494:pharmacology; D034421:Sus scrofa; D041623:Tomography, Optical Coherence; D014057:Tomography, X-Ray Computed; D014513:Ureter / Q000000981:diagnostic imaging / Q000187:drug effects* / Q000473:pathology*; D014567:Urography; D019459:Urothelium / Q000187:drug effects / Q000473:pathology
chemical_list: D008670:Metals; C489443:zotarolimus; D020123:Sirolimus