Healing of experimental defects on the stomach: influence of autologous and heterologous materials.

This study was undertaken to evaluate the influence of various autologous and heterologous structures on gastric defect healing. In 210 rats, standard gastric defects were closed using the following structures as patches: (1) pedicled colonic patches, (a) mucosal layer to lumen, and (b) peritoneal surface to lumen; (2) leiomuscular colonic buttons; and (3) lyophilized bovine tendon collagen sponges. The specimens were removed from the defect areas at standard time intervals ranging from 2 to 12 months after surgery; the samples were then examined by light microscopy (hematoxylin-eosin; Azan Mallory; Grimelius methods) and by transmission and scanning electronmicroscopy. The colonic mucosa appeared to be the most resistant of the structures to gastric secretions; it showed no mucosal disruption during the entire period of observation and also underwent a progressive gastric-like morphological transformation. In all the other cases, the healing process involved the initial development of granulation tissue followed by scar tissue with gastric mucosa growing over the scar tissue to fill the defects.