Magnetic Resonance-Visible Polypropylene Mesh for Pelvic Organ Prolapse Repair

Abstract

Aim: To develop a magnetic resonance (MR)-visible mesh using iron oxides and prove visibility. Methods: In a phantom study, a suitable iron oxide, Fe₃O₄ [iron(II,III) oxide] and FeOOH [iron(III) oxide-hydroxide], concentration was determined using relaxometric MR measurements of the transverse relaxation rates R2 and R2*. Next, a nonabsorbable mesh was designed from the MR-visible threads woven into a polypropylene mesh. The mesh was implanted into a fresh female cadaver via the transobturator route, and MR visibility was assessed with various MR pulse sequences in a clinical 3-tesla system. Results: Optimal contrast was achieved with Fe₃O₄ at 0.2 weight-% in all imaging sequences, and the optimal contrast was achieved in a 3D spoiled gradient-echo (fast low-angle shot) acquisition. In this concentration range the apparent transverse relaxation rate R2* is below 10 ms. The mesh was visible in the cadaver on T1-weighted 3D spoiled gradient-echo images and T1-weighted fast spin-echo images. Conclusion: Mesh materials can be manufactured to be visible on MR with a negative contrast. Fe₃O₄ meshes could simplify follow-up examinations and help diagnose origins of postsurgical lesions after urogynecological procedures with mesh material.

MRI visible Fe3O4 polypropylene mesh: 3D reconstruction of spatial relation to bony pelvis and neurovascular structures

“…To date, studies published have shown MR-visibility of mesh material experimentally, in a cadaver [9], rat models [11] and abdominal hernia reconstruction using polyvinylidene fluoride (PVDF) as matrix [10, 18–20], and only one study group using a MR-visible PVDF-mesh for pelvic floor reconstruction [13]. This report extends what has previously been reported in literature by demonstrating the feasibility of using Fe 3 O 4 -polypropylene mesh in living women and reconstructing the 3D course of its body and arms in relationship to important anatomical landmarks.…”

“…These meshes have six fixational arms of which the posterior arms are fixed in the sacrospinous ligaments while the middle and anterior arms are placed via the obturator muscle-membrane-complex [12]. The non-absorbable material is MR-visible, as described in our previous study [9]. The two meshes (Seratom® E PA MR being 6×10cm and the Seratom® P PA MR 4×9cm) differ only in size/shape.…”

“…The two meshes (Seratom® E PA MR being 6×10cm and the Seratom® P PA MR 4×9cm) differ only in size/shape. The MR-visibility of this alloplastic material is created with a defined concentration of (0.2 weight-%) Fe 3 O 4 added to the polypropylene - unlike other MR-visible meshes on the market that integrate paramagnetic Fe 3 O 4 microparticles into polyvinylidene fluoride (PVDF) polymer filaments [9, 13]. The MR-visible meshes produced by Serag Wiessner GmbH & Co. KG have been on the clinical market with CE certification since 2013.…”

“…It is difficult, however, to visualize the entire mesh including the course of the arms through deep body structures such as the obturator neurovascular bundle or the sacrospinous ligament and the pudendal neurovascular structures. In order to achieve full mesh visualization in the female pelvis a MR-visible mesh was developed applying an iron compound onto the mesh material, for iron has previously shown to be visible with some MR-imaging sequences [9–11]. The newly developed MR-visible Fe 3 O 4 -polypropylene-mesh has demonstrated MR-visibility in a cadaver study [9].…”

“…In order to achieve full mesh visualization in the female pelvis a MR-visible mesh was developed applying an iron compound onto the mesh material, for iron has previously shown to be visible with some MR-imaging sequences [9–11]. The newly developed MR-visible Fe 3 O 4 -polypropylene-mesh has demonstrated MR-visibility in a cadaver study [9]. Whether or not the fine mesh structure could be seen in living women where tissue movement from vascular pulsation and breathing and muscle activity might reduce visibility is not known.…”