Prospective cohort study on mesh shrinkage measured with MRI after robot-assisted minimal invasive retrorectus ventral hernia repair using an iron-oxide-loaded polyvinylidene fluoride mesh.

BACKGROUND: Mesh-reinforced ventral hernia repair is considered the gold standard treatment for all but the smallest of hernias. Human data on mesh shrinkage in the retrorectus mesh position is lacking. A prospective observational cohort study was performed to measure mesh shrinkage in robot-assisted minimal invasive retrorectus repair of ventral hernias. METHODS: A cohort of 20 patients underwent a robot-assisted minimal invasive retrorectus repair of their ventral hernia. Magnetic resonance imaging (MRI) imaging was performed one month and thirteen months after implantation of an iron-oxide-impregnated polyvinylidene fluoride (PVDF) mesh to assess the decrease in mesh surface area. Inter-rater reliability among three radiologists regarding measurement of the mesh dimensions was analyzed. Quality of Life scoring was evaluated. RESULTS: The inter-rater reliability between the radiologists reported as the intra-class correlations proved to be excellent for mesh width (ICC 0.95), length (ICC 0.98) and surface area (ICC 0.99). Between MRI measurements at one month and thirteen months postoperatively, there was a significant increase in mesh surface area (+ 12.0 cm2, p = 0.0013) and mesh width (+ 0.8 cm, p < 0.001), while the length of the mesh remained unchanged (-0.1 cm, p = 0.754). Quality of Life Scoring showed a significant improvement in Quality of Life after one month and a further improvement at thirteen months (p < 0.001). CONCLUSION: There was an excellent inter-rater reliability between three radiologists when measuring width, length, and surface area of an iron-oxide-impregnated PVDF mesh using MRI visualization. Mesh shrinkage was not observed, instead the effective mesh surface area and width of the mesh increased.

Spinal Non-Hodgkin Lymphoma Mimicking Epidural Hematoma.

A patient, recently diagnosed with non-Hodgkin lymphoma, presented with acute tetraplegia after surgical cervical lymph node biopsy. MRI of the cervical spine demonstrated an epidural space-occupying lesion with compressive myelopathy. While epidural hematoma was the tentative diagnosis, intra-operatively non-Hodgkin lymphoma was found. Several factors may have accounted for the inaccurate interpretation of the MRI: the acute clinical presentation appearing shortly after surgery, the non-specific signal intensities of (hyper-) acute hematomas, the lack of contrast-enhanced images, and the absence of the FDG-avid spinal mass in the PET/CT-report. Without radiological features of invasiveness and contrast-enhanced images, careful interpretation is mandatory for space-occupying epidural lesions. Teaching Point: Caution is needed when interpreting an epidural space-occupying lesion in the absence of contrast-enhanced images.