Effect of Upper Abdomen Tissue Manipulation on Adhesion Formation between Injured Areas in a Laparoscopic Mouse Model

Study ObjectiveThese experiments were designed to examine the effect of manipulation during surgery as a cofactor in adhesion formation at trauma sites.DesignRandomized, controlled trial. Canadian Task Force Classification–class 1.SettingUniversity laboratory research center.SubjectsA standardized laparoscopic mouse model (Balb\c mice 9–10 weeks old) for adhesion formation after opposing bipolar lesions and 60 minutes of carbon-dioxide pneumoperitoneum. In this model adhesions are known to decrease after the addition of 3% of oxygen, dexamethasone, or both. In addition, adhesions decrease with experience (i.e., with a decreasing amount of manipulation during the learning curve).InterventionsA factorial design was used to evaluate the effects of dexamethasone and of adding 3% of oxygen on manipulation-enhanced adhesion formation during a learning curve. Blocks of 4 animals were thus randomized as controls (carbon-dioxide pneumoperitoneum only) or received an additional 3% of oxygen, dexamethasone, or both. In a second experiment, the effects of manipulation on adhesion formation were quantified. In a third experiment we evaluated whether dexamethasone had a specific effect on manipulation-enhanced adhesion formation.Measurements and Main ResultsQualitative and quantitative adhesion scoring 7 days after the intervention. The first experiment confirmed that adhesion formation decreased during the learning curve (p <.0001) and after the addition of dexamethasone whether assessed as the total adhesion score (p <.0001 and p =.0009, respectively) or a quantitative score (p <.0001 and p <.0001, respectively). The second experiment showed that adhesion formation increased by standardized touching and grasping of omentum and bowels (proportion score p =.0059 and p =.0003, respectively) and this effect increased with duration of touching (p =.0301). In the third experiment, dexamethasone was confirmed to decreased adhesion formation (p =.0001) but this effect was not specific for manipulation-enhanced adhesion formation.ConclusionManipulation of intraperitoneal organs in the upper abdomen enhances adhesion formation at trauma sites, confirming that the peritoneal cavity is a cofactor in adhesion formation. Dexamethasone decreases adhesion formation but the effect is not specific for manipulation-enhanced adhesion formation.