Astragalus polysaccharide reduces the incidence of postoperative urethral fistula in the rabbit model of hypospadias

Background: Hypospadias is a common congenital malformation in pediatric urology. Surgery is the only treatment option for hypospadias, and urinary fistula is the most common complication after hypospadias repair. Purpose The purpose of this study was to establish a model of surgical hypospadias in New Zealand rabbits followed by TIP urethroplasty, postoperative administration of Astragalus polysaccharides (APS), and to study the effect and mechanism of APS on the prevention and treatment of urinary fistula after surgery. Material and Methods New Zealand male rabbits were randomly divided into 5 groups: Control group, was fed normal feed without surgery; The operation group, TIP was performed after the establishment of a surgical hypospadias model, and normal feed feeding was given after surgery. In the intervention groups, after the establishment of the surgical hypospadias model, TIP was performed, and the low dose of APS (100mg/kg), the medium dose (200mg/kg), and the high dose (300mg/kg) were mixed into feed feeding, and the urinary fistula rate was statistically calculated after 10 consecutive days of feeding. Results The incidence of urinary fistula was significantly lower than that in the surgical group after the addition of APS, and with the increase of the intervention dose of APS, the incidence of urinary fistula showed a decreasing trend. After removing penile tissue, HE examination and WB analysis were performed, compared with the control group, the urethral epithelial cells at the incision site of the operation group were loosely arranged, the layers were reduced, and the inflammatory cells were significantly increased. Compared with the operation group, the urethral epithelial cells at the incision site of the APS intervention group were closely arranged, the layers increased, the inflammatory cells were significantly reduced, and the number of new capillaries increased. In addition, compared with the operation group, the expression levels of TNF-a and NF-kb2 proteins in the intervention group were significantly reduced, and the levels of TGF-β1 and FGF-1 were significantly increased. Conclusion The intervention of APS can reduce local inflammatory response, enhance local fibrosis, and reduce the incidence of urinary fistula after hypospadias.