Reconstruction of penile urethra with the 3-dimensional porous bladder acellular matrix in a rabbit model

To evaluate the effect of reconstruction of penile urethra with the 3-dimensional (3-D) porous bladder acellular matrix (BAM) in a rabbit model.

In 30 male rabbits, a ventral urethral mucosal defect (1.5 × 0.8 cm) was created. Substitution urethroplasty was performed with 5% peracetic acid (PAA)-treated BAM (3-D porous BAM; 15 rabbits, PAA-treated BAM group) and non-PAA-treated BAM (15 rabbits; non-PAA-treated BAM group) in an onlay fashion. At 1, 2, and 3 months after surgery (5 rabbits at each time point) in the 2 groups, retrograde urethrogram and histologic analysis were performed to evaluate the outcomes of urethroplasty.

In the PAA-treated BAM group, 13 rabbits maintained a wide urethral caliber without a fistula or stricture. In contrast, 10 rabbits kept a wide caliber in the non-PAA-treated BAM group. Histologically, at 1, 2, and 3 months after the surgery, the speed of urothelium regeneration in the PAA-treated BAM group was faster than that in the non-PAA-treated BAM group. The smooth muscle-to-collagen ratio and the content of smooth muscle in the PAA-treated BAM group were significantly higher than that in the non-PAA-treated BAM group at each time point (P <.05). The endothelium density between the non-PAA-treated BAM and the PAA-treated BAM groups revealed a significant increase at all 3 time points (P <.05).

Our results confirmed that PAA-treated BAM urethroplasty enhanced urothelium, smooth muscle regeneration and neovascularization compared with those of the non-PAA-treated BAM. The 3-D porous BAM as an optimized biological scaffold may be used for cell-based tubular and long-segmental urethral reconstruction in the future.