Introducing the Mesh Integration (MINT) Index: a standardised ratio scale for assessing in vivo hernia mesh performance.

Background: One in 15 people throughout their lifetime will develop an incisional hernia. Poor mesh tissue integration is thought to be responsible for hernia repair failure years after surgery. The aim was to develop a mesh integration index for standardised assessment of in vivo hernia mesh behaviour in the abdominal wall.

Methods: The core properties of the Index were defined by the authors a priori, requiring the Index to be objective, reproducible, independent of animal models, compatible with past and future research and utilises equipment typically available at biomedical research institutes. The structure of the Index was built upon experience obtained in an earlier pilot study, incorporating key measurements and testing methods identified from previous publications. High precision test methods aligning with local and international standards were utilised where possible.

Results: The proposed Mesh Integration (MINT) Index is a 0-5 ratio scale that numerically represents the integration, fibrosis, adhesion and degradation behaviour of hernia mesh in vivo, using pre-existing standardised assessments. Assessments fell into four broad categories of visual, histological, biomechanical and molecular. Biomarkers were not included due to uncertainty of interpretation. Score calculations and rationale were explained in detail.

Conclusion: An objective index was created to assess in vivo hernia mesh behaviour. The index will need validation via studies using explanted mesh tissue complex from living abdominal walls.