Ischemic preconditioning improves stability of intestinal anastomoses in rats

Background  The aim of our study was to establish whether ischemic preconditioning (IPC) directly before performing a small bowel anastomosis has an effect on anastomotic stability and healing. Material and methods  Forty male Wistar rats were randomized to five groups: control (CO, n = 8) with preparation of the superior mesenteric artery (SMA) but without IPC. IPC groups had different intervals of ischemia (occlusion of the SMA) and reperfusion: 10 min ischemia and 20 min reperfusion (IPC10/20, n = 7), 10 min ischemia and 30 min reperfusion (IPC10/30, n = 8), 15 min ischemia and 20 min reperfusion (IPC15/20, n = 8), and 15 min ischemia and 30 min reperfusion (IPC15/30, n = 9). On the fourth postoperative day, the animals were relaparotomized: bursting pressure, hydroxyproline concentration, and histological ischemia mucosal injury scale of the anastomosis were assessed. Results  Four days after operation, the mean bursting pressure was 73 ± 6 mmHg in the control group, whereas it was significantly higher in IPC10/20 (113 ± 11 mmHg; p = 0.018), IPC10/30 (110 ± 13 mmHg; p = 0.001), and IPC15/30 (124 ± 9 mmHg; p = 0.003). IPC15/20 did not show a significant difference (63 ± 2 mmHg; p = 0.4). We did not find a significant effect regarding hydroxyproline concentration, but IPC diminished mucosal injury. Conclusions  IPC directly before performing a small bowel anastomosis has a time-dependent beneficial effect on anastomotic stability, thus indicating a new clinical approach to improve the healing process of intestinal anastomosis.