Effects of tamoxifen citrate on postoperative intra-abdominal adhesion in a rat model.

Background/aims: The aim of this study was to evaluate the effects of oral tamoxifen citrate on postoperative intra-abdominal adhesions.

Materials And Methods: Forty five rats were randomly separated in to 3 groups. Group 1: Control group (15 rats), Group 2: tmx 1 group (15 rats) and Group 3: tmx 10 group (15 rats). The cecum was abraded with a sterile gauze until subserosal hemorrhage had developed. Full- thickness 4-0 silk sutures were also placed in the traumatized anterior cecal wall to increase the adhesive reaction. In Group 1 (control group), adhesion induction was performed and no treatment was given. In Group 2 (tmx 1 group), after adhesion induction, 1 mg/kg/day tamoxifen citrate was given by orogastric gavage. In Group 3 (tmx 10 group), adhesion induction was performed and 10 mg/kg/day tamoxifen citrate was given by orogastric gavage. Rats were sacrificed on postoperative day 30. At the time of second surgery, after the abdominal fascia had been opened blood samples were collected to evaluate serum TGFβ-1 levels and following the macroscopic adhesion scoring, tissue specimens of the bowel and adhesions were subjected to histopathological investigation.

Results: In group 1 and group 2 we detected higher scores for the macroscopic classification (2.25 ± 1.13 vs. 1.53 ± 0.77) and histopathological scores (2.72 ± 0.64 vs. 2.53 ± 0.87) for fibrosis and serum TGFβ-1 levels (42000 ± 2935 vs. 32988 ± 10804). In group 3 we have detected decreased scores for macroscopic classification (0.91 ± 0.51) and histopathological scores (1.58 ± 0.90) for fibrosis and serum TGFβ-1 levels (22847 ± 4976). There were no significant differences between group 1 and group 2 according to the macroscopic classification and pathological scores for fibrosis. There were statistically significant difference between tamoxifen 10 mg/kg group and the other groups according to macroscopic classification ( P: G1-3: 0.004; G2-3: 0.046), pathological scores for fibrosis (P: G1-3: 0.004; G2-3: 0.011) and serum TGFβ-1 levels (P: G1-3:<0.001).

Conclusions: In conclusion tamoxifen citrate seems to be useful for preventing postoperative intra-abdominal adhesions. Its effects are in a dose and time dependent manner. Further studies must be carried out to use tamoxifen for preventing intra-abdominal postoperative adhesions in clinical practice.