The influence of inguinal mesh repair on the spermatic cord: a pilot study in the rabbit

The permanent implantation of a polypropylene mesh during inguinal hernia repair causes chronic inflammatory changes in the surrounding tissue. We investigated the effect of this foreign body reaction on the structures of the spermatic cord in the rabbit. Eight Chinchilla rabbits underwent unilateral inguinal hernia repair by the Lichtenstein technique using Marlex (n = 4) or Ultrapro (n = 4) mesh. The contralateral side was operated upon using the Shouldice repair. Three animals served as controls. Three months after operation we analyzed testicular size, testicular temperature, and arterial perfusion by excitation light of a 780-nm laser after injection of 0.5 mg/kg indocyanin green. Histological evaluation included spermatogenesis (Johnsen score) and foreign-body reaction. Testicular volume increased about 10% after each operation. The decrease of arterial perfusion and testicular temperature was more significant after mesh repair than following Shouldice operation. After mesh implantation we found fewer seminiferous tubules classified as Johnsen 10 (Marlex: 51.3%, Ultrapro: 45.0%) than after Shouldice repair (63.8%) or in the controls (65.8%). The spermatic cord showed a typical foreign-body reaction at the interface between mesh and surrounding tissue, which was not detectable after Shouldice repair. Preserved cremasteric muscle fibers protected the structures of the spermatic cord. The inflammatory foreign-body reaction of the surrounding tissue induced by the inguinal prosthetic mesh includes the structures of the spermatic cord. This may have an influence also on spermatogenesis. Therefore, we recommend strict indications for implantation of a prosthetic mesh during inguinal hernia repair.