DOI 10.1136/neurintsurg-2020-015938
Correction notice Since the online publication of this article, it was noticed that author Michael Forsting was missing an affiliation. This has now been corrected.
Contributors Conception and design: VM. Acquisition of data: VM, HS, CM, LLLY, CC, AK, NA, DB, CJM, LM. Analysis and interpretation of data: VM, HS, LG, BI, BYQT, DL, PP, CK, ACH, AB, JF, SF, MF. Drafting the article: HS. All authors have read and approved the manuscript.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval According to the guidelines of the ethics committee (Medical Faculty, University of Duisburg Essen, University Hospital Essen, 19-9013-BO), ethical approval was given for this anonymous retrospective study, which was conducted in accordance with the Declaration of Helsinki. A patient’s consent for treatment was obtained according to the individual institutional guidelines. Due to the retrospective nature of the study additional informed consent was deemed unnecessary.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement All data relevant to the study are included in the article or uploaded as supplementary information.