Endovascular Ablation of the Right Greater Splanchnic Nerve in Heart Failure With Preserved Ejection Fraction: Rationale, Design and Lead-in Phase Results of the REBALANCE-HF Trial.

OBJECTIVE: Splanchnic vasoconstriction augments transfer of blood volume from the abdomen into the thorax, which may increase filling pressures and hemodynamic congestion in patients with noncompliant hearts. Therapeutic interruption of splanchnic nerve activity holds promise to reduce hemodynamic congestion in patients with heart failure with preserved ejection fraction (HFpEF). Here we describe (1) the rationale and design of the first sham-controlled, randomized clinical trial of splanchnic nerve ablation for HFpEF and (2) the 12-month results of the lead-in (open-label) trial's participants. METHODS: REBALANCE-HF is a prospective, multicenter, randomized, double-blinded, sham-controlled clinical trial of endovascular, transcatheter, right-sided greater splanchnic nerve ablation for volume management (SAVM) in patients with HFpEF. The primary objectives are to evaluate the safety and efficacy of SAVM and identify responder characteristics to inform future studies. The trial consists of an open-label lead-in phase followed by the randomized, sham-controlled phase. The primary efficacy endpoint is the reduction in pulmonary capillary wedge pressure (PCWP) at 1-month follow-up compared to baseline during passive leg raise and 20W exercise. Secondary and exploratory endpoints include health status (Kansas City Cardiomyopathy Questionnaire), 6-minute walk test distance, New York Heart Association class, and NTproBNP levels at 3, 6 and 12 months. The primary safety endpoint is device- or procedure-related serious adverse events at the 1-month follow-up. RESULTS: The lead-in phase of the study, which enrolled 26 patients with HFpEF who underwent SAVM, demonstrated favorable safety outcomes and reduction in exercise PCWP at 1 month post-procedure and improvements in all secondary endpoints at 6 and 12 months of follow-up. The randomized phase of the trial (n = 44 SAVM; n = 46 sham) has completed enrollment, and follow-up is ongoing. CONCLUSION: REBALANCE-HF is the first sham-controlled randomized clinical trial of greater splanchnic nerve ablation in HFpEF. Initial 12-month open-label results are promising, and the results of the randomized portion of the trial will inform the design of a future pivotal clinical trial. SAVM may offer a promising therapeutic option for patients with HFpEF. TRIAL REGISTRATION: NCT04592445.

Hepatic Oxygenation Changes and Symptomatic Intradialytic Hypotension.

INTRODUCTION: Clinical studies on differences among changes in cerebral and hepatic oxygenation during hemodialysis (HD) in patients with and without intradialytic hypotension (IDH) are limited. We investigated changes in intradialytic cerebral and hepatic oxygenation before systolic blood pressure (SBP) reached the nadir during HD and compared these differences between patients with and without symptomatic IDH. METHODS: We analyzed data from 109 patients with (n = 23) and without (n = 86) symptomatic IDH who were treated with HD. Cerebral and hepatic regional oxygen saturation (rSO2), as a marker of tissue oxygenation and circulation, was monitored during HD using an INVOS 5100c oxygen saturation monitor. Changes in cerebral or hepatic rSO2 when SBP reached the nadir during HD were compared between the groups of patients. RESULTS: The cerebral rSO2 before HD in patients with and without symptomatic IDH was 49.7 ± 11.2% and 51.3 ± 9.1% (p = 0.491). %Changes in cerebral rSO2 did not significantly differ between the two groups from 60 min before the SBP nadir during HD. Hepatic rSO2 before HD in patients with and without symptomatic IDH was 58.5 ± 15.4% and 57.8 ± 15.9% (p = 0.869). The %changes in hepatic rSO2 were significantly lower in patients with symptomatic IDH than in those without throughout the observational period (p < 0.001). We calculated the area under the receiver operating characteristic curve (AUC) and estimated cutoff values for changes in hepatic rSO2 as a symptomatic IDH predictor. The predictive ability at 5 and 40 min before symptomatic IDH onset was excellent, with AUCs and cutoff values of 0.847 and 0.841, and -10.9% and -5.0%, respectively. CONCLUSIONS: Hepatic oxygenation significantly decreased more in patients with symptomatic IDH before its onset, than in those without symptomatic IDH, whereas changes in cerebral oxygenation did not differ. Evaluating changes in hepatic oxygenation during HD might help to predict symptomatic IDH.

Splanchnic Vein Thrombosis in Myelofibrosis-An Underappreciated Hallmark of Disease Phenotype.

Splanchnic vein thrombosis (SVT) encompasses thrombosis in the vessels of the splanchnic basin and has a relatively rare occurrence with a reported frequency in the general population of 1-2%. An episode of seemingly unprovoked SVT almost always triggers a diagnostic work-up for a Philadelphia chromosome-negative myeloproliferative neoplasm (MPN), since atypical site thrombosis is a hallmark of MPN-associated thrombophilia. Primary myelofibrosis (PMF) is a rare MPN with an estimated incidence between 0.1 and 1/100,000 per year. Although prothrombotic tendency in PMF is not envisioned as a subject of specific therapeutic management, unlike other MPNs, such as polycythemia vera (PV) and essential thrombocythemia (ET), thrombotic risk and SVT prevalence in PMF may be comparably high. Additionally, unlike PV and ET, SVT development in PMF may depend more on procoagulant mechanisms involving endothelium than on blood cell activation. Emerging results from registry data also suggest that PMF patients with SVT may exhibit lower risk and better prognosis, thus highlighting the need for better thrombotic risk stratification and identifying a subset of patients with potential benefit from antithrombotic prophylaxis. This review highlights specific epidemiological, pathogenetic, and clinical features pertinent to SVT in myelofibrosis.

An Update on Acute Mesenteric Ischemia.

Acute mesenteric ischemia (AMI) is an uncommon yet highly lethal cause of acute abdomen in the emergency setting. Computed tomography (CT) imaging, in particular a biphasic protocol consisting of angiographic and venous phase scans, is widely used to corroborate non-specific clinical findings when suspicions of AMI are high. Techniques such as low kilovoltage peak scanning, dual energy acquisition, or a combined arterial/enteric phase can improve iodine conspicuity and evaluation of bowel enhancement. Biphasic CT with CT angiography is mandatory to directly assess for the 3 primary etiologies of AMI-arterial, venous, and non-occlusive mesenteric ischemia (NOMI), and the CT angiographic findings may be the first visible in the disease. In addition, numerous non-vascular CT findings have also been reported. Bowel wall thickening, mesenteric stranding, and ascites are common but non-specific findings that correlate poorly with disease severity. Pneumatosis intestinalis and portomesenteric venous gas, while not pathognomonic for ischemia, are highly specific in cases of high clinical suspicion. Bowel wall hypoenhancement is an early and specific sign but requires a protocol optimizing iodine conspicuity to confidently identify. Finally, intraperitoneal free air and solid organ infarcts are also highly specific ancillary findings in AMI. AMI occurs as a complication in 10% of small bowel obstruction (SBO) patients, and understanding imaging findings of ischemia in the context of SBO is necessary to aid in treatment planning and reduce over- and under-diagnosis of strangulation. Familiarity with the imaging features of ischemia by radiologists is vital to establish an early diagnosis before irreversible necrosis occurs.

Therapeutic anticoagulation for splanchnic vein thrombosis in acute pancreatitis: A systematic review and meta-analysis.

OBJECTIVES: The optimal management of patients with acute pancreatitis (AP) and splanchnic vein thrombosis (SVT) remains unknown. This systematic review and meta-analysis aimed to see if therapeutic anticoagulation (AC) improves outcomes in patients with AP and SVT. METHODS: A systematic review was performed according to PRISMA guidelines. Main outcomes were recanalization, recurrent venous thromboembolism, development of varices, collaterals or cavernoma, haemorrhage and mortality. Meta-analysis were performed with the Mantel-Haenszel random effect models. RESULTS: Seven retrospective cohort studies (3495 patients) were included. SVT occurred in 233 (7%) patients and involved most frequently the splenic vein (44%). Therapeutic AC was administered to 109 (47%) patients, most frequently to those with triple vessel thrombosis (72%) and least to those with isolated splenic vein (22%) or superior mesenteric vein thrombosis (0%). Most studies administered (low molecular weight) heparin followed by warfarin (duration ranged between 1.5 and 12 months). This meta-analysis showed an absolute risk difference of 9% (95% confidence interval [CI] = -11-28%) for recanalization, -3% (95% CI = -19-12%) for the development of varices, collaterals or cavernoma, 3% (95% CI = -6-12%) for haemorrhage and 2% (95% CI = -8-12%) for mortality. CONCLUSIONS: Based on the currently available data, it remains unclear if therapeutic anticoagulation provides benefit to acute pancreatitis patients with splanchnic vein thrombosis. These results are based on low quality data underlining the need for further higher quality studies.

Hemodynamic pathways of gestational hypertension and preeclampsia.

Gestational hypertension and preeclampsia are the 2 main types of hypertensive disorders in pregnancy. Noninvasive maternal cardiovascular function assessment, which helps obtain information from all the components of circulation, has shown that venous hemodynamic dysfunction is a feature of preeclampsia but not of gestational hypertension. Venous congestion is a known cause of organ dysfunction, but its potential role in the pathophysiology of preeclampsia is currently poorly investigated. Body water volume expansion occurs in both gestational hypertension and preeclampsia, and this is associated with the common feature of new-onset hypertension after 20 weeks of gestation. Blood pressure, by definition, is the product of intravascular volume load and vascular resistance (Ohm's law). Fundamentally, hypertension may present as a spectrum of cardiovascular states varying between 2 extremes: one with a predominance of raised cardiac output and the other with a predominance of increased total peripheral resistance. In clinical practice, however, this bipolar nature of hypertension is rarely considered, despite the important implications for screening, prevention, management, and monitoring of disease. This review summarizes the evidence of type-specific hemodynamic profiles in the latent and clinical stages of hypertensive disorders in pregnancy. Gestational volume expansion superimposed on an early gestational closed circulatory circuit in a pressure- or volume-overloaded condition predisposes a patient to the gradual deterioration of overall circulatory function, finally presenting as gestational hypertension or preeclampsia-the latter when venous dysfunction is involved. The eventual phenotype of hypertensive disorder is already predictable from early gestation onward, on the condition of including information from all the major components of circulation into the maternal cardiovascular assessment: the heart, central and peripheral arteries, conductive and capacitance veins, and body water content. The relevance of this approach, outlined in this review, openly invites for more in-depth research into the fundamental hemodynamics of gestational hypertensive disorders, not only from the perspective of the physiologist or the scientist, but also in assistance of clinicians toward understanding and managing effectively these severe complications of pregnancy.

Assessment of hepatic arterial hemodynamics with 4D flow MRI: in vitro analysis of motion and spatial resolution related error and in vivo feasibility study in 20 volunteers.

OBJECTIVES: To assess the ability of four-dimensional (4D) flow MRI to measure hepatic arterial hemodynamics by determining the effects of spatial resolution and respiratory motion suppression in vitro and its applicability in vivo with comparison to two-dimensional (2D) phase-contrast MRI. METHODS: A dynamic hepatic artery phantom and 20 consecutive volunteers were scanned. The accuracies of Cartesian 4D flow sequences with k-space reordering and navigator gating at four spatial resolutions (0.5- to 1-mm isotropic) and navigator acceptance windows (± 8 to ± 2 mm) and one 2D phase-contrast sequence (0.5-mm in -plane) were assessed in vitro at 3 T. Two sequences centered on gastroduodenal and hepatic artery branches were assessed in vivo for intra - and interobserver agreement and compared to 2D phase-contrast. RESULTS: In vitro, higher spatial resolution led to a greater decrease in error than narrower navigator window (30.5 to -4.67% vs -6.64 to -4.67% for flow). In vivo, hepatic and gastroduodenal arteries were more often visualized with the higher resolution sequence (90 vs 71%). Despite similar interobserver agreement (κ = 0.660 and 0.704), the higher resolution sequence had lower variability for area (CV = 20.04 vs 30.67%), flow (CV = 34.92 vs 51.99%), and average velocity (CV = 26.47 vs 44.76%). 4D flow had lower differences between inflow and outflow at the hepatic artery bifurcation (11.03 ± 5.05% and 15.69 ± 6.14%) than 2D phase-contrast (28.77 ± 21.01%). CONCLUSION: High-resolution 4D flow can assess hepatic artery anatomy and hemodynamics with improved accuracy, greater vessel visibility, better interobserver reliability, and internal consistency. KEY POINTS: • Motion-suppressed Cartesian four-dimensional (4D) flow MRI with higher spatial resolution provides more accurate measurements even when accepted respiratory motion exceeds voxel size. • 4D flow MRI with higher spatial resolution provides substantial interobserver agreement for visualization of hepatic artery branches. • Lower peak and average velocities and a trend toward better internal consistency were observed with 4D flow MRI as compared to 2D phase-contrast.

Endovascular Treatment of Chronic and Acute on Chronic Mesenteric Ischaemia: Results From a National Cohort of 245 Cases.

OBJECTIVE: Endovascular treatment of chronic mesenteric ischaemia (CMI) is linked to low early morbidity and mortality but a higher risk of recurrence than open repair. Mid and long term outcomes after endovascular treatment remain to be proven in larger series. The aim of this study was to assess short and mid term outcome after first line endovascular revascularisation of CMI and acute on chronic mesenteric ischaemia (AoCMI). METHODS: This was a prospective population and registry based cohort study supplemented by a retrospective review of medical records and imaging files. A national cohort was created based on data extracted from the Danish National Registry for Vascular Surgery (Karbase) for all patients treated endovascularly for CMI or AoCMI between 2011 and 2015 in Denmark. Survival data, bowel resection, complications, re-intervention rate, and improvement of clinical symptoms were analysed, as were potential risk factors. RESULTS: In total, 245 patients had an endovascular intervention for CMI (n = 178; 72.6%) and AoCMI (n = 67; 27.3%). One and three year survival estimates were 85% (95% confidence interval [CI] 79 - 90) and 74% (95% CI 67 - 80) in the CMI-group, and 67% (95% CI 54 - 77) and 54% (95% CI 41 - 65) in the AoCMI group. The hazard ratio for death was 1.89 (95% CI 1.23 - 2.9) for AoCMI, relative to patients with CMI. Superior mesenteric artery (SMA) stenosis, rather then occlusion, significantly increased the success of SMA recanalisation: OR 19.4 (95% CI 6.2 - 61.4) and 9.3 (95% CI 1.6 - 53.6) in the CMI and AoCMI groups, respectively. The proportion of patients reporting clinical improvement was 71% (n = 127) in the CMI group and 59% (n = 39) in the AoCMI group. Five patients (3%) in the CMI and 30 (45%) in the AoCMI groups underwent bowel resection (p < .001), and the overall length of hospital stay (LoS) was a median of two days (interquartile range [IQR] 1 - 3 days) in the CMI group and seven days (IQR 3 - 23 days) in the AoCMI group. Within the first year, re-intervention was performed in 14 patients (5.7%). CONCLUSION: First line endovascular treatment of CMI carries a three year mortality rate of 25%, and low risk of re-occurrence of symptomatic ischaemia. Relative to CMI, patients suffering AoCMI have significantly higher morbidity and mortality, more bowel resections, and longer LoS.

Splenic Rhythms and Postprandial Dynamics in Physiology, Portal Hypertension, and Functional Hyposplenism: A Review.

BACKGROUND: Before the discovery of immunological and haematological functions of the spleen, it had for centuries been considered to be a digestive organ of variable size with a role in the portal vein system and nutritional metabolism. In the 19th and 20th centuries, volume changes in the spleen related to nutrition were studied using plethysmographic measurements. Rhythmical and regulatory functions of the spleen were demonstrated in the haemodynamics of the splanchnic region and were described as a "hepatolienal pendulum," a "Windkessel function," or a "pressure compensation." These studies were mainly published in German-speaking countries and have not, as far as is known, been discussed in the English-speaking world so far. SUMMARY: This review explores the historical development of the rhythmical regulatory function of the spleen in the splanchnic region. Older studies and results are followed up in the modern literature, wherever possible, up to the present. The clinical relevance is illustrated with portal hypertension (with congestive or hyperdynamic splenomegaly), coeliac disease, and chronic inflammatory bowel diseases (with functional hyposplenism). Key Message: The spleen's rhythmical regulatory function in nutrition is based on an autonomous rhythm comprising cycles of contractions and dilations of the spleen of around 1 min. These cycles can be influenced by sympathetically mediated single contractions with a release of pooled blood or by portal vein congestion. After food ingestion, the spleen responds either with contraction according to a vasomotor reaction or postprandial congestion with significant increases in volume. The spleen's rhythmical function is lost in the clinical picture of portal hypertension or in coeliac disease and chronic inflammatory bowel diseases. In the aforementioned gastrointestinal diseases, we recommend taking more account of the haemodynamics between the spleen, liver, and intestine. New innovative techniques for recording splenograms are required which, besides elastographic measurements of spleen stiffness, could offer an important tool for early detection, diagnosis, and therapeutic evaluation.

Splanchnic vein closures.

Closures in the splanchnic venous system (SVS) represent a broad medical problem. Anatomically, individual or even multiple sections of SVS may be affected at the same time. Main sections of SVS include the venous liver outflow system, the portal vein, and the upper mesenteric vein and its basin. Thrombosis is clearly the predominant cause of closure. The closures can present as acute, subacute, chronic occult or chronic manifest. The main pathological and anatomical units are the Budd-Chiari syndrome (BCS), extrahepatic portal vein obstruction (EHPVO) and mesenteric vein thrombosis (MVT). Advanced laboratory, imaging and intervention methods substantially modify the approach to prevention, diagnosis and treatment; surgical approach also plays a role. The problem of SVS closures is interdisciplinary.

The association between portal system vein diameters and outcomes in acute pancreatitis.

BACKGROUND/OBJECTIVES: Acute pancreatitis (AP) progresses to necrotizing pancreatitis in 15% of cases. An important pathophysiological mechanism in AP is third spacing of fluids, which leads to intravascular volume depletion. This results in a reduced splanchnic circulation and reduced venous return. Non-visualisation of the portal and splenic vein on early computed tomography (CT) scan, which might be the result of smaller vein diameter due to decreased venous flow, is associated with infected necrosis and mortality in AP. This observation led us to hypothesize that smaller diameters of portal system veins (portal, splenic and superior mesenteric) are associated with increased severity of AP. METHODS: We conducted a post-hoc analysis of data from two randomized controlled trials that included patients with predicted severe and mild AP. The primary endpoint was AP-related mortality. The secondary endpoints were (infected) necrotizing pancreatitis and (persistent) organ failure. We performed additional CT measurements of portal system vein diameters and calculated their prognostic value through univariate and multivariate Poisson regression. RESULTS: Multivariate regression showed a significant inverse association between splenic vein diameter and mortality (RR 0.75 (0.59-0.97)). Furthermore, there was a significant inverse association between splenic and superior mesenteric vein diameter and (infected) necrosis. Diameters of all veins were inversely associated with organ failure and persistent organ failure. CONCLUSIONS: We observed an inverse relationship between portal system vein diameter and morbidity and an inverse relationship between splenic vein diameter and mortality in AP. Further research is needed to test whether these results can be implemented in predictive scoring systems.

Glutamate Supply and Metabolism in Infants.

Glutamate (Glu) is the most abundant amino acid (AA) in human milk. Available information on Glu supply and metabolism was reviewed, based on an electronic literature search. In 22 cross-sectional global studies with 4,747 women, free Glu increases with lactation duration and contributes to about 38% of total and 63% of dispensable milk AA. Based on these data, a typical breastfed infant obtains a mean free Glu intake of 35.7 mg/kg body weight (bw; upper end of the normal range 134.6 mg/kg), while precisely collected longitudinal data indicate mean intakes of 40 mg/kg and upper range intakes of 70.2 mg/kg. Mean intakes with cows' milk formula at median concentrations are 0.7 mg/kg (upper range 1.0 mg/kg) and with extensive protein hydrolysate formula 171.7 mg/kg bw (upper range 249.8 mg/kg bw), with no indication of untoward effects. Infants almost entirely utilize dietary Glu in splanchnic organs, with no appreciable effect on plasma Glu concentrations. Estimated free Glu intakes in breastfed infants are up to 4.5-fold higher than the acceptable daily intake (ADI) set by the European Food Safety Authority for the total population including infants, and the respective intakes of infants fed a formula based on an extensive protein hydrolysate are up to 8.3-fold higher. There is no reason to assume that feeding human milk or an extensive protein hydrolysate infant formula would be unsuitable or unsafe for infants. Setting an ADI below the range of the normal intake with a safe diet in generally healthy individuals, that is, below 250 mg/kg per day, seems inappropriate.

Emerging therapies for portal hypertension in cirrhosis.

INTRODUCTION: Counteracting splanchnic vasodilatation and increased portal-collateral blood flow has been the mainstay for the treatment of portal hypertension (PH) over the past three decades. However, there is still large room for improvement in the treatment of PH. AREAS COVERED: The basic mechanism leading to portal hypertension is the increased hepatic vascular resistance to portal blood flow caused by liver structural abnormalities inherent to cirrhosis and increased hepatic vascular tone. Molecules modulating microvascular dysfunction which have undergone preclinical and clinical trials are summarized, potential drug development issues are addressed, and situations relevant to design of clinical trials are considered. EXPERT OPINION: Experimental and clinical evidence indicates that molecules modulating liver microvascular dysfunction may allow for 30-40% reduction in portal pressure. Several agents could be utilized in the earlier stages of cirrhosis (antifibrotics, antiangiogenics, etiological therapies) may allow reduction of fibrosis and halt progression of PH. This 'nip at the bud' policy, by combining therapies with existing agents used in advanced phase of cirrhosis and novel agents which could be used in early phase of cirrhotic spectrum, which are likely to hit the market soon would be the future strategy for PH therapy.

Clinical presentations, risk factors, treatment and outcomes in patients with splanchnic vein thrombosis: a single-center experience.

Splanchnic vein thrombosis (SVT) is an uncommon form of venous thrombosis. Management can be challenging due to underlying conditions, increased bleeding risk, and lack of evidence from clinical trials. We sought to characterize the presentation and management of patients with SVT at a large tertiary hospital. A total of 43 patients' electronic medical records were reviewed. Median age at diagnosis was 43 (18-71). Sixteen patients had isolated portal vein thrombosis (37.2 %), and 16 (37.2 %) had thrombosis involving multiple splanchnic veins. Abdominal pain was the most common clinical presentation (67.4 %). Thrombophilia was present in 18 patients (41.9 %), nine had underlying liver disease (20.9 %) and seven had inflammatory bowel disease (16.3 %). Thirty-nine (90.7 %) patients were treated with anticoagulation, and 11(25.6 %) of these patients underwent interventional procedures. Thirty (69.8 %) patients remained on indefinite anticoagulation. Results of follow-up imaging at least 1 month after diagnosis were available for 29 patients; imaging showed chronic, stable thrombosis in 14 patients (48.3 %), resolution of thrombosis in 13 patients (44.8 %) and asymptomatic progression in two patients (6.9 %). Recurrent thrombosis occurred in four patients (9.3 %). Major bleeding occurred in eight patients who received anticoagulation (18.6 %), including fatal subdural hematoma in one patient. In this cohort of patients managed by hematologists and gastroenterologists, the majority of patients were treated with anticoagulation. Interventional procedures were higher than in previously reported series. Our study strongly supports the interdisciplinary management of splanchnic venous thrombosis.

Median arcuate ligament syndrome: Predictor of ischemic complications?

Median arcuate ligament syndrome (MALS) is a pathologic entity that can affect the celiac axis. Due to the extensive collateral network of mesenteric circulation, stenosis of one mesenteric artery does not lead to significant symptoms. The purpose of this study was to describe multidetector computed tomography (MDCT) angiography findings of celiac artery entrapment by the median arcuate ligament and determine those patients with high risks of ischemic complications. From January 2012 to March 2016, 103 patients with celiac artery (CA) compression by median arcuate ligament were detected. In 23 patients collateral circulation was developed. In order to investigate the problem, we managed to estimate the correlation between range of stenosis of CA and presence of collateral circulation between the celiac artery (CA) and superior mesenteric artery (SMA). A statistically significant correlation was found between range of CA stenosis and collateral circulation presence (Spearman's correlation coefficient 0.339, P < 0.0001). In conclusions, based on our observations, we hypothesize that ischemia as a result of mesenteric vessel narrowing by the median arcuate ligament may occur more often than indicated by clinical symptoms and described in literature. Clin. Anat. 29:1025-1030, 2016. © 2016 Wiley Periodicals, Inc.

The influence of the gastrointestinal tract and the liver on cystatin C serum concentrations.

OBJECTIVE: The purpose of this study in humans was to examine the influence of the gastrointestinal tract and liver on the serum concentrations of cystatin C. METHODS: Eighteen healthy volunteers and 28 patients suspected of having chronic intestinal ischemia underwent catheterization of the abdominal aorta and the central hepatic vein. Blood samples were taken simultaneously from the abdominal aorta and the central hepatic vein 60, 90 and 120 minutes after the start of the investigation. After the first blood sample, a standard liquid meal was ingested. Measurement of splanchnic blood flow was performed using the Fick principle with constant infusion of (99m)Tc-Bridatec. Angiography was performed at the end of the investigation. RESULTS: The splanchnic blood flow increased significantly postprandially in the healthy volunteers and in the patients with normal angiography by 0.613-0.698 L/min and increased non- significantly in the patients with abnormal angiography (n = 5) by 0.135 L/min on average. ANOVA and the Bonferroni's multiple comparison test showed no significant difference between the means of cystatin C, creatinine or urea in the samples taken 60, 90 and 120 minutes after the start of the investigation in the abdominal aorta and the hepatic vein in the healthy volunteers or in the patients suspected of chronic intestinal ischemia with normal angiography. CONCLUSION: There was no indication of hepatic elimination of cystatin C, creatinine or urea. The serum concentrations of cystatin C, creatinine and urea in the central hepatic vein and the abdominal aorta were independent of the splanchnic blood flow.

Natural history of cancer-associated splanchnic vein thrombosis.

BACKGROUND: There is uncertainty in the management of cancer-associated isolated splanchnic vein thrombosis (SpVT). OBJECTIVES: To describe the natural history of SpVT by cancer type and thrombus composition and to review anticoagulation (AC) practices and associated rates of usual-site venous thromboembolism (VTE), major and clinically relevant nonmajor bleeding (MB/CRNMB), recanalization/progression, and mortality. METHODS: We performed a retrospective cohort study in patients with SpVT at 2 cancer care centers in Houston, Texas. We estimated the incidence of usual-site VTE and MB/CRNMB at 6 months using competing risk methods and examined venous patency in a subset of patients with repeat imaging. We assessed associations with mortality using Cox regression. RESULTS: Among 15 342 patients with an incident cancer diagnosis from 2011 to 2020, we identified 298 with isolated SpVT. Patients with hepatocellular carcinoma (HCC) and SpVT (n = 146) had the highest disease prevalence (20%), lowest rate of AC treatment (2%), and similar rate of usual-site VTE (4.2%) vs those without SpVT (5.2%) at 6 months, though tumor thrombus vs bland was associated with worse overall survival. In patients with non-HCC bland SpVT (n = 114), AC (n = 37) was more common in those with non-upper gastrointestinal cancers and fewer comorbidities. AC was associated with more recanalization (44% vs 15%, P = .041) but no differences in usual-site VTE, MB/CRNMB, or mortality at 6 months. CONCLUSION: Cancer-associated isolated SpVT is a common but heterogeneous thrombotic disease that is treated differently from usual-site VTE. Tumor thrombus is a negative prognostic factor. Initiation of AC in bland thrombi requires judicious consideration of thrombotic and bleeding risk.

Efficacy and safety of direct oral anticoagulants in splanchnic vein thrombosis: a pooled analysis of literature studies.

BACKGROUND: Limited evidence is available on management of splanchnic vein thrombosis (SVT). OBJECTIVES: This study aimed to evaluate safety and efficacy of direct oral anticoagulants (DOACs) for SVT treatment. METHODS: Studies were systematically searched in the PubMed, Web of Science, and Scopus databases according to PRISMA guidelines. We assessed any recanalization, full recanalization, recurrence, mortality, and major bleeding as outcomes of interest. Results were reported as weighted mean prevalence (WMP) with 95% CI. Subgroup analyses and meta-regressions have been performed to address heterogeneity and adjust for potential confounders. RESULTS: We included a total of 16 studies (17 datasets) on 648 patients with SVT treated with DOACs. We found any recanalization in 60.3% (95% CI: 41.8%-76.3%; I2 = 84.9%; P < .001) and full recanalization in 51.7% (95% CI: 36.0%-67.0%; I2 = 87.4%; P < .001). Recurrent venous thromboembolism occurred in 2.8% (95% CI: 1.4%-5.9%; I2 = 0%; P = .787) and death in 3.4% (95% CI: 1.6%-7.3%; I2 = 13.2%; P = .318) of patients. Major bleeding was reported by 5.8% (95% CI: 3.7%-8.9%; I2 = 29.2%; P = .125) of patients. Results were consistent when separately analyzing prospective studies, retrospective studies, studies on cirrhotic patients, and studies enrolling patients with portal vein thrombosis. Meta-regression analyses showed that an increasing age and cancer impacted the rate of recanalization. Cirrhosis was associated with a higher rate of major bleeding and mortality. CONCLUSION: The results of the present study, mostly based on observational studies, suggest good safety and efficacy profiles of DOACs in patients with SVT. Randomized studies are needed to corroborate our findings.

Recent Advances in the Pathogenesis and Clinical Evaluation of Portal Hypertension in Chronic Liver Disease.

In chronic liver disease, hepatic stellate cell activation and degeneration of liver sinusoidal endothelial cells lead to structural changes, which are secondary to fibrosis and the presence of regenerative nodules in the sinusoids, and to functional changes, which are related to vasoconstriction. The combination of such changes increases intrahepatic vascular resistance and causes portal hypertension. The subsequent increase in splanchnic and systemic hyperdynamic circulation further increases the portal blood flow, thereby exacerbating portal hypertension. In clinical practice, the hepatic venous pressure gradient is the gold-standard measure of portal hypertension; a value of ≥10 mm Hg is defined as clinically significant portal hypertension, which is severe and is associated with the risk of liver-related events. Hepatic venous pressure gradient measurement is somewhat invasive, so evidence on the utility of risk stratification by elastography and serum biomarkers is needed. The various stages of cirrhosis are associated with different outcomes. In viral hepatitis-related cirrhosis, viral suppression or elimination by nucleos(t)ide analog or direct-acting antivirals results in recompensation of liver function and portal pressure. However, careful follow-up should be continued, because some cases have residual clinically significant portal hypertension even after achieving sustained virologic response. In this study, we reviewed the current and future prospects for portal hypertension.

[Hemodynamic Changes in Chronic Liver Disease].

Chronic liver disease causes hemodynamic changes in the body depending on the degree of progression. These hemodynamic changes begin with splanchnic vasodilation, with complications beginning to appear as the hyperdynamic changes occur. As chronic liver disease progresses, increased splanchnic vasodilation and hyperdynamic changes worsen portal hypertension and help cause or worsen chronic liver disease complications, such as ascites. Ultimately, the effective plasma volume and blood pressure decrease in the terminal stage.