Histopathological evaluation of suture materials and tissue adhesives for the repair of goat urethra

Fifteen healthy male goats of 6–9 months of age were used to compare the efficacy of two suture materials and two tissue adhesives in the repair of urethral incision. Post-scrotal urethrotomy was performed in all the animals under lumbosacral epidural analgesia to create a 2 cm long urethral incision. The goats were randomly divided in 5 groups of three animals each depending upon the suture material(s) and tissue adhesive used for closing the wound viz. polyglycolic acid suture (group I), silk suture (group II), cyanoacrylate glue (group III), fibrin glue (group IV) and a combination of polyglycolic acid suture and cyanoacrylate glue (group V). Animals of all the groups were sacrificed on 30ᵗʰ postoperative day and urethral samples were collected from the site of surgery to evaluate the healing by histopathological examination. Histopatholigical findings in group I were suggestive of complete healing as evidenced by the presence of fibroblasts with collagen phenotype. In group II almost complete healing was seen in 1 case, however, detachments, necrosis, roughening and thinning of the mucosa near the suture site was seen in two cases together with mild to moderate infiltration of mononuclear cells in the erectile tissue and tunica albugenia. In group III, the incision through serosa to mucosa in penile urethra indicated good amount of healing tissue with little neutrophils and mononuclear cell infiltration in propria and albugenia connective tissue. However, penile urethral lining was intact. In group IV, no healing reaction was noticed. However, the connective tissue around the incision site showed mild infiltration of cells. In combination group healing tissue was more as compared with cyanoacrylate alone, but it contained more number of inflammatory cells and necrotic debris in the tunica albugenia. It was concluded that polyglycolic acid induced better healing than the silk. Cyanoacrylate glue also induced good healing, which was comparable to that induced by polyglycolic acid. Cyanoacrylate glue may be recommended for easy and complication free repair of urethra in goats.