Use of methylene blue and N,O-carboxymethylchitosan to prevent postoperative adhesions in a rat uterine horn model.

OBJECTIVES: To compare the anti-adhesion potential of 1% methylene blue (MB) solution and 2% N,O-carboxymethylchitosan (NOCC) gel in a rat uterine horn model. DESIGN: Experimental animal study. SETTING: University medical center. ANIMAL(S): Forty female Wistar albino rats randomized into four groups. INTERVENTION(S): We examined the effects of 1% MB solution and 2% NOCC gel to reduce the extent and severity of postoperative adhesions in a rat uterine horn model: no adjuvant therapy in control group, 2 mL of normal saline (NS) solution in NS group, 2 mL of 1% MB solution in MB group, and 2 mL of 2% NOCC gel in NOCC group was instilled onto uterine horns of the rats. MAIN OUTCOME MEASURE(S): Adhesions were scored according to their extent and severity. RESULT(S): The extent and severity scores of adhesions in MB and NOCC groups were significantly lower than those of control and NS groups. There was no statistically significant difference between the extent and severity scores of adhesions between MB and NOCC groups. CONCLUSION(S): These findings suggest that MB and 2% NOCC gel should be considered as an adjuvant in the prevention of postoperative intra-abdominal adhesions. Future experimental and clinical studies are required to find their optimal formulation and usage.

Reduction of postoperative adhesions by N,O-carboxymethylchitosan and spermine NONOate in rats.

BACKGROUND: Postsurgical adhesions can occur following virtually all types of surgery, resulting in serious clinical complications. Therefore, prevention of adhesions is an important goal of surgical practice. A rat uterine horn model was used to investigate the efficacy of N,O-carboxymethylchitosan (NOCC) and spermine NONOate (SPER/NO) alone and in combination in preventing adhesion formation. METHODS: Sixty Wistar albino rats underwent bilateral uterine horn injury with a unipolar cautery. Study groups were as follows: (i) control group, no adjuvant therapy; and those with adjuvant applied, (ii) normal saline group, 2 ml of normal saline was given; (iii) NOCC group, 2 ml of 2% NOCC gel was given; (iv) SPER/NO group, 2 ml of SPER/NO (0.5 mg/ml) was given, and (v) NOCC plus SPER/NO group, 2 ml of 2% NOCC gel including SPER/NO (0.5 mg/ml) was given. After 14 days, all animals were euthanatized, and a standard adhesion scoring system including extent and severity scores was applied by a blinded examiner. RESULTS: The extent score in NOCC plus SPER/NO group was significantly lower than those of control and normal saline groups (p < 0.05). The extent score in NOCC group was significantly lower than that of normal saline group (p < 0.05). The extent score in NOCC plus SPER/NO group was significantly lower than that of SPER/NO group (p < 0.05). The severity score was significantly lower in NOCC plus SPER/NO and NOCC groups than that of control group (p < 0.05). The severity score was significantly lower in NOCC plus SPER/NO group than that of SPER/NO group (p < 0.05). CONCLUSIONS: Postoperative administration of NOCC gel and SPER/NO alone and especially in combination to the site of peritoneal injury reduces the formation of adhesions in the rat uterine horn model.