Acknowledgements
We would like to thank the patient and attending doctors for their participation in this study.
This work is supported by funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) for the Cluster of Excellence REBIRTH (from Regenerative Biology to Reconstructive Therapy) (EXC 62/3).
Potential conflict of interest
Disclosure forms provided by the authors are available with the full text of this article online at https://doi.org/10.1080/10428194.2018.1427861.