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

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.

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.

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.

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.