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Article History

Received: 1 March 2018

Accepted: 27 June 2018

First Online: 6 July 2018

Ethics approval and consent to participate

: The study was approved by the Ethical committee of the Medical University (EK 24–135).As no individual patient data have been used other than date of surgery and of death an informed consent from the patients was regarded as unnecessary by the Ethics Committee of the Medical University. The Ethics Committee required that the patients data have to be anonymized. An informed consent was however given by the patients to use their tissues for research when surgery was done. This was however, not available in the years prior to 2008. In 2008 new regulations were installed by the Ethics Committee of the University.(website:ExternalRef removed).

: No material images or videos relating to individual persons have been used.

: The authors declare that they have no competing interests.

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