Effects of intraperitoneal nitroglycerin on the strength and healing attitude of anastomosis of rat intestines with ischemia–reperfusion injury

Abstract

Background: Ischemic conditions in the intestine result in deterioration of anastomosis healing process. In this study, our aim was to evaluate the possible effects of intraperitoneal nitroglycerin on the intestinal anastomosis healing and anastomosis burst pressures in rats with ischemia and reperfusion injury (I/R). Materials and Methods: Fifty four Wistar albino rats were divided into six groups. In the first two groups, the rats underwent I/R. In the Group 1, the rats had normal saline (S) and in Group 2, the rats had nitroglycerin (N) injection. In the 3rd and 4th groups, an intestinal anastomosis was made at the 10 cm proximally to the ileocecal valve. In Group 3, S and in Group 4, N were injected. In Group 5, the rats received I/R, intestinal anastomosis and intraperitoneal S injection. I/R, intestinal anastomosis and intraperitoneal N injection were made in Group 6 rats. All nitroglycerin (50 μg/kg) injections were made at postoperative days of 0, 1, 2, 3, 4, 5 consecutively. On the sixth day, all rats were killed. In all rats with anastomosis, anastomotic burst pressure (ABP) was measured. Histopathological specimens were collected from all rats and evaluated under light microscopy. Results: Serious tissue damage was only detected in the Group 1 histopathologically (8 rats had grade 4 damage). In Group 2, there was a decrease in tissue damage according to histopathologic examination (5 rats had grade 1 damage). The effect onto the healing was similar in S and N groups. Nitroglycerin was noted to have a positive effect on collagen production. Nitroglycerin increased the ABP levels in rats both with and without I/R (the means are 17.93, 21.10, 14.67, and 17.63 in Groups 3, 4, 5, and 6, respectively). Conclusion: I/R may weaken the strength of intestinal anastomosis. Intraperitoneal application of nitroglycerin may prevent the histopathologic changes within a limited degree. Intraperitoneal nitroglycerin has also positive effects on the healing of intestinal anastomosis of rats with and without I/R. It may increase the fibroblast proliferation and the strength of the anastomosis.

Key words: Anastomotic burst pressure, intraperitoneal nitroglycerin, ischemia–reperfusion