The biocompatibility of titanium clips after laparoscopic appendectomy.

Background: In laparoscopic appendectomy, various methods of securing the appendix base are used. However, the use of different materials may cause inflammation, foreign body reaction and infection in the surgical field. It would be ideal to use material which cause the minimum tissue response. Methods: One hundred twenty rats were divided randomly into three groups: the first group, in which the base of the appendix was secured using an endoloop, was divided into two sub-groups: subgroup a: consisted of 30 rats in which the appendix base was secured using a Vicryl ligature, subgroup b consisted of 30 rats in which the appendix base was secured using a PDS ligature. The second group, in which the appendix base was secured with a Hem-o-lok plastic clip, consisted of 30 rats. The third group, in which the resection of the appendix was performed with a 45 mm Stapler, consisted of 30 rats. Ten animals from each group of subjects were sacrificed on days 7, 28 and 60 post-surgery for histo-pathological testing, to establish the presence and scope of reaction of the tissue to the clip, where an inflammation was semi-quantified graded as mild, moderate and severe. After opening the abdomen, the formation of adhesion was assessed according to the Surgical Membrane Study Group on Days 7, 28, and 60. Results: On day 7 after surgery, a mild mucosa inflammation was present in the Hem-o-lok group (7/10) and the Stapler group (2/10). The exact Fisher Test established that the frequency of mild and moderate inflammation was statistically significantly greater in the PDS, Hem-o-lok and Stapler groups than in the Vycril group (p= 0.01, using the Bonferroni correction, p=0.04). However, there was no statistically significant difference in the frequency of mild and moderate inflammation between the PDS, Hem-o-lok and Stapler groups (p=1 in each comparison). On day 28 and 60 there is no significant difference between studied materials. The SMSG score was statistically significantly higher on Day 7 than on Day 28 (U=466.5, p=0.0005) and Day 60 (U=154.0, p<0.0001). The PDS group had a statistically significantly lower score than the Hem-o-lok group (U=15.5, p=0.003), but it was not statistically differ ent from the score of the Stapler group (U=44.5, p=0.343). The Stapler group had a statistically lower score than the Vycril group (U=10.00, p=0.0005) and the Hem-o-lok group (U=5.9, p<0.0001). Conclusions: Considering our results, it may be said with caution that titanium clips and