Prevention of Postoperative Adhesions with N, O-carboxymethyl Chitosan in Rabbit: A Large-sample Gross and Histopathological Observation

  Objective  To assess the effect of N, O-carboxymethyl chitosan (NOCC) in preventing postoperative adhesion in a rabbit model.

  Methods  Double uterine horn model was established in 220 female rabbits to induce postoperative adhesion. The rabbits were randomized to receive either adhesion-inducing operation only (control group) or adhesion-inducing operation + intraperitoneal injection of NOCC before closure (NOCC group). All the operations were performed by one operator. Twenty-two rabbits from each group were euthanized at one of the five different time points (postoperative day 3, 7, 14, 28, and 42), and adhesion formation was scored both grossly (extent, type, and tenacity) and histopathologically (inflammation, fibrosis, and vascularization).

  Results  The extent (P=0.0337) and tenacity of adhesion (P=0.0271) as well as inflammation(P < 0.0001) were lower in the NOCC group than in the control group on day 3. Fibrosis was less obvious in the NOCC group compared to the control group (P < 0.0005) before day 14. The tenacity scores of adhesion on day 14, 28, and 42 were significantly lower in the NOCC group than in the control group(all P < 0.05), while the type scores were obviously lower in the NOCC group on day 28 and 42(all P < 0.05).

  Conclusions  Treatment with NOCC could reduce both gross and histopathological scores of surgery-induced abdominopelvic adhesions in rabbits. NOCC could be an effective therapy for preventing postoperative abdominopelvic adhesion.