Reconstruction of rabbit urinary baldder with human acellular amniotic membrane grafts

Objective To explore the effectiveness of bladder reconstruction in New Zealand white rabbits with human acellular amniotic membrane(HAM) grafts.Methods HAM grafts were prepared by physical approach and enzymatic digestion.Bladder repair with HAM grafts was performed in 12 of 18 rabbits receiving hemicystectomy, so was simple bladder suture as control in the remaining 6.Postoperative bladder volume was measured and histological examination was performed on weeks 2,4,and 8.Results The maximum bladder volume on weeks 2, 4, and 8 differed significantly between the experimental group and the control group(P 0.05);the bladder volume in the two groups was significantly reduced as compared with the baseline(P 0.05 and P 0.01).On week 2, HAM was absorbed and degraded, transitional cells and smooth muscle cells started to form, and inflammatory reaction was evident;on weeks 4 and 8, a near-normal bladder was formed with three marked layers and slight inflammatory reaction.In the control group, inflammatory reaction was mild on week 2 and the reaction disappeared on weeks 4 and 8, and the three layers of the bladder were normal.Stones were formed in most of the bladders(8 / 12) in the experimental group but in one(1 / 6) in the control group.Conclutions HAM as grafts for bladder repair can be rapidly absorbed and degraded.Transitional cells and smooth muscle cells regenerate in the graft.So HAM should be studied further as scaffold materials to bladder tissue engineering.