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The MR representation of metallic stents commercially available at the time, especially of nitionol stents, can be optimized with a suitable adaptation of the imaging parameters. However, a profound improvement can only be expected from new stent material and design.

Introduction Extensive scar tissue formation after peripheral nerve injury or surgery is a common problem. To avoid perineural scarring, implanting a mechanical barrier protecting the nerve from inflammation processes in the perineural environment has shown promising results for functional recovery. This study investigates the potential of an acellular collagen-elastin matrix wrapped around a peripheral nerve after induction of scar tissue formation. Materials and methods In the present study, 30 Lewis rats were separated into three groups and sciatic nerve scarring was induced with 2.5% glutaraldehyde (GA-CM) or 2.5% glutaraldehyde with a supplemental FDA-approved acellular collagen-elastin matrix application (GA+CM). Additionally, a sham group was included for control. Nerve regeneration was assessed by functional analysis using the Visual Statisc Sciatic Index (SSI) and MR neurography during the 12-week regeneration period. Histological and histomorphometry analysis were performed to evaluate the degree of postoperative scar tissue formation. Results Histological analysis showed an extensive scar tissue formation for GA-CM. Connective tissue ratio was significantly (p < 0.009) reduced for GA+CM (1.347 ± 0.017) compared to GA-CM (1.518 ± 0.057). Similarly, compared to GA+CM, MR-Neurography revealed extensive scar tissue formation for GA-CM with a direct connection between nerve and paraneural environment. Distal to the injury site, quantitative analysis presented significantly higher axon density (p = 0.0145), thicker axon diameter (p = 0.0002) and thicker myelinated fiber thickness (p = 0.0008) for GA+CM compared to GA-CM. Evaluation of functional recovery revealed a significantly faster regeneration for GA+CM. Conclusion The supplemental application of an acellular collagen-elastin matrix showed beneficial effects in histological, radiological, and functional analysis. Therefore, applying a collagen-elastin matrix around the nerve after peripheral nerve injury or surgery may have beneficial effects on preventing scar tissue formation in the long run. This represents a feasible approach to avoid scar tissue formation in peripheral nerve surgery.

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Um minimalinvasive microchirurgische Eingriffe MRT-unterstutzt durchföhren zu können, ist es notwendig, das Artefaktverhalten metallischer Instrumente und Implantate zu minimieren bzw. optimieren. Anhand der MRT-Abbildung verschiedener Probekörper aus dem Bereich der vaskulären Stents und einfacher chirurgischer Instrumente konnte gezeigt werden, dass durch eine geeignete Wahl der Messsequenzen und eine optimale Anpassung der Parameter das Artefaktverhalten wesentlich verbessert werden kann. Durch die genaue Kenntnis der Einflussgrössen kann damit durch eine angepasste Messstrategie in der MRT die Artefaktbildung angepasst werden. Dies bedeutet eine wesentliche Unterstützung in der minimal-invasiven Mikrochirurgie unter MRT-Monitoring.