Z Gastroenterol 2011; 49 - P515
DOI: 10.1055/s-0031-1285786

In vivo MRI-visualization of mesh shrinkage using SPIO-loaded surgical implants

N Kühnert 1, J Otto 1, N Kraemer 2, HCW Donker 2, I Slabu 3, M Baumann 3, C Kuhl 2, U Klinge 1
  • 1Universitätsklinikum Aachen, Viszeralchirurgie, Aachen, Germany
  • 2Universitätsklinikum Aachen, Diagnostische Radiologie, Aachen, Germany
  • 3RWTH Aachen, Helmholtz Institute für Medical Engineering, Aachen, Germany

Objective: To assess visibility and shrinkage of surgical mesh implants under in vivo conditions by MRI.

Background: Prosthetic mesh implants are widely used in hernia surgery. To reveal long-term mesh-related complications such as shrinkage or adhesions, a precise visualization of meshes and their vicinity in vivo is important. By supplementing ferro particles to mesh fibres, MRI can help to delineate the mesh itself. Aim of this study was to demonstrate and to quantify time-dependent mesh shrinkage in vivo by MRI.

Materials and methods: PVDF-meshes with incorporated super-paramagnetic iron oxides (SPIO) were implanted as an abdominal wall replacement in 30 rats. MRI was performed on day 1, on day 7, 14, or on day 21 using gradient-echo sequences TR/TE=50/4.6, flip-angle 20°. Length, width and area of the device were measured on axial, coronal and sagittal images and geometrical deformations were assessed by surgical explantation.

Results: In all cases, the meshes were visualized and its area was estimated by measuring length and width of the mesh. MRI presented a mean shrinkage of area in vivo of 13% at day 7, of 23% at day 14 and of 23% at day 21. Post-mortem measurements were statistically different from MRI with a mean shrinkage of area of 23% at day 7, of 28% at day 14 and of 30% at day 21. Ex-vivo measurements of shrinkage exposed an overestimation about 8% of in vivo measurements. Delineation of the mesh helped to reveal folding or adhesions with close neighborhood to intestine.

Conclusion: SPIO loading of surgical meshes allows their precise visualization in MRI and guarantees an accurate in vivo assessment of their shrinkage. Our observation clearly indicates that shrinkage in vivo is remarkably lower than illustrated explantation measurements. MR imaging of such meshes could be a reliable technique to check for proper operation of implanted meshes and reveal related complications, obviating the need for exploratory open surgical revision.

Keywords: Time dependent mesh shrinkage, SPIO-loaded mesh, MRI