[1] Turku Univ Hosp, Dept Vasc Surg, FI-20521 Turku, Finland
[2] Univ Helsinki, Cent Hosp, Helsinki City Hlth Ctr, Helsinki, Finland
[3] Univ Helsinki, Cent Hosp, Finnish Patient Insurance Ctr, Helsinki, Finland
[4] Univ Helsinki, Cent Hosp, Dept Otorhinolaryngol, Helsinki, Finland