The femoral vein diameter and its correlation with sex,age and body mass index – An anatomical parameter with clinical relevance

Abstract

Background

The femoral vein diameter is a critical factor when assessing endoprosthetic valve size for the treatment of chronic venous insufficiency. To examine the previously stated correlation between body mass index and femoral vein diameter and to re-assess the anatomical and physiological demands for a valve implant for chronic venous insufficiency treatment, we measured the femoral vein diameter in 82 subjects.

Method

Femoral vein diameters (164 legs) were measured with B-mode sonography both in supine position at rest and in upright position during Valsalva maneuver.

Result

The mean femoral vein diameter differed significantly between supine position (13.6 ± 3.0 mm) and upright position (16.4 ± 2.6 mm). Males possessed a significant bigger diameter than females. A significant positive correlation between femoral vein diameter and body mass index was observed.

Conclusion

Assuming an increased femoral vein diameter due to obesity would further impair valve functionality by increasing distance between both valve cusps. For the development of artificial venous valves, it is crucial to consider patient- and condition-dependent vein dilation.

Keywords

Deep venous insufficiency endovascular treatment obesity statistics venous anatomy

Introduction

The femoral vein diameter (FVD) is an anatomical parameter with underestimated clinical relevance. Basically, the FVD can be used to estimate the central venous pressure (CVP),¹ but it is also an important predictor of chronic venous insufficiency (CVI)^2,3 and a critical factor when assessing endoprosthetic valve size for CVI treatment.^4,5

Besides deep venous thrombosis (DVT), dilation of the deep venous system might also play an important role for CVI-causing valve dysfunction. Interestingly, the body mass index (BMI) seems to correlate with an increased diameter of the femoral vein (FV)^6–10 which in turn marks adipositas as a potential factor in the development of venous valve dysfunction due to phlebotic dilation.

To assess the vascular diameters in the limbs, sonographic measurement is an efficient method. However, in the last two decades, only a few sonographic studies have contributed to our knowledge of the adult FVD and its correlation with various subject parameters.^1–4,6–12 Moreover, physico-anatomical parameters of the FV have been neglected in past approaches developing artificial venous valves for minimally invasive therapy of CVI – attempts which have failed since almost 40 years.¹³

To re-assess the anatomical and physiological demands for an artificial valve implant and to examine the correlation between BMI and FVD, we have measured the FVDs of a small representative population sample at various positions and under defined conditions.

Materials and methods

The study was approved by the local ethics committee. Patients (n = 75) and employees of the University Medical Center Rostock (n = 7) gave informed consent to the study protocol. All subjects were Caucasian. Patients have presented at the hospital due to minor ambulatory surgery (e.g. hand surgery, orthopedic surgery, port implantation). None of the subjects had severe diseases exceeding American Society of Anesthesiologists Physical Status (ASA PS) classifications 1 and 2.¹⁴ Varicosis or CVI prevalence was not examined systematically. At least one male patient (61 years) had varicose veins on the right lower leg – his measurement data which featured no outlier and were within the range of the respective sub-cohorts were kept in the statistical analysis to retain representativeness. Measurements were done between 8:00 a.m. and 3:40 p.m. (mean: 12:35 a.m.)

The left and right FV was measured both supine and in upright position by an experienced anesthetist specialized in ultrasound-guided regional anesthesia and focused ultrasound in emergency settings (including venous compression ultrasonography).

Measurements

The supine position promotes (passive) venoconstriction to assess the minimum vein diameter. The measured leg is slightly tilted outwards to minimize the distance between ultrasound transducer and thigh vessels.

The upright position with Valsalva maneuver promotes venodilation to assess the maximum vein diameter. The measured leg is slightly tilted outwards.

The diameter of three positions was assessed for each side: (a) the common femoral vein (CFV; Vena femoralis communis) proximal to the orifice of the great saphenous vein (Vena saphena magna) (“CFV” position; Figure 1), (b) the proximal section of the FV about 1–2 cm distal to the orifice of the deep FV (Vena profunda femoris) (“proximal” position; Figure 1), and (c) the distal section of the FV about 20 cm distal to the orifice of the deep FV (“distal” position). Time between supine position and measurements in upright position plus Valsalva maneuver was about 1 min. To estimate a possible influence of time between supine and upright position on vein dilation, measurements were repeated in upright position combined with Valsalva maneuver after 5 min in three subjects for the right leg.

Figure 1.

Spatial relations between measured upper segments (“CFV", “prox”) and anatomical landmarks in the right pelvis region (“distal” position not shown here). 3D reconstructions based on contrast medium enhanced magnet resonance imaging of male volunteer. CFV: common femoral vein; dfv: deep femoral vein; f: femur; fa: femoral artery; gsv: great saphenous vein; il: inguinal ligament. Scale bar = 2 cm.

The ultrasound machine (Sonosite, Bothell, WA, United States) had a 38 mm linear transducer (6–13 MHz).

The mean diameter for each measuring position was calculated by assessing both minimum and maximum diameter (cross measurement) with B-mode sonography (Figure 2). Besides their estimated anatomical location veins were identified by being compressed by brief transducer push and through differentiation with color Doppler sonography. Body height, weight and age were recorded for each subject.

Figure 2.

Exemplary sonographic B-Mode image with measurement of the common femoral vein diameter (right to the common femoral artery). Scale bar = 10 mm.

Intraobserver variation was tested under same conditions for six subjects 21 months after the first measurements. Interobserver variation was tested for five subjects by re-measuring the FVD in raw digital ultrasound images (n = 29) with the analyze-tool in the image processing program ImageJ (Fiji).¹⁵

Statistics

Cohort mean, standard deviation, minimum and maximum values are computed based on the single values for left and right leg. Statistics were computed with Microsoft Excel 2007 and R¹⁶ and RStudio,¹⁷ respectively.

Normal distribution was tested using the Shapiro–Wilk normality test (Shapiro.test in R). Variance similarity was assessed using the F-test (FTEST in Excel). For categorical comparisons of two groups without normal distribution, the Mann–Whitney U-test was run (Wilcox.test in R). For two groups with normal distribution, unpaired Student's or Welch's t-test, depending on variance similarity, was run (t.test in R; two-tailed). Bilateral differences between left and right leg were tested with the paired t-test.

P-values of ≤ 0.05 in group comparisons are supposed to represent significant differences between cohorts (0.01 < p ≤ 0.05 = slightly significant; 0.001 < p ≤ 0.01 = significant; p ≤ 0.001 = highly significant). P-value adjustments concerning cumulated alpha errors (familywise error rate) due to multiple testing^18,19 were done with the Holm–Bonferroni correction²⁰ (for number of tests per “family” (k) see Supplementary Tables 1 and 2).

For the statistic tests (except for bilateral differences), the mean FVD (left + right leg) for each subject was used.

Age cohorts (mixed-sex) were classified as the following:

age ≤ 30 yr = “young”

30 < age > 65 = “middle-aged”

age < 65 = pre-65

age ≥ 65 = “old”

Height cohorts (mixed-sex) were classified as the following:

height ≤ 170 cm = “small”

170 cm < height < 180 cm = “medium”

height ≥ 180 cm = “tall”

BMI values (kg/m²) (mixed-sex) were classified according to the WHO²¹:

BMI < 18.5 = underweight

18.5 ≤ BMI < 25 = normal weight

BMI ≥ 25 = adiposity

25 ≤ BMI < 30 = overweight

BMI ≥ 30 = obesity

Male and female cohorts were further divided into approximate equal sub-cohorts according to their median value for each subject parameter (age, height, BMI) and tested for significant differences between sub-cohorts correlated with these parameters (unpaired Student's t-test, Welch's t-test or Mann–Whitney U-test).

Simple and multiple linear regression (Analysis-ToolPak in Microsoft Excel 2007) with subject parameters (age, height, BMI) was done for FVDs of male and female cohort. In the multiple linear regression, variables with non-significant coefficients were excluded in a second step to re-calculate and optimize the linear regression model.

Results

A total of 164 legs of 82 subjects were examined (Table 1); 56.1% of subjects were male. Subject age ranged from 19 to 84 years (mean age: 48.7 ± 15.4 yr). The BMI ranged from 16.7 (underweight) to 39.8 (WHO class II obesity). The mean BMI was 26.5 ± 4.6 (overweight). The male cohort (n = 46; mean age: 49.4 ± 16.5 yr) had a mean BMI of 27.4 (overweight), the female cohort (n = 36; mean age: 47.8 ± 13.6 yr) had a mean BMI of 25.3 (slight overweight).

Table 1.

Characteristics and femoral vein diameter for overall, male, and female cohort.

		Overall cohort (n = 82)		Male cohort (n = 46)		Female cohort (n = 36)
Age (yr)	Range	19–84		19–84		24–77
Age (yr)	Mean	48.7 ± 15.4		49.4 ± 16.5		47.8 ± 13.6
Body height (cm)	Range	154–192		167–192		154–180
Body height (cm)	Mean	174.1 ± 8.2		179.0 ± 6.0		167.9 ± 6.0
Body weight (kg)	Range	51–123		60–123		51–115
Body weight (kg)	Mean	80.5 ± 16.9		87.8 ± 13.5		71.3 ± 14.9
BMI (kg/m²)	Range	16.7–39.8		18.7–38.5		16.7–39.8
BMI (kg/m²)	Mean	26.5 ± 4.6		27.4 ± 4.0		25.3 ± 4.9
Male (%)		56.1		100		0
Measuring position		Supine	Upright + Valsalva	Supine	Upright + Valsalva	Supine	Upright + Valsalva
CFV (mm)	Range	5.6–21.3	9.5–24.5	9.2–2.0	13.1–23.5	5.9–17.3	10.5–19.9
CFV (mm)	Mean	13.6 ± 3.0	16.4 ± 2.6	14.9 ± 2.6	17.5 ± 2.2	11.9 ± 2.3	15.1 ± 2.1
Proximal FV (mm)	Range	4.3–15.8	6.0–16.9	6.0–14.0	8.7–15.2	4.8–13.3	6.7–13.2
Proximal FV (mm)	Mean	9.8 ± 2.3	11.3 ± 2.0	10.3 ± 1.9	11.8 ± 1.6	9.1 ± 1.9	10.6 ± 1.6
Distal FV (mm)	Range	3.4–13.3	4.4–15.2	4.9–12.4	5.5–13.5	3.9–10.9	6.1–11.7
Distal FV (mm)	Mean	8.6 ± 1.8	9.8 ± 1.7	9.2 ± 1.4	10.4 ± 1.4	7.9 ± 1.5	9.1 ± 1.4

Note: Mean values are given with standard deviation and ranges.

BMI: body mass index; CFV: common femoral vein; FV: femoral vein.

Coherence between FVD and subject position

The FVD differed significantly (p ≤ 0.001; paired t-test) between supine position at rest and upright position during Valsalva maneuver (Figure 3). The mean diameter of the CFV measured 13.6 ± 3.0 mm in supine position (range: 5.6–21.3 mm) and 16.4 ± 2.6 mm in upright position during Valsalva (range: 9.5–24.5 mm), which is a mean diameter increase of 21% in upright position. The mean diameter of the middle position (proximal FV) distal to the orifice of the deep FV measured 9.8 ± 2.3 mm in supine position (range: 3.8–19.8 mm) and 11.3 ± 2.0 mm in upright position during Valsalva (range: 6.0–16.9 mm), which is a mean diameter increase of 15% in upright position. The distal position (distal FV) measured 8.6 ± 1.8 mm in supine position (range: 3.4–13.3 mm) and 9.8 ± 1.7 mm in upright position during Valsalva (range: 4.4–15.2 mm), which is a mean diameter increase of 14% in upright position.

Figure 3.

Comparison of the mean femoral vein diameter (FVD) for different subject positions (supine at rest or upright during Valsalva maneuver). Standard deviation and probability indices for paired t-test (comparison for mean value difference) are shown. *** = highly significant (p ≤ 0.001, k = 3). CFV: common femoral vein.

To estimate a possible influence of time between supine and upright position on vein dilation, measurements were repeated in upright position combined with Valsalva maneuver for the right leg in three subjects. The mean difference after 5 min was only minor: minus 0.3 ± 0.5 mm (mean absolute value: 0.4 ± 0.7 mm).

Correlations between FVD and sex

The male cohort possessed a significant bigger diameter than the female cohort for all measured segments and for both subject conditions (Figure 4; Supplementary Table 1). BMI-adjusted differences between males and females remained significant for the CFV in the cohorts with normal BMI (supine; p = 8.39 E-03) and adiposity (upright; p = 2.48 E-02). Age-adjusted differences remained significant for the CFV (p ≤ 0.001) and distal FV (p ≤ 0.05) for both conditions in the “middle-aged” and “pre-65” cohort (Supplementary Table 1).

Figure 4.

Comparison of the mean femoral vein diameter (FVD) for male and female cohort and different subject positions (supine at rest or upright during Valsalva maneuver). Standard deviation and probability indices for unpaired t-test (comparison for mean value difference) are shown. ** = significant (0.001 < p ≤ 0.01, k = 6), *** = highly significant (p ≤ 0.001, k = 6). CFV: common femoral vein; dist: distal femoral vein; prox: proximal femoral vein; sup: supine position at rest; up: upright position during Valsalva maneuver.

Correlations between FVD and age

The FVD for all segments increased with increasing age (Figure 5; Supplementary Tables 3 and 4). However, significant mean value differences between the various age cohorts are present for certain segments of the FV in certain subject positions, only (Supplementary Table 1).

Figure 5.

Comparison of the mean femoral vein diameter (FVD) for different age cohorts and different subject positions (supine at rest or upright during Valsalva maneuver). Standard deviation and probability indices for unpaired t-test (comparison for mean value difference) are shown. ** = significant (0.001 < p ≤ 0.01, k = 24), *** = highly significant (p ≤ 0.001, k = 24). CVF: common femoral vein; dist: distal femoral vein; prox: proximal femoral vein; sup: supine position at rest; up; upright position during Valsalva maneuver; yr: years.

An age-related FVD increase was observed independent from sex (same-sex cohort comparison) which was significant for the CFV (p = 3.61 E-02) and proximal FV (p = 2.24 E-04) in supine position in males, only (Supplementary Figures 1 and 2; Supplementary Table 2). A positive correlation between FVD and age is also seen in the linear regression models (Supplementary Figures 3 and 4, 9 and 10, 15 and 16) which was significant for male and female CFV in supine and female CFV in upright position.

Differences of mean values adjusted for BMI were not significant after p-value correction (k = 24).

The FVD ratios between supine position at rest and upright position during Valsalva maneuver likewise differed between the different age cohorts (Table 2). While the dilation ratio was highest in the “young” cohort with a mean dilation of + 43.7% for the CFV, the ratio decreased with age down to about 11% for all segments.

Table 2.

Differences between supine position at rest and upright position during Valsalva maneuver in the different age-cohorts (mixed-sex) indicating age-dependent vascular compliance.

Cohort	“Young” (≤ 30 yr)	“Middle-aged” (> 30, < 65 yr)	Pre-65 (< 65 yr)	“Old” (≥ 65)
	Difference upright + rest vs. supine + Valsalva (%)
CFV	43.7 ± 34.0	21.5 ± 20.8	26.4 ± 25.8	11.2 ± 11.6
Proximal FV	36.6 ± 15.5	14.8 ± 18.6	19.7 ± 20.0	11.1 ± 15.7
Distal FV	20.5 ± 12.5	14.3 ± 17.8	15.6 ± 17.0	11.0 ± 12.7

Note: Mean percentage is given with standard deviation.

CFV: common femoral vein.

Correlations between FVD and height

The mean FVD was increased for medium and tall subjects (mixed-sex) compared to small subjects for all measured segments and both conditions (Figure 6; Supplementary Table 5). None of these differences was significant. In the cohorts separated according to sex, FVD differences between smaller and taller same-sex sub-cohorts were marginal or without clear tendency or significance (Supplementary Figures 5 and 6, 11 and 12, 17 and 18).

Figure 6.

Comparison of the mean femoral vein diameter (FVD) for different height classes (mixed-sex). Standard deviation is shown. FVD differences between cohorts are not significant (p > 0.05). CVF: common femoral vein; dist: distal femoral vein; prox: proximal femoral vein; sup: supine position at rest; up: upright position during Valsalva maneuver; yr: years.

Correlations between FVD and BMI

A total of 58.5% of subjects (n = 48) had a BMI bigger than 25 (adiposity), 15 (18.3%) of these had a BMI bigger than 30 (obesity). The FVD increased with increasing BMI for all measured segments (Figure 7; Supplementary Tables 6 and 7; Supplementary Figures 21 and 22). Differences were slightly to highly significant for the CFV in supine and upright position both between the cohorts with normal BMI and adiposity (BMI ≥ 25) and between the cohorts with normal BMI and obesity (BMI ≥ 30) (Supplementary Tables 1 and 6). Between normal BMI and overweight cohort, differences were not significant. After adjustment for age, significant differences of the CFV in supine and upright position (p ≤ 0.01) were present in the cohort younger than 65 years (“pre-65”) between sub-groups with “normal BMI” and “adiposity” and between “normal BMI” and “obesity”, respectively (Supplementary Table 1).

Figure 7.

Comparison of the mean femoral vein diameter (FVD) for different classes of body mass index (BMI). Standard deviation and probability indices for unpaired t-test (comparison for mean value difference) are shown. ** = significant (0.001 < p ≤ 0.01, k = 24), *** = highly significant (p ≤ 0.001, k = 24). CVF: common femoral vein; dist: distal femoral vein; prox: proximal femoral vein; sup: supine position at rest; up: upright position during Valsalva maneuver.

The FVD likewise increased with increasing BMI independent from sex (same-sex cohort comparison; Figure 8; Supplementary Figures 7 and 8, 13 and 14, 19 to 22, Supplementary Table 7).

Figure 8.

Significant correlation between body mass index (BMI) and diameter of the common femoral vein (d CFV) in supine position at rest (a) and in upright position during Valsalva maneuver (b). Mean values for the CFV for each subject and regression lines for both sexes are plotted (males supine: p = 4.68 E-03; females supine: p = 4.02 E-07; males upright: p = 1.82 E-03; females upright: p = 1.43 E-03). Measuring points of males (n = 46) are colored blue, females (n = 36) are colored red.

Multiple linear regression of CFV diameter with age, height, and BMI

In the multiple linear regression of the CFV diameter with age, height and BMI for male and female cohort, non-significant coefficients were excluded and the linear regression model was re-calculated in a second step to optimize the model. An increased BMI had the strongest positive effect on the CFV diameter. Age was only a minor factor. Age had no significant effect on the CFV diameter in males during Valsalva maneuver, while height appeared to be a factor with slight significance in this case (in contrast to the simple linear regression; Supplementary Figure 6).

Multiple linear regression CFV males (supine):

y = 0.17 × BMI + 0.07 × age + 6.84

R²= 0.33; p [BMI] = 4.90 E-02; p [age] = 2.76 E-02

Multiple linear regression CFV females (supine):

y = 0.30 × BMI + 0.07 × age + 1.17

R²= 0.67; p [BMI] = 7.56 E-07; p [age] = 6.91 E-04

Multiple linear regression CFV males (upright/Valsalva maneuver):

y = 0.26 × BMI + 0.10 × height − 7.61

R²= 0.27; p [BMI] = 7.34 E-04; p [height] = 4.13 E-02

Multiple linear regression CFV females (upright/Valsalva maneuver):

y = 0.18 × BMI + 0.06 × age + 7.69

R²= 0.40; p [BMI] = 6.33 E-03; p [age] = 9.23 E-03

A summary of the various tested cohorts (mean value comparison) in this study is shown in Supplementary Tables 1 and 2. The linear regression models for FVD and subject parameters of cohorts separated according to sex are shown in the Supplementary Figures 3 to 20.

Bilateral symmetry/asymmetry

In terms of the diameter, slight bilateral asymmetry was present between left and right FV, but none was significant after p-value adjustment (k = 6; p > 0.05) (Supplementary Figure 23). The diameter of the CFV differed 10.0% in supine and 8.1% in upright position on average between both limbs in the same subject with the right FV being bigger in 63.4% and 59.8% of subjects, respectively. In the proximal segment, the diameter differed 15.0% in supine (R > L in 52.5% of subjects) and 12.1% in upright position (R > L in 48.8% of subjects); in the distal segment, 14.0% in supine (R > L in 59.5% of subjects) and 11.7% in upright position (R > L in 45.6% of subjects).

Discussion

This present study adds new morphometric and epidemiologic data to our knowledge on the FV, including variability of the FV diameter (FVD), FV dilation properties, bilateral asymmetry and cohort differences correlated to sex, age and BMI.

Basically, the measurements of the FVD in our study are in accordance with previous studies,^{1–4,6,10–12,22} although we have detected slightly bigger absolute diameters for our overall cohort (Table 3). These differences can be explained to some extent by different subject conditions during measurement (e.g. upright vs. reverse Trendelenburg position) and possible differences in the overall cohorts, and on the other hand by observer-related systematic differences. Diameter differences due to different ethnicity of regional populations might also play a role.⁶

Table 3.

Comparison of the femoral vein diameter (FVD) of the common femoral vein (CFV) with previous studies.

		FVD (CFV) (mm)	Condition	n (legs/subjects)	Age (yr)	BMI (kg/m²)
Present study		13.6 ± 3.0	Supine + rest	164/82	48.7 ± 15.4	27.4 ± 4.0
Present study		16.4 ± 2.6	Upright + Valsalva	164/82	48.7 ± 15.4	27.4 ± 4.0
Fronek et al.⁶		11.8 ± 2.1	Reverse Trendelenburg + rest	3539/1975	58.7 ± 11.4	26.9 ± 5.2
Fronek et al.⁶		14.3 ± 2.5	Reverse Trendelenburg + Valsalva	3539/1975	58.7 ± 11.4	26.9 ± 5.2
Salles-Cunha et al.⁴		11.2 ± 2.5	Supine + rest	40/20	27–74	n.a.
Salles-Cunha et al.⁴		14.4 ± 2.3	Upright + after activity	40/20	27–74	n.a.
Hertzberg et al.¹²		10.5 ± 2.9	Supine + rest	768/721	n.a.	n.a.
Dyszynski et al.²		14.2 ± 1.8 (L)	Supine + manual Valsalva	47/n.a.	n.a.	n.a.
Dyszynski et al.²		14.4 ± 1.7 (R)	Supine + manual Valsalva	54/n.a.	n.a.	n.a.
Jeanneret et al.⁸		8.3 ± 2.2	Supine + rest	80/40	20–66	21.8
Jeanneret et al.⁸		11.1 ± 2.8	Supine + Valsalva	80/40	20–66	21.8
Mortensen et al.²¹	9.4		Supine	32	1–79	n.a.
Mortensen et al.²¹	11.7		Reverse Trendelenburg	32	1–79	n.a.

Note: Means are given with standard deviation, if available.

BMI: body mass index.

Valsalva-induced dilation

The Valsalva-induced mean dilation of the CFV in our study (24.6%) is in accordance with previous data of 21.2% to 33.7%.^4,6,8,23 Values reaching far beyond these means (up to 149.1% in our measurements), or even decreased diameters for the CFV (down to −15.4% in our measurements) in only one leg might be due to Valsalva-induced changes in muscle tension in the legs or slight positional changes to some extent.

A true dilation by up to 100% (FVD doubling) or above, however, cannot be ruled out: in three of our subjects (23, 27, and 47 years old), the CFV reached such a doubling in both legs. Although such a correlation between age and distensibility has been denied in the past,²³ venous wall compliance decreases with age.^24,25 Age-dependent alterations of extra cellular matrix components such as elastic and collagenous fibers in the venous wall might be responsible for the loss of compliance similar to the vascular ageing stated for arterial systems.²⁶ Possible correlations and causes for the age-related loss of venous compliance in the FV, however, must be further studied.

Bilateral asymmetry

In our study, the overall mean CFV diameter of left and right leg differs less than 1 mm (3.8% supine, 2.5% upright/Valsalva maneuver). This is in accordance with previous studies with differences below 1 mm.^2,3,12 Within the same subject, we have found a higher bilateral asymmetry between left and right FV, e.g. 10.0% difference on average in supine and 8.1% for the CFV in upright position. Bilateral differences between leg muscle volumes due to different footedness might contribute to these vascular differences but reliable data are lacking for such a coherence. Anatomical variations such as the May–Thurner syndrome with clinically underestimated prevalence might also play a role in causing bilateral asymmetry of the FVD.²⁷

Correlations between FVD and sex

According to our data, the FVD is sex-related and males possess a bigger FVD than females, which is significant for the CFV, also after adjustment for age. This finding stands in line with previous studies,^6,7,28 while others⁸ could not verify such a correlation. Distinct differences in mean body size (height) between males and females might contribute to sex-related differences of the FVD since body height was found to correlate to some degree with the FVD.⁶ We have, however, not found an unambiguous sex-adjusted correlation between height and FVD in our cohort. Since the FVD is correlated with the diameter of the femoral artery to some extent,¹² differences in blood flow due to sex-related differences of the lower limbs' muscle mass²⁹ might play a role for these differences of the FVD.

Correlations between FVD and age

We have observed an age-dependent increase of the FVD in all segments and detected a strong correlation between CFV diameter in supine position and age. An age-related increase of CFV and proximal FVD in supine position was independent from sex and significant for males. In this context, data from previous studies are contradictory. While in the study by Kröger et al.,⁷ the FVD was not correlating with age, Fronek et al.⁶ observed a decrease[!] of the CFV diameter with increasing age⁶ – which is opposite to our findings. Such an FVD decrease has been already discussed as being probably affected by age-related changes of blood volume, sympathetic activity and venous compliance.⁷ However, we expect the CFV in the elderly to be “worn” due to aging processes within the vascular wall which is congruent with our own preliminary observations on post-mortem material from body donors. This assumption fits to the finding that FV compliance seems to decrease with age.

Correlations between FVD and BMI

The previously observed positive correlation between FVD and BMI^6–10 is supported by our data. A BMI-dependent increased diameter has also been observed for the great saphenous vein (V. saphena magna).⁷ It remains open what the direct cause for such a BMI-related dilation is. Arfvidsson et al.³⁰ observed an increased iliofemoral venous pressure which is ascribed to the increased intraabdominal pressure which is usually associated with obesity. The elevated venous pressure enhances the transmural pressure affecting the venous wall – if and how this contributes to an FVD change is unclear and subject to future studies. Sufficient data to test an FVD decrease in subjects with underweight is lacking. Moreover, it is not clear if diameter plasticity for the FV is seen in underweight subjects at all, since the FVD might have its homoeostatic minimum and maximum.

Interestingly, there is some evidence for a positive correlation between femoral arterial and venous diameter.¹² In athletic subjects, the diameter of the femoral artery is significantly increased compared to non-athletic subjects.³¹ According to current knowledge, athletic lifestyle does not increase vascular diameter per se, since muscular arteries are subject to changes more than the larger elastic vessels.³¹ How an athletic lifestyle affects the FVD is unknown.

Clinical relevance of the FVD

An increased FVD is of clinical relevance for several reasons. An abnormally increased CFV diameter might increase the risk for insufficient venous valve closing leading to venous reflux. According to our observations on post mortem material from body donors, height of CFV valve cusps in elderly is often reduced impairing valve functionality. Assuming an increased CFV diameter due to adiposity or other causes would further impair valve functionality by increasing distance between both cusps.

It has been observed that a CFV diameter bigger than 16 mm provides a higher risk for a phlebodem.³ Similar to that finding, it has been postulated that females with a CFV diameter bigger than 14 mm have a 15-fold risk being affected by CVI.² FVs with acute DVT were found to have a larger diameter than normal veins, while those with chronic DVT have a smaller diameter.¹²

If we assume FV plasticity making it possible to increase the FVD coherently coupled to the BMI – either directly or indirectly – the question arises whether or not this process is reversible, e.g. by reducing body weight, and thus the risk for CVI or even the severity of persisting CVI can be reduced.

For the successful development and application of artificial venous valve implants for minimally invasive CVI treatment – something which has failed since almost 40 years for several reasons¹³ – it is crucial to consider patient- and condition-dependent FV dilation up to 100%. These temporary FVD changes certainly have an effect on implant fixation and possibly its hemodynamic performance on the one hand, and on implant-tissue interactions possibly promoting adverse fibrotic growth by mechanical irritation of the intimal layer on the other. These physico-anatomical aspects of the FV have been neglected in the past.

Limitations of this study

From a statistical perspective, the number of studied subjects in this study is moderate and in line with similar previous studies on the FVD.^1,2,8 Diseases such as diabetes are further potential factors which might influence the FVD. Further data from patient records, however, were not available for this study and statistical validity would require a bigger overall sample size to allow more convincing statements on sub-cohort statistics.

Intraobserver variation was tested 21 months after first measurements and under same conditions for 6 subjects (n = 68 measurements) and resulted in a mean variation of 1.26 ± 1.21 mm for all measurement positions and a variation of 13.9 ± 15.2% for the CFV (n = 24 measurements). Interobserver variation was tested with blinded re-measurement of raw digital ultrasound images (n = 29) from five subjects and resulted in a mean variation of 0.36 ± 0.37 mm for all measurement positions and a variation of 2.8 ± 2.4% for the CFV (n = 10 images). In addition, we were able to test the difference between sonographic assessment and magnetic resonance imaging (MRI) for the CFV in one of our subjects (male, 34 yr, normal BMI; Figure 1). The deviation for the MRI scan (contrast medium-enhanced; XY-resolution = 0.78 mm) compared to the sonography was plus 1.3 mm ( + 11.1%) for the left and minus 0.7 mm (−5.7%) for the right VFC in supine position with a mean deviation of 8.4% for both sides.

Our measurement variations are in accordance with similar studies in which interobserver variability was 8.3 ± 7.2% (n = 20),¹ and in which a coefficient of variation of 13.1% was tested for the CFV diameter during Valsalva for 21 subjects.⁶

Supplemental Material

Supplemental material for The femoral vein diameter and its correlation with sex, age and body mass index – An anatomical parameter with clinical relevance

Supplemental material for The femoral vein diameter and its correlation with sex, age and body mass index – An anatomical parameter with clinical relevance by Jonas Keiler, Ronald Seidel and Andreas Wree in Phlebology

Footnotes

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was funded in part by the German Federal Ministry of Education and Research within RESPONSE “Partnership for Innovation in Implant Technology” (FKZ: 03ZZ0902A, 03ZZ0909A).

Ethical Approval

The study was approved by the local ethics committee.

Guarantor

Dr. Jonas Keiler

Contributorship

Conceived and designed the experiments: JK, AW, RS. Performed the experiments: RS Analyzed the data: JK. Contributed materials/analysis tools: RS. Wrote the paper: JK, RS, AW

Acknowledgements

We thank all volunteers for their participation. Teresa Mann is thanked for helpful advices with statistics.

References

Cho

Williams

Leatherman

. Measurement of femoral vein diameter by ultrasound to estimate central venous pressure. Ann Am Thorac Soc 2016; 13: 81–85.

Dyszynski

Marshall

Lewandowski

. Parameter für die CVI. Phlebologie 1999; 28: 126–131.

Dyszynska AB. Stellenwert des Diameters der Vena femoralis communis für die Ödemneigung bei chronischer Veneninsuffizienz im Rahmen dilatativ-degenerativer Venenerkrankungen. PhD Thesis, Ludwig-Maximilians-University Munich, Germany, 2008.

Salles-Cunha

Shuman

Beebe

et al.

Planning endovascular vein valve implantation: significance of vein size variability. J Vasc Surg 2003; 37: 984–990.

Tien

Zhao

Chen

et al.

Role of vessel-to-prosthesis size mismatch in venous valve performance. J Vasc Surg Venous Lymphat Disord 2017; 5: 105–113.e1.

Fronek

Criqui

Denenberg

et al.

Common femoral vein dimensions and hemodynamics including Valsalva response as a function of sex, age, and ethnicity in a population study. J Vasc Surg 2001; 33: 1050–1056.

Kröger

Ose

Rudofsky

et al.

Peripheral veins: influence of gender, body mass index, age and varicose veins on cross-sectional area. Vasc Med 2003; 8: 249–255.

Jeanneret

Labs

Aschwanden

et al.

Physiological reflux and venous diameter change in the proximal lower limb veins during a standardised valsalva manoeuvre. Eur J Vasc Endovasc Surg 1999; 17: 398–403.

Willenberg

Schumacher

Amann-Vesti

et al.

Impact of obesity on venous hemodynamics of the lower limbs. J Vasc Surg 2010; 52: 664–668.

10.

van Rij

De Alwis

Jiang

et al.

Obesity and impaired venous function. Eur J Vasc Endovasc Surg 2008; 35: 739–744.

11.

Bulitta

Kock

Hanke

et al.

Förderung des venösen Rückstroms im Liegegipsverband durch das AV-Impulssystem. Unfallchirurgie 1996; 22: 145–152.

12.

Hertzberg

Kliewer

DeLong

et al.

Sonographic assessment of lower limb vein diameters: implications for the diagnosis and characterization of deep venous thrombosis. Am J Roentgenol 1997; 168: 1253–1257.

13.

Zervides

Giannoukas

. Historical overview of venous valve prostheses for the treatment of deep venous valve insufficiency. J Endovasc Ther 2012; 19: 281–290.

14.

American Society of Anesthesiologists. ASA physical status classification system, www.asahq.org/resources/clinical-information/asa-physical-status-classification-system (2014, accesssed 7 April 2018).

15.

Schindelin

Arganda-Carreras

Frise

et al.

Fiji: an open source platform for biological image analysis. Nat Meth 2012; 9: 676–682.

16.

R Core Team. A language and environment for statistical computing, www.r-project.org (2017, accessed 7 April 2018).

17.

Team Rs. RStudio: integrated development for R, http://rstudio.com/ (2016, accessed 7 April 2018).

18.

Bender

Lange

. Adjusting for multiple testing – when and how? J Clin Epidemiol 2001; 54: 343–349.

19.

Wason

JMS

Stecher

Mander

. Correcting for multiple-testing in multi-arm trials: is it necessary and is it done? Trials 2014; 15: 1–7.

20.

Holm

. A simple sequentially rejective multiple test procedure. Scand J Stat 1979; 6: 65–70.

21.

World Health Organization. BMI classification. Global Database on body mass index, http://apps.who.int/bmi/index.jsp?introPage=intro_3.html (accessed 28 August 2017).

22.

Nagahiro

Watanuki

Sato

et al.

Venous velocity of the right femoral vein decreases in the right lateral decubitus position compared to the supine position: a cause of postoperative pulmonary embolism?

Acta Med Okayama 2007; 61: 57–61.

23.

Mortensen

Talbot

Burkart

. Cross-sectional internal diameters of human cervical and femoral blood vessels: relationship to subject’s sex, age, body size. Anat Rec 1990; 226: 115–124.

24.

Olsen

Länne

Goldman

et al.

Reduced venous compliance in lower limbs of aging humans and its importance for capacitance function. Am J Physiol 1998; 275: H878–H886.

25.

Young

Stillabower

DiSabatino

et al.

Venous smooth muscle tone and responsiveness in older adults. J Appl Physiol 2006; 101: 1362–1367.

26.

Wagenseil

Mecham

. Vascular extracellular matrix and arterial mechanics. Physiol Rev 2009; 89: 957–989.

27.

Kibbe

Ujiki

Goodwin

et al.

Iliac vein compression in an asymptomatic patient population. J Vasc Surg 2004; 39: 937–943.

28.

Macchi

Corcos

Cecchi

et al.

Internal diameters of human femoral blood vessels in 50 healthy subjects using color Doppler ultrasonography. Ital J Anat Embryol 1996; 101: 107–114.

29.

Wells

JCK

. Sexual dimorphism of body composition. Best Pract Res Clin Endocrinol Metab 2007; 21: 415–430.

30.

Arfvidsson

Eklof

Balfour

. Iliofemoral venous pressure correlates with intraabdominal pressure in morbidly obese patients. Vasc Endovascular Surg 2005; 39: 505–509.

31.

Green

Spence

Rowley

et al.

Vascular adaptation in athletes: is there an ‘athlete’s artery’?

Exp Physiol 2012; 97: 295–304.

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