Common femoral vein dimensions and hemodynamics including Valsalva response as a function of sex, age, and ethnicity in a population study.

PURPOSE: In this study we assessed the normal common femoral vein (CFV) dimensions and related hemodynamics in a cohort assembled to permit contrasts by means of sex, age, and ethnicity.
METHODS: The CFV diameter and the flow velocity were analyzed by means of duplex ultrasonography at rest and with a standardized Valsalva maneuver, with the subject in a 15% reverse Trendelenberg position. Mean levels of each of the CFV measurements were analyzed with age category, sex, and ethnicity, each adjusted for the other two. Multiple linear regression was used as a means of assessing the independent associations of age, sex, ethnicity, body mass index (BMI), and height to the CFV measurements.
RESULTS: The average CFV diameter at rest was 11.84 mm, increasing to 14.27 mm during the Valsalva maneuver. There was a significant (P <.0001) decline in both diameter measures beginning in patients 60 years old. The CFV diameter was larger in men (12.90 mm) than in women (11.22 mm; P <.0001). The average CFV diameter in Hispanics, Africian Americans, and Asians was significantly smaller (P <.001) than in the non-Hispanic whites in multivarate analysis. The independence of these associations was confirmed by means of multivariate analysis, and positive associations of CFV diameter with height and BMI were documented. The Valsalva response was higher in men than in women (2.67 mm vs 2.29 mm), but the percentage change was similar. CFV velocity at rest decreased significantly (P <.0001) in patients older than 50 years. The mean CFV velocity was 13.87 cm/s, and the values were significantly (P <.0001) higher in women (14.58 cm/s) than in men (12.67 cm/s). In multivariate analysis CFV velocity was higher in African Americans than in the other ethnic groups. We also documented an independent inverse association of CFV with BMI. The CFV velocity response (peak expiration post-Valsalva) increased significantly at all ages, from 52% to 83%. The percentage increase in women (68%) was slightly higher than that in men (58%). African American subjects had a somewhat higher percentage increase (74%) than the other three ethnic groups (63% to 64%). Because the flow rate is determined more by the diameter than the velocity, CFV flow associations were similar to those for diameter. Because an older age predicted both decreased diameter and velocity, the flow reduction with age was pronounced.
CONCLUSION: Quantitative normative data that are age-, sex-, and ethnic group-specific are reported on CFV diameter, velocity, and total flow rate, both at rest and with the Valsalva maneuver. CFV diameter, velocity, and flow rate varied significantly as a function of age, sex, ethnicity, height, and BMI. The data also provide a baseline assessment for subsequent evaluations of changes with time in this cohort.