Objective      To investigate the application of 3-D microporous small intestinal submucosa (SIS) in bladder regeneration of a rabbit model.       Methods      3-D microporous SIS was made with physical and chemical method. A total of 24 male New Zealand white rabbits were inflicted with partial cystoplasty and then randomly divided into 3 groups (n=8 for each group)

and respectively treated with 3 types of SIS for bladder reconstruction. They were group A repaired with treated SIS without peroxyacetic acid (PAA)

group B with PAA treated SIS

and group C with PAA treated SIS and then with 100% fetal bovine serum infiltration. The bladder capacity was measured preoperatively and in 4 weeks postoperatively. Then the rabbits were sacrificed for gross observation and histological examination of bladder in order to evaluate the bladder regeneration.       Results      In 4 weeks after partial cystoplasty

the tissue adhesion with the surrounding was reduced in turn in groups A

B and C

and the stone formation rate was 33.3%

28.6% and 14.31% respectively. The bladder capacity was decreased first and then increased in turn in the 3 groups

and significant difference was seen among the 3 groups (P0.05). Histological observation revealed that urothelial cells were well regenerated in the 3 groups

with those of the groups B and C better than those of group A

and no difference was seen between the marginal zone and the central zone. However

smooth muscle regeneration was not ideal in the 3 groups

but those in the marginal zone were better than the cells in the central zone with significant difference in the groups (P0.05). The regeneration area of blood vessels were increased in groups A

B and C in turn

and there was statistically significance in the groups (P0.05).       Conclusion      3-D microporous SIS treated with PAA and fetal bovine serum has ability of promoting the bladder tissue regeneration

and can be regarded as an ideal alternative to repair materials.