PREVENTION OF POSTSURGICAL ADHESIONS WITH N,O-CARBOXYMETHYL CHITOSAN - EXAMINATION OF THE MOST EFFICACIOUS PREPARATION AND THE EFFECT OF N,O-CARBOXYMETHYL CHITOSAN ON POSTSURGICAL HEALING

Background. Adhesion formation after operation can result in major com plications. We have previously demonstrated that N,O-carboxymethyl chi tosan (NOCC) is an effective inhibitor of postsurgical peritoneal adhe sion formation. However, the optimal form of NOCC (i.e., cross-linked gel versus solution), as well as the best time of administration for o ptimal reduction in adhesion development, was not investigated. In add ition, because adhesion formation and normal wound healing are related events and weakening of wound healing would be a serious drawback to the use of NOCC clinically, we wished to assess the effect of NOCC on the healing of surgical incisions. Methods. Three surgical models were used: (1) an abdominal aortic anastomosis, (2) a large bowel anastomo sis, and (3) an abdominal skin incision. In the first model Sprague-Da wley rats received an abdominal aortic transection and repair NOCC sol ution or gel was administered at different time points throughout the procedure. Control and NOCC-treated animals were killed 14 days after operation. The condition of the anastomosed vessel was examined, and a dhesion frequency and intensity in the abdomen were scored. In the sec ond model Sprague-Dawley rats underwent large bowel transection and re pair. Control and NOCC-treated animals were killed on postoperative da ys 4, 7, and 14, and strength of repair was assessed by removal of the large bowel and measurement of the bursting strength of the repaired incision. In the third model rats received an abdominal incision and w ere immediately closed. Control and NOCC-treated animals were killed 1 4 days after operation, and the skin tensile strength of the wound was measured with a tensiometer. Results. In all three models studied, NO CC treatment did not adversely affect the strength of the repaired inc ision. NOCC solution administered before operation did not greatly red uce adhesion formation whereas the delivery of both NOCC gel and solut ion after operation was most efficacious. Conclusions. The administrat ion of both NOCC gel and solution after operation is most efficacious, and NOCC does not compromise postsurgical healing in rats at doses th at prevent peritoneal adhesion formation.