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

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.