The comparison of the effect of phenylephrine and epinephrine on penile spongy tissue in rats after experimental hypospadias surgery: a quantitative stereological study

BACKGROUND: Many factors including vasoconstrictor agents can interfere with wound healing process. This study aimed to compare the histopathological outcome of injection of two sympathomimetic drugs used during urologic surgery, including phenylephrine and epinephrine, on the structure of spongy tissue and urethra in a rat model of experimental hypospadias repair using stereological methods. METHODS: Male rats were allocated into three groups. The first group underwent surgery without using any agents. The second and third groups underwent surgery with diluted phenylephrine (1:5000) and diluted epinephrine (1:100000) injection in the urethral plate before operation, respectively. Quantitative histological evaluation of all penises was performed after 3 weeks. RESULTS: The results indicated no significant differences among the three groups regarding the vessels and urethral lumen and epithelium. However, the volumes of the spongy tissue and collagen bundles and the number of fibroblasts were significantly higher (35–55%) in surgery + phenylephrine and surgery + epinephrine groups in comparison to the surgery group (p < 0.05), with no preferences. CONCLUSIONS: Hypospadias repair using phenylephrine and epinephrine injection showed no adverse effects. Furthermore, they might lead to better postoperative structural outcomes without any preferences. However, further experimental and human studies are required to draw a firm conclusion.