Impact of the inferior vena cava morphology on fluid dynamics of the hepatic veins.

We reported previously that a large vertical interval between the hepatic segment of the inferior vena cava (IVC) and right atrium (RA), referred to as the IVC-RA gap, was associated with more intraoperative bleeding during hemi-hepatectomy. We conducted a computational fluid dynamics (CFD) study to clarify the impact of fluid dynamics resulting from morphologic variations around the liver. The subjects were 10 patients/donors with a large IVC-RA gap and 10 patients/donors with a small IVC-RA gap. Three-dimensional reconstructions of the IVC and hepatic vessels were created from CT images for the CFD study. Median pressure in the middle hepatic vein was significantly higher in the large-gap group than in the small-gap group (P = 0.008). Differences in hepatic vein pressure caused by morphologic variation in the IVC might be one of the mechanisms of intraoperative bleeding from the hepatic veins.

Effect of breathing on venous return during delayed cord clamping: an observational study.

OBJECTIVE: To investigate the effect of spontaneous breathing on venous return in term infants during delayed cord clamping at birth. METHODS: Echocardiographic ultrasound recordings were obtained directly after birth in healthy term-born infants. A subcostal view was used to obtain an optimal view of the inferior vena cava (IVC) entering the right atrium, including both the ductus venosus (DV) and the hepatic vein (HV). Colour Doppler was used to assess flow direction and flow velocity. Recordings continued until the umbilical cord was clamped and were stored in digital format for offline analyses. RESULTS: Ultrasound recordings were obtained in 15 infants, with a median (IQR) gestational age of 39.6 (39.0-40.9) weeks and a birth weight of 3560 (3195-4205) g. Flow was observed to be antegrade in the DV and HV in 98% and 82% of inspirations, respectively, with flow velocity increasing in 74% of inspirations. Retrograde flow in the DV was observed sporadically and only occurred during expiration. Collapse of the IVC occurred during 58% of inspirations and all occurred caudal to the DV inlet (100%). CONCLUSION: Spontaneous breathing was associated with collapse of the IVC and increased antegrade DV and HV flow velocity during inspiration. Therefore, inspiration appears to preferentially direct blood flow from the DV into the right atrium. This indicates that inspiration could be a factor driving placental transfusion in infants.

Relationship between hepatic venous anatomy and hepatic venous blood loss during hepatectomy.

PURPOSE: Predicting increased blood loss based on anatomical intervascular relationships is essential in major hepatectomy. METHODS: We assessed 63 consecutive patients undergoing anatomical hepatectomy exposing the hepatic vein (HV) trunk at two institutes. Correlations between anatomical alterations of the hepatic inferior vena cava (IVC), HV, hepatic IVC, or right atrium (RA) and the blood loss per standard weight (BLSW) or blood transfusion (n = 18) were analyzed. The results of IVC partial clamping (PC) were additionally examined. RESULTS: The BLSW in type V-up anatomical morphology was significantly higher than that in straight type (p < 0.05). The parameters associated with an increased BLSW (> 13.5 mL/kg) were tumor size (> 4 cm), prothrombin activity (< 87%), CVP (> 7 mmHg), area of suprahepatic IVC (< 360 mm2), IVC-RA gap (> 28 mm), longitudinal angle of IVC (< 160°), and axial angle of the MHV (< 55°). A multivariate analysis revealed that a high IVC-RA gap was a significant independent risk factor (odds ratio; 4.32, p < 0.05). Among 25 patients undergoing IVC-PC, only three showed a remarkable decrease in hepatic venous bleeding. No other statistically significant differences in the surgical records were observed in most cases. CONCLUSION: The IVC-RA gap might be a promising novel predictive parameter reflecting increased blood loss leading to blood transfusion in anatomical hepatectomy.

Outcomes of transjugular liver biopsies for liver transplant recipients with bicaval and piggyback hepatic vein anastomoses.

BACKGROUND: Liver transplant hepatic venous anastomoses are usually created using "bicaval" or "piggyback" techniques, which may result in unfavorable angulation between the inferior vena cava and hepatic veins, and makes hepatic vein catheterization and tissue sampling during transjugular liver biopsy (TLB) technically challenging. PURPOSE: To compare the technical successes and complications of TLBs for recipients of liver transplants with bicaval and piggyback hepatic vein anastomoses. MATERIAL AND METHODS: Information on type of hepatic vein surgical anastomosis was available for 190 adult patients in whom 306 consecutive TLBs were performed during 2009-2017: 158 with bicaval and 148 with piggyback anastomoses. The primary outcome of procedural success was defined as obtaining a tissue sample sufficient to make a pathologic diagnosis. RESULTS: A technical success rate of 97% with adequate liver tissue for diagnosis was similar between the anastomotic groups (P = 0.50). TLB was unsuccessful in 3% of patients with piggyback anastomoses due to unfavorable hepatic venous anatomy whereas biopsy was successful in all patients with bicaval anastomoses (P = 0.02). Fluoroscopy times were not significantly different (12.1 vs. 13.9 min, P = 0.08). Rates of major complication were similar between the two groups (3% vs. 3%, P > 0.99). CONCLUSION: TLB is safe and effective for liver transplant patients regardless of the type of hepatic vein anastomosis. While failure to catheterize or advance the stiffened biopsy cannula into the hepatic vein is more likely to occur in patients with piggyback anastomoses, this is a rare occurrence.

Intra-abdominal Inferior Vena Cava Injuries: Operative Strategies and Outcomes.

Visceral vascular injuries are relatively uncommon even in busy urban trauma centers. The inferior vena cava (IVC) is the most frequently injured visceral vein and can be a complex operative challenge. Despite advances in early volume resuscitation, improved transport times, prompt operative intervention, and hemorrhage control, mortality rates have remained largely unchanged. This article conducts an in-depth review of the literature surrounding IVC injuries and a detailed discussion of operative strategies and management as survivability is ultimately dependent on the grade of injury, location, and the presence of hemorrhagic shock.

Duplication of the inferior vena cava: evidence of a novel type IV.

Anatomical variations of the inferior vena cava, including the double inferior vena cava or isolated left inferior vena cava, are uncommon and of great clinical importance. Inferior vena cava variations signify predisposition to deep vein thrombosis and may complicate retroperitoneal surgeries including abdominal aortic surgery. Failure to recognize such variations may predispose a patient to life- threatening complications. This prospective anatomical study assessed 129 cadavers for variations of the inferior vena cava. One of the 129 cadavers (0.78%) possessed a double inferior vena cava and none (0%) possessed an isolated left inferior vena cava. The left-sided inferior vena cava was of a larger diameter than that of the right-sided inferior vena cava - opposite of what would be seen in a Type III duplication. Therefore, this observation expands the three-type classification system to include a Type IV duplication.

Association of inferior vena cava diameter ratio measured on computed tomography scans with the outcome of patients with septic shock.

The collapsibility and diameter of the inferior vena cava (IVC) are known to predict the volume state in critically ill patients. However, no study has examined the prognostic value of the IVC diameter ratio measured on computed tomography (CT) in patients with septic shock. A retrospective observational study was conducted on adult septic shock patients visiting the emergency department at a university hospital in Korea. The IVC diameter ratio was calculated by dividing the maximal transverse and anteroposterior diameters. Multivariable logistic regression analysis was conducted to investigate whether the IVC diameter ratio predicted in-hospital mortality. The area under the curve (AUC) was calculated, and the sensitivity, specificity, positive predictive value, and negative predictive value with the cut-off values were computed. A total of 423 adult septic shock patients were included, and the in-hospital mortality rate was 17%. The median IVC diameter ratio in non-survivors was significantly greater than in survivors (1.56 cm vs 1.4 cm, P = .004). The IVC diameter ratio was found to be significantly associated with in-hospital mortality on multivariate logistic regression analysis after adjustment for confounding variables (odds ratio = 1.48, confidence interval: 1.097-1.998, P = 0.01). The AUC for IVC diameter ratio was 0.607. A cut-off IVC diameter ratio of ≥1.31 cm had 75% sensitivity and 42% specificity for predicting in-hospital mortality. The IVC diameter ratio measured on CT may to be helpful in predicting the prognosis of septic shock patients. However, due to its low diagnostic performance and sensitivity, further research is warranted.

Age-Related Histological Changes in Vena Caval System of Human Foetus and Adult: A Comparative Study.

BACKGROUND: It has been documented that cardiac musculature is present in both venae cavae, and they contract together with the atrium, contributing to the pumping mechanism of the heart. So, in the present study, we measured the relative thicknesses of the three histological layers at formation, termination and intermediate levels of the venae cavae along with their histological characteristics. MATERIALS AND METHODS: Ten foetal and 10 adult cadavers were used. The Superior and Inferior Venae Cavae from all three regions were excised and processed for histology. The qualitative and quantitative features of the vessels were observed and recorded. The data thus obtained was then assessed statistically. RESULTS: In superior vena cava, the tunica intima grows actively especially during late gestation. The tunica media shows active growth. The tunica adventitia growth is significant at the middle and termination levels. In inferior vena cava, the tunica intima grows actively at the level of formation. The tunica media shows the active overall growth during early gestation. The tunica adventitia shows active growth during late gestation. In qualitative analysis the plump, spindle-shaped primitive mesenchymal cells were observed. Muscle and collagen fibers show reciprocal abundance with increasing age, with the former being lesser in amount than the latter in earlier stages. Appearance of vasa vasorum was notable from 2nd trimester. The cardiac myocytes were located in the middle and outer tunics of the superior vena cava. CONCLUSION: Cardiac musculature was absent in the inferior vena; however, the vessel shows advanced rate of overall development.

The diaphragm affects echocardiographic measurement of inferior vena cava diameter to predict right atrial pressure.

PURPOSE: It is recommended in current guidelines that the inferior vena cava (IVC) diameter should be measured at 1.0-2.0 cm from the junction with the right atrium. However, right atrial pressure (RAP) is underestimated in some patients who have a small IVC diameter (IVCD) because of a high-echo structure compressing the IVC from the back at that portion. The aim of this study was to identify the structure behind the IVC and to evaluate its influence on RAP. METHODS: We retrospectively studied 116 patients who underwent right-heart catheterization. We reviewed computed tomography (CT) scans and analyzed the relation between RAP and IVCD measured by echocardiography not only in the way recommended in the guidelines, but also in a way that avoided the structure. RESULTS: CT scans revealed that the diaphragm, not the vertebra, was located just behind the IVC in most patients. Sixteen patients (13.8%) had RAP ≥ 10 mmHg. In those patients, when IVCs were measured in a way that avoided the diaphragm, IVCDmax diameter was larger and IVC collapsibility index (IVCCI) tended to be smaller than those when IVCDs were measured according to the guideline methods. The sensitivity of IVCD to predict RAP ≥ 10 mmHg (IVCDmax > 21 mm, IVCCI < 50%) increased from 31.3% to 68.8% with our method. CONCLUSIONS: The high-echo structure pushing the IVC from the back is the diaphragm in most patients. It might be better to measure IVCD using a method that avoids the diaphragm to accurately estimate RAP.

Posterior extrapelvic tributaries to the internal iliac veins: Morphometrics, types, and variants.

BACKGROUND: In the distribution of the veins, it corresponds in the path and by its affluent to their arterial counterpart. For the pelvic surgeon faced with pelvic surgical pathology, the knowledge of the distribution of the venous vessels is especially important in view of novel surgical techniques and current approaches. The majority of the reports are on common iliac vein (CIV) or the inferior vena cava. To the best of our knowledge, there are no papers describing posterior extrapelvic affluents that drain into the internal iliac vein (IIV). OBJECTIVE: The aim of this work was to describe the pattern of the constitution of the IIV in 17 dissection specimens taken at our institution. MATERIALS AND METHODS: We dissected and registered the anatomic variations of the posterior extrapelvic tributaries to the IIVs. RESULTS: Moreover, we describe the presence of a vein here that is, as far as we know, the first report of a vein that is formed from the posterior extrapelvic veins that drain exactly onto the anterior surface of the CIV. We also describe herein the variants that we have found. CONCLUSIONS: The ignorance of the anatomic variations in the posterior extra-pelvic tributaries to the IIVs (internal iliac veins) can lead to fatal consequences in the patients undergoing pelvic surgery.

ANTECEDENTES: En la descripción de los trayectos venosos, estos corresponden casi exactamente a la distribución de su contraparte arterial, como es el caso de la vena iliaca interna. Para el cirujano que se enfrenta a la patología pélvica, el conocimiento de la distribución de los vasos venosos es de particular importancia. Los reportes que describen los grandes vasos venosos pélvicos se enfocan en las venas iliacas comunes o la vena cava inferior. En nuestro conocimiento, no existen ­reportes que describan los afluentes venosos posteriores que drenan a la vena iliaca interna ni las distancias que separan los vasos entre sí. OBJETIVO: Describir el patrón de constitución de la vena iliaca interna en 17 especímenes cadavéricos disecados en nuestra institución. MATERIAL Y MÉTODOS: Se identificaron los trayectos vasculares de los afluentes venosos posteriores extrapélvicos de las venas iliacas primitivas. RESULTADOS: En específico, describimos la presencia de una variante venosa que, hasta donde hemos revisado, es el primer reporte, pues esta vena posterior extrapélvica drena exactamente en la superficie anterior de la vena iliaca común. También describimos otras variantes encontradas. CONCLUSIONES: Conocer las variantes de los afluentes venosos posteriores extrapélvicos es de vital importancia para el cirujano que realiza cirugía pélvica.

Automated Ultrasound Measurement of the Inferior Vena Cava: An Animal Study.

Because of continuous movement and variation in diameter of the inferior vena cava (IVC) with respiration, the measurements on IVC are labor-intensive and with considerable inter-operator variations. Some computer-assisted techniques have been developed to track the movement of the IVC semi-automatically. However, existing methods predominantly rely on reference marker selection and require many manual inputs. In this study, we developed a cross-correlation (CC)-based method for automated IVC movement tracking and measurement, which requires minimal manual input and avoids manual selection of reference markers. Based on the CC method, two approaches, named direct and relative approaches, were used to calculate the maximum, minimum, and variation of the IVC diameter, and compared with the manual measurement. Fifty-four ultrasound cine-loops collected from nine pigs were tested. The results reveal that both the proposed approaches were well agreed with the manual measurement. The errors of the direct approach were less than 9%, while those of relative approach were as high as 26.7%. It is concluded that the proposed direct approach is superior for IVC diameter measurements, which can be comparable with manual counterpart, serving as an alternative to traditional IVC measurement.

[Index from Diameter of Inferior Vena Cava and Abdominal Aorta of Newborns - A Relevant Method for Evaluation of Hypovolemia]. / Index aus Diameter der Vena cava inferior und Aorta abdominalis bei Neugeborenen ­ eine praxisrelevante Methode zur Erfassung einer Hypovolämie.

Hypovolemia is one of the important problems in sick neonates. Ultrasound is a safe, noninvasive diagnostic tool for the assessment of volume status. For that reason, the aim of the study was to determine normal values of the diameter of inferior vena cava (IVC), abdominal aorta (Ao) and the index IVC/Ao. PATIENTS AND METHODS: 97 healthy, term neonates were included in the study and investigated at first and third day of life. The diameter of IVC, Ao was measured and the index from IVC/Ao was estimated. Using statistics mean and median values of the parameters and correlations to birth weight were determined. RESULTS: Diameter of Ao at first day was 6.1 (+/-0.6) mm and at third day 6.2 (+/-0.6) mm, of IVC at first day was 2.5 (+/-0.5) and at third day 2.61 (+/-0.5). The Index from diameters of IVC/Ao was evaluated at day 1 as 0.4 (+/-0.1) and day 3 as 0.4 (+/-0.1). We found a positive correlation to the birth weight. We identified a significant difference of the index in SGA and LGA - neonates (0.36 vs 0.47). Despite a significant reduced weight from first to third day in the neonates, we determined no influence on the diameter of IVC, Ao and the index IVC/Ao. CONCLUSION: We determined normal values of diameter of IVC and Ao and the Index of IVC/Ao. It is our opinion, that it is possible to assess the intravascular volume using the index. The importance of the index can be underlined by the results in SGA-neonates. More research is needed to understand some points of the pathophysiology in SGA.

Tratamento endovascular de síndrome congestiva venosa pélvica em paciente com duplicação de veia cava inferior e anatomia venosa pélvica incomum: revisão bibliográfica / Endovascular treatment of pelvic venous congestion syndrome in a patient with duplication of the inferior vena cava and unusual pelvic venous anatomy: literature review

Resumo A dor pélvica crônica afeta aproximadamente 1/3 de todas as mulheres e é responsável por cerca de 20% de todas as consultas ginecológicas. Os autores relatam um raro caso de congestão venosa pélvica sintomática na presença de duplicação de veia cava inferior e comunicação interilíaca através de veia hipogástrica direita tratado com abordagem endovascular, por embolização das veias varicosas pélvicas e revisão da literatura publicada.

Abstract Chronic pelvic pain affects approximately one-third of all women and is responsible for about 20% of all gynecological consultations. The authors report a rare case of symptomatic pelvic venous congestion in the presence of duplication of the inferior vena cava and inter-iliac communication through the right hypogastric vein that was treated via an endovascular approach with embolization of varicose pelvic veins. The published literature is reviewed.

Allogeneic Venous Grafts of Different Origin Used for Portal Vein Reconstruction After Pancreaticoduodenectomy - Experimental Study.

BACKGROUND: In clinical medicine, little is known about the use of allografts for portal vein (PV) reconstruction after pancreaticoduodenectomy (PD). Portal and caval systems are physiologically different, therefore the properties of allografts from caval and portal systems were studied here in a pig model. MATERIALS AND METHODS: PD with PV reconstruction with allogeneic venous graft from PV or inferior vena cava (IVC) was performed in 26 pigs. Biochemical analysis and ultrasonography measurements were performed during a 4-week monitoring period. Computer simulations were used to evaluate haemodynamics in reconstructed PV and explanted allografts were histologically examined. RESULTS: The native PV and IVC grafts varied in histological structure but were able to adapt morphologically after transplantation. Computer simulation suggested PV grafts to be more susceptible to thrombosis development. Thrombosis of reconstructed PV occurred in four out of five cases in PV group. CONCLUSION: This study supports the use of allografts from caval system for PV reconstruction in clinical medicine when needed.

Caval-aortic ratio and caudal vena cava diameter in dogs before and after blood donation.

OBJECTIVE: To investigate whether the donation of 1 unit of blood results in a significant decrease in the caudal vena cava diameter (CVCd) and the caudal vena cava diameter to aortic diameter (CVCd:Aod) ratio measured at the iliac location. INTERVENTIONS: Eight healthy client-owned Greyhounds underwent ultrasound of their caudal vena cava and aorta before and after blood donation. The principal investigator obtained M-mode images of the blood vessels from all dogs and a secondary investigator measured the CVCd and aortic diameter in a blinded manner from stored images. The ratio of CVCd:Aod was then calculated. After assessing for normality, paired-sample t-tests were performed to compare mean values before and after donation. MAIN RESULTS: The mean (±SD) CVCd before and after blood donation were 15.84 mm (±5.06 mm) and 15.82 mm (±5.42 mm) and the CVCd:Aod ratios were 0.93 (±0.23) and 1.00 (±0.27), respectively. There was no statistical difference between pre- and postdonation values for CVCd (P = 0.99) or CVCd:Aod (P = 0.34). CONCLUSION: The measurement of CVCd and CVCd:Aod ratio with ultrasound at the iliac location failed to detect mild-to-moderate blood loss produced by the donation of 1 unit of blood in Greyhounds.

Interobserver agreement between non-cardiologist veterinarians and a cardiologist after a 6-hour training course for echographic evaluation of basic echocardiographic parameters and caudal vena cava diameter in 15 healthy Beagles.

OBJECTIVE: To evaluate cardiovascular focused assessment with sonography for trauma and triage (CV-FAST) interobserver agreement for echocardiographic parameters and caudal vena cava (CVC) diameter measurement, between a cardiologist and 2 non-cardiologists after a 6-hour training course. SETTING: University veterinary teaching hospital. ANIMALS: Fifteen healthy Beagle dogs. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Echocardiography parameters were assessed via standardized views. Caudal vena cava was assessed via a subxiphoid window (CVC-SubX) using 3 measurements (minimal and maximal CVC diameter, and collapsibility index) and via a dorsolateral window (CVC-DL) using 1 measurement (CVC diameter). Bland-Altman analysis assessed agreement of each non-cardiologist with the cardiologist; coefficients of variation (CoV) quantified variability between observers. The 95% limits of agreement (LOA) and CoVs were considered acceptable for left atrial diameter, left atrium to aortic ratio, normalized left ventricle diameter in diastole and systole but non-acceptable for fractional shortening and pulmonary vein to pulmonary artery ratio. For CVC-SubX, the 95% LOA for maximum CVC diameter were acceptable, while minimum CVC diameter and CVC collapsibility index were non-acceptable. The CoVs were good for maximum and minimum CVC (7%) and poor for collapsibility index (37%). For CVC-DL, the 95% LOA were non-acceptable, although the CoV was considered good (11%). CONCLUSIONS: A 6-hour training course in echocardiography allows non-cardiologists to assess left atrial diameter, left atrium to aortic ratio, normalized left ventricle diameter in diastole and systole, and CVCmax of the CV-FAST exam in healthy Beagles. Standardization of the CVC-SubX technique and assessment of the impact of the respiratory phase on CVC diameter in dogs is needed. Further studies are required to determine whether interobserver agreement remains acceptable when including different breeds. Assessment of basic echocardiographic parameters and the CVC to estimate volume status in small animal medicine merits further clinical evaluation.

The methods for inserting lumbar bicortical pedicle screws from the anatomical perspective of the prevertebral great vessels.

BACKGROUND: At present, bicortical pedicle screws (BPSs) are not used clinically because they carry the potential risk of damaging the prevertebral great vessels (PGVs). The authors observed the anatomical relationship between the PGVs and simulated BPSs at different transverse screw angles (TSAs), exploring the insertion method of the BPS. METHODS: Computed tomography angiography (CTA) images from 65 adults were collected. A total of 4-5 TSAs of the BPSs were simulated on the left and right sides of L1-L5 (L1-L3: 0°, 5°, 10°, 15°; L4-L5: 0°, 5°, 10°, 15°, 20°). There were three types of distances from the anterior vertebral cortex (AVC) to the PGVs (DAVC-PGV); DAVC-PGV < 0.50 cm, DAVC-PGV ≥ 0.50 cm, and DAVC-PGV↑; these distances represented close, distant, and noncontact PGV, respectively. RESULTS: The ratio of every type of PGV was calculated, and the appropriate TSA of the BPS was recommended. In L1, the recommended left TSA of the BPS was 0°, and the ratio of the close PGV was 7.69%, while the recommended right TSA was 0°-10°, and the ratio of the close PGV was 1.54-4.62%. In L2, the recommended left TSA of the BPS was 0° and the ratio of the close PGV was 1.54%, while the recommended right TSA was 0°-15° and the ratio of the close PGV was 3.08-9.23%. In L3, the recommended left TSA was 0°-5°, and the ratio of the close PGV was 1.54-4.62%. In L4, the recommended left TSA was 0°, and the ratio of the close PGV was 4.62%. BPS use was not recommended on the right side of either L3 or L4 or on the either side of L5. CONCLUSIONS: From the anatomical perspective of the PGVs, BPSs were not suitable for insertion into every lumbar vertebra. Furthermore, the recommended methods for inserting BPSs were different in L1-L4.

Slc:Hartley guinea pigs frequently possess duplication of the caudal vena cava.

The formation of the caudal vena cava is a complex process involving development, regression, and anastomosis. In mammals, the normal caudal vena cava runs to the right side of the abdominal aorta, while duplication of the caudal vena cava has been identified as a congenital abnormality in both companion animals and humans. The present study demonstrates that Slc:Hartley guinea pigs frequently possess asymptomatic duplicated caudal vena cava. The prevalence was 30% and 24% for males and females, respectively, with no sex-related differences. In accordance with Saad et al. (2012)'s criteria, duplicated caudal vena cava were classified into two distinct variations. The dominant variation was a complete duplication without iliac anastomosis where the left caudal vena cava continued from the left common iliac vein and joined the left renal vein; the left renal vein ran to the right to join the right caudal vena cava. The alternative variation was an incomplete duplication where the left caudal vena cava joined the right infrarenal caudal vena cava at a more cranial point than in normal cases; the renal segment was unchanged. Iliac anastomosis was not found in any cases. Duplicated caudal vena cava neither affected the body weight nor the kidney weight. In conclusion, Slc:Hartley guinea pigs frequently possess asymptomatic duplicated caudal vena cava in the absence of iliac anastomosis and appear to be a novel and useful animal model for duplicated caudal vena cava in animals and humans.

The utility and limitation of inferior vena cava diameter as a dry weight marker.

BACKGROUND: IVC diameter on expiration (IVCdexp) is measured by echocardiography routinely. It is used to estimate volume status and designated as a definitive marker for determining dry weight (DW) in patients undergoing hemodialysis (HD). METHODS: A cross-sectional study. Outpatients (n = 107), and inpatients (n = 35) undergoing HD were enrolled. IVCdexp was measured on non-dialysis days in outpatients and dialysis days before and after the dialysis session in inpatients. In outpatients, the relationship of IVCdexp with echocardiography findings and clinical characteristics was analyzed. IVCdexp was compared with the other DW markers as a predictive factor for intradialytic hypotension. In inpatients, IVCdexp was analyzed by dividing inpatients with or without fluid in extravascular space. RESULTS: IVCdexp ranged from 5.4 to 16.9 mm in outpatients who had optimal DW. IVCdexp could reflect on volume status, but not predictive for intradialytic hypotension and not suggestive of fluid in extravascular space. CONCLUSIONS: IVCdexp was a rough marker to estimate volume status and only useful in suggesting apparent hypervolemia or hypovolemia. We should know that the IVCdexp value is affected by a lotof factors and not a definitive marker for estimating practical DW. J. Med. Invest. 66 : 172-177, February, 2019.

The inferior vena cava: a pictorial review of embryology, anatomy, pathology, and interventions.

The inferior vena cava (IVC) is the largest venous conduit below the diaphragm. Although this structure is often overlooked both clinically and radiographically, it can be involved in many different pathologic processes. A thorough understanding of the IVC will assist the radiologist in recognizing anatomic variants, identifying abnormalities, and providing accurate differential diagnoses. In this comprehensive pictorial review of the IVC, we depict embryology behind anatomic variants, present a wide range of pathology with a focus on diagnostic imaging, and describe relevant endovascular interventions.