Search

Adrenal venous sampling (AVS) is crucial for subtyping primary aldosteronism (PA) to explore the possibility of curing hypertension. Because AVS availability is limited, efforts have been made to develop strategies to bypass it. However, it has so far proven unsuccessful in applying clinical practice, partly due to heterogeneity and missing values of the cohorts. For this purpose, we retrospectively assessed 210 PA cases from three institutions where segment-selective AVS, which is more accurate and sensitive for detecting PA cases with surgical indications, was available. A machine learning-based classification model featuring a new cross-center domain adaptation capability was developed. The model identified 102 patients with PA who benefited from surgery in the present cohort. A new data imputation technique was used to address cross-center heterogeneity, making a common prediction model applicable across multiple cohorts. Logistic regression demonstrated higher accuracy than Random Forest and Deep Learning [(0.89, 0.86) vs. (0.84, 0.84), (0.82, 0.84) for surgical or medical indications in terms of f-score]. A derived integrated flowchart revealed that 35.2% of PA cases required AVS with 94.1% accuracy. The present model enabled us to reduce the burden of AVS on patients who would benefit the most., (© 2023. The Author(s).)

Objective: To evaluate the changes in the diameters of superior vena cava (SVC) and inferior vena cava (IVC) and to measure the ratio between SVC and IVC in growth-restricted fetuses and compare these results with normally grown fetuses., Methods: Twenty-three consecutive patients with fetal growth restriction (FGR) (Group I) and 23 pregnant gestational age-matched controls (Group II) between 24 and 37 weeks of gestation were enrolled in the study between January 2018 and October 2018. The diameter of the SVC and IVC from inner wall to inner wall was measured in all patients by sonographic examination. The ratio between the diameter of the SVC and IVC was also measured in each patient to eliminate the gestational age factor. We have named this ratio the "vena cava ratio" (VCR). All parameters were compared between the two groups., Results: The diameter of the SVC was significantly greater in the fetuses with FGR (2.6-7.7 [5.4]) than in controls (3.2-5.6 [4.1]; P = .002; P < .01). The diameter of the IVC was significantly less in the fetuses with FGR (1.6-4.5 [3.2]) than in controls (2.7-5 [3.7]; P = .035; P < .05). The VCR was between 1.1 and 2.3 and the median value was 1.8 in Group I. The VCR was between 0.8 and 1.7 and the median value was 1.2. VCR was significantly higher in fetuses with FGR (P = .001 P < .01)., Conclusion: This study shows that VCR is higher in fetuses with growth restriction. Further studies are needed to clarify the association between VCR and antenatal prognosis and postnatal results., (© 2023 American Institute of Ultrasound in Medicine.)

Vascular pathologies show locational predisposition throughout the body; further insights into the transcriptomics basis of this vascular heterogeneity are needed. We analyzed transcriptomes from cultured endothelial cells and vascular smooth muscle cells from nine adult canine macrovessels: the aorta, coronary artery, vena cava, portal vein, femoral artery, femoral vein, saphenous vein, pulmonary vein, and pulmonary artery. We observed that organ-specific expression patterns persist in vitro, indicating that these genes are not regulated by blood flow or surrounding cell types but are likely fixed in the epigenetic memory. We further demonstrated the preserved location-specific expression of GATA4 protein in cultured cells and in the primary adult vessel. On a functional level, arterial and venous endothelial cells differed in vascular network morphology as the arterial networks maintained a higher complexity. Our findings prompt the rethinking of the extrapolation of results from single-origin endothelial cell systems., (© 2023. Springer Nature Limited.)

Competing Interests: The authors report no conflict of interest.

Venovenous extracorporeal membrane oxygenation (ECMO) can be performed with two single lumen cannulas (SLCs) or one dual-lumen cannula (DLC) where low recirculation fraction ([Formula: see text]) is a key performance criterion. DLCs are widely believed to have lower [Formula: see text], though these have not been directly compared. Similarly, correct positioning is considered critical although its impact is unclear. We aimed to compare two common bi-caval DLC designs and quantify [Formula: see text] in several positions. Two different commercially available DLCs were sectioned, measured, reconstructed, scaled to 27Fr and simulated in our previously published patient-averaged computational model of the right atrium (RA) and venae cavae at 2-6 L/min. One DLC was then used to simulate ± 30° and ± 60° rotation and ± 4 cm insertion depth. Both designs had low [Formula: see text] (< 7%) and similar SVC/IVC drainage fractions and pressure drops. Both cannula reinfusion ports created a high-velocity jet and high shear stresses in the cannula (> 413 Pa) and RA (> 52 Pa) even at low flow rates. Caval pressures were abnormally high (16.2-23.9 mmHg) at low flow rates. Rotation did not significantly impact [Formula: see text]. Short insertion depth increased [Formula: see text] (> 31%) for all flow rates whilst long insertion only increased [Formula: see text] at 6 L/min (24%). Our results show that DLCs have lower [Formula: see text] compared to SLCs at moderate-high flow rates (> 4 L/min), but high shear stresses. Obstruction from DLCs increases caval pressures at low flow rates, a potential reason for increased intracranial hemorrhages. Cannula rotation does not impact [Formula: see text] though correct insertion depth is critical., (© 2023. The Author(s).)

Aim: To clarify manufacturer's instructions for inferior vena cava (IVC) filter use and implications for practice., Materials and Methods: Three vendors of IVC filters were contacted for clarification, with all stating that caval diameter limits are to be true maximum and true minimum cross-sectional diameters. To determine the implications of this, measurements were performed on 302 abdominal computed tomography studies in four transaxial dimensions perpendicular to the long axis including true maximum and minimum diameters, and measurements reflecting those typically taken on fluoroscopic cavography., Results: Based on the true maximum and true minimum caval diameter limits as clarified by vendors, 22% of patients who would typically be considered suitable for IVC filter insertion based on frontal and lateral fluoroscopic cavography would be contraindicated, and 40% of patients who would typically be considered suitable for IVC filter insertion based on only frontal fluoroscopic cavography (as lateral projection is often not performed) would be contraindicated., Conclusion: There is a marked discordance between the vendor-clarified caval diameter limits of three common IVC filter devices and real-world caval geometry. Given the rarity of complications, this suggests a pressing need for revision of manufacturers' instructions for use statements to better reflect current safe routine clinical use, particularly from a medicolegal perspective., (Copyright © 2023 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.)

Background: Successful vascular adult thymus transplant has been reported in different animal models but not in rabbits. These animal models are slightly larger than the murine and substantially smaller than the porcine. We describe in rabbits a supermicrosurgical technique for vascular neonatal thymus transplant and provide histologic evidence of tissue viability., Methods: Newborn (New Zealand, n = 12, 6 female) and adult (New Zealand, n = 12, 6 female) rabbits were used as donors and recipients, respectively. Whole thymuses were extracted from donors and grafted into recipients. Immediate direct vascularization was accomplished by anastomosis to the right common carotid artery and the right external vena cava. At day 14, graft sites were surgically explored, and grafted thymuses were explanted for histologic evaluation. All recipients were followed over 2 weeks for clinical signs of graft-vs-host reaction., Results: The vascular pedicles of the thymus grafts ranged 0.5 to 0.8 mm in vessel diameter. From the 12 transplants, 3 recipients (3/12; 25%) died during the surgical procedure because of blood loss after clamp release. On histology, from the 9 (9/12; 75%) successful at revascularization, none (0/9; 0%) had signs of acute rejection or necrosis, and all (9/9; 100%) evidenced normal cytoarchitecture. No clinical signs of graft-vs-host reaction were evidenced during follow-up., Conclusions: Vascular neonatal thymus transplant in rabbits is surgically feasible. This technique will enable a novel approach for studying the biology of the thymus., Competing Interests: DISCLOSURE The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this article., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)

The left inferior phrenic vein (LIPV) is a major drainage vessel of gastric varices and serves as an important conduit in endovascular treatment for gastric varices. The narrowing of LIPV has been empirically demonstrated and sometimes hinders catheter insertion for the treatment of gastric varices. We herein investigated the morphology of narrowed LIPV in patients with portal hypertension. Venograms of LIPV on 25 patients with gastric varices (15 males; 10 females; age range, 45-79 years with a mean of 67 years) were retrospectively reviewed, the following four parameters were measured: the diameter of LIPV, the diameter of narrowed LIPV, the narrowing rate, and the distance to narrowed LIPV from the left renal vein. On all 25 venograms, a narrowing was detected just above the common trunk with the left adrenal vein. The diameter of LIPV was 9.0 ± 4.2 mm, the diameter of narrowed LIPV was 5.1 ± 2.3 mm, the narrowing rate was 40.6 ± 16.0%, and the distance to narrowed LIPV from the left renal vein was 20.0 ± 7.4 mm. This anatomical information about the narrowing of LIPV may contribute to the safe and efficacious treatment of gastric varices., (© 2022. The Author(s).)

Dual-lumen "acute" central venous catheters (CVC) for dialysis were developed in the 1970s and tunneled "chronic" CVC in the 1980s. Fibrous sheathing of these catheters diminished the patency after weeks to months of use. Double catheters like Canaud/Tesio worked better and longer than single body catheters but were tedious to place. I decided that the optimal CVC design would be a single body that split into two tips within the vena cava. The "Ash Split Cath (TM) " was developed in cooperation with a company focused on dialysis access catheters, and quickly became widely used around the world. However, the patent did not prevent other companies from marketing split-tip catheters. A disagreement on the terms of a royalty agreement further weakened the relationship between the marketing company and our R&D company., (© 2022 International Center for Artificial Organ and Transplantation (ICAOT) and Wiley Periodicals LLC.)

The right atrium (RA) combines the superior vena cava (SVC) and inferior vena cava (IVC) flows. Treatments like extracorporeal membrane oxygenation (ECMO) and hemodialysis by catheter alter IVC/SVC flows. Here we assess how altered IVC/SVC flow contributions impact RA flow. Four healthy volunteers were imaged with computerized tomography (CT), reconstructed and combined into a patient-averaged model. Large eddy simulations (LESs) were performed for a range of IVC/SVC flow contributions (30%-70% each, increments of 5%) and common flow metrics were recorded. Model sensitivity to reconstruction domain extent, constant/pulsatile inlets, and hematocrit was also assessed. Consistent with literature, a single vortex occupied the central RA across all flowrates with a smaller counter-rotating vortex, not previously reported, in the auricle. Vena cava flow was highly helical. RA turbulent kinetic energy (TKE; P = 0.027) and time-averaged wall shear stress (WSS; P < 0.001) increased with SVC flow. WSS was lower in the auricle (2 Pa, P < 0.001). WSS in the vena cava was equal at IVC/SVC = 65/35%. The model was highly sensitive to the reconstruction domain with cropped geometries lacking helicity in the venae cavae, altering the RA flow. The RA flow was not significantly affected by constant inlets or hematocrit. The commonly reported vortex in in the central RA is confirmed; however, a new, smaller vortex was also recorded in the auricle. When IVC flow dominates, as is normal, TKE in the RA is reduced and WSS in the venae cavae equalize. Significant helicity exists in the vena cava, as a result of distal geometry and this geometry appears crucial to accurately simulating RA flow. NEW & NOTEWORTHY Right atrium turbulent kinetic energy increases as the proportion of flow entering from the superior vena cava is increased. Although the commonly reported large right atrium vortex was confirmed across all flow scenarios, a new smaller vortex is observed in the right auricle. The caval veins exhibit highly helical flow and this appears to be the result of distal venous morphology.

Introduction:  The treatment of newborns with congenital diaphragmatic hernia (CDH) is associated with a significant complication rate. Information on major thrombotic complications and their incidence in newborns with CDH is lacking. The aims of our analysis were to evaluate the frequency of vena cava thrombosis and to determine its predictors within a consecutive series of patients with CDH., Materials and Methods:  We retrospectively analyzed charts of all neonates of our department that underwent CDH repair from 2007 to 2021, focusing on vena cava thrombosis. Vena cava thrombosis was diagnosed sonographically and classified as complete or partial venous occlusion. Complete occlusion was confirmed by cavography. Variables evaluated were CDH side, liver position, central vein line, surgical approach, and extracorporeal membrane oxygenation (ECMO). Univariate and multivariate tests were utilized., Results:  Among 57 neonates who underwent CDH repair, vena cava thrombosis was diagnosed in 14 (24.6%), seven of whom had complete occlusion of the vena cava. Factors associated with vena cava thrombosis were femoral or saphenous venous catheter ( p  = 0.044), right sided CDH ( p  = 0.027) and chylothorax ( p  < 0.0001). ECMO was not associated with vena cava thrombosis. Seven patients (50%) with vena cava thrombosis were treated interventionally with angioplasty and seven (50%) conservatively with anticoagulation only. Mortality was not higher in patients with compared with patients without vena cava thrombosis., Conclusion:  The incidence of vena cava thrombosis in newborns with CDH in our series is high. Routine postoperative abdominal sonography focusing on vena cava thrombosis is mandatory in all patients with CDH. Patients who developed vena cava thrombosis were more likely to develop chylothorax after CDH repair. Considering the good outcome of medical therapy of partial vena cava thrombosis, it may be discussed whether low dose anticoagulation may be provided to all newborns with CDH., Competing Interests: None declared, (Thieme. All rights reserved.)

Stenosis of the Inferior Caval Vein is rarely encountered in the paediatric setting. A 5-year-old male sustained severe injuries secondary to a fall from a three story balcony and was subsequently found to have severe stenosis of the inferior caval vein resulting in extensive lymphatic drainage with chylothorax, chyloperitoneum, and severe abdominal ascites. This was successfully treated with transcatheter stent placement resulting in complete resolution of the stenosis and significant clinical improvement allowing for transfer to a rehabilitation centre and eventual discharge home.

To evaluate the age of caval thrombus that experimentally induced in swine by use of magnetic resonance imaging (MRI). Caval thrombus was experimentally created in 15 swine by autologous clot injection assisted with caval net knitting. Serial high-resolution MR images were obtained using magnetic resonance venography (MRV) and T1 high-resolution isotropic volume examination (THRIVE) sequences in a 3.0-T MR system at 1, 7, 14, 21, and 28 days post model creation. At each time point, three pigs were sacrificed and the thrombotic vena cava was processed for histopathological examinations respectively. Caval thrombus was successfully induced in 15 pigs in group A. The signal intensity (SI) change of caval thrombus on THRIVE was age-dependent, with a typical sign of circle or semi-circle hyper-intensity at 7-day-old model while SI of thrombus was lower than that of muscle from day 14 throughout day 28. The histo-pathological findings revealed that RBCs-rich thrombus at day 1 without blue-stained particles, RBCs layers with infiltration of inflammatory cells and sporadically distributed blue-stained particles at 7-day-old thrombus. At day 14, 21 and 28, blue-stained particles became richer, coupled with formation of granulation tissue and fibrous tissue. The swine model in the study is good for age evaluation of venous thrombosis. The peripheral circle or semi-circle hyperintensity on THRIVE indicates the young age of caval thrombus in swine., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background: Cone-shaped vena cava filters (VCFs) are widely used to treat venous thromboembolism. However, in the long term, the problem of occlusion persists even after the filter is deployed. A previous study hypothesized that the reverse deployment of a cone-shaped VCFs may prevent filter blockage., Methods: To explore this hypothesis, a comparative study of the traditional and reverse deployments of VCFs was conducted using a computational fluid dynamics approach. The distribution of wall shear stress (WSS) and shear stress-related parameters were calculated to evaluate the differences in hemodynamic effects between both conditions. In the animal experiment, we reversely deployed a filter in the vena cava of a goat and analyzed the blood clot distribution in the filter., Results: The numerical simulation showed that the reverse deployment of a VCF resulted in a slightly higher shear rate on the thrombus, and no reductions in the oscillating shear index (OSI) and relative residence time (RRT) on the vessel wall. Comparing the traditional method with the reversely deployed cases, the shear rate values is 16.49 and 16.48 1/s, respectively; the minimal OSI values are 0.01 and 0.04, respectively; in the vicinity of the VCF, the RRT values are both approximately 5 1/Pa; and the WSS is approximately 0.3 Pa for both cases. Therefore, the reverse deployment of cone-shaped filters is not advantageous when compared with the traditional method in terms of local hemodynamics. However, it is effective in capturing thrombi in the short term, as demonstrated via animal experiments. The reversely deployed cone-shaped filter captured the thrombi at its center in the experiments., Conclusions: Thus, the reverse deployment of cone-shaped filters is not advantageous when compared with the traditional method in terms of local hemodynamics. Therefore, we would not suggest the reverse deployment of the cone-shaped filter in the vena cava to prevent a potentially fatal pulmonary embolism.

A 13-year-old, 5.6-kg castrated-male Maltese was presented for reverse sneezing. A dome-shaped round mass abutting diaphragm was incidentally found ventral to caudal vena cava, which had the same echogenicity and density as that of the liver during ultrasonography and computed tomography, showing isoattenuation with a contrast study. Vascular distribution was identified throughout the mass. A caval foramen hernia (CFH) was diagnosed tentatively, followed by a herniorrhaphy and splenectomy of the chronically congested spleen. The patient had been doing well for 5-month postoperative but died because of aspiration pneumonia. CFH is an extremely rare condition, requiring surgery due to compression of the vena cava. It should be considered as a differential diagnosis when intrathoracic, mass-like lesions are identified near the diaphragm.

Isolated atrial defects usually lead to left-to-right shunt and right ventricular volume load. Descriptions of cyanosis with this congenital heart defect are rare.We describe a rare case of inferior caval vein flow directed through an atrial septal defect in the fossa ovalis leading to severe cyanosis, but without any additional intracardiac anatomical abnormalities. The baby with clinical features of Marfan's syndrome had an eventration of the right-sided diaphragm. Surgical closure of the defect resolved the cyanosis, but the child died 10 weeks later of severe valvar dysfunction, related to Marfan's syndrome.Mechanisms of cyanosis in patients with atrial septal defects are discussed. Echocardiographic bubble studies both from the lower and upper half of the body may help to clarify the mechanism of an otherwise unexplained cyanosis.

Background: Although they are at lower risk, patients with previous extracardiac conduit (EC) Fontan still may require catheter ablation for supraventricular arrhythmia., Objective: The purpose of this study was to determine the optimal approach to pulmonary venous atrium (PVA) access after EC Fontan operation., Methods: All electrophysiological procedures requiring PVA over a 10-year period at the UCLA Medical Center were reviewed. PVA was grouped by transcaval cardiac puncture (TCP) or direct conduit puncture. Procedural characteristics and outcomes were compared., Results: Between June 2009 and November 2019, 23 electrophysiological procedures requiring PVA access were performed in 17 EC Fontan patients (53% male; median age 25 years; interquartile range 11-34). Cavoatrial overlap was identified in 14 patients by preprocedural imaging (10 cardiac computed tomography, 4 cardiac magnetic resonance). PVA access was obtained via TCP in 11, direct conduit puncture in 6, pre-existing fenestration in 5, and pulmonary artery puncture in 1. Time to PVA was significantly shorter for TCP vs direct conduit puncture (0.2 vs 1.1 hours, respectively; P = .03). The only predictor of successful TCP was the length of cavoatrial overlap by preprocedural imaging (14 vs 3 mm; P = .02). No procedural complications occurred. No change in oxygen saturation was noted, and no evidence of residual shunting was detected by follow-up echocardiography., Conclusion: TCP is feasible in most patients after EC Fontan surgery and can be predicted by preprocedural advanced imaging. TCP is associated with shorter time to PVA and was uncomplicated in this single-center study. Preoperative assessment of cavoatrial overlap should be considered before catheter ablation for EC Fontan., (Published by Elsevier Inc.)

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., (© 2020 Robert K., et al.)

Background: The spermatic cord and testis are very rare sites for metastasis from gastric cancer. Although several mechanisms have been suggested to explain this unusual metastasis, the actual mechanism remains unclear. We report a case of right spermatic cord and testicular metastasis, review its imaging findings, and suggest a mechanism of tumor spread., Case Presentation: A 61-year-old man complained of a palpable mass in the right inguinal area. He had been treated with distal gastrectomy with chemotherapy for advanced gastric cancer 5 years ago. Computed tomography, ultrasound, and magnetic resonance imaging showed a mass surrounding the right spermatic cord, involving the right testis. Another mass was observed in the aortocaval space, presumed to be a metastatic lymph node. The imaging features of the right testicular lesion were different than those of the primary testicular cancer. The lesions at both sites showed similar radiologic features of abundant internal necrosis, which is consistent with metastatic lesions. Pathology confirmed metastatic adenocarcinoma. He underwent a series of chemotherapy sessions, and all metastatic masses had partially decreased in size at the 5-month outpatient follow-up., Conclusions: The imaging features of testicular mass and spermatic cord involvement are important clues for accurate differential diagnosis of metastasis from other primary tumors in patients with a history of stomach cancer. This unusual metastasis can be explained via retrograde tumor spread along the lymphatic channels in terms of concurrent aortocaval lymph node metastasis. A suspicion of metastasis should not be overlooked, even if a patient has undergone curative treatment, including surgery and adjuvant chemotherapy, many years ago.

Background: Long-term outcomes are not well established at the population level after completion of the total cavopulmonary connection (TCPC) among patients with functional univentricular hearts., Purpose: To evaluate the incidence of cardiovascular events after TCPC completion., Methods: From a validated population-based cohort, we identified 178 patients with TCPC circulation completed after January 1, 1995. We established a comparison cohort by frequency-matching patients 1:200 on sex, and month and year of birth to the general Danish population (n = 35,600 population controls). We started follow-up at date of TCPC completion for cases and, for controls, at the index date of their matched case. The risks of cardiovascular events were assessed using cumulative incidence rates and Poisson regression models adjusted for age, sex, and calendar year., Results: The median age at TCPC completion was 3.3 years (interquartile range 2.6 to 5.3 years). Over a median follow-up of 12.5 years, 10 (5.6%) TCPC patients died and 7 (4.5%) had a heart transplantation compared with a 0.2% mortality in the matched population. In TCPC patients, 15.7% had an arrhythmia (11.8% supraventricular tachycardia), 3.4% had a stroke (all ischemic), and 21.4% of TCPC patients initiated a combination of a diuretic and a renin-angiotensin system (RAS)-inhibitor. These rates were >50-fold higher than in the comparison cohort: 0.2% arrhythmia, 0.06% stroke, and 0.04% starting a diuretic and a RAS-inhibitor., Conclusions: Patients with TCPC circulation face a high risk of cardiovascular events during intermediate term follow-up., Competing Interests: Declaration of competing interest The authors declare that they have no conflicts of interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Right heart surgery is challenging in the minimally invasive cardiac surgery setting, particularly in terms of caval isolation procedures in patients with enlarged and pressurized atria. We describe a novel minimally invasive caval occlusion technique with the use of a balloon catheter designed for temporary large vessel occlusion. A patient with a large ostium secundum atrial septal defect and significant shunt flow underwent a successful minimally invasive closure of the pathological connection between atria with a bovine pericardial patch. The utilized occlusion technique provided excellent visibility of the surgical site and may facilitate minimally invasive procedures in various clinical scenarios., (Copyright © 2020 The Society of Thoracic Surgeons. Published by Elsevier Inc. All rights reserved.)

Background: Veno-venous extracorporeal membrane oxygenation is an established therapy for patients with refractory acute respiratory distress syndrome (ARDS). One complication related to the use of veno-venous extracorporeal membrane oxygenation is thrombosis despite proper anticoagulation. We report the diagnosis and management of a clot-obstruction in a single site cannula placed through the internal jugular vein, guided by transesophageal echocardiography., Case Report: A 39 year-old male developed acute respiratory distress syndrome and hemodynamic instability after an episode of pulmonary aspiration in the ICU. Eight hours after placement of a single site veno-venous extracorporeal membrane oxygenation, suddenly the perfusionist noticed a reduction in flow. TEE showed a thrombus-like mass obstructing the inflow port in SVC and inflow at IVC was intact. After unsuccessful attempts to reposition the cannula, the team decided to insert additional femoral inflow cannula through the IVC. The single site catheter was then pulled out until its tip was positioned in the right atrium and all three ports of the catheter were switched to the infusion ports. After this, flows and oxygenation improved significantly. Unfortunately, despite all of the efforts, the patient died 2 days later., Discussion: The diagnosis of veno-venous extracorporeal membrane oxygenation cannula obstruction is based on reduced inflow rates, hemodynamic instability and poor oxygenation of blood. TEE allows evaluation of the flows inside the cannula and in this case, an obstruction was found. The management presented points to the fact that in a situation of catheter obstruction caused by a clot, there is a feasible alternative to assure minimal interruption of the hemodynamic support offered by the veno-venous extracorporeal membrane oxygenation., (Copyright © 2020. Publicado por Elsevier Editora Ltda.)

BACKGROUND Post-reperfusion syndrome (PRS) during liver transplantation can range from a benign event to a profound hemodynamic excursion from baseline with significant morbidity. Multiple variables can be responsible for the diverse presentations. Over time, our group noticed that a blood flush of the liver graft via a caval vent (in addition to a standard chilled flush via the portal vein) appeared to result in a milder reperfusion effect. Attenuation of PRS via caval vent seemed to minimize hemodynamic instability and reduce metabolic derangements associated with reperfusion. MATERIAL AND METHODS This was a prospective observational pilot study of standard practice with the addition of lab values and hemodynamic evaluations. We methodically observed normal clinical flow in 20 adult orthotopic liver transplant recipients. We analyzed blood and fluid samples at set time intervals during the peri-reperfusion phase. RESULTS Sixteen out of 20 patients received a blood flush via caval venting. Mean arterial pressure (MAP) and heart rate were better preserved in the patient population that received a caval blood flush vent. Elevations in central venous pressure (CVP) were similar between the 2 groups. Lab values (blood gas, electrolyte, and hemoglobin) of the patients' blood were similar, with no notable differences. Analysis of the initial blood flushed through the liver graft proved to be hypothermic, acidotic, and hyperkalemic. CONCLUSIONS Pre-reperfusion caval venting in liver transplantation (in addition to a portal vent and a chilled LR/albumin portal flush solution) appears to have favorable hemodynamic effects. The literature on this technique is sparse and larger studies are needed.

Congenital anomalies of the systemic venous return to the right atrium are rare and stem from variations in the embryogenesis of the venous system. They are usually asymptomatic, and such the major clinical significance of their recognition is to prevent misdiagnosis, in addition to some having technical implications on invasive procedures.Typically, the venous blood from the upper half of the body is carried by the right-sided, superior vena cava (SVC), and some common congenital abnormalities found are persistent left SVC, SVC duplication, anomalous drainage of the brachiocephalic veins, or interruption of the SVC. The venous blood from the lower body is carried by the right-sided, inferior vena cava (IVC), and some common congenital abnormalities found are left-sided IVC, IVC duplication, the absence of IVC (total or just the infrarenal segment), and azygos continuation of the IVC. The azygos system of veins, running up the side of the thoracic vertebral column, connects both systems and can provide an alternative path to the right atrium when either of the venae cavae is absent. Other associated azygos-hemiazygos system anomalies are the azygos lobe and variable configuration of the azygos and hemiazygos veins.Such anomalies are reviewed with particular respect to their embryology and imagiological presentation, as knowledge of the normal anatomy and the most common congenital anomalies of the systemic venous return by a radiologist is important, being incidentally found.

Introduction: Recent advances to make cardiopulmonary bypass more physiological include the use of kinetic-assisted venous drainage but without a venous reservoir. Despite manipulation of intravascular volume and patient positioning, arterial flow is frequently reduced. Negative venous line pressures can be generated, which may elicit gaseous microemboli. We investigated the influence of venous cannula design on venous return and negative venous line pressures., Methods: In a single-centre, single-surgeon, prospective, randomized, double-blind trial, 48 patients undergoing isolated coronary artery, aortic valve or combined coronary artery and aortic valve surgery, with a minimally invasive circuit, were randomized to a conventional two-stage (2S) or three-stage venous cannula (3S), or to a three-stage venous cannula with additional 'fenestrated' ridges (F3S). Blood flow, venous line pressures and gaseous microemboli number and size were measured., Results: The pump flow achieved was the same between groups, but in each case fell below the target range of 2.2-2.4 L min -1  m -2 . The three-stage cannula recorded significantly lower negative pressure than the other cannulae. The total count and volume of gaseous emboli detected with the F3S cannulae was very high in some cases, with wide heterogeneity., Discussion: The low negative pressures recorded with three-stage cannula, despite having a larger drainage orifice area, suggest that negative pressure may be more influenced by lumen diameter and vena cava collapse rather than drainage hole size. The additional fenestrations resulted in flow characteristics and negative pressures similar to the larger two-stage cannula but are associated with generation of gaseous microemboli.

Background: Implantation of a retrievable vena cava filter (VCF) is an effective method for preventing pulmonary embolism. Retrieval of filters, however, may be difficult due to intimal hyperplasia and inflammation in the cava wall. The transcription factor nuclear factor-kappaB (NF-κB) plays an important role in regulation of numerous genes participating in the inflammatory and proliferative responses of cells. The present study was to determine whether VCF implantation resulted in activation of NF-κB in the venous neointima., Methods: Filters were placed in vena cava (VC) in four swine for 30 days and then removed. Intimal specimens adhering to the filter struts were analyzed with reference to normal VC tissues. Immunohistochemical analyses were used to assess the NF-κB subunits p65 and p50 and the phosphorylated inhibitor of κB-α (phosphor-IκB-α) in the tissues. NF-κB DNA-binding activity was measured with enzyme-linked immunosorbent assay., Results: As compared to normal VC tissues, the intimal tissues contained higher percentages of cell nucleus-located p65 and p50, and NF-κB DNA-binding activity. Elevated immunoreactivities of p65, p50 and phosphor-IκB-α were also present in the intima., Conclusion: The present study demonstrates for the first time that VCF implantation caused NF-κB activation in neointima. We further demonstrate the activation is at least partly due to phosphorylation of IκB-α. Our data suggest that NF-κB activation would significantly contribute to development of intimal hyperplasia and inflammation in filter-inserted vena cava walls. NF-κB might be a therapeutic target for inhibiting filter-induced neointima and improving filter retrieval.

Vacuum-assisted thrombectomy (VAT) is a mechanical suction device that can be deployed to aspirate thrombi in the heart and vascular system. Successful percutaneous aspiration of iliocaval, right heart, and pulmonary arterial thrombi have been reported, in addition to the debulking of intravascular and intracardiac masses and vegetations. VAT is indicated for patients who are poor surgical candidates and/or have a contraindication to thrombolysis. This review discusses the mechanism, current results, potential clinical indications, and limitations of VAT for iliocaval and intracardiac mass removal., (© 2018 Wiley Periodicals, Inc.)

Currently available treatment methods for acute lung failure show high rates of complications. There is an urgent need for alternative treatment methods. A catheter device which can be minimal invasively inserted into the vena cava for intracorporeal gas exchange was developed. Main components of the device are a drive unit and a membrane module. In this study, the flow behavior in a vena cava model with inserted catheter prototype was investigated in experiments and basic computational fluid dynamic (CFD) simulations. Main findings are that the miniature blood pump has suitable characteristics and generates sufficient power to overcome the pressure drop induced in the membrane module, and that the design of the membrane outlet might be critical to avoid additional pressure losses. Parts manufactured with a high resolution 3D printer have proven to be suitable for the prototyping process.

Clinical success of pediatric veno-venous (VV) extracorporeal membrane oxygenation (ECMO) is associated with the double lumen cannula cardiovascular device design as well as its anatomic orientation in the atrium. The positions of cannula ports with respect to the vena cavae and the tricuspid valve are believed to play a significant role on device hemodynamics. Despite various improvements in ECMO catheters, especially for the neonatal and congenital heart patients, it is still challenging to select a catalogue size that would fit to most patients optimally. In effect, the local unfavorable blood flow characteristics of the cannula would translate to an overall loss of efficiency of the ECMO circuit. In this study, the complex flow regime of a neonatal double lumen cannula, positioned in a patient-specific right atrium, is presented for the first time in literature. A pulsatile computational fluid dynamics (CFD) solver that is validated for cardiovascular device flow regimes was used to perform the detailed flow, oxygenated blood transport, and site-specific blood damage analysis using an integrated cannula and right atrium model. A standard 13Fr double lumen cannula was scanned using micro-CT, reconstructed and simulated under physiologic flow conditions. User defined scalar transport equations allowed the quantification of the mixing and convection of oxygenated and deoxygenated blood as well as blood residence times and hemolysis build-up. Site-specific CFD analysis provided key insight into the hemodynamic challenges encountered in cannula design and the associated intra-atrial flow patterns. Due to neonatal flow conditions, an ultra high velocity infusion jet emanated from the infusion port and created a zone of major recirculation in the atrium. This flow regime influenced the delivery of the oxygenated blood to the tricuspid valve. Elevated velocities and complex gradients resulted in higher wall shear stresses (WSS) particularly at the infusion port having the highest value followed by the aspiration hole closest to the drainage port. Our results show that, in a cannula that is perfectly oriented in the atrium, almost 38% of the oxygenated blood is lost to the atrial circulation while only half of the blood from inferior vena cava (IVC) can reach to the tricuspid valve. As such, approximately 6% of venous blood from superior vena cava (SVC) can be delivered to tricuspid. High values of hemolysis index were observed with blood damage encountered around infusion hole (0.025%). These results warrant further improvements in the cannula design to achieve optimal performance of ECMO and better patient outcomes., (© 2018 The Authors. Artificial Organs published by Wiley Periodicals, Inc. on behalf of International Center for Artificial Organ and Transplantation (ICAOT).)

Background: Many clinicians use the strategy of prophylactically placing an endovascular balloon before transvenous lead extraction, yet there are no data regarding this practice., Objective: This study assesses long-term outcomes of prophylactic placement of an endovascular balloon in the venae cavae of patients during transvenous lead extraction., Methods: From April 1, 2016 to March 31, 2017 data were prospectively collected at 2 international cardiovascular centers on patients who had the balloon prophylactically placed in the venae cavae. Patients were monitored for a minimum of 3 months to capture any associated adverse events., Results: Twenty-one patients had the balloon prophylactically placed in the venae cavae during lead extraction. Sixteen patients were male (76%); the mean age was 57.6 ± 18.7 years; and the mean body mass index was 26.1 ± 4.4 kg/m 2 . The mean lead dwell time was 11.2 ± 8.3 years, with an average of 2.2 ± 1.1 leads per case, and most indications for extraction were noninfectious (62%). Two minor complications (10%, pocket hematomas) and 1 major complication (5%, cardiac tamponade) occurred during the procedure. All cases (100%) were procedural successes, and all patients (100%) were discharged alive. On follow-up (6.8 ± 3.7 months), all patients were alive and reported no adverse events related to prophylactic balloon placement, such as pulmonary emboli or deep venous thrombi., Conclusion: During the study period, we observed no acute or long-term adverse outcomes associated with prophylactic placement of an endovascular balloon in the venae cavae of patients undergoing transvenous lead extraction., (Copyright © 2017 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Purpose: Pulmonary embolism with viable tumor cells developed after surgery for renal cell carcinoma may metastasize to lung. We investigated the incidence and fate of newly developed pulmonary embolism after surgery for renal cell carcinoma with vena cava thrombus., Methods: Among 4549 renal cell carcinoma patients treated with curative surgery at our institute from 1998 to 2015, 81 non-metastatic renal cell carcinoma patients with vena cava thrombus were included. The clinical course of pulmonary embolism and its impact on oncological outcomes were assessed., Results: Postoperatively, pulmonary embolism developed in 13 patients (16.0%), who had higher level of vena cava thrombus (p = 0.004), more frequent liver mobilization (p = 0.005), and higher amount of intraoperative transfusion (p = 0.024) than patients without pulmonary embolism. The rate of lung metastasis was similar between patients with and without pulmonary embolism (30.8 vs. 35.3%, p = 1.000). In the multivariate analysis, the significant risk factors for disease recurrence were non-clear cell histology (p = 0.014) and larger primary renal tumor size (p = 0.032). Non-clear cell histology (p = 0.003) was the only significant risk factor for cancer-specific survival. Pulmonary embolism was not associated with both recurrence-free and cancer-specific survival., Conclusions: Pulmonary embolism after surgery for renal cell carcinoma with vena cava thrombus was not associated with worse oncological outcomes and can be closely followed up with anticoagulation therapy.

The primed-continuous (PC) phenylalanine (Phe) stable isotope infusion methodology is often used as a proxy for measuring whole body protein breakdown (WbPB) in sepsis. It is unclear if WbPB data obtained by an easy-to-use single IV Phe isotope pulse administration (PULSE) are comparable to those by PC. Compartmental modeling with PULSE could provide us more insight in WbPB in sepsis. Therefore, in the present study, we compared PULSE with PC as proxy for WbPB in an instrumented pig model with Pseudomonas aeruginosa- induced severe sepsis (Healthy: n = 9; Sepsis: n = 13). Seventeen hours after sepsis induction, we compared the Wb rate of appearance (WbR a ) of Phe obtained by PC (L-[ ring - 13 C 6 ]Phe) and PULSE (L-[ 15 N]Phe) in arterial plasma using LC-MS/MS and (non)compartm e ntal modeling. PULSE-WbR a was highly correlated with PC-WbR a ( r  = 0.732, P < 0.0001) and WbPB ( r  = 0.897, P < 0.0001) independent of the septic state. PULSE-WbR a was 1.6 times higher than PC-WbR a ( P < 0.001). Compartmental and noncompartmental PULSE modeling provide comparable WbR a values, although compartmental modeling was more sensitive. WbPB was elevated in sepsis (Healthy: 3,378 ± 103; Sepsis: 4,333 ± 160 nmol·kg BW -1 ·min -1 , P = 0.0002). With PULSE, sepsis was characterized by an increase of the metabolic shunting (Healthy: 3,021 ± 347; Sepsis: 4,233 ± 344 nmol·kg BW -1 ·min -1 , P = 0.026). Membrane transport capacity was the same. Both PC and PULSE methods are able to assess changes in WbR a of plasma Phe reflecting WbPB changes with high sensitivity, independent of the (patho)physiological state. The easy-to-use (non)compartmental PULSE reflects better the real WbPB than PC. With PULSE compartmental analysis, we conclude that the membrane transport capacity for amino acids is not compromised in severe sepsis., (Copyright © 2017 the American Physiological Society.)

This paper describes the use of 18 F-FDG and micro-PET/CT imaging to determine in vivo glucose metabolism kinetics in mice (and is transferable to rats). Impaired uptake and metabolism of glucose in multiple organ systems due to insulin resistance is a hallmark of type 2 diabetes. The ability of this technique to extract an image-derived input function from the vena cava using an iterative deconvolution method eliminates the requirement of the collection of arterial blood samples. Fitting of tissue and vena cava time activity curves to a two-tissue, three compartment model permits the estimation of kinetic micro-parameters related to the 18 F-FDG uptake from the plasma to the intracellular space, the rate of transport from intracellular space to plasma and the rate of 18 F-FDG phosphorylation. This methodology allows for multiple measures of glucose uptake and metabolism kinetics in the context of longitudinal studies and also provides insights into the efficacy of therapeutic interventions.

The aim of the present study was to explore the relationship between systemic and local progesterone secretion and LH pulsatility during implantation in the pig. Differences in progesterone concentrations measured locally in the caudal vena cava and systemically in the jugular vein were studied in eight primiparous sows on Day 14 of pregnancy. LH pulsatility was analysed for its effects on the local progesterone-releasing pattern. Mean (±s.d.) progesterone concentrations in the vena cava (65.5±19.8ngmL -1 ) were approximately double basal concentrations (33.6±13.1ngmL -1 ). Basal concentrations of progesterone and LH were calculated as the average of the lowest six values. Basal caudal vena cava and mean jugular (27.6±1.5ngmL -1 ) progesterone concentrations did not differ significantly. Pre- and postprandial jugular progesterone concentrations were significantly different in the morning and afternoon (P=0.025 and 0.023). Mean LH ranged from 0.24 to 0.43ngmL -1 and was approximately double as high as basal LH in individual sows. In 60.8% of cases, LH pulses were followed by a progesterone pulse within 1h. In conclusion, the present study showed that corpus luteum function appears to respond to LH pulsatility on Day 14 of pregnancy. However, the response varies at the level of individual sows. In addition, systemic postprandial decreases in progesterone were confirmed on Day 14 of pregnancy.

Background: Transcaval access may enable fully percutaneous transcatheter aortic valve replacement (TAVR) without the hazards and discomfort of transthoracic (transapical or transaortic) access., Objectives: The authors performed a prospective, independently adjudicated, multicenter, single-arm trial of transcaval access for TAVR in patients who were ineligible for femoral artery access and had high or prohibitive risk of complications from transthoracic access., Methods: A total of 100 patients underwent attempted percutaneous transcaval access to the abdominal aorta by electrifying a caval guidewire and advancing it into a pre-positioned aortic snare. After exchanging for a rigid guidewire, conventional TAVR was performed through transcaval introducer sheaths. Transcaval access ports were closed with nitinol cardiac occluders. A core laboratory analyzed pre-discharge and 30-day abdominal computed tomograms. The Society of Thoracic Surgeons predicted risk of mortality was 9.6 ± 6.3%., Results: Transcaval access was successful in 99 of 100 patients. Device success (access and closure with a nitinol cardiac occluder without death or emergency surgical rescue) occurred 98 of 99 patients; 1 subject had closure with a covered stent. Inpatient survival was 96%, and 30-day survival was 92%. Second Valve Academic Research Consortium (VARC-2) life-threatening bleeding and modified VARC-2 major vascular complications possibly related to transcaval access were 7% and 13%, respectively. Median length of stay was 4 days (range 2 to 6 days). There were no vascular complications after discharge., Conclusions: Transcaval access enabled TAVR in patients who were not good candidates for transthoracic access. Bleeding and vascular complications, using permeable nitinol cardiac occluders to close the access ports, were common but acceptable in this high-risk cohort. Transcaval access should be investigated in patients who are eligible for transthoracic access. Purpose-built closure devices are in development that may simplify the procedure and reduce bleeding. (Transcaval Access for Transcatheter Aortic Valve Replacement in People With No Good Options for Aortic Access; NCT02280824)., (Published by Elsevier Inc.)

This study describes the imaging features and characteristics of caval foramen hernias in 7 dogs diagnosed by computed tomography (CT). On lateral radiographs, 6 of 7 dogs showed dome-shaped, broad-based, caudal mediastinal lesions. CT findings included caudal vena cava (CVC) compression (n=7), right lateral (n=6) or medial (n=1) liver lobe involvement, hepatic vein dilation (n=5) and biliary tract involvement (n=1) with partial (n=6) or entire (n=1) liver lobe hernias. A caval foramen hernia should be part of the differential diagnosis when the aforementioned imaging features are detected. CT is considered as a useful tool for diagnosis and evaluation in dogs with a caval foramen hernia.

Patients with a cancer at time of first venous thromboembolism (VTE) have not been thoroughly analyzed. Our study aimed to (1) determine the frequency of cancer diagnosed in patients hospitalized for a first VTE episode, (2) investigate the characteristics of VTE and cancer in such patients. All consecutive adults patients hospitalized over a 6-years period for a first VTE episode in a tertiary care hospital were considered. Patients with congenital or acquired thrombophilia were excluded. Demographic, medical history, and follow up data were retrieved from medical records. 216 patients (63.6 ± 19.7 years, 63.4 % females) hospitalized for a first VTE were analyzed. Among them, 64 patients (29.6 %) had cancer, either revealed (n = 26) or already known (n = 38) at VTE diagnosis. Cancer was in an advanced stage in 26 patients (40.6 %). Patients with cancer were older and displayed a higher frequency of vena cava thrombosis, as compared to patients without cancer. VTE was more recurrent and mortality was higher in patients with cancer. Cancer occurred after VTE diagnosis in only 2 (2/127, 1.6 %) cases during a protracted follow-up of 24.1 ± 22.5 months. Overall, VTE preceded cancer diagnosis in only 3 % (2/66) of cases. Frequency of cancer is high among patients hospitalized for a first VTE. In such setting, VTE often involved unusual sites such as vena cava. In most cases, cancer was either already known or diagnosed at time of VTE, with a poor prognosis.

Peripherally inserted central catheters (PICCs) are widely used in the pediatric population, and their use continues to grow in popularity. These catheters provide a reliable source of venous access to neonatal patients but can also be the cause of life-threatening complications. There are several well-documented complications such as infections, catheter thrombosis, vascular extravasations, and fractured catheters. However, the complication of vascular erosion into the pleural space using both small and silicone-based catheters is rarely described. After obtaining institutional review board approval, we identified 4 cases to review of PICCs complicated by vascular erosions in the past 2 years. Herein, we also review the current literature of PICC complications. Getting the catheter tip as close to the atrial-caval junction as possible and confirmation of this placement are of the utmost importance. The thick wall of the vena cava near the atrium seems to be less likely to perforate; in addition, this position provides increased volume and turbulence to help dilute the hyperosmolar fluid, which seems to also be a factor in this complication. A daily screening chest x-ray in patients with upper extremity PICCs and ongoing parenteral nutrition (PN) are not necessary at this time given the overall low rate of vascular erosion and concerns regarding excessive radiation exposure in pediatric populations. However, a low threshold for chest x-ray imaging in patients with even mild respiratory symptoms in the setting of upper extremity PN is recommended., (© 2015 American Society for Parenteral and Enteral Nutrition.)

Guinea pigs are useful animal models for the study of many human diseases including diabetes mellitus and infectious diseases. Often, these studies involve collecting blood samples of considerable volume. This column describes safe techniques for restraint and blood collection from the jugular vein and cranial vena cava from alert and anesthetized guinea pigs.

A 67-year-old man was admitted with severe abdominal pain and back pain. Computed tomography showed an infrarenal abdominal aortic aneurysm (8.4 × 8.3 cm) and a large retroperitoneal hematoma. Immediately afterwards, the patient suffered circulatory collapse and was rushed to the operating theater. A fistula communicating with the left iliac vein was found. It was repaired with a Dacron patch while balloon-tipped catheters controlled the bleeding. The abdominal aortic aneurysm was replaced with a bifurcated graft. The postoperative course was uneventful. There have been few reports of successful repair of a ruptured abdominal aortic aneurysm associated with aortoiliac arteriovenous fistula., (© The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.)