Bovine tunica vaginalis: a new material for umbilical hernioplasty in sheep

In this study, fresh patches of bovine tunica vaginalis (BTV), was used as implants for the repair of experimentally-created umbilical hernias in eight sheep. The scrotum were harvested immediately after slaughter and thoroughly washed with sterile distilled water for 5-7 times. The scrotal skin together with the fatty tissues and the loose connective tissues and the tunica adventitia were mechanically stripped by means of a sterile surgical knife, and finally washed with sterile physiological saline solution for 5-7 times. The prepared patches were immersed in the sterile saline solution and preserved at 2-4 oC in sterile jars, ready for use within 4 hrs from their harvesting for hernioplasty of sheep umbilical hernias. The eight implanted grafts were examined clinically and histologically, and all were successfully healed except one (87.5%). Clinically, the successfully implanted BTV patches didn't show signs of rejection, except for the presence of cardinal signs of local inflammatory reaction which were subsided 48 hrs post-operation, and disappeared within 4-5 days post-operation. The healing processes showed no significant abnormalities, except for the occurrence of a few simple multifocal stitch abscess infections. The histopathological examinations showed invasion of dense fibrous connective tissues, consisted of heavy bundles of collagen fibers, through which newly formed capillaries and mononuclear inflammatory cells and melanin pigments deposition, were infiltrated through the graft. As a first report on this new tissue implant in sheep, BTV is proved to be a suitable biocompatible heterogenic surgical patch for reconstruction of umbilical hernias, because of its availability as a cheap tissue, with a high tensile strength and flexibility. However, further investigation is required regarding preservation efficiency and employment for reconstruction of soft tissue defects in man and animals.