title: Augmentation cystoplasty using decellularized vermiform appendix in rabbit model.
abstract: OBJECTIVE
  The aim of this study was to produce a decellularized rabbit vermiform appendix (sacculus rotundus) and investigate its feasibility in bladder augmentation or appendicovesicostomy. The superiority of sacculus rotundus over other tissues is its unique mechanical properties as well as its abundant collagen content.
  
  
  METHODS
  The acellular matrix of vermiform appendix underwent different laboratory investigations prior to transplantation. We divided 12 rabbits into 3 groups: group I underwent bladder augmentation cystoplasty by detubularized acellular matrix. Group II underwent implantation of the tapered (tubularized) acellular matrix just beneath the seromuscular part of the bladder without connection to the bladder urothelium. Group III underwent the same procedure as group II plus reimplantation of tapered and tubularized acellular matrix (simulating an appendicovesicostomy). The distal end of the transplanted graft was connected to the bladder mucosal opening and was intubated by a 5Fr double blind ended feeding tube catheter. Biopsies were taken 3, 12, and 36months post-operatively for further histological and immunohistochemical analyses.
  
  
  RESULTS
  The results of the examinations performed prior to transplantation, revealed a decellularized structure resembling the native tissue with intact extracellular matrix, normal pits and appropriate gaps that will be suitable for further cell seeding. Histopathology examination of the biopsies after transplantations confirmed successful cell seeding with urothelial lining in groups I and III, while the inner lumen in group II showed no urothelial lining.
  
  
  CONCLUSIONS
  The results suggest that we can prospect to perform bladder reconstruction by the application of this method without complications of previously reported augmentation cystoplasty. In the current study we used the bladder as a natural bioreactor for autologous recellularization which may pave the road for clinical application in acellular matrix augmentation cystoplasty.
authors.affiliation: Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI).
authors.forename: Nastaran
authors.initials: N
authors.lastname: Sabetkish
authors.affiliation: Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI). Electronic address: kajbafzd@sina.tums.ac.ir.
authors.forename: Abdol-Mohammad
authors.initials: AM
authors.lastname: Kajbafzadeh
authors.affiliation: Pediatric Urology Research Center, Section of Tissue Engineering and Stem Cells Therapy, Children's Hospital Medical Center, Tehran University of Medical Sciences, Tehran, Iran (IRI).
authors.forename: Shabnam
authors.initials: S
authors.lastname: Sabetkish
authors.affiliation: Department of Pathology, Shariati Hospital, Tehran University of Medical Sciences, Tehran, Iran (IRI).
authors.forename: Seyyed Mohammad
authors.initials: SM
authors.lastname: Tavangar
mesh_terms: D000199:Actins / Q000032:analysis; D000818:Animals; D018952:Antigens, CD34 / Q000032:analysis; D001065:Appendix; D001672:Biocompatible Materials / Q000627:therapeutic use*; D005109:Extracellular Matrix / Q000648:ultrastructure; D048091:Guided Tissue Regeneration / Q000379:methods*; D008297:Male; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning; D018919:Neovascularization, Physiologic; D011817:Rabbits; D011897:Random Allocation; D013718:Tensile Strength; D054457:Tissue Scaffolds; D001743:Urinary Bladder / Q000601:surgery*; D013520:Urologic Surgical Procedures / Q000379:methods*; D019459:Urothelium / Q000737:chemistry / Q000648:ultrastructure; D016474:Weight-Bearing
chemical_list: D000199:Actins; D018952:Antigens, CD34; D001672:Biocompatible Materials
keywords: Bladder augmentation; Decellularization; Sacculus rotundus