Abstract: Objective    To investigate the epidemiology of left common iliac vein (LCIV) compression in unselected population in Guangdong province of China.    Methods   Nonprobability sampling method was used in this multiple center study. CT parameters, such as LCIV minimum diameter, right common iliac vein minimum diameter, inferior vena cava bifurcation angle (IVC-BA), abdominal aorta bifurcation angle (AA-BA) and lower lumbar lordosis angle (LLLA) were measured, and presence of lumbar vertebral hyperostosis(LVH) and iliac arterial calcification(IAC) near the compression site were recorded. The compression percentage of LCIV (LCIV-CP) was calculated. Compression severity (CS) was classified as mild (CP≤50%), moderate (50% 70%).    Results    One thousand and seventy-eight subjects were enrolled, including 584 males and 494 females, with a median age of 56.0. The median LCIV-CP was 44.21% and the range was 0-89.9%. 61.41%, 29.31%, and 9.28% of subjects were graded with mild-, moderate-, and severe CS, respectively. The median LCIV-CPs of females and males were 46.61% and 42.12%, with a significant difference. The median LCIV-CPs of the young, middle-aged, and elderly groups were 52.0%, 45.2%, and 38.1%, respectively. Age differences were observed. Middle-aged females comprised the highest percentage of subjects with moderate or severe CS. The factors affecting the LCIV-CP and CS distribution were gender and age.    Conclusions    LCIV compression is common, and gender and age affect the LCIV-CP and CS distribution. Middle-aged females are the high-risk population with moderate-severe compression.

Key words: Iliac vein compression; ,  , Compression percentage; ,  , Compression severity; ,  , Prevalence, High-risk population; ,  ,  Middle-aged female