Femoral Vein Cross-sectional Area Research Articles

Effect of obesity on venous hemodynamics of the lower limbs during laparoscopic cholecystectomy.

The present study aims to compare the changes of venous flow parameters of the lower limbs under the assessment based on the duplex ultrasound scanning in obese and non-obese individuals by complying with body mass index during laparoscopic cholecystectomy. A prospective cohort study was conducted in non-obese (body mass index <25kg/m2) and obese individuals (body mass index >30kg/m2) during laparoscopic cholecystectomy to analyze venous hemodynamics of the lower limbs. The assessment was conducted on Femoral vein diameter, Femoral vein cross-sectional area, Femoral vein peak velocity, and Femoral vein volume flow. The change values (%) of venous flow parameters of the lower limbs were calculated as a percentage by: (intra-operative parameter-pre-operative parameter)/ pre-operative parametersX100%. 45 right lower limbs were examined in 45 non-obese individuals and 33 right lower limbs in 33 obese individuals during laparoscopic cholecystectomy. The statistically significant difference was identified in the pre-operative and intra-operative values of Femoral vein diameter, Femoral vein cross-sectional area, Femoral vein peak velocity, as well as Femoral vein volume flow in both groups when these were analyzed independently (p = .00). When the change values of venous flow parameters of the lower limbs of the two groups were compared, more changes were identified significantly in the obese group, Femoral vein diameter (p = .042), Femoral vein cross-sectional area (p = .013), Femoral vein peak velocity (p = .002), and Femoral vein volume flow (p = .032). The changes of lower limb venous flow parameters showed more significant difference in obese than in non-obese individuals during laparoscopic cholecystectomy. The mentioned findings may in part explain why obese patients undergoing laparoscopic cholecystectomy have a higher rate of post op deep venous thrombosis.

Effect of the lateral tilt position on femoral vein cross-sectional area in anesthetized adults

Effect of the lateral tilt position on femoral vein cross-sectional area in anesthetized adults

Pelvic cardiovascular magnetic resonance venography: venous changes with patient position and hydration status

BackgroundTo determine the effect of hydration as well as prone versus supine positioning on the pelvic veins during cardiovascular magnetic resonance (CMR) venography.MethodsUnder institutional review board approval, 8 healthy subjects were imaged with balanced steady state free precession, non-contrast CMR venography to measure common and external iliac vein volumes and common femoral vein cross-sectional area in the supine, prone and decubitus positions after dehydration and again following re-hydration. CMR venography from 23 patients imaged both supine and prone were retrospectively reviewed and measurements of common femoral and iliac veins areas were compared using Wilcoxon test.ResultsCommon femoral vein area on CMR venography increased with prone positioning (83 ± 35 mm2) compared to supine positioning (59 ± 21 mm2) (p = 0.02) and further increased with hydration to 123 ± 44 mm2 (p < 0.01). With right and left side down decubitus positioning, the common femoral vein area on dehydration increased from 29 ± 17 mm2 in the ante-dependent position to 134 ± 36 mm2 in the dependent position (p < 0. 001). Similarly, common and external iliac veins increased in volume with prone, 5.4 ± 1.9 cm3 and 5.8 ± 1.9 cm3 compared to supine positioning 4.6 ± 1.8 cm3 and 4.5 ± 1.9 cm3 (p = 0.01) and further increase with hydration to 6.7 ± 2.1 cm3 and 6.3 ± 1.9 cm3 (p = 0.01). CMR venography on patients also demonstrated an increase in mean common femoral vein luminal area from 103 ± 44 mm2 in supine position to 151 ± 52 mm2 with prone positioning (p < 0.001) as well as increases in common and external iliac vein volumes from 6.5 ± 2.6 cm3 and 8.0 ± 3.4 cm3 in the supine position to 7.5 ± 2.5 cm3 and 9.3 ± 3.6 cm3 with prone positioning (p < 0.01).ConclusionsCommon femoral and common/external iliac vein size on CMR venography may be affected by position and hydration status. Routine clinical CMR venography of the pelvis could include prone positioning and avoiding dehydration to maximize pelvic vein distension.

Novel body positioning maximizes femoral venous size in adults: An ultrasonographic evaluation

Introduction: Increased femoral vein size may lead to a higher first pass success rate during central venous cannulation. The aim of this study was to evaluate the effects of body position on femoral vein anatomy for cannulation. Methods: This prospective study examined the femoral vein of healthy volunteers by ultrasound scanner. The changes in cross-sectional area and diameter of the femoral vein were evaluated. Right-sided measurements were taken at four different leg positions: neutral, frog leg, back-up, and back-up/frog leg position. Results: A total of 50 subjects were enrolled in the study. The mean femoral vein cross-sectional area were 0.57 ± 0.29 cm2, 0.90 ± 0.26 cm2, 1.05 ± 0.33 cm2, and 1.47 ± 0.34 cm2, and the mean femoral vein diameter were 0.75 ± 0.20 cm, 1.05 ± 0.28 cm, 1.25 ± 0.21 cm, and 1.46 ± 0.25 cm in order of neutral, back-up, frog leg, and back-up/frog leg position (p &lt; 0.001). Conclusion: Performing the right femoral vein catheterization in back-up and frog leg position is associated with a greater cross-sectional area of the femoral vein.

Measurements of jugular, portal, femoral, and calf vein cross-sectional area for the assessment of venous blood redistribution with long duration spaceflight (Vessel Imaging Experiment).

To determine if 6 months in microgravity resulted in significant changes in the major central and peripheral veins indicating a redistribution of venous blood flow. Ten astronauts participated in the study. Jugular vein (JV), portal vein (PV), femoral vein (FV), tibial vein (TibV), and gastrocnemius vein (Gast V) were assessed by echography for the measurement of vessel cross-sectional area. Inflight exams were conducted by astronauts using a volume capture method in which images collected were processed to produce a 3D reconstruction of the vessel which was later analyzed by a trained sonographer. Measurements were conducted pre-flight, at the beginning of the flight (day 15), near the end of the flight (4-5.5 months), and post-flight. During the flight, JV, PV, JV/PV ratio, and FV were found significantly increased from pre-flight at 15 days and 4-5.5 months (JV: 178 and 225%, p < 0.05; PV: 36 and 45%, p < 0.05; JV/PV ratio: 102 and 120%, p < 0.05; FV: 124 and 169%, p < 0.05). Conversely, calf veins decreased at day 15 and at 4-5.5 months (TibV: -45 and-52 %, p < 0.05; Gast V: -68 and -55%, p < 0.05). All veins returned to base line conditions 4 days after returning to Earth. The increase in JV, PV, and FV cross-sectional area during spaceflight confirmed that there was venous blood pooling in the cephalic, splanchnic, and pelvic regions. Further investigation is needed to determine the consequences of this fluid stagnation on the brain, eye, splanchnic, and pelvic organ morphology and or function.

Combined Use of Ultrasound and Reverse Trendelenburg Position to Facilitate Cannulation of a Femoral Vein Completely Overlapped by the Femoral Artery

To the Editor: When the femoral artery totally overlaps the femoral vein, inadvertent femoral artery puncture may be inevitable when attempting to cannulate the femoral vein using traditional external landmarks. We describe a case in which successful femoral vein cannulation was achieved without arterial puncture, despite complete overlap of the vein by the femoral artery. Central venous cannulation via the femoral vein was planned in a 3-mo-old infant (7 kg, male) undergoing excision of a lymphangioma on the forehead. After induction of general anesthesia, ultrasound examination of both femoral vessels just distal to the inguinal crease (Sonos 4500®, Philips, MA, equipped with a 5 MHz linear probe) showed that both femoral veins were completely overlapped by the respective femoral arteries (Fig. 1a). Reverse Trendelenburg position and inguinal compression were used to increase the femoral vein cross-sectional area after which the femoral vein cross-sectional area increased from 0.035 cm2 to 0.128 cm2, and the degree of overlap of the femoral vein by the femoral artery was reduced considerably (Fig. 1b). Real-time ultrasound-guided femoral vein catheterization was performed successfully just lateral to the femoral artery on the first attempt without arterial puncture (Fig. 1c).Figure 1.: Ultrasonographic findings of the femoral vein showing the increase in cross-sectional area with inguinal compression in reverse Trendelenburg position (b) from the baseline (a). When the needle (black arrow) entered just lateral to the artery on the ultrasonographic image, the vessel wall was observed to be somewhat collapsed (c). FA = femoral artery; FV = femoral vein.Reverse Trendelenburg position has been reported to increase the diameter of the femoral vein in children and inguinal compression has been reported to increase its size in adults.1,2 In this case, combined use of inguinal compression and reverse Trendelenburg position along with ultrasound guidance allowed us to reduce the risk of arterial puncture facilitating femoral vein cannulation in a child in whom the femoral artery completely overlapped the femoral vein.3 Eun Ha Suk, MD, PhD Department of Anesthesiology and Pain Medicine Asan Medical Center Ulsan university, College of Medicine Seoul, Korea Dong Hun Kim, MD, PhD Department of Radiology Soonchunhyang University College of Medicine Bucheon, Korea [email protected]

Effects of reverse Trendelenburg position and inguinal compression on femoral vein cross‐sectional area in infants and young children

This study evaluated the effects of the reverse Trendelenburg position and additional inguinal compression on the cross-sectional area of the femoral vein in paediatric patients. Seventy subjects were allocated to two groups: the infants group and the children group. Cross-sectional area of the femoral vein was measured just below the inguinal ligament using ultrasound. Three measurements were obtained for each patient: (i) supine, (ii) reverse Trendelenburg position and (iii) reverse Trendelenburg position with inguinal compression. In the infants group, femoral vein cross-sectional area increased by a mean (SD) of 21.1 (15.2) % in the reverse Trendelenburg position and by 60.7 (30.8) % in the reverse Trendelenburg position with inguinal compression; whereas in the children group, femoral vein cross-sectional area increased by 24.7 (15.8) % in the reverse Trendelenburg position and by 100.3 (50.7) % in the reverse Trendelenburg position with inguinal compression. Inguinal compression in the reverse Trendelenburg position offers a useful means of increasing femoral vein cross-sectional area in paediatric patients.

Abdominal Compression Effectively Increases the Size of the Common Femoral Vein, as Measured by Ultrasonography

We determine the effect of abdominal compression on common femoral vein cross-sectional area. The effects of Valsalva maneuver and reverse Trendelenburg's position are also studied. Prospective, observational, comparative evaluation performed on sequential patients presenting to an adult emergency department. Using ultrasonography, common femoral vein area was measured with patients in supine and reverse Trendelenburg's positions. In each position measurements were taken at baseline while abdominal compression was performed and while the patient performed the Valsalva maneuver. Abdominal compression involved pressing with an examining hand over the patient's right upper abdomen. Fifty patients were enrolled in the study. The average common femoral vein area measured 0.89 cm2 at baseline in the supine position. It increased 0.47 cm2 (95% confidence interval [CI] 0.38 to 0.57 cm2) to 1.36 cm2 with abdominal compression and by 0.90 cm2 (95% CI 0.74 to 1.07 cm2) to 1.79 cm2 with the Valsalva maneuver. In the reverse Trendelenburg's position, the common femoral vein area averaged 1.10 cm2, 0.22 cm2 bigger than the supine baseline area (95% CI 0.13 to 0.30 cm2). With additional abdominal compression, the vein area increased by 0.71 cm2 to 1.59 cm2 (95% CI 0.59 to 0.83 cm2). With the patient performing the Valsalva maneuver in the reverse Trendelenburg's position, the vein increased in area 1.07 cm2 (95% CI 0.91 to 1.24 cm2) to 1.96 cm2. Abdominal compression increases the cross-sectional area of the common femoral vein, and the reverse Trendelenburg's position has a further additive effect. Abdominal compression may be useful when femoral venous cannulation is attempted. In patients who can comply, the Valsalva maneuver may be even more effective.

Ultrasonographic Investigation of the Effect of Inguinal Compression on the Cross‐sectional Area of the Femoral Vein

The reverse Trendelenburg position increases the cross-sectional area (CSA) of the femoral vein, making it easier to cannulate, although this position is potentially harmful in hypovolemic patients. The authors hypothesized that compression above the femoral vein increases the CSA of the femoral vein during emergency cannulation. Ultrasound was used to measure the CSA of the femoral vein of 20 healthy volunteers. The following five measurements were made inferior to the inguinal crease: 1) in the horizontal supine position (control), 2) with inguinal compression 2 cm above the inguinal crease (at the point of arterial pulsation and its medial side), 3) in the Trendelenburg position 15 degrees, 4) in the Trendelenburg position 15 degrees plus inguinal compression, and 5) in the reverse Trendelenburg position 15 degrees. Femoral vein CSA was increased by 35% by inguinal compression in the horizontal supine position (p < 0.001) and was decreased by the Trendelenburg position (p < 0.001). However, inguinal compression increased the CSA by 66% in the Trendelenburg position (p < 0.001). The reverse Trendelenburg position also increased the CSA of the femoral vein by 50% (p < 0.001). Inguinal compression presents an alternative method for increasing the CSA of the femoral vein for venous catheterization in normal patients.

Ultrasonographic investigation of the effect of Reverse Trendelenburg on the cross-sectional area of the femoral vein

Emergency physicians often obtain central venous access via the femoral vein in critically ill patients or patients with difficult peripheral access due to chronic intravenous drug use. Previous studies using two-dimensional ultrasonography have demonstrated that the Trendelenburg position increases the cross-sectional area of the internal jugular vein. This study is designed to determine the effect of the Reverse Trendelenburg position on femoral vein dimensions using bedside ED ultrasonography. A prospective, non-randomized observational study was conducted that enrolled subjects at an urban Level I Trauma Center and an affiliated School of Medicine over a 2-month period. Informed consent was obtained from 52 adult subjects with no history of deep venous thrombosis or vascular surgery in the lower limbs. Using two-dimensional ultrasound with a 7.5-MHz linear transducer, femoral vein cross-sectional areas on the right and left sides were measured with subjects supine, and in approximately 15 degrees reverse Trendelenburg. The data was analyzed using a two-tailed Student’s t test. The mean cross-sectional area of the femoral vein with subjects supine was 0.85 cm 2 (SD ± 0.41 cm 2), and 1.22 cm 2 (SD ± 0.51 cm 2) with subjects in reverse Trendelenberg. The cross-sectional area of the femoral vein increased significantly ( p < 0.001) with the reverse Trendelenburg position [55.2% ± 9.1% (95% CI)]. In conclusion, a significant increase in femoral vein cross-sectional area can be achieved with the reverse Trendelenburg position. This maneuver may increase the rate of successful femoral vein catheterization.

Adaptation of the left heart, cerebral and femoral arteries, and jugular and femoral veins during short- and long-term head-down tilt and spaceflights.

The objective of this investigation was to identify the major cardiovascular changes induced by exposure to real or simulated Og (spaceflights: 6, 14, 21 and 25 days, and 6 months; head down tilt, HDT: 10 h, 4, 5, 7, 30 and 42 days), with a minimum of counter-measures. The following cardiovascular data were measured by echocardiography and Doppler ultrasonography: left ventricle end-diastolic volume (LVDV), stroke volume (SV), cardiac output (CO), ejection fraction (EF), middle cerebral artery flow velocity (Qca), femoral artery flow velocity (Qfa), cerebral vascular resistance (Rca), femoral vascular resistance (Rfa), jugular vein cross-sectional area (Ajv), femoral vein cross-sectional area (Afv), heart rate (HR), and mean blood pressure (MBP). LVDV remained decreased compared to pre-HDT or pre-flight levels after 1 week of spaceflight or HDT (-8 to -13%, P<0.05), EF did not change. HR tended to increase (5-10%) during spaceflight and HDT, whereas MBP tended to decrease during flight, but did not change in HDT. These findings are consistent with the existence of a moderate and stable hypovolemia. Qca and Rca fluctuated between +10 and -10% from pre-HDT or pre-flight values, and always showed opposing variations. There was no significant decrease in cerebral perfusion. Lower-limb resistance (Rfa) remained decreased (-5% to -18%, P<0.05) throughout the flights or HDT after week 1. Ajv remained significantly enlarged (+40% P < 0.05) after 1 week in spaceflight or in HDT. Afv was enlarged in spaceflight after week 1 (+15% to +35%, P<0.05), whereas it decreased after 4-5 days of HDT (-20% to -35%, P<0.05). The cardiovascular system reached a new and stable equilibrium during flight and HDT within less than 1 week. With the exception of the femoral vein, there was no significant difference in either the amplitude or the time course of the cardiovascular changes in both situations after 1 week.