Footnotes

• Contributors JFB-C gathered the data, made the statistical analysis, conceptualised and wrote the first draft of the manuscript. JJ gathered the data, conceptualised and reviewed the manuscript.

• Competing interests None declared.

• Patient consent Obtained.

• Ethics approval This is a retrospective, observational study, but patients signed written informed consent to be videotaped and release of specific health information for research and educational purposes such as publishing in professional journals.

• Provenance and peer review Not commissioned; internally peer reviewed.