Morphological response of the peritoneum and spleen to intraperitoneal biomaterials.

The present study was performed to evaluate the morphological response of the peritoneum and spleen to biomaterials. Silicone elastomer, knitted dacron or rubber was implanted, respectively, into a rat's peritoneal cavity and the morphology of the peritoneum and spleen was studied at 4 hours and on the 1st, 4th, 7th and 21st day after surgery. The morphological changes were identical among groups with different implanted materials. After intraperitoneal implantation of biomaterials from 4 hours and on, an infiltration of inflammatory cells was found in the slackened edematous superficial part of the peritoneum. Also noted in the spleen were stasis, vessel dilatation and fibrin deposition. With the help of scanning electron microscopy, a marked denudation and separation of the mesothelial cells, with infiltration of inflammatory cells, were observed. Peripheral leucocytes significantly increased in number one day after intraperitoneal implantation. Three weeks after intraperitoneal implantation, the materials were completely encapsulated and the morphological aberration of the peritoneum and spleen disappeared. The findings reveal the consequence and the resolution of the host-biomaterial interaction, which could contribute to the explanation of various pathophysiological alterations, including the translocation of enteric bacteria and the development of infectious complications after intraperitoneal biomaterial implantation.