Tissue-Engineered Tubular Substitutions for Urinary Diversion in a Preclinical Rabbit Model

Qianliang WangQingling Liu^*

• Affiliated Hospital of Guangdong Medical University, Zhanjiang, China

Clinically, autologous ileal segments remain the traditional standard for urinary diversion following cystectomy. However, this approach is frequently associated with significant complications. Tissue engineering offers a promising alternative strategy. This study aimed to develop and evaluate tissue-engineered tubular constructs for urinary diversion in a rabbit model, utilizing homologous adipose-derived stem cells (ASCs), smooth muscle cells (SMCs), and a decellularized fish swim bladder (DFSB) matrix.Rabbit ASCs and SMCs were isolated and expanded in vitro. These cultured cells were subsequently seeded onto opposite sides of the decellularized FSB scaffold and incubated for seven days. The resulting cell-seeded matrices were then shaped into tubular constructs. To promote vascularization, these constructs were implanted within the omental pouch in vivo for two weeks prior to urinary diversion surgery.In the experimental group (n=24), the bladder was completely resected and replaced with the pre-vascularized, tissue-engineered tubular construct for urinary diversion. The control group (n=6) underwent an identical procedure using tubular substitutes made solely from the unseeded DFSB matrix (without cells).Constructs were explanted for histological examination at postoperative weeks 2, 4, 8, and 16. Intravenous urography (IVU) was additionally performed at the 16-week endpoint.All rabbits in the experimental group survived until their scheduled sacrifice. Histological analysis revealed well-organized tissue structures: a multilayer urothelium lined the luminal surface, smooth muscle tissue developed on the abluminal side, and neovascularization of varying diameters was evident throughout the constructs. IVU confirmed the absence of urinary leakage, stricture, or obstruction.In stark contrast, all control group animals died within two weeks post-operation. Autopsy findings implicated urine leakage, extensive scar formation, and severe inflammation as the cause of mortality.This study demonstrates the feasibility of utilizing tissue-engineered tubular constructs-fabricated from homologous ASCs, SMCs, and a DFSB scaffold-as a viable alternative for urinary diversion in a rabbit model.