Monitoring the venous circulation: novel techniques and applications.

PURPOSE OF REVIEW: Venous pressure is an often-unrecognized cause of patient morbidity. However, bedside assessment of PV is challenging. We review the clinical significance of venous pressure measurement, existing techniques, and introduce the Venous Excess Ultrasound (VExUS) Score as a novel approach using doppler ultrasound to assess venous pressure. RECENT FINDINGS: Studies show clear associations between elevated venous pressure and adverse outcomes in critically ill patients. Current venous pressure measurement techniques include physical examination, right heart catheterization (RHC), two-dimensional ultrasound, and a variety of labor-intensive research-focused physiological maneuvers. Each of these techniques have specific shortcomings, limiting their clinical utility. To address these gaps, Beaubien-Souligny et al. introduced the VExUS Score, a novel doppler ultrasound-based method that integrates IVC diameter with doppler measurements of the hepatic, portal, and renal veins to generate a venous congestion assesment. Studies show strong correlations between VExUS score and RHC measurements, and well as an association between VExUS score and improvement in cardiorenal acute kidney injury, diuretic response, and fluid status shifts. However, studies in noncardiac populations have been small, heterogenous, and inconclusive. SUMMARY: Early studies evaluating the use of doppler ultrasound to assess venous congestion show promise, but further research is needed in diverse patient populations and clinical settings.

Fluid responsiveness assessment using inferior vena cava collapsibility among spontaneously breathing patients: Systematic review and meta-analysis / Evaluación de la capacidad de respuesta de fluidos mediante el colapso de la vena cava inferior en pacientes que respiran espontáneamente: revisión sistemática y metaanálisis

Objective To synthesize the evidence about diagnostic accuracy of inferior vena cava collapsibility (IVCc) in prediction of fluid responsiveness among spontaneously breathing patients. Design Systematic review of diagnostic accuracy studies. Setting Intensive care units or emergency departments. Patients and participants spontaneously breathing patients with indication for fluid bolus administration. Interventions A search was conducted in MEDLINE and EMBASE. We included studies assessing IVCc accuracy for fluid responsiveness assessment with a standard method for cardiac output measure as index test. Main variables of interest General information (year, setting, cutoffs, standard method), sensitivity, specificity, and area under the receiving operator characteristics curve (AUROC). Risk of bias was assessed with QUADAS 2 tool. We obtained the pooled sensitivity, specificity and summary ROC curve, with estimated confidence intervals from a bivariate model. We also calculated positive and negative likelihood ratios and developed a Fagon nomogram. Result Eight studies were included with 497 patients. Overall, the studies presented a high risk of bias. IVCc sensitivity was 63% (95% CI – 46–78%) and specificity 83% (95% CI – 76–87%). Despite moderate accuracy of IVCc (SROC 0.83, 95% CI – 0.80–0.86), post-test probability of being fluid responsive based on a 50% pre-test probability led to considerable misclassification. Conclusions IVCc had moderate accuracy for fluid responsiveness assessment in spontaneously breathing patients and should not be used in isolation for this purpose (AU)

Objetivo Sintetizar la evidencia sobre la precisión diagnóstica de la colapsabilidad de la vena cava inferior (cVCI) en la predicción de la respuesta a los líquidos en pacientes que respiran espontáneamente. Diseño Revisión sistemática de estudios de precisión diagnóstica. Ámbito Unidades de cuidados intensivos o servicios de urgencias. Pacientes o participantes Pacientes con respiración espontánea con indicación de administración de bolos de líquidos. Intervenciones Se realizó una búsqueda en MEDLINE y EMBASE. Se incluyeron los estudios que evaluaban la precisión de la cVCI con un método estándar para medir el gasto cardíaco como prueba índice. Variables de interés principales Información general (año, entorno, puntos de corte, método estándar), sensibilidad, especificidad y área bajo curva. El riesgo de sesgo se evaluó con la herramienta QUADAS2. Obtuvimos la sensibilidad combinada, la especificidad y la curva ROC resumida, con intervalos de confianza (IC) estimados a partir de un modelo bivariado. Resultados Se incluyeron 8 estudios con 497 pacientes. La sensibilidad de la cVCI fue del 63% (IC95%: 46-78%) y la especificidad del 83% (IC95%: 76-87%). A pesar de la precisión moderada de cVCI (SROC: 0,83; IC95%: 0,80-0,86), la probabilidad posterior a la prueba de responder a los fluidos basada en una probabilidad anterior al 50% dio lugar a una clasificación errónea considerable. Conclusiones La cVCI tuvo una exactitud moderada para la evaluación de la respuesta a los líquidos en pacientes que respiran espontáneamente y no debe usarse de forma aislada para este propósito (AU)

Parametric investigation of an injection-jet self-powered Fontan circulation.

Approximately [Formula: see text] babies are born with only one functioning ventricle and the Fontan is the third and, ideally final staged palliative operation for these patients. This altered circulation is prone to failure with survival rates below [Formula: see text] into adulthood. Chronically elevated inferior vena cava (IVC) pressure is implicated as one cause of the mortality and morbidity in this population. An injection jet shunt (IJS) drawing blood-flow directly from the aortic arch to significantly lower IVC pressure is proposed. A computer-generated 3D model of a 2-4 year old patient with a fenestrated Fontan and a cardiac output of 2.3 L/min was generated. The detailed 3D pulsatile hemodynamics are resolved in a zero-dimensional lumped parameter network tightly-coupled to a 3D computational fluid dynamics model accounting for non-Newtonian blood rheology and resolving turbulence using large eddy simulation. IVC pressure and systemic oxygen saturation were tracked for various IJS-assisted Fontan configurations, altering design parameters such as shunt and fenestration diameters and locations. A baseline "failing" Fontan with a 4 mm fenestration was tuned to have an elevated IVC pressure (+ 17.8 mmHg). Enlargement of the fenestration to 8 mm resulted in a 3 mmHg IVC pressure drop but an unacceptable reduction in systemic oxygen saturation below 80%. Addition of an IJS with a 2 mm nozzle and minor volume load to the ventricle improved the IVC pressure drop to 3.2 mmHg while increasing systemic oxygen saturation above 80%. The salutary effects of the IJS to effectively lower IVC pressure while retaining acceptable levels of oxygen saturation are successfully demonstrated.

Decreased inferior vena cava diameter as an early marker in postpartum hemorrhage.

OBJECTIVES: To examine the association between inferior vena cava (IVC) diameter and postpartum blood loss and assess whether IVC diameter is a useful marker in the evaluation of intravascular volume status in women with postpartum hemorrhage (PPH). METHODS: This was a prospective case-control study conducted in a university medical teaching center in Afula, Israel, between November 2018 and March 2020. The study cohort consisted of women with a singleton pregnancy who delivered vaginally at term. The PPH group included women diagnosed with PPH based on visually estimated blood loss of 1000 mL or more at the time of enrolment. Hemodynamically unstable women or women with major bleeding at the time of diagnosis were not included. The control group consisted of women with an uneventful fourth stage of labor. IVC diameter was measured using transabdominal ultrasonography during inspiration (IVCi diameter) and expiration (IVCe diameter), and the collapsibility index was calculated ((IVCe - IVCi)/IVCe × 100). The primary outcome was the percentage difference in IVC diameter and collapsibility index between the PPH group and controls. The performance of the IVC collapsibility index in the prediction of the need for blood transfusion in women with PPH was assessed. In order to demonstrate a difference of 20% with a power of 80% and alpha of 0.05, 108 women, at a ratio of 1:2 in the study and control groups, respectively, were needed. RESULTS: Overall, 36 and 72 women were included in the final analysis in the PPH and control groups, respectively. IVCi and IVCe diameters were significantly smaller in the PPH group (0.93 ± 0.30 cm and 1.26 ± 0.32 cm, respectively) than in controls (1.42 ± 0.31 cm and 1.75 ± 0.28 cm, respectively) (P = 0.001 for both). The percentage reductions in IVCi and IVCe diameters in the PPH group compared with controls were 35.0% and 28.0%, respectively. IVC collapsibility index was increased significantly, by 42.9% (26.04 ± 8.67% vs 18.15 ± 5.07%; P = 0.001) in the PPH group compared with controls. IVC collapsibility index was a significant predictor of the need for blood transfusion and correctly predicted 81% of cases. Logistic regression analysis demonstrated that IVC collapsibility index was also a significant predictor of a drop in hemoglobin level of ≥ 2 g/dL (P = 0.001). CONCLUSIONS: IVC diameter changes in response to postpartum blood loss. Measurement of IVC diameter using transabdominal ultrasonography is an objective and useful non-invasive method for the early evaluation of intravascular volume status in women with PPH and for the prediction of cases that might require blood transfusion. © 2021 International Society of Ultrasound in Obstetrics and Gynecology.

Impact of cavotricuspid isthmus depth on the ablation index for successful first-pass typical atrial flutter ablation.

Cavotricuspid isthmus (CTI) linear ablation has been established as the treatment for typical atrial flutter. Recently, ablation index (AI) has emerged as a novel marker for estimating ablation lesions. We investigated the relationship between CTI depth and ablation parameters on the procedural results of typical atrial flutter ablation. A total of 107 patients who underwent CTI ablation were retrospectively enrolled in this study. All patients underwent computed tomography before catheter ablation. From the receiver-operating curve, the best cut-off value of CTI depth was < 4.1 mm to predict first-pass success. Although the average AI was not different between deep CTI (DC; CTI depth ≥ 4.1) and shallow CTI (SC; CTI depth < 4.1), DC required a longer ablation time and showed a lower first-pass success rate (p < 0.01). In addition, the catheter inversion technique was more frequently required in the DC (p < 0.01). The lowest AI sites of the first-pass CTI line were determined in both the ventricular (2/3 segment of CTI) and inferior vena cava (IVC, 1/3 segment of CTI) sides. The best cut-off values of the weakest AIs at the ventricular and IVC sides for predicting first-pass success were > 420 and > 386, respectively. Among patients with these cut-off values, the first-pass success rate was 89% in the SC and 50% in the DC (p < 0.01). Although ablation parameters were not significantly different, the first-pass success rate was lower in the DC than in the SC. Further investigation might be required for better outcomes in deep CTIs.

Vena cava presents endothelial dysfunction prior to thoracic aorta in heart failure: the pivotal role of nNOS uncoupling/oxidative stress.

Arterial endothelial dysfunction has been extensively studied in heart failure (HF). However, little is known about the adjustments shown by the venous system in this condition. Considering that inferior vena cava (VC) tone could influence cardiac performance and HF prognosis, the aim of the present study was to assess the VC and thoracic aorta (TA) endothelial function of HF-post-myocardial infarction (MI) rats, comparing both endothelial responses and signaling pathways developed. Vascular reactivity of TA and VC from HF post-MI and sham operated (SO) rats was assessed with a wire myograph, 4 weeks after coronary artery occlusion surgery. Nitric oxide (NO), H2O2 production and oxidative stress were evaluated in situ with fluorescent probes, while protein expression and dimer/monomer ratio was assessed by Western blot. VC from HF rats presented endothelial dysfunction, while TA exhibited higher acetylcholine (ACh)-induced vasodilation when compared with vessels from SO rats. TA exhibited increased ACh-induced NO production due to a higher coupling of endothelial and neuronal NO synthases isoforms (eNOS, nNOS), and enhanced expression of antioxidant enzymes. These adjustments, however, were absent in VC of HF post-MI rats, which exhibited uncoupled nNOS, oxidative stress and higher H2O2 bioavailability. Altogether, the present study suggests a differential regulation of endothelial function between VC and TA of HF post-MI rats, most likely due to nNOS uncoupling and compromised antioxidant defense.

Postnatal Right Ventricular Developmental Track Changed by Volume Overload.

Background Current right ventricular (RV) volume overload (VO) is established in adult mice. There are no neonatal mouse VO models and how VO affects postnatal RV development is largely unknown. Methods and Results Neonatal VO was induced by the fistula between abdominal aorta and inferior vena cava on postnatal day 7 and confirmed by abdominal ultrasound, echocardiography, and hematoxylin and eosin staining. The RNA-sequencing results showed that the top 5 most enriched gene ontology terms in normal RV development were energy derivation by oxidation of organic compounds, generation of precursor metabolites and energy, cellular respiration, striated muscle tissue development, and muscle organ development. Under the influence of VO, the top 5 most enriched gene ontology terms were angiogenesis, regulation of cytoskeleton organization, regulation of vasculature development, regulation of mitotic cell cycle, and regulation of the actin filament-based process. The top 3 enriched signaling pathways for the normal RV development were PPAR signaling pathway, citrate cycle (Tricarboxylic acid cycle), and fatty acid degradation. VO changed the signaling pathways to focal adhesion, the PI3K-Akt signaling pathway, and pathways in cancer. The RNA sequencing results were confirmed by the examination of the markers of metabolic and cardiac muscle maturation and the markers of cell cycle and angiogenesis. Conclusions A neonatal mouse VO model was successfully established, and the main processes of postnatal RV development were metabolic and cardiac muscle maturation, and VO changed that to angiogenesis and cell cycle regulation.

Endovascular Release of a 50-Year-Old Adams-Deweese IVC Clip to Facilitate Percutaneous Repair of Mitral Valve Regurgitation.

Percutaneous mitral valve (MV) repair using MitraClip requires large-caliber venous access. We describe a patient with a ligated inferior vena cava due to an Adams-DeWeese clip placed 50 years prior, who had progressive shortness of breath and lower extremity symptoms secondary to severe mitral regurgitation and chronic iliocaval deep venous thrombosis. Due to comorbidities, MitraClip was recommended over surgery for MV repair. Caval luminal gain was required to facilitate endovascular access for the MitraClip system. Stent-mediated release of the inferior vena cava clip allowed successful passage of the delivery sheath from the common femoral vein to MV and subsequent valve repair.

Retrograde inferior vena caval perfusion for total aortic arch replacement surgery: a randomized pilot study.

OBJECTIVES: Antegrade cerebral perfusion (ACP) under moderate hypothermic circulatory arrest is used during total aortic arch replacement surgery (TARS) in patients with acute type A aortic dissection, but it is associated with high mortality and morbidity. We hypothesized that combining ACP with retrograde inferior vena caval perfusion (RIVP) improves outcomes. METHODS: This pilot study was prospective, randomized, controlled and assessor-blinded. Patients scheduled for TARS were randomly treated with either ACP or RIVP + ACP. The primary outcome was a composite of mortality and major complications including paraplegia, postoperative renal failure, severe liver dysfunction, and gastrointestinal complications. Secondary outcomes included neurological complications, length of intubation and requirement of blood products. RESULTS: A total of 76 patients were recruited (n = 38 per group). Primary outcome occurred in 23 patients (61%) in the ACP group and 16 (42%) in the RIVP + ACP group (OR: 0.60, 95% CI: 0.21-1.62; p = 0.31). There was a lower incidence of transient neurological deficits in the RIVP + ACP group (26% vs. 58%, OR: 0.26; 95% CI: 0.10-0.67,p = 0.006;). The RIVP + ACP group underwent shorter intubation (25 vs 47 h, p = 0.022) and required fewer blood products (red cells, 3.8 units vs 6.5 units, p = 0.047; platelet: 2.0 units vs 2.0 units, p = 0.023) compared with the ACP group. CONCLUSIONS: RIVP + ACP may be associated with lower incidence of transient neurological deficits, shorter intubation and less blood transfusion requirement than ACP alone during TARS. Multi-center, randomized trials with larger samples are required to determine whether RIVP + ACP is associated with lower rates of mortality and major complications. TRIAL REGISTRATION: Pilot study of a RCT registered in clinicaltrials.gov (NCT03607786), Registered 30 July, 2018-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03607786 .

Respiratory variability of inferior vena cava at different mechanical ventilator settings.

BACKGROUND: Assessment of the respiratory changes of the inferior vena cava (IVC) diameter have been investigated as a reliable tool to estimate the volume status in mechanically ventilated and spontaneously breathing patients. Our purpose was to compare the echocardiographic measurements the IVC diameter, stroke volume and cardiac output in different positive pressure ventilation parameters. METHODS: This prospective clinical study with crossover design was conducted in the Intensive Care Unit (ICU). Twenty-five sedated, paralyzed, intubated, and mechanically ventilated patients with volume control mode (CMV) in the ICU due to respiratory failure were included in the study. Positive End-Expiratory Pressure (PEEP) and Tidal Volume (TV) were changed in each patient consecutively (Group A: TV 6 ml/kg, PEEP 5 cmH20, B: TV 6, PEEP 8, C: TV 8, PEEP 5, D: TV 8, PEEP 8) and the changes in vital parameters, central venous pressure (CVP) and ultrasonographic changes in IVC and cardiac parameters were measured. All measures were compared between groups by robust repeated measures ANOVA with trimmed mean. RESULTS: The respiratory changes of the IVC diameter and echocardiographic parameters showed no significant difference in separate mechanical ventilator settings. Significant difference was found in peak and plateau pressure values among groups (p < 0.05). CONCLUSION: The results of our study suggest that IVC related parameters are not affected with different ventilatory settings. Further studies are needed to confirm the reliability of these parameters as a predictor of fluid assessment.

A Systematic Review and Meta-Analysis of Ligation Versus Repair of Inferior Vena Cava Injuries.

OBJECTIVE: Inferior vena cava (IVC) injuries have a high mortality rate that may be related to the location of injury and type of repair. Previous studies have been either single center series or database studies lacking granular detail. These have reported conflicting results. We aimed to perform a systematic review and meta-analysis of published literature evaluating ligation versus repair. METHODS: Studies published in English on MEDLINE or EMBASE from 1946 through October 2018 were examined to evaluate mortality among patients treated with ligation versus repair of IVC injuries. Studies were included if they provided mortality associated with ligation versus repair and reported IVC injury by level. Risk of bias was assessed regarding incomplete and selective outcome reporting with Newcastle-Ottawa score of 7 or higher to evaluate study quality. We used a random-effects model with restricted maximum likelihood estimation method in R using the Metafor package to evaluate outcomes. RESULTS: Our systematic review identified 26 studies, of which 14 studies, including 855 patients, met our inclusion criteria for meta-analysis. IVC ligation was associated with higher mortality than IVC repair (OR: 3.12, P < 0.01, I2 = 49%). Ligation of infrarenal IVC injuries was not statistically associated with mortality (OR: 3.13, P = 0.09). Suprarenal injury location compared to infrarenal (OR 3.11, P < 0.01, I2 = 28%) and blunt mechanism compared to penetrating (OR: 1.91, P = 0.02, I2 = 0%) were also associated with higher mortality. CONCLUSIONS: In this meta-analysis, ligation of IVC injuries was associated with increased mortality compared to repair, but not specifically for infrarenal IVC injuries. Suprarenal IVC injury, and blunt mechanism was associated with increased mortality compared to infrarenal IVC injury and penetrating mechanism, respectively. Data are limited regarding acute renal injury and venous thromboembolic events after IVC ligation and may warrant multicenter studies. Standardized reporting of IVC injury data has not been well established and is needed in order to enable comparison of outcomes across institutions. In particular, reporting of injury location, severity, and repair type should be standardized. A contemporary prospective, multicenter study is needed in order to definitively compare surgical technique.

Filtro de vena cava inferior, resultados a mediano y largo plazo / Inferior vena cava filter medium to long-term results

Resumen Introducción: El tromboembolismo pulmonar sin tratamiento, presenta un riesgo de recurrencia del 20%, con una mortalidad del 18% al 26%, en pacientes con embolia pulmonar donde esta contraindica o fracasa la anticoagulación, es necesario interrumpir parcialmente la vena cava inferior, siendo los filtros de vena cava la alternativa más utilizada. Objetivo: Analizar las variables epidemiológicas involucradas en la enfermedad tromboembólica y los resultados de la inserción del filtro de vena cava inferior. Materiales y Método: Estudio retrospectivo, observacional y descriptivo, donde se analiza la inserción sucesiva de 82 filtros de vena cava inferior, en un período de 10 años (2009 al 2019), en el Hospital Dr. Eduardo Pereira de Valparaíso, Chile. Resultados: Sexo femenino 53,6%, edad promedio 60,4 años (rango 19-86), la principal causa para desarrollar enfermedad tromboembólica fueron las enfermedades oncológicas (56,09%), la principal vía de acceso fue la vena femoral común (69,51%), localización del filtro suprarrenal (4,87%), se obtuvo un seguimiento actualizado en el 89,02%, la supervivencia a 5 años fue de 73,17% y a 10 años de 57,32%, morbilidad en relación al procedimiento (9,75%), éxito del procedimiento (97,5%), no hubo mortalidad relacionada. Discusión: Los grandes ensayos, demuestran el beneficio de la interrupción de la vena cava inferior mediante filtros, especialmente en pacientes oncológicos, con elevado riesgo de embolia pulmonar. Conclusión: La inserción de un filtro de vena cava inferior, adecuadamente indicado, es un procedimiento mínimamente invasivo, de bajo riesgo y con excelentes resultados en la profilaxis de la embolia pulmonar.

Introduction: Pulmonary thromboembolism without treatment presents a risk of recurrence of 20%, with a mortality of 18% to 26%. In patients with pulmonary embolism, when anticoagulation therapy is contraindicated or failed, it is necessary to intervene partially the inferior vena cava on which cava vein filters are the main used alternative. Aim: Analyze the epidemiological variables involved on thromboembolic disease, and the outcomes of the inferior vena cava filter insertions. Materials and Method: Retrospective, observational and descriptive study, which analyzes the successive insertion of 82 inferior vena cava filters, over a period of 10 years (2009 to 2019), in the Dr. Eduardo Pereira Hospital, Valparaíso, Chile. Results: Female sex 53.6%, average age 60.4 years (range 19-86), the main cause to develop thromboembolic disease were oncological diseases (56.09%); the main access path was the common femoral vein (69.51%); in a 4.87% the location of the filter was suprarenal. Complete follow-up was obtained in 89.02% of the cases, 5-year survival with 73.17% ratio and 10-years survival of 57.32%, morbidity in relation to the procedure was 9.75%; success of the procedure 97.5%; there was no mortality related. Discussion: Large studies demonstrate the benefits of interruption on the inferior vena cava through filters, especially in cancer patients with high risk of pulmonary embolism. Conclusion: The insertion of an inferior vena cava filter when indication is adequate, is a minimally invasive procedure with low risk and excellent results in the prophylaxis of pulmonary embolism.

Do changes in pulse pressure variation and inferior vena cava distensibility during passive leg raising and tidal volume challenge detect preload responsiveness in case of low tidal volume ventilation?

BACKGROUND: In patients ventilated with tidal volume (Vt) < 8 mL/kg, pulse pressure variation (PPV) and, likely, the variation of distensibility of the inferior vena cava diameter (IVCDV) are unable to detect preload responsiveness. In this condition, passive leg raising (PLR) could be used, but it requires a measurement of cardiac output. The tidal volume (Vt) challenge (PPV changes induced by a 1-min increase in Vt from 6 to 8 mL/kg) is another alternative, but it requires an arterial line. We tested whether, in case of Vt = 6 mL/kg, the effects of PLR could be assessed through changes in PPV (ΔPPVPLR) or in IVCDV (ΔIVCDVPLR) rather than changes in cardiac output, and whether the effects of the Vt challenge could be assessed by changes in IVCDV (ΔIVCDVVt) rather than changes in PPV (ΔPPVVt). METHODS: In 30 critically ill patients without spontaneous breathing and cardiac arrhythmias, ventilated with Vt = 6 mL/kg, we measured cardiac index (CI) (PiCCO2), IVCDV and PPV before/during a PLR test and before/during a Vt challenge. A PLR-induced increase in CI ≥ 10% defined preload responsiveness. RESULTS: At baseline, IVCDV was not different between preload responders (n = 15) and non-responders. Compared to non-responders, PPV and IVCDV decreased more during PLR (by - 38 ± 16% and - 26 ± 28%, respectively) and increased more during the Vt challenge (by 64 ± 42% and 91 ± 72%, respectively) in responders. ∆PPVPLR, expressed either as absolute or as percent relative changes, detected preload responsiveness (area under the receiver operating curve, AUROC: 0.98 ± 0.02 for both). ∆IVCDVPLR detected preload responsiveness only when expressed in absolute changes (AUROC: 0.76 ± 0.10), not in relative changes. ∆PPVVt, expressed as absolute or percent relative changes, detected preload responsiveness (AUROC: 0.98 ± 0.02 and 0.94 ± 0.04, respectively). This was also the case for ∆IVCDVVt, but the diagnostic threshold (1 point or 4%) was below the least significant change of IVCDV (9[3-18]%). CONCLUSIONS: During mechanical ventilation with Vt = 6 mL/kg, the effects of PLR can be assessed by changes in PPV. If IVCDV is used, it should be expressed in percent and not absolute changes. The effects of the Vt challenge can be assessed on PPV, but not on IVCDV, since the diagnostic threshold is too small compared to the reproducibility of this variable. TRIAL REGISTRATION: Agence Nationale de Sécurité du Médicament et des Produits de santé: ID-RCB: 2016-A00893-48.

Recanalization and Reconstruction of a Chronically Occluded Inferior Vena Cava Through an Existing Transjugular Intrahepatic Portosystemic Shunt in the Setting of Budd-Chiari Syndrome.

Budd-Chiari syndrome (BCS) results from the occlusion or flow reduction in the hepatic veins or inferior vena cava and can be treated with transjugular intrahepatic portosystemic shunt when hepatic vein recanalization fails.1-3 Hypercoagulable patients with primary BCS are predisposed to development of new areas of thrombosis within the TIPS shunt or IVC. This case details a patient with BCS, pre-existing TIPS extending to the right atrium, and chronic retrohepatic IVC thrombosis who underwent sharp recanalization of the IVC with stenting into the TIPS stent bridging the patient until his subsequent hepatic transplantation.

Curcumin promotes venous thrombi resolve process in a mouse deep venous thrombosis model via regulating miR-499.

BACKGROUND/AIMS: The morbidity of deep venous thrombosis (DVT) is increasing rapidly and the current therapeutic strategies for DVT are unsatisfactory. Accumulating evidence suggest that venous thrombi resolve (VTR) may provide new insights into DVT therapeutic strategies. The aim of this study was to investigate the role of curcumin in VTR process and try to reveal the potential mechanism. METHODS: Immunofluorescence and HE staining were performed to investigate the therapeutic angiogenesis effect of curcumin in VTR process. Microarray analysis and RT-PCR were performed to examine the expression level of miR-499 in thrombosis after curcumin administration. Cell proliferation, migration and angiogenesis capacity were tested by CCK8 assay, Transwell assay and Tube formation assay, respectively. Dual-luciferase reporter assay (DLR) was used to confirm the connection between miR-499 and paired phosphate and tension homology deleted on chromosome ten (PTEN). RESULTS: We found that curcumin could effectively promote VTR process by activating angiogenesis in thrombus in vivo. The expression of miR-499 exhibited notably downregulated after curcumin administration. The proangiogenic effect of curcumin in HUVECs could be blocked by miR-499 overexpression. In addition, we confirmed that miR-499 directly target to the 3'UTR region of PTEN. CONCLUSION: Curcumin promotes VTR process in DVT through activating therapeutic angiogenesis. Mechanically, curcumin promotes therapeutic angiogenesis by regulating miR-499 mediated PTEN/VEGF/Ang-1 signaling pathway.

Computational fluid dynamics simulation of time-resolved blood flow in Budd-Chiari syndrome with inferior vena cava stenosis and its implication for postoperative efficacy assessment.

BACKGROUND: This study aimed to adopt computational fluid dynamics to simulate the blood flow dynamics in inferior vena cava stenosis based on time-dependent patient-specific models of Budd-Chiari syndrome as well as a normal model. It could offer valuable references for a retrospective insight into the underlying mechanisms of Budd-Chiari syndrome pathogenesis as well as more accurate evaluation of postoperative efficacy. METHODS: Three-dimensional inferior vena cava models of Budd-Chiari syndrome patient-specific (preoperative and postoperative) and normal morphology model were reconstructed as per magnetic resonance images using Simpleware. Moreover, computational fluid dynamics of time-resolved inferior vena cava blood flow were simulated using actual patient-specific measurements to reflect time-dependent flow rates. FINDINGS: The assessment of the preoperative model revealed the dramatic variations of hemodynamic parameters of the stenotic inferior vena cava. Moreover, the comparison of the preoperative and postoperative models with the normal model as benchmark showed that postoperative hemodynamic parameters were markedly ameliorated via stenting, with the attenuation of overall velocity and wall shear stress, and the increase of pressure. However, the comparative analysis of the patient-specific simulations revealed that some postoperative hemodynamic profiles still bore some resemblance to the preoperative ones, indicating potential risks of restenosis. INTERPRETATION: Computational fluid dynamics simulation of time-resolved blood flow could reveal the tight correlation between the hemodynamic characteristics and the pathological mechanisms of inferior vena cava stenosis. Furthermore, such time-resolved hemodynamic profiles could provide a quantitative approach to diagnosis, operative regimen and postoperative evaluation of Budd-Chiari syndrome with inferior vena cava stenosis.

Inferior Vena Cava Collapsibility Index to Assess Central Venous Pressure in Perioperative Period Following Cardiac Surgery in Children.

The inferior vena cava collapsibility index (IVCCI) is an ultrasound method used to assess central venous pressure (CVP). Our objective was to evaluate the correlation between IVCCI and CVP in children during the early period following surgery for congenital heart disease (CHD). Prospective study performed in a single tertiary care center. Patients ≤ 18 years old, who underwent cardiopulmonary bypass surgery for CHD, were enrolled. Ultrasound images of the inferior vena cava (IVC) were obtained at two time points; the first was within 2 h of arrival to the CICU and the second was 12-18 h from the first measurement. CVP measured by catheter placed during surgery was recorded within minutes of performing ultrasound. Maximum and minimum IVC diameters were measured by 2D images and M mode method. Seventy patients (47.1% males), with median age 7 months (IQR 4-47 months) and weight 6.9 kg (IQR 4.8-13.5 kg), were evaluated. The 2D IVCCI had inverse correlation with CVP in patients breathing spontaneously; r = - 0.76 (p < 0.01) and r = - 0.73 (p < 0.01), during the first and second measurements, respectively. The 2D IVCCI ≤ 0.24 had sensitivity, specificity, and negative predictive value of 94%, 79%, and 88.9% , respectively, to detect CVP ≥ 10 mmHg. No correlation was found between IVCCI and CVP during positive pressure ventilation. There is a significant inverse correlation between 2D IVCCI and CVP in spontaneously breathing children after surgery for CHD. Use of 2D IVCCI for monitoring CVP could reduce the frequency and duration of CVP catheters and their inherent complications.

[Evaluation of infrahepatic inferior vena cava clamping in robot-assisted laparoscopic liver resection].

Objective: To evalutate the safety and efficacy of infrahepatic inferior vena cava clamping robot-assisted laparoscopic liver resection. Methods: All data about 24 patients with robotic liver resection at Hepatic Surgery Center,Tongji Hospital,Tongji Medical College,Huazhong University of Science and Technology between February 2015 and December 2017 were collected and analyzed. These patients were divided into two groups based on different methods to decrease central venous pressure. Eight patients(6 males and 2 females,aged 49 years(range:50 to 56 years)) were applied with infrahepatic inferior vena cava clamping,and the other 16 matched cases (15 males and 1 female,aged 53 years(range:38 to 69 years)) were categorized into lowering central venous pressure group. Intraoperative blood loss,blood transfusion,intraoperative hemodynamic parameters,postoperative complications,and renal function were compared by t-test,non-parametric test,χ2 test,or Fisher exact test. Results: There was significantly difference in the intraoperative blood loss between the infrahepatic vena cava clamping group and the lowering central venous group(200(220) ml (range:100 to 400 ml) vs. 750(800) ml (range:100 to 2 000 ml),Z=‒2.169,P=0.030). The clamping time of portal triad and infrahepatic inferior vena cava were 24 (18) minutes and 29 (20) minutes in the infrahepatic inferior vena cava clamping group, and portal triad clamping time was 23 (23) minutes in the low central venous group. There was no significant difference between the two groups (Z=‒0.323, P=0.747). There was no intraoperative blood transfusion in the infrahepatic inferior vena cava clamping group, and 5 cases in the low central venous group, with a transfusion volume of 1.5(1.5)U. The difference between the two groups was statistically significant (Z=‒3.353, P=0.001). However, the mean arterial pressure in the infrahepatic vena cava clamping group decreased from (88.6±4.9) mmHg to (67.4±3.8) mmHg(1 mmHg=0.133 kPa), which was lower than that of lowering central venous group (72.4±3.3) mmHg (t=2.315,P=0.003). And there were no significant differences related to postoperative complications rate or hepatic and renal function in both groups. Conclusion: The infrahepatic inferior vena cava technology is safe and feasible to decrease central venous pressure during robotic liver resections,which will not affect the recovery of hepatic and renal functions.