Novel Macromolecular Crosslinking Hydrogel to Reduce Intra-Abdominal Adhesions

Background: The aim of this study was to compare the anti-adhesion efficacy of a biodegradable, in situ, macromolecular cross-linking hydrogel made from oxidized dextran/N-carboxyethyl chitosan (Odex/CEC) with a commercially available carboxymethylcellulose/modified hyaluronan barrier film (Seprafilm; Genzyme Corporation, Cambridge, MA) in a rat cecum abrasion model. Methods: The rat model utilized a cecal abrasion and abdominal wall insult surgical protocol. The 2% Odex/CEC hydrogel treatment was applied by syringe to coat both the cecal and the abdominal wall insults, while other animals were treated with Seprafilm applied to the cecal injury only. Control animals did not receive any treatment. Animals were sacrificed after post operative day 21 and adhesion severity was quantitatively graded using a whole number scale from 0 - 3. Histological analysis was also performed for animals receiving Odex/CEC hydrogel treatment and no treatment (control). Results: Mean adhesion score was 2.09 ± 1.22 for control animals, 1.00 ± 1.00 for 2% Odex/CEC hydrogel animals, and 1.25 ± 1.22 for Seprafilm animals. Hydrogel treated animals showed significantly lower adhesion scores than control animals (P < 0.05), while Seprafilm demonstrated a marginally lower adhesion score (P < 0.1) compared with the controls. Histological analysis of an Odex/CEC treated rat showed tissue repair and small fragments of hydrogel inside both healed abdominal and cecal surfaces. Conclusions: Both Seprafilm and the 2% Odex/CEC hydrogel showed a significantly decreased adhesion score compared with the control. However, the hydrogel, compared with Seprafilm, offers ease of application and ability to conform to complex tissue geometries that could provide surgeons with another prophylactic treatment to prevent abdominal adhesions.