Authors’ contributions {31b}
MH
OB and TK are sponsors and chief investigators; they conceived the study and led the proposal and protocol development. GB, MH, LN and MAd contributed to the study design and to the development of the proposal. GB and EH designed the protocol for the CT venography. OB and PS designed the protocol for the ultrasound/Doppler investigation and LN wrote the questions for the questionnaires. All authors read and approved the final manuscript.