The maximum traction force value that the tissue endured before rupture was measured in Newtons. A sample of the anastomotic scar was collected for histopathological analysis, fixed in formalin and stained by hematoxylin and eosin. The amount of collagen, fibroblast, mononuclear and polymorphonuclear infiltrations and neovascularization XAV-939 in vivo were marked with values 0, 1, 2 or 3 each, in which 0 means nothing and 3 a large amount. The parameters of abscess, bacterial colony, foreign body, crust and fibrin were signalized as 0 or 1, meaning absent or present, respectively. The results were analyzed using SPSS software (Special Package for Social Sciences) version 18.0. Parametric and nonparametric tests were performed,

according to the nature of the variables. The paired samples t test was used for the weight variations and Kruskal-Wallis selleck compound test for anastomotic breaking strength. The Fisher exact test was used to perform the statistical analysis of all histopathological variables. Significance was set at a value of p <0.05. Results There was an overall mortality of four deaths (11,11%). Three animals from the group AS died (16,6%), one of them in the subgroup AS1 and two in the AS7. In the S group

only an animal died, in the S3 group, a death rate of 5,5%. (Figure 3). Figure 3 Number of animals that died are in green and those that survived are in blue. There was weight loss in almost every group, from the operation day to the day of euthanize (p < 0,05), as shown in the Table 1. The average preoperative weight of all groups was 321,05 grams, and the post operative weight was 299,6 grams. Table 1 Preoperative and postoperative average weight of each group. The statistically significant differences were signaled. Weight per group   Preoperative Postoperative P AS1 320,2 309,7 <0,05* AS3 326,0 291,3 <0,05* AS7 292,6 269,4 <0,05* S1 351,6 348,3 >0,05 S3 308,9 272,1 <0,05* S7 313,8 292,6 <0,05* The anastomotic breaking strength (ABS) was not different between groups AS and S, from the first to the third day (p > 0.05). There was no statistical

difference between groups AS1 and S1, AS3 and S3 or AS7 and S7 (p > 0.05), Figure 4 and Table 2. Figure 4 Anastomotic breaking strength distribution in Newtons: superior and inferior limits, interquartils interval TCL and the median in the central part of the boxes. All groups have been displayed. Table 2 Minimum, Maximum, median, mean and standard deviation for the colonic anastomosis breaking strength at each group and subgroups. Values measured in Newtons. Anastomosis Breaking Strength   AS1 S1 AS3 S3 AS7 S7 n (survived) 5 6 6 5 4 6 Minimum 0,03 0,15 0,09 0,07 0,31 0,25 Maximum 0,37 0,41 0,31 0,29 0,49 0,52 Median 0,23 0,22 0,14 0,19 0,31 0,42 Mean 0,20 0,24 0,17 0,18 0,35 0,40 Std. Deviation 0,14 0,09 0,08 0,08 0,09 0,09 There was no difference between the groups AS1, AS3 and AS7 (p > 0,05). The S7 group had a higher anastomotic breaking strength than S1 and S3 (p < 0,05).