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Gracilis muscle flap with a tissue‐engineered lining for experimental bladder wall reconstruction
Author(s) -
Schoeller T.,
Lille S.,
Bauer T.,
PizaKatzer H.,
Wechselberger G.
Publication year - 2001
Publication title -
bju international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.773
H-Index - 148
eISSN - 1464-410X
pISSN - 1464-4096
DOI - 10.1046/j.1464-410x.2001.02237.x
Subject(s) - gracilis muscle , anatomy , haematoxylin , urothelial cell , fibrin glue , urinary bladder , medicine , immunohistochemistry , biology , pathology , urinary system , surgery , urothelium
Objective To assess a pedicled gracilis muscle flap pre‐laminated with autologous, in vitro ‐expanded urothelial cells to reconstruct an entire supratrigonal bladder‐wall defect in rats. Materials and methods A gracilis muscle flap was harvested from 36 male Wistar rats, transposed into the abdomen and wrapped around a silicon‐block space holder. Urothelial cells were harvested and expanded ex vivo . Cells were then suspended in fibrin glue and seeded into the gracilis muscle pocket. One week later this pre‐laminated flap was transposed into a surgically created supratrigonal bladder‐wall defect. All animals underwent such a pre‐laminated gracilis flap bladder reconstruction and were categorized into three experimental groups. All surviving animals with urothelial‐culture pre‐laminated gracilis flap bladder reconstruction were killed 12 weeks (group 1) later. Control rats had gracilis flaps with no cell seeding and treated only with fibrin glue (group 2) or a standard culture medium (group 3) before reconstruction. Results Specimens stained with haematoxylin and eosin, and a specific immunohistochemical staining (AE 1 and AE 3 ‐anti‐cytokeratin monoclonal antibody stain) showed a continuous, multilayered functioning urothelial lining along the transposed pre‐laminated gracilis flap in group 1. All animals in group 1 with an intact urothelial lining on the gracilis muscle survived, in contrast to most animals in groups 2 and 3, where eight and all 12 animals died, respectively. The surviving four animals in group 2 had no detectable urothelial lining. Conclusion Successful urinary reconstruction requires a contractile neo‐reservoir resistant to resorption over time and a stable, protective urothelial lining. A gracilis muscle flap can be seeded with autologous cultured urothelial cells suspended in fibrin glue. This pre‐laminated flap can be safely transposed on its pedicle and be successfully integrated into the remaining bladder wall, with a urothelial lining and the potential to contract. Further studies in larger animals, with a urodynamic assessment, are warranted to determine if this type of bladder‐wall replacement technique is suitable for urinary reconstruction in humans.