Advanced age alone does not suppress anastomotic healing in the intestine

Abstract

Because retrospective clinical studies yield conflicting results and experimental data are completely absent, this study was performed to determine whether anastomotic repair in the intestine deteriorates with age. Ileal and colonic anastomoses were constructed in two groups of healthy rats, ages 2 to 3 months and 27 to 30 months, respectively. Healing was assessed, both 3 and 7 days after operation, by measuring anastomotic bursting pressure, breaking strength, and collagen content, the latter both biochemically (hydroxyproline) and morphometrically. In addition, the ex vivo collagen synthetic capacities were compared. The development of anastomotic strength was similar in young and old rats; average strength increased from 3 to 7 days and was never lower in the older animals. This was true for both bursting pressure and breaking strength. The collagen production capacity was suppressed in the old rats, particularly in the ileum (p < 0.05), whereas the synthesis of noncollagenous protein remained unaltered. However, this did not result in a reduced accumulation of collagen in the anastomotic area--both anastomotic hydroxyproline content and the volume percentage of collagen in the actual wound area were unchanged. Advanced age per se does not affect development of strength or deposition of collagen during early repair of intestinal anastomoses.