Effect of Platelet-Rich Plasma (PRP) Gel on a Qualified Healing of Urethra Damage: an Animal Experiment

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Relevance and Purpose Platelet-Rich Plasma is a kind of blood products, which is prepared from whole blood by high speed centrifugation [1]. As an excellent source of platelet and cytokines [2], it contributes to cell proliferation, differentiation and tissue repair. Currently, PRP has been applied in many a clinical treatment[3][4], but rarely in urinary system diseases’. Surgery intervention is a valid therapy for urethra damage. However, urethrostenosis and urethral fistula may occur postoperatively. Aiming at a qualified healing and a reducing of the incidence of complications, we investigate the effect of PRP on the healing of urethra damage. Material and Methods 24 male New Zealand white rabbits, weighting 3800-4200g, were purchased from the Experimental Animal Center of Harbin Medical University. Randomly, they were divided into 4 groups. The groups were named Group A, Group B, Group C and Group D. 6 rabbits in each one were fed for 1 week, 2 weeks, 4 weeks and 8 weeks respectively after operation. Self-prepared PRP gels were applied to 3 rabbits among each group. Meanwhile, the remaining 3 were set as a control. 5 ml whole blood was taken from median auricular artery of each 12 experimental group rabbits. A “Secondary Centrifugation” method and Hemocoagulase Atrox for injection were used to prepare the PRP gels. Each rabbit was anesthetized with 3% Sodium Pentobarbital solution satisfactorily. Then, urethra damage was modeled after skin preparation, disinfection and draping. Self-prepared PRP gel was daubed on the surface of sutured urethra. As a contrast, the rabbits of control group were sutured directly without application of anything. After the operations, the rabbits were raised with free drinking, feeding and cage activity as the 4 time periods mentioned above. After 1 week, the 6 rabbits from the first group (Group A) were euthanized. Records of the Incision Healing Grade and complications were taken for gross observation. Moreover, the urethral tissues were sampled to be stained with HE and Masson dye for histological observation. The other 3 groups (Group B, Group C and Group D) were processed as uniformly. Results Gross observation In Group A, the Incision Healing Grades of all the 3 rabbits treated with PRP gels were Class B. However, no infection and urethral fistula occurred. The Incision Healing Grades of all the other 3 rabbits whose incisions were sutured directly were Class C. The incidence of infection and urethral fistula was 100%. Except 1 rabbit applied with PRP gel in Group B, all the 17 rabbits’ urethral incisions healed at a Class A level without the occurence of complications. Histological observation: Neovascularization was evident in the tissues from Group A. It is obvious that tissue repair with PRP gel was better than that of control one in all the 4 groups. Compared with normal tissues, the amount of collagen fibers of all the 24 experimental rabbits undergone operations increased. Though, the collagen fibers in the tissues treated with PRP gels were more regular and the sum was less than the ones without the application of PRP gels. Conclusions A qualified healing was observed after the application of PRP. It promotes tissue healing and shortens healing time. Furthermore, PRP regulates the production of collagen fibers during tissue repair and alleviates scar formation histologically. Consequently, PRP may have clinical application prospects in the treatment of urethra damage.