Effect of aging on the healing of colonic anastomoses in rats

Abstract

PURPOSE: To evaluate the healing of the colonic anastomoses in old and young adult rats. METHODS: Fifty six Wistar rats were allocated in two groups, the young animals aged on average 110 days and the old animals aged average 762 days. Under anesthesia, the rats underwent a midline laparotomy and the colon was sectioned 2 cm above the peritoneal deflection. An end-to-end interrupted one layer colonic anastomosis was performed and the animals sacrificed on the 3rd, 7th, 14th and 21st postoperative days. A 4 cm segment of colon containing the anastomosis was submitted to bursting pressure tests. The paraffin-embedded tissue blocs were sectioned and stained with haematoxylin and eosin and Sirius Red. Histochemical methods such as PCNA, LCA and CD34 were also used. RESULTS: The colonic anastomosis resistance was greater in the old rats group on the 3rd postoperative day (p=0,0000). Collagen concentration was higher in the anastomosis of the young animals on the 14th and 21st postoperative days (p=0,0475, p=0,0346 respectively), with a significantly greater concentration of collagen type I. The concentration of collagen type III, the epithelial lining rate and the angiogenesis were similar in the study groups. CONCLUSION: Despite some differences between the two groups regarding the healing process and considering that failures in the colonic anastomosis wound healing could not be demonstrated, we can concluded that aging itself does not interfere in the wound healing process.

Influence of arterial hypertension on colonic healing in rats

“…Despite the lower concentration of collagen, the aging did not increase the risk of left colon anastomoses in Wistar rats 12,16 , nevertheless, still turned away from the influence of aging on the anastomosis studied, opting for the young animals.…”

“…Anastomosis is the site which has smaller radius, so it has a higher resistance to the intestinal wall 27 . Biondo-Simões et al 12 evaluated the healing of colonic Wistar rats with a mean age of 110 days and 762 days. Bowel suture held an inch from the peritoneal reflection and observed that the rupture occurred at the anastomosis on the third day after surgery.…”

“…Anastomosis pressure resistance was measured by the inflation of 0.5 l/min of oxygen 12 . It was considered as resistance to inflation, the pressure recorded at the time of exhaust gas by the anastomosis or the intestinal wall.…”

Jaundice in second intention wound healing in rats

“…In a recent study carried out in our laboratory, we observed a lower concentration of total collagen and collagen fractions I and III in jaundiced animals during the initial phases of skin healing up to day 7. During the later phases, total collagen and collagen I concentrations continued to be lower in jaundiced animals, demonstrating a delay in collagen synthesis and maturation 12 .…”

Effects of hyperglycemia and aging in angiogenesis and reepithelization of colonic anastomoses in rats

“…Old age has also been described as a hindering factor in the healing process. As for the gastrointestinal tract, studies show that anastomosis strength is preserved, while collagen deposition, migration of inflammatory cells, and reepithelization are changed [6][7][8] . This study aims to analyse reepithelization and angiogenesis of colonic anastomoses in young and old normoglycemic rats comparing them to old chronically hyperglycemic rats.…”