Different bladder defects reconstructed with bladder acellular matrix grafts in a rabbit model

Objective. To evaluate the potential use of the bladder acellular matrix graft (BAMG), two different bladder defects in the rabbit model were reconstructed. Materials and methods. Two groups of rabbits underwent partial bladder wall cystectomy (group A, 30-40%; group B, 70-60%) and reconstruction of the defects with an equally sized BAMG. After 4, 12, and 24 weeks, bladder cystographs were performed. Then the rabbits were killed after uneventful postoperative periods, and the grafts were harvested for H&E staining and immunohistochemical staining. Results. Two rabbits died on the postoperative days 3 and 6 in group A due to urinary peritonitis. At 24 weeks, in group A, the reconstructed bladders reached a mean volume of 94.39 +/- 0.54% of the precystectomy bladder capacity. Histologically, complete regeneration of smooth muscle and urothelium tissue was evident. Regenerated SMCs and urothelium stained positive for alpha-smooth muscle actin and AE1/AE3. In group B, the mean bladder volume was 64.5 +/- 3.19% of the precystectomy volume. Histologically, group B was characterized by multilayered urothelium without organized muscle tissue. Conclusion. The BAMG was an effective scaffold for bladder wall regeneration in the rabbit model. However, the use of BAMG reconstruction in larger bladder defects did not induce the same quality and quantity of bladder regeneration as the reconstruction of smaller bladder defects.