Bladder autoaugmentation using various biodegradable scaffolds seeded with autologous smooth muscle cells in a rabbit model.

BACKGROUND/PURPOSE: The prolapsed mucosa after bladder autoaugmentation usually collapses, and the volume increment is limited. This study is aimed at evaluating the efficacy of autoaugmentation assisted with 2 different scaffolds, polyglycolic acid (PGA) mesh and small intestinal submucosa (SIS), seeded with autologous bladder smooth muscle cells in a rabbit model.

METHODS

One month after an initial 70% partial cystectomy, various autoaugmentation surgeries were performed. These procedures included traditional autoaugmentation (n = 6) and traditional autoaugmentation covered with PGA or SIS without cell seeding (N) (PGA-N, n = 6; SIS-N, n = 6) or covered with scaffolds seeded with autologous bladder smooth muscle cells (C) (PGA-C, n = 6; SIS-C, n = 6). All were followed up by bladder volume measurement and retrieved on 1, 2, 3, and 6 months. Statistical analysis was by analysis of variance.

RESULTS

A normal urothelial layer was maintained in all groups. Only PGA-C group showed a significant bladder capacity increment as compared with the other groups in all time-points (P = .001, .000, .000, and .001 at first, second, third, and sixth months, respectively). The PGA-C group showed grossly normal bladder wall with scattered smooth muscle bundles. The other groups had marked graft shrinkage with only unorganized muscle fibers.

CONCLUSION

Cell-seeded PGA polymer facilitates smooth muscle regeneration, offers sufficient bladder wall backup, and achieves satisfactory volume increment after the autoaugmentation with time. The collagen matrix, although seeded with cells, did not offer adequate mechanical support after the surgery.