A novel innovation using modified platelet-rich plasma (mPRP) for preventing urethral stricture recurrence in a rabbit model

Abstract

Abstract Urethroplasty is the gold standard for urethral stricture but is limited by technical complexity and surgeon expertise. Thus, urethrotomy and dilatation remain common despite high recurrence rates (40–60%) from fibrosis. Platelet-rich plasma (PRP), a regenerative therapy, promotes tissue healing but contains transforming growth factor-β1 (TGF-β1), which may worsen fibrosis. To overcome this, a modified PRP (mPRP) was developed by neutralizing TGF-β1, aiming to enhance healing while reducing fibrosis and recurrence in urethral stricture management. An experimental study was conducted using New Zealand White rabbits (Oryctolagus cuniculus). A urethral stricture model was induced through surgical urethral injury followed by TGF-β injection. Animals were treated with either standard PRP or mPRP. Outcomes were assessed through immunohistochemistry (IHC) and retrograde urethrography. Collagen thickness decreased in the PRP group (16.2 ± 2.4 µm; p < 0.05) and further in the mPRP group (11.38 ± 1.46 µm; p < 0.05). IHC revealed lower collagen type III levels in the mPRP group (3.0 ± 1.0) compared with PRP (6.8 ± 0.83), yielding a higher collagen I:III ratio (1:2.6 vs. 1:1.36). Urethrography demonstrated a wider lumen (2.72 ± 0.14 mm) and shorter stricture length (0.60 ± 0.63 cm) in the mPRP group compared to PRP (2.41 ± 0.10 mm and 2.48 ± 0.16 cm; p < 0.05). mPRP effectively reduces fibrosis and inhibits stricture recurrence, as evidenced by decreased collagen expression and improved urethral lumen dimensions, supporting its potential as an adjunctive therapy for urethral stricture management.