Ultrasound-Guided Umbilical Venous Catheter Insertion With Alignment of the Umbilical Vein and Ductus Venosus.

Previous studies have highlighted the importance of confirming the position of an umbilical venous catheter (UVC) tip by an ultrasound (US) examination. However, methods for preventing insertion into the portal circulation under US guidance have not yet been established. We report 15 cases in which a UVC was successfully passed through the ductus venosus by compressing the upper abdomen near the portal sinus of the liver to align the umbilical vein and ductus venosus under US guidance. The UVC was inserted into the correct position in 14 of the 15 neonates (93%) without complications.

Umbilical venous catheter insertion depth estimation using birth weight versus surface measurement formula: a randomized controlled trial.

OBJECTIVE: To determine if umbilical venous catheter (UVC) insertion depth estimated by surface measurement (SM) results in optimal catheter tip position on ultrasound as compared with formula using birth weight (BW). METHODS: In this randomized controlled trial, eligible infants were randomized to UVC insertion depth estimated by SM or BW method. We compared proportion of optimum UVC position on ultrasound read by neonatologist masked with group assignment. RESULTS: UVC was inserted to estimated depth in 164 of 200 enroled infants. There was no difference in the proportion of correctly positioned UVCs between the groups (SM 33/82 (40.2%) vs BW 27/82 (32.9%), p = 0.33). Among BW < 1000 g, SM method had higher correctly positioned UVC (43.7% vs 22.5%, p = 0.07). CONCLUSION: There was no difference in the rate of optimally positioned UVC tip between the two methods for estimating UVC insertion depth. However, SM method results in more optimal positioning of UVC tip among BW < 1000 g infants.

Variation of the maximum velocity along the umbilical vein supports the Reynolds pulsometer model.

OBJECTIVE: To challenge, with a modern sonographic approach and a numerical model, the Reynolds's concept which suggests that the vascular structure of the umbilical cord could act as a pulsometer facilitating the venous return to the foetus. METHOD: Forty-five patients between 20 and 28 weeks of gestation were included in the study. The blood maximum velocity in the umbilical vein, measured at both foetal and placental ends, was assessed. Several sonographic parameters of the cord, including the diameter of the umbilical vein at both extremities, cord cross-sectional area and Wharton's jelly section surface were measured. We compare our data with those of a numerical model. RESULTS: A difference in maximum velocity between the two extremities of the umbilical vein (ΔUVVmax) was noted. The maximum velocity was significantly higher at the foetal umbilical end (14.12 +/-3.18 cm/s) than at the placental end (11.93 +/-2.55 cm/s; p < 0.0001). The mean difference is 2.2 +/- 2.3 cm/s. No difference in the umbilical vein diameter was measured at both cord ends (umbilical 4.85 +/-0.9 mm, placental 4.86 +/-0.87 mm, p < 0.0001). There is no significant relationship between ΔUVVmax and the cord cross-sectional area or Wharton's jelly index. CONCLUSION: Modifications of the spatial velocity profile together with the pulsometer model could explain the maximum velocity changes that is measured in the umbilical vein along the cord. This numerical model consolidates the sonographic observations.

The types of connections between the portal sinus and main portal vein in foetuses / Tipos de conexiones entre el seno portal y la vena porta principal en fetos

In the prenatal period, the three types of connections between the portal sinus and main portal vein have been published in the literature: T, X and H-shaped. The T type is the most frequent in the literature, and the aim of our study is to define the percentage of the connection types during the prenatal period in our population. In this prospective study, 237 women between 20 and 38 weeks of pregnancy without a foetal anomaly or pregnancy-related complications were included, and the precordial veins of the foetuses were examined using a wide-band color Doppler technique. The types of connections were determined by two specialists according to the shape of the colour coded vessels in Doppler examinations. The criteria of Czubalski & Aleksandrowicz (2000) were used. All of the connection types in patients were confirmed using video clips and were stored in the picture archiving and communication system. In 237 patients, the types of connection were determined by the first specialist as 189 foetuses (79.7 %) with the X-shaped or side-to-side connection, 16 foetuses (6.8 %) with the T-shaped or end-to-side type and 32 foetuses (13.5 %) with the H-shaped or parallel-coursed vessels connected with a short segment. The most common types of connections between the portal sinus and main portal vein in foetuses are X shaped or side-to-side, which is contrary to previous studies.

En el período prenatal, se han publicado en la literatura los tres tipos de conexiones entre el seno portal y la vena porta principal: en forma de T, X y H. El tipo T es el más frecuente, y el objetivo de nuestro estudio fue definir el porcentaje de tipos de conexión durante el período prenatal en nuestra población. En este estudio prospectivo, se incluyeron 237 mujeres entre 20 y 38 semanas de embarazo, sin anomalías fetales o complicaciones relacionadas con el embarazo, y se examinaron las venas precordiales de los fetos utilizando una técnica Doppler de banda ancha. Los tipos de conexiones fueron determinados por dos especialistas según la forma de los vasos codificados por color en los exámenes Doppler. Se utilizaron los criterios del estudio de Czubalski & Aleksandrowicz. Todos los tipos de conexión en los pacientes se confirmaron mediante videoclips y se almacenaron en el sistema de comunicación y en archivo de imágenes. En 237 pacientes, el primer especialista determinó en 189 fetos (79,7 %) la conexión en forma de X o de lado a lado; en 16 fetos (6,8 %) la forma de T o Tipo de extremo a lado; y en 32 fetos (13,5 %) los vasos en forma de H o paralelos, conectados con un segmento corto. Los tipos más comunes de conexiones entre el seno portal y la vena porta principal en los fetos son en forma de X o de lado a lado, lo que es contrario a estudios anteriores.

Umbilical cord twist - Does it play a role in placental morphology?

Studies have described the placental morphology and its changes in a pathological scenario. But the role of a twisting pattern of umbilical vessels in determining the placental morphology of uncomplicated pregnancy has not been discussed. The objective of the study was to determine the clinical significance of umbilical cord twist in determining the umbilical cord coiling index, the diameter of hyrtl's anastomosis, branching pattern of the placental vasculature, placental weight, Eccentricity index and Cord centrality index. The proportion of umbilical cords with left and right twist were 246 (78.6%) and 67 (21.4%) respectively. The right twisted cords had significant higher umbilical artery diameter, higher umbilical cord coiling index and preferential magistral pattern of blood vessels. This proves that twisting of the cord might play a minor role in altering the blood flow and determining the vasculature pattern but not sufficient enough to influence the placental weight, the shape of the placenta and umbilical cord insertion

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Investigation of umbilical venous vessels anatomy and diameters as a guideline for catheter placement in newborns.

Umbilical cord catheters (UCC) are important for the primary care of critically ill newborns. To analyze anatomical variations of the umbilical vein (UV) and its further course, we performed abdominal spiral-CT examinations on stillborns. The aim of the study was to explore the high incidence of mal-positioned UCCs and to improve their positioning. Eighteen stillborns were investigated (29.2 weeks ± 6.7 weeks (IQR)). CTs were performed using either air or contrast medium injection into the UV. We measured the diameter at the narrowest points of (i) the umbilical vein, (ii) the segmental portal vein, (iii) the left portal vein, (iv) the umbilical recess, and (v) the ductus venosus. The branching angles between (a) the umbilical vein and intrahepatic veins and (b) the ductus venosus and umbilical recess were measured. The diameter of the UV increases from 3.4 to 11 mm (median [IQR]:4.6 mm [4.2-6.9]: r2 = 0.64). The left portal vein has a larger diameter (3.6 mm [2.6-4.55]; r2 = 0.43) than the left segmental portal vein (2.3 mm [1.8-2.75]; r2 = 0.23). The diameter of the ductus venosus (2.5 mm [1.6-3.4]; r2 = 0.59) is half that of the umbilical recess (5.1 mm [3.3-6.2]; r2 = 0.43). The most obtuse angle is formed by the junction between the umbilical recess and ductus venosus (151° [133-159]; r2 = 0.001). The branch angle from the outgoing UV into the left portal vein is more obtuse (128° [123-144]; r2 = 0.0001) than that of the segmental portal vein (115° [105-119]; r2 = 0.0001). To avoid mal-positioning, our data suggest the use of a soft catheter. The UV and its extensions are wide enough to admit a 4 Fr. catheter without complete obstruction. Clin. Anat. 31:269-274, 2018. © 2017 Wiley Periodicals, Inc.

Histological characterization of umbilical cord in alpaca (Vicugna pacos).

The histomorphometric features of umbilical cord constituents in seven foetuses of alpaca (Vicugna pacos) from Cerro de Pasco, Department, Peru, were determined. Sections of 2-5 cm of umbilical cord were fixed in 10% neutral buffered formalin and processed for light microscopy. Standard histological slides stained with haematoxylin and eosin, Masson's trichrome and Van Gieson's trichrome were obtained. Histologically, common features of umbilical artery and vein were observed as well as mucous connective tissue, some cell features that compound this tissue constituted by cells presented features of myofibroblasts. Among most important findings that were observed, the lumen of umbilical vein was obliterated into star-shaped form with the thinner umbilical artery wall; the smooth muscles and fibroblast were comparatively more in number in umbilical artery than that of umbilical vein, and the tunica media was larger in dimension than the tunica adventitia in umbilical vein. Conclusively, this histological study features an observation of the umbilical cord of alpaca foetuses and shows the similarity between them and those of other mammal species, including dromedaries and South American camelids.

Longitudinal reference range for umbilical cord cross-sectional area in twin pregnancies at 18-32 weeks of gestation.

OBJECTIVES: The objectives of this study were to establish gestational age-specific reference ranges for cross-sectional area of the umbilical cord, and its components, in twin pregnancies and to compare them with previously reported singleton reference ranges. METHODS: This was a prospective longitudinal study involving uncomplicated dichorionic twin pregnancies. Sonographic measurements of the cross-sectional area of the umbilical cord, umbilical vein and arteries and Wharton's jelly were obtained in a plane adjacent to the fetal abdomen, every 3 weeks, between 18 and 32 weeks of gestations. Multilevel regression analysis was used to determine gestational age-specific reference ranges for each parameter, and these were plotted against singleton pregnancy references. RESULTS: Three hundred and thirty four ultrasound scans were performed in 44 twin pregnancies, between 18 and 32.9 weeks (mean: 3.8 ± 0.7 scans/pregnancy and mean interval between scans: 3.3 ± 0.9 weeks). All umbilical cord cross-sectional areas (total, vein, artery and Wharton's jelly) showed a significant increase with gestational age. Compared with singleton pregnancy ranges, mean values were considerably lower in twin pregnancies and resemble the lower limits observed in singletons. CONCLUSION: In twin pregnancies, cross-sectional area of the umbilical cord, and its components, increases between 18 and 32 weeks, and mean values are substantially lower compared with singleton pregnancies.

Simple measurements to place umbilical catheters using surface anatomy.

OBJECTIVE: To use external anatomical landmarks to determine a new method for the estimation of appropriate insertion length of umbilical catheters, suitable for newborn infants of varying birth weight (BW) and gestational age. STUDY DESIGN: Neonates who had umbilical venous (UVC) or arterial (UAC) catheters placed soon after birth were included in the study. Catheters were placed using formulas derived by Shukla (1986) and/or Wright (2007), and adjusted to appropriate positions confirmed radiologically: UAC tip between T6-T10 vertebral bodies and UVC at the level of the diaphragm±0.5 cms. Final catheter length was compared with the length estimated by Shukla/Wright formulas and to four additional morphometric measurements: umbilicus to nipple (UN), umbilicus to midpoint of inter-mammary distance, umbilicus to xiphoid process and umbilicus to symphysis pubis (USp). RESULT: Of 216 infants, 32 were excluded; UVC was placed in 170 infants and UAC in 125 infants. Among the morphometric measurements, UN-1 cm ( UN distance minus 1 cm) provided the best estimate of accurate insertion length of UVC, (r=0.984, P<0.001) and estimated correct insertion length of 94% of UVCs compared with 57% accuracy with Shukla formula for all BW categories (P<0.001). Morphometric measurement UN-1+2 USp (UN distance minus 1 cm plus twice the distance from umbilicus to symphysis pubis) showed significantly better correlation with appropriate insertion length of UAC (r=0.985, P<0.001) and estimated correct insertion length of 92% of UACs in all infants as compared with 57% accuracy with Shukla formula (P<0.001), and the correct insertion length in 94% of very low BW infants as compared with 68% accuracy with Wright formula (P<0.001). CONCLUSION: Simple and intuitive morphometric measurements UN and USp provide more accurate estimates of appropriate insertion lengths for umbilical catheters in infants with all BWs than commonly used BW-based formulas.

A comparative study on the uniaxial mechanical properties of the umbilical vein and umbilical artery using different stress-strain definitions.

The umbilical cord is part of the fetus and generally includes one umbilical vein (UV) and two umbilical arteries (UAs). As the saphenous vein and UV are the most commonly used veins for the coronary artery disease treatment as a coronary artery bypass graft (CABG), understating the mechanical properties of UV has a key asset in its performance for CABG. However, there is not only a lack of knowledge on the mechanical properties of UV and UA but there is no agreement as to which stress-strain definition should be implemented to measure their mechanical properties. In this study, the UV and UA samples were removed after caesarean from eight individuals and subjected to a series of tensile testing. Three stress definitions (second Piola-Kichhoff stress, engineering stress, and true stress) and four strain definitions (Almansi-Hamel strain, Green-St. Venant strain, engineering strain, and true strain) were employed to determine the linear mechanical properties of UVs and UAs. The nonlinear mechanical behavior of UV/UA was computationally investigated using hyperelastic material models, such as Ogden and Mooney-Rivlin. The results showed that the effect of varying the stress definition on the maximum stress measurements of the UV/UA is significant but not when calculating the elastic modulus. In the true stress-strain diagram, the maximum strain of UV was 92 % higher, while the elastic modulus and maximum stress were 162 and 42 % lower than that of UA. The Mooney-Rivlin material model was designated to represent the nonlinear mechanical behavior of the UV and UA under uniaxial loading.

Umbilical vein catheterization in the critical newborn: a review of anatomy and technique.

Why attempt a UVC line when intraosseous access is often available and the literature has demonstrated its ease of placement and effectiveness even in neonates? This article is not intended to suggest giving up IO vascular access if you currently have it in your toolbox. The intent was to discuss an alternative to IO vascular access when it fails--for example, when a tibia is fractured during an IO attempt or is not an option for other reasons. The Fast-Cath UVC is another tool in the advance EMS clinician's arsenal that can be easily learned and utilized. It is an effective option for vascular access in the distressed newborn when other options have failed or are not available.

Sonographic measurement of the umbilical cord area and the diameters of its vessels during pregnancy.

The objective was to determine the cross-sectional area of the umbilical cord, its diameter and the diameter of its vessels to establish a reference curve for these parameters during pregnancy, through a prospective cross-sectional study, including 2,310 low-risk pregnancies between 12 and 40 weeks' gestation. Means and standard deviations (SDs), plus the 10th, 50th and 90th percentiles for each measurement were calculated using polynomial regression analysis. Mann-Whitney, Kruskal-Wallis and Wilcoxon tests were used for statistical analysis. These parameters increased significantly with gestational age. The area of the cord also varied significantly with parity. Their new reference curves for low risk pregnancies were calculated using polynomial regression, and an almost linear increase in values was found up to 32 weeks of pregnancy, tending to stabilise from then onwards. The regression equation of the umbilical cord area according to gestational age (GA) was: -1.417 + 0.3026*GA-0.008*GA(2) + 0.000007*GA(3) and the degree of adjustment (R(2)) was 0.89.

Positive correlation between the quantity of Wharton's jelly in the umbilical cord and birth weight.

OBJECTIVE: To determine the possible protective effects of Wharton's jelly (WJ) in umbilical cord and fetal growth by investigating the relationship between the amount of WJ and fetal birth weight. MATERIALS AND METHODS: This study enrolled 299 women who delivered after an uneventful pregnancy. After separation of the placenta, a 5cm long section of umbilical cord was removed by scalpel. The weight of the cord section; the weight, volume, and density of its WJ; and the weight of the newborn and placenta were measured. RESULTS: A significant positive correlation was found between WJ quantity, birth weight (p=0.002), and placental weight (p=0.003), whereas a significant negative correlation was observed for WJ density, fetal growth (p=0.035), and placental growth (p=0.002). WJ density was 1.63 ± 0.27g/mL. No significant correlation was found between the amount of WJ and weight gained during pregnancy (p=0.274) or maternal age (p=0.220). CONCLUSION: As the amount of WJ increases, fetal weight increases. Accordingly, the amount of WJ might be a factor that influences fetal growth.

Amlodipine treatment prevents angiotensin II-induced human umbilical vein endothelial cell apoptosis.

BACKGROUND AND AIMS: Amlodipine, a long-acting dihydropyridine calcium channel blocker, is able to improve angiotensin II-mediated vascular endothelial dysfunction. However, the underlying mechanism remains not fully understood. In the present study we attempted to determine whether the protective effect of amlodipine against Ang II-induced endothelial impairment was mediated through blockage of endothelial cell apoptosis. METHODS: We pretreated human umbilical venous endothelial cells with increasing doses of amlodipine (10(-8)-10(-6) M) followed by the addition of Ang II. Cell apoptosis was assessed by acridine orange/ethidium bromide staining and by annexin-V/propidium iodide double-labeled cytometry. The involvement of the apoptosis regulators, Bcl-2, Bax, and lectin-like oxidized low-density lipoprotein receptor-1, was determined. RESULTS: Pretreatment with amlodipine resulted in a dose-dependent suppression of Ang II-induced HUVEC apoptosis. Moreover, the Bcl-2/Bax ratio was found to be increased in cells pretreated with amlodipine, indicating an enhanced anti-apoptosis potential. Additionally, the induction of LOX-1 by Ang II was remarkably counteracted by the pre-exposure to amlodipine. CONCLUSIONS: Our data demonstrate that amlodipine ameliorates Ang II-induced endothelial apoptosis, which is likely associated with the elevation of Bcl-2/Bax ratio and reduction of the LOX-1 expression.

Where the O2 goes to: preservation of human fetal oxygen delivery and consumption at high altitude.

Fetal growth is decreased at high altitude (> 2700 m). We hypothesized that variation in fetal O(2) delivery might account for both the altitude effect and the relative preservation of fetal growth in multigenerational natives to high altitude. Participants were 168 women of European or Andean ancestry living at 3600 m or 400 m. Ancestry was genetically confirmed. Umbilical vein blood flow was measured using ultrasound and Doppler. Cord blood samples permitted calculation of fetal O(2) delivery and consumption. Andean fetuses had greater blood flow and oxygen delivery than Europeans and weighed more at birth, regardless of altitude (+208 g, P < 0.0001). Fetal blood flow was decreased at 3600 m (P < 0.0001); the decrement was similar in both ancestry groups. Altitude-associated decrease in birth weight was greater in Europeans (-417 g) than Andeans (-228 g, P < 0.005). Birth weight at 3600 m was > 200 g lower for Europeans at any given level of blood flow or O(2) delivery. Fetal haemoglobin concentration was increased, decreased, and the fetal / curve was left-shifted at 3600 m. Fetuses receiving less O(2) extracted more (r(2) = 0.35, P < 0.0001). These adaptations resulted in similar fetal O(2) delivery and consumption across all four groups. Increased umbilical venous O(2) delivery correlated with increased fetal O(2) consumption per kg weight (r(2) = 0.50, P < 0.0001). Blood flow (r(2) = 0.16, P < 0.001) and O(2) delivery (r(2) = 0.17, P < 0.001) correlated with birth weight at 3600 m, but not at 400 m (r(2) = 0.04, and 0.03, respectively). We concluded that the most pronounced difference at high altitude is reduced fetal blood flow, but fetal haematological adaptation and fetal capacity to increase O(2) extraction indicates that deficit in fetal oxygen delivery is unlikely to be causally associated with the altitude- and ancestry-related differences in fetal growth.

Hematoma espontáneo del cordón umbilical / Spontaneous haematoma of the umbilical cord

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Umbilical venous blood flow measurement: accuracy and reproducibility.

Umbilical venous blood flow could be considered a direct and physiological measurement of vascular placental function, representing the quantity of oxygen and nutrients reaching the fetus. The advent of high-technology ultrasound and pulsed Doppler has overcome some of the limitations of early studies. Indeed, Doppler measurement of umbilical venous blood flow has been found to be accurate when compared with several gold standards for in-vivo flow calculation. Nevertheless, small errors in volume flow components, the vessel area and the mean velocity, result in large errors in the calculation of volume flow. Therefore, technique standardization is of paramount importance. Validation studies in animal models have demonstrated accurate venous blood flow measurements by estimating the vessel's cross-sectional area from perpendicular views of longitudinal sections of free-floating portions of the cord. On the other hand, estimation of the mean velocity from the maximum velocity, rather than using the intensity-weighted mean velocity, is less software-dependent and more clearly defined, yielding estimates with more predictable and systematic errors. By adhering to stringent methodological recommendations, umbilical venous blood flow calculation has moderate to good intra- and interobserver reproducibility. Having been found to be accurate and reproducible, further studies are required to establish the clinical value of umbilical vein flow measurement.