Trace element levels in ischemia-reperfusion injury after left colonic anastomosis in rats and effects of papaverine and pentoxiphylline on vascular endothelial growth factor in anastomosis healing.

BACKGROUND AND STUDY AIMS

Due to their high morbidity and mortality, anastomotic leakage and disruption are still serious problems in colonic surgery. Bowel clamps applied during anastomosis in order to prevent abdominal contamination with colonic contents, may cause microcirculation and perfusion problems and subsequent ischemia-reperfusion injury. Papaverine, a myorelaxant and vasodilatator, and pentoxiphylline, a hemorrheologic agent are used for microcirculation disorders and vascular endothelial growth factor (VEGF) is a stimulator of angiogenesis. With this experimental study, we aimed to measure trace element [copper (Cu) and zinc (Zn)] levels in ischemia-reperfusion injury due to clamps after left colonic anastomosis in rats and show the effects of papaverine and pentoxiphylline on VEGF that stimulates angiogenesis in anastomotic healing.

MATERIALS AND METHODS

50 female Wistar albino rats were randomized in 5 groups (n: 10). Laparotomy in group 1, left colonic transsection and anastomosis in group 2, and clamp application 1 cm proximal and distal to the anastomosis (for about 20 minutes long) during left colonic transsection and anastomosis in groups 3, 4 and 5 were performed. Additionally, after the operations, pentoxiphylline (Group 4) and papaverin (Group 5) were injected intraperitoneally. On the 10th postoperative day, plasma trace element and plasma VEGF levels were measured.

RESULTS

In this study, VEGF levels in group 1 were significantly low and this was explained as being exposed to hypoxic damage less than the other groups. In group 3, VEGF levels were significantly higher showing that the hypoxic stimulus continued without any treatment and in Group 4, significantly lower than Group 3 related to the inhibition of pentoxiphylline. Lower VEGF levels in Group 1 were thought to be related to lower VEGF induction due to less hypoxic effect. Zinc, an important trace element of the antioxidant system showed significantly higher levels in Group 4 with pentoxiphylline treatment, and this was thought to be related to the antioxidant characteristics of pentoxiphylline.

CONCLUSIONS

During surgical procedures, care should be taken not to cause ischemia to the intestinal tissues, and trace elements that are important in ischemia reperfusion injury should be replaced appropriately. Although the antioxidant effect of pentoxiphylline in ischemia reperfusion injury may be benefical in treatment, its inhibition of VEGF is a disadvantage in wound healing.