Macroscopic, radiologic, and microscopic analysis of explanted abdominal wall prosthesis.

PURPOSE: Characterize the textile structure, degradation patterns, and calcification of explanted parietal reinforcement implants (PRI), in order to better understand potential mechanisms contributing to mesh-related complications.

METHODS

A multimodal analytical approach combining macroscopic examination, high-resolution radiographic imaging and microscopic analysis was performed before and after removal of surrounding biological tissues on explanted PRI.

RESULTS

Twenty-two explanted PRI were analyzed, including five biosynthetic meshes and seventeen fully synthetic non-resorbable meshes. Mean implantation duration was 41 months (range, [0-220]). Indications for explantation were hernia recurrence (n = 14, 64%), mesh infection (n = 4, 18%), unrelated surgery (n = 3, 14%), and bowel obstruction (n = 1, 4%). Macroscopic analysis showed encapsulation within biological tissues (n = 16), rigidity (n = 6), and fragmentation (n = 3), sometimes combined. Radiographic imaging revealed suggestive calcifications in four explants, and suggestive fibrosis and/or milder mineralized deposits in twelve. Nineteen non-resorbable meshes underwent digital optical microscopy after enzymatic cleaning (2 explants each contained 2 devices). Textile structures included warp-knitted meshes (n = 16), weft-knitting mesh (n = 1), and nonwoven materials (n = 2); six devices also incorporated a plastic membrane. Monofilament yarns predominated (n = 15) whereas multifilament yarns (n = 4) showed signs of fibrillation. Fixation systems included staples (n = 3) and suture threads (n = 6). Structural abnormalities included holes (n = 7), clean cuts (n = 7), tearing (n = 1), and forceps marks (n = 3), variably attributable to surgical/handling artefacts or pre-existing degradation, though this could not be established with certainty.

CONCLUSION

This pilot study demonstrates the feasibility of a multimodal approach for characterizing explanted PRI. Larger studies are needed to clarify mesh failure mechanisms and thereby optimize implant selection and surgical use.