Nils Andreas Kraemer, Presenter: Nothing to Disclose

Nienke Lynn Hansen MD, Abstract Co-Author: Nothing to Disclose

Alexander Ciritsis, Abstract Co-Author: Nothing to Disclose

Alexandra Barabasch MD, Abstract Co-Author: Nothing to Disclose

Martina Distelmaier, Abstract Co-Author: Nothing to Disclose

Jens Otto MD, Abstract Co-Author: Nothing to Disclose

Nicolas Kuehnert, Abstract Co-Author: Nothing to Disclose

Joachim Conze, Abstract Co-Author: Nothing to Disclose

Christiane Katharina Kuhl MD, Abstract Co-Author: Advisory Board Member, Bayer AG

Surgical hernia treatments using polymer based mesh implants are one of the most frequent operations worldwide. As the implants are invisible using conventional imaging methods, iron-oxides were integrated into the mesh polymer base material to visualize them in MRI. The purpose of this study is to evaluate the conspicuity of these mesh implants in patients treated for inguinal hernia and assessment of immediate post surgical mesh configuration. 

Approved by the ethics committee, 13 patients treated with iron-loaded mesh implants via laparoscopic or via open surgical procedure were prospectively examined beginning March 2012. MRI was conducted one day after surgery at a 1.5 Tesla scanner using three different conventional gradient echo (GRE1-3) and one T2-weighted turbospin echo (TSE) sequences. Three radiologists independently assessed mesh conspicuity and diagnostic value by the following criteria using a 4-point-scale: visual contrast-to-noise ratio, conspicuity to air artifacts, and diagnostic quality rating with respect to the mesh and to the surrounding anatomy. Mesh deformation and coverage of the hernia were visually assessed and rated using a 5-point semi-quantitative scoring system. Additionally, mesh deformation and localisation in relation to the hernia were rated. Using linear contrast and mixed models, statistical analysis was performed.

MRI successfully visualized all implants. GRE sequences clearly exhibited the mesh implants as a thick hypointense line. GRE1 was rated best (3.8; p<0.05) for diagnostic quality with respect to the mesh whereas GRE3 was suited best for combined evaluation of mesh and surrounding anatomy (2.9;  p<0.05). TSE was preferred for exclusive evaluation of the anatomy (3.8; p<0.05) but insufficient in mesh delineation. Local air slightly reduced mesh delineation. Overall, in both implantation techniques, the meshes exhibited mild to moderate deformations. 

The combination of iron-loaded implants and MRI facilitates mesh visualization for the first time in patients. After surgical hernia repair, mesh localization and configuration can be clearly assessed. For MRI protocol, we propose a combination of different gradient echo sequences and T2-weighted TSE sequences.  

Using this new technique, MRI could become a non-invasive alternative to open surgical exploration if mesh-related complications after hernia surgery are suspected.

Kraemer, N, Hansen, N, Ciritsis, A, Barabasch, A, Distelmaier, M, Otto, J, Kuehnert, N, Conze, J, Kuhl, C, First In-patient MR-Visualisation of Polymer-based Mesh Implants Used for Surgical Hernia Treatment.  Radiological Society of North America 2013 Scientific Assembly and Annual Meeting, December 1 - December 6, 2013 ,Chicago IL. http://archive.rsna.org/2013/13044336.html