New quantitative variables to measure postoperative pericardial adhesions: useful tools in experimental research

Abstract

PURPOSE: To improve the measurement system, during a research for the prevention of adhesions, we explored the feasibility of introducing three continuous numeric variables to quantify the intensity of pericardial adhesions. METHODS: To validate these three new numeric variables - time spent to dissect the adhesions (Δt), the amount of sharp dissection (ShpD) and the adhesion's collagen area (ACA) - as useful tools in measuring the severity of pericardial adhesions, data from a randomized study on adhesion prevention enrolling twenty-four swine, were analysed. A statistical Spearman's test and regressions models were applied to verify the correlation and the relationship between the results of a standard severity score (SS) and Δt, between SS and ShpD used in adhesiolysis and, also, between SS and ACA. RESULTS: There was a statistically significant correlation between SS and Δt, between SS and ShpD, as well as between SS and ACA, all measured by the Spearman's test (r=0.897, r=0.932, r=0.66; p<0.01, respectively). Through a non-linear regression, an exponential relation of SS with ShpD (R²=0.915) and SS with Δt (R²= 0.917) was found. CONCLUSION: The time spent to dissect the adhesions (Δt) and the amount of sharp dissection (ShpD) are new powerful measurement tools in evaluating outcomes of the methods used to prevent pericardial adhesions.