[1] Goodheart Inst, Blood Coagulat & Vasc Med Ctr, Rotterdam, Netherlands
[2] Rijnmond Rotterdam, Med Diagnost Ctr, Rotterdam, Netherlands
[3] Erasmus MC, Dept Dermatol, Sect Phlebol, NL-3000 CA Rotterdam, Netherlands
[4] Charles Univ Prague, Cent European Vasc Forum, Prague, Czech Republic
[5] Leiden Univ, Med Ctr, Dept Primary Care Med, Leiden, Netherlands
[6] Univ Hosp, Fac Med, Hradec Kralove, Czech Republic
[7] Comenius Univ, Internal Med Med Fac, Bratislava, Slovakia
[8] Univ So Calif, Keck Sch Med, Dept Family Med, Los Angeles, CA 90033 USA
[9] Univ Hosp, Policlin S Orsola Malpighi, Dept Angiol & Blood Coagulat, Bologna, Italy