Time-dependent changes of magnetic resonance imaging-visible mesh implants in patients

Area of Science:

• Biomedical Engineering
• Radiology
• Surgical Innovation

Background:

• Mesh implants are crucial for hernia repair but can cause long-term complications due to shrinkage and deformation.
• Noninvasive monitoring of mesh behavior post-implantation is essential for assessing outcomes and improving patient care.

Purpose of the Study:

• To quantify time-dependent mesh shrinkage, migration, and configuration changes after inguinal hernia repair using magnetic resonance imaging (MRI).
• To develop and validate a noninvasive method for assessing MRI-visible mesh implants.

Main Methods:

• An agarose phantom study validated the MRI quantification process for mesh shrinkage and folding.
• Seven patients with iron-loaded mesh implants for inguinal hernia were prospectively examined using MRI at 1 and 90 days post-surgery.
• Semiautomated segmentation of mesh-induced signal voids and polygonal surface modeling were used to compare mesh area and centroid position over time.

Main Results:

• The MRI quantification method showed a maximum deviation of 3.6% compared to actual mesh size in phantom studies.
• A mean mesh shrinkage of 20.9% was observed 90 days after surgery.
• The mean centroid movement was 1.17 cm, with marginal local configuration changes (0.23 cm).

Conclusions:

• Significant mesh shrinkage (20.9%) occurs within 90 days post-implantation, while local configuration changes are minimal.
• Centroid shifts are attributed to patient positioning and abdominal distension, not inherent mesh instability.
• The developed algorithm enables noninvasive assessment of MRI-visible meshes, potentially improving mesh technology and surgical techniques.