Simultaneous implantation of bilateral ureters into bladder acellular matrix graft after partial cystectomy in a porcine model

Abstract

What's known on the subject? and What does the study add? The process of bladder regeneration with a bladder acellular matrix graft (BAMG) is thought to be accelerated by administration of vascular endothelial growth factor into the host bladder. In the present study, we showed that simultaneous implantation of bilateral ureters into a BAMG after a partial cystectomy is reasonable and provides an increased opportunity to the bio-scaffold for communication with host tissues from which a blood supply and stem cells will be generated.

Objective: • To evaluate if the implantation of bilateral ureters into a bladder acellular matrix graft (BAMG) at the time of its implantation would enhance bladder regeneration in a partial substitution BAMG.

Materials and methods: • Partial cystectomies were performed under general anaesthesia in 12 pigs, followed by augmentation with a BAMG. • Six (ureteric implantation group) also received simultaneous implantation of bilateral ureters into the BAMG, while the remaining six (control group) did not have ureteric implantation. • In both groups, bladder regeneration was evaluated using endoscopic and histopathological methods at 1, 2, 4, and 8 weeks after implantation.

Results: • At 1 week after BAMG implantation, there were significant inflammatory changes on the host bladder in both groups, while no significant endoscopic changes were seen on the BAMG luminal surfaces. • At 2 weeks, inflammatory changes were diminished and epithelialisation on the BMAG was identified, especially near the host bladder in both groups. • Similarly, epithelialisation on the BAMG near the implanted ureters was seen in the ureteric implantation group. • At 4 and 8 weeks, epithelialisation remained in progress in both groups, although it was more active and expansive in the ureteric implantation group.

Conclusions: • In our porcine model, endoscopic and histopathological examinations showed that simultaneous implantation of bilateral ureters into a BAMG enhanced epithelialisation of the AMG. • This new approach using host ureters and bladder as a potential source of bladder regeneration may provide for rapid and complete regeneration of a bladder substitute.