Iodine doping of a photocuring, one-component embedding medium for µCT and histology.

OBJECTIVE: Evaluation of µCT scans of bone implant complexes often shows a specific problem: if an implant material has a very similar radiopacity as the embedding medium (e.g. methacrylate resin), the implant is not visible in the µCT image. Segmentation is not possible, and especially osseointegration as one of the most important parameter for biocompatibility is not evaluable. METHODS: To ensure µCT visualisation and contrast enhancement of the evaluated materials, the embedding medium Technovit® VLC7200 was doped with an iodine monomer for higher radiopacity in different concentrations and tested regarding to handling, polymerisation, and histological preparation, and visualisation in µCT. Six different µCT devices were used and compared with regard to scan conditions, contrast, artefacts, image noise, and spatial resolution for the evaluation of the bone-implant blocks. RESULTS: Visualisation and evaluation of all target structures showed very good results in all µCT scans as well as in histology and histological staining, without negative effects caused by iodine doping. Subsequent evaluation of explants of in vivo experiments without losing important information was possible with iodine doped embedding medium. CONCLUSION: Visualisation of implants with a similar radiopacity as the embedding medium could be considerably improved. µCT scan settings should be selected with the highest possible resolution, and different implant materials should be scanned individually for optimal segmentation. µCT devices with higher resolutions should be preferred. ADVANCES IN KNOWLEDGE: Iodine doped embedding medium is a useful option to increase radiopacity for better visualisation and evaluation of special target structures in µCT.

Electrospun mucosal wound dressings containing styptics for bleeding control.

Two major aspects need to be focused to accelerate wound healing of mucosal damages especially in the field of otorhinolaryngology. (i) The problem of application due to the small access during surgery, (ii) the fixation of the wound dressing to reveal a stable healing process. In the present work the high request to a mucosal wound dressing which additionally support hemostasis was addressed. We developed an electrospun fabric made of poly(l-lactide-co-d/l-lactide) (PLA) which can be loaded with the hemostatic agents adrenaline and tranexamic acid to cover mucosal lesions analogues to common skin patches. These loaded electrospun fabrics were demonstrated to be biocompatible, thin and flexible, and thus could be adapted individually to the mucosal defect with respect to localization and size of the lesion. The treatment of mucosal defects with these loaded PLA wound dressings induced a faster and time controlled hemostatic reaction, which significantly improved the healing process.

Computed tomography-based training model for otoplasty.

Otoplasty for the correction of protruding ears is characterized by various techniques and a common and popular cosmetic procedure. For the surgeon, whether beginner or advanced, it is essential to understand the principles and master techniques for standard auricular deformities before applying further sophisticated methods, because a lot of complications and failures are caused by wrong indication and incorrect surgical techniques. The different surgical steps are best learned from teaching models. Therefore, we developed two different silicone models of protruding ears with moderate auricular deformities: one with conchal hyperplasia for the training of conchal resection, and one without antihelix for creating an antihelical fold by suturing technique, based on computed tomography scans of patients. The silicone ear models were evaluated during four standardized surgery courses for residents in otorhinolaryngology by 91 participants using specially designed questionnaires. Nearly all participants rated the training on the auricular models as very helpful (n = 51) or good (n = 31); the scores for the different techniques and properties of the models ranged from 2.0 to 2.6 in a range from 1 (very good) to 4 (inadequate). The good results demonstrate the possibility for learning different surgical otoplasty techniques with this newly designed teaching tool.