This work describes a new procedure aimed to semi-automatically identify clusters of active persistent scatterers and preliminarily associate them with different potential types of deformational ...processes over wide areas. This procedure consists of three main modules: (i) ADAfinder, aimed at the detection of Active Deformation Areas (ADA) using Persistent Scatterer Interferometry (PSI) data; (ii) LOS2HV, focused on the decomposition of Line Of Sight (LOS) displacements from ascending and descending PSI datasets into vertical and east-west components; iii) ADAclassifier, that semi-automatically categorizes each ADA into potential deformational processes using the outputs derived from (i) and (ii), as well as ancillary external information. The proposed procedure enables infrastructures management authorities to identify, classify, monitor and categorize the most critical deformations measured by PSI techniques in order to provide the capacity for implementing prevention and mitigation actions over wide areas against geological threats. Zeri, Campiglia Marittima–Suvereto and Abbadia San Salvatore (Tuscany, central Italy) are used as case studies for illustrating the developed methodology. Three PSI datasets derived from the Sentinel-1 constellation have been used, jointly with the geological map of Italy (scale 1:50,000), the updated Italian landslide and land subsidence maps (scale 1:25,000), a 25 m grid Digital Elevation Model, and a cadastral vector map (scale 1:5000). The application to these cases of the proposed workflow demonstrates its capability to quickly process wide areas in very short times and a high compatibility with Geographical Information System (GIS) environments for data visualization and representation. The derived products are of key interest for infrastructures and land management as well as decision-making at a regional scale.
This study focuses on assessing the defensiveness of medieval fortresses situated along the Mediterranean coast, including the Northern Algerian coast and Southeastern Spain. The proposed methodology ...involved a two-fold process comprising identification and evaluation. Initially, we identified and geolocated our case studies, deriving their locations from archival sources. We then seamlessly integrated them into a Geographic Information System (GIS) for precise georeferencing on a rasterized landscape. Subsequently, we conducted assessments of visibility, intervisibility, and elevation, which we consider pivotal in determining the degree of defensibility of the fortified sites. Specifically, the aim of this research was to investigate the intricate relationship between natural landscapes and architectural defensive features, with a focus on discerning the influence that the chosen location has on the strategic and defensive significance of the studied fortresses. Our findings reveal that the evolution of those defensive systems within our study context is intricately tied to the physical elements comprising the landscape. These natural constituents have served as a foundation for the architectural and defensive characteristics adopted by medieval builders. Furthermore, we delineated two distinct typologies: the isolated type, intentionally designed to obscure visibility, and the exposed type, characterized by a higher visibility index.
This study presents the results of the geoenvironmental characterization of La Matildes riverbed, affected by mine tailings in the Cartagena–La Unión district, Murcia (southeast Spain). Soils and ...riverbeds in this area are highly polluted. Two Electrical Resistivity Imaging (ERI) profiles were carried out to obtain information about the thickness of the deposits and their internal structure. For the mine tailings deposits of La Murla, a tributary of the El Miedo riverbed, the geophysical method imaged two different units: the upper one characterized by low resistivity values and 5–8 m thickness, correlated with the mine tailings deposits; and the lower more resistive unit corresponding to the Paleozoic metasediments bedrock. The ERI profile transverse to the Las Matildes dry riverbed revealed the existence of three different units. The uppermost one has the lowest resistivity values and corresponds to the tailings deposits discharged to the riverbeds. An intermediate unit, with intermediate resistivity values, corresponds to the riverbed sediments before the mining operations. The lower unit is more resistive and corresponds to the bedrock. Significant amounts of pyrite, sphalerite, and galena were found both in tailings and riverbed sediments. The geochemical composition of borehole samples from the riverbed materials shows significantly high contents of As, Cd, Cu, Fe, Pb, and Zn being released to the environment. Mining works have modified the natural landscape near La Unión town. Surface extraction in three open-pit mines have changed the summits of Sierra de Cartagena–La Unión. Rock and metallurgical wastes have altered the drainage pattern and buried the headwaters of ephemeral channels. The environmental hazards require remediation to minimize the environmental impact on the Mar Menor coastal lagoon, one of the most touristic areas in SE Spain.
Porto-sinusoidal vascular liver disorder (PSVD) is a rare disease that occasionally requires liver transplantation (LT), despite usually presenting preserved liver function. There remains a paucity ...of data pertaining to LT in PSVD. The aim was to identify features associated with post-LT outcomes in PSVD.
Retrospective multicentre study of 79 patients who received LT for PSVD.
Median post-LT follow-up was 37 (range 1-261) mo. Refractory ascites 24 (30%), hepatic encephalopathy 16 (20%), and hepatopulmonary syndrome 13 (16.3%) were the most frequent indications for LT. Hepatocellular carcinoma was the indication in only 2 patients. Twenty-four patients died, 7 due to liver and 17 to non-liver related causes. Post-LT survival was 82.2%, 80.7%, and 68.6% at 1, 2, and 5 y, respectively. Post-LT survival was significantly better in patients without (n = 58) than in those with a persistent severe PSVD-associated condition (n = 21). Pre-LT hyperbilirubinemia levels and creatinine >100 µmol/L were also independently associated with poor survival. Six patients (7.6%) required a second LT. Recurrence of PSVD was confirmed by liver biopsy in only 1 patient and in 3 further patients it was likely.
LT in PSVD is associated with an acceptable outcome in the absence of associated severe conditions. However, persistence of a severe associated condition, pre-LT high bilirubin levels, or creatinine >100 µmol/L impact outcome, and these are features that should be considered when evaluating PSVD patients for LT. PSVD recurrence is possible after LT and needs to be explored, at least, in cases of posttransplant portal hypertension.
Clinically significant portal hypertension (CSPH), defined as a hepatic venous pressure gradient (HVPG) ≥10 mmHg, persists 24 weeks after sustained virological response (SVR) in up to 78% of patients ...with HCV-related cirrhosis treated with direct-acting antivirals. These patients remain at risk of decompensation. However, long-term paired clinical and hemodynamic data are not available for this population.
We conducted a prospective multicenter study in 226 patients with HCV-related cirrhosis and CSPH who achieved SVR after antiviral therapy. Patients with CSPH 24 weeks after end of treatment (SVR24) were offered another hemodynamic assessment 96 weeks after end of treatment (SVR96).
All patients were clinically evaluated. Out of 176 patients with CSPH at SVR24, 117 (66%) underwent an HVPG measurement at SVR96. At SVR96, 55/117 (47%) patients had HVPG <10 mmHg and 53% had CSPH (65% if we assume persistence of CSPH in all 59 non-evaluated patients). The proportion of high-risk patients (HVPG ≥16 mmHg) diminished from 41% to 15%. Liver stiffness decreased markedly after SVR (median decrease 10.5 ± 13 kPa) but did not correlate with HVPG changes (30% of patients with liver stiffness measurement <13.6 kPa still had CSPH). Seventeen (7%) patients presented with de novo/additional clinical decompensation, which was independently associated with baseline HVPG ≥16 mmHg and history of ascites.
Patients achieving SVR experienced a progressive reduction in portal pressure during follow-up. However, CSPH may persist in up to 53–65% of patients at SVR96, indicating persistent risk of decompensation. History of ascites and high-risk HVPG values identified patients at higher risk of de novo or further clinical decompensation.
As a major complication of cirrhosis, clinically significant portal hypertension (CSPH) is associated with adverse clinical outcomes. Herein, we show that CSPH persists at 96 weeks in just over half of patients with HCV-related cirrhosis, despite HCV elimination by direct-acting antivirals. Despite viral cure, patients with CSPH at the start of antiviral treatment remain at long-term risk of hepatic complications and should be managed accordingly.
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•HVPG ≥10 mmHg persists 2 years after therapy in 53–65% of patients with HCV-related cirrhosis despite HCV eradication.•Changes in liver stiffness do not correlate with changes in HVPG after a sustained virological response.•Baseline HVPG ≥16 mmHg and ascites identify patients with persistent CSPH and risk of decompensation.
Patients with hepatitis C virus-associated cirrhosis and clinical significant portal hypertension (CSPH, hepatic venous pressure gradient HVPG 10 mmHg or greater), despite achieving sustained ...virological response (SVR) to therapy, remain at risk of liver decompensation. We investigated hemodynamic changes following SVR in patients with CSPH and whether liver stiffness measurements (LSMs) can rule out the presence of CSPH.
We performed a multicenter prospective study of 226 patients with hepatitis C virus-associated cirrhosis and CSPH who had SVR to interferon-free therapy at 6 Liver Units in Spain. The portal pressure gradient was determined based on HVPG at baseline and 24 weeks after therapy; patients also underwent right-heart catheterization and LSM at these time points. Primary outcomes were effects of SVR on the hepatic, pulmonary, and systemic hemodynamics; factors related to HVPG ≥10% reduction and to CSPH persistence; and whether LSMs can rule out the presence of CSPH after SVR.
Most patients (75%) had esophageal varices, 21% were Child-B, and 29% had at least 1 previous episode of liver decompensation. Overall, HVPG decreased from 15 (IQR: 12–18) before treatment to 13 (10–16) mmHg after SVR (reduction of 2.1 ± 3.2 mmHg; P < .01). However, CSPH persisted in 78% of patients. HVPG decreased by 10% or more from baseline in 140 patients (62%). Baseline level of albumin below 3.5 g/dL was the only negative factor associated with an HVPG reduction of 10% or more. LSM decreased from 27 (20–37) kPa before treatment to 18 (14–28) kPa after SVR (P < .05). One third of patients with a reduction in LSM to below 13.6 kPa after SVR still had CSPH. A higher baseline HVPG and a lower decrease in LSM after treatment were associated with persistence of CSPH after SVR. Systemic hemodynamics improved after SVR. Interestingly, pulmonary hypertension was present in 13 patients at baseline and 25 after SVR, although only 3 patients had increased pulmonary resistance.
In a multicenter prospective study of patients with hepatitis C virus-associated cirrhosis, an SVR to all-oral therapy significantly reduced HVPG, compared with before treatment. Nevertheless, CSPH persists in most patients despite SVR, indicating persistent risk of decompensation. In this population, changes in LSM do not correlate with HVPG and cut-off values are not reliable in ruling out CSPH after SVR.
In the past few years, unmanned aerial systems (UAS) have achieved great popularity for civil uses. One of the present main uses of these devices is low-cost aerial photogrammetry, being especially ...useful in coastal environments. In this work, a high-resolution 3D model of a beach section in Guardamar del Segura (Spain) has been produced by employing a low maximum takeoff mass (MTOM) UAS, in combination with the use of structure-from-motion (SfM) techniques. An unprecedented extensive global navigation satellite system (GNSS) survey was simultaneously carried out to statistically validate the model by employing 1238 control points for that purpose. The results show good accuracy, obtaining a vertical root mean square error (RMSE) mean value of 0.121 m and a high point density, close to 30 pt/m2, with similar or even higher quality than most coastal surveys performed with classical techniques. UAS technology permits the acquisition of topographic data with low time-consuming surveys at a high temporal frequency. Coastal managers can implement this methodology into their workflow to study the evolution of complex, highly anthropized dune-beach systems such as the one presented in this study, obtaining more accurate surveys at lower costs.
Non-invasive tests (NITs) for clinically significant portal hypertension (CSPH; hepatic venous pressure gradient HVPG ≥10 mmHg) have predominantly been studied in patients with active HCV infection. ...Investigations after HCV cure are limited and have yielded conflicting results. We conducted a pooled analysis to determine the diagnostic/prognostic utility of liver stiffness measurement (LSM)/platelet count (PLT) in this setting.
A total of 418 patients with pre-treatment HVPG ≥6 mmHg who achieved sustained virological response (SVR) and underwent post-treatment HVPG measurement were assessed, of whom 324 (HVPG/NIT-cohort) also had paired data on pre-/post-treatment LSM/PLT. The derived LSM/PLT criteria were then validated against the direct endpoint decompensation in 755 patients with compensated advanced chronic liver disease (cACLD) with SVR (cACLD-validation-cohort).
HVPG/NIT-cohort: Among patients with cACLD, the pre-/post-treatment prevalence of CSPH was 80%/54%. The correlation between LSM/HVPG increased from pre- to post-treatment (r = 0.45 vs. 0.60), while that of PLT/HVPG remained unchanged. For given LSM/PLT values, HVPG tended to be lower post- vs. pre-treatment, indicating the need for dedicated algorithms. Combining post-treatment LSM/PLT yielded a high diagnostic accuracy for post-treatment CSPH in cACLD (AUC 0.884; 95% CI 0.843–0.926). Post-treatment LSM <12 kPa & PLT >150 G/L excluded CSPH (sensitivity: 99.2%), while LSM ≥25 kPa was highly specific for CSPH (93.6%). cACLD-validation-cohort: the 3-year decompensation risk was 0% in the 42.5% of patients who met the LSM <12 kPa & PLT >150 G/L criteria. In patients with post-treatment LSM ≥25 kPa (prevalence: 16.8%), the 3-year decompensation risk was 9.6%, while it was 1.3% in those meeting none of the above criteria (prevalence: 40.7%).
NITs can estimate the probability of CSPH after HCV cure and predict clinical outcomes. Patients with cACLD but LSM <12 kPa & PLT>150 G/L may be discharged from portal hypertension surveillance if no co-factors are present, while patients with LSM ≥25 kPa require surveillance/treatment.
Measurement of liver stiffness by a specific ultrasound device and platelet count (a simple blood test) are broadly used for the non-invasive diagnosis of increased blood pressure in the veins leading to the liver, which drives the development of complications in patients with advanced liver disease. The results of our pooled analysis refute previous concerns that these tests are less accurate after the cure of hepatitis C virus (HCV) infection. We have developed diagnostic criteria that facilitate personalized management after HCV cure and allow for a de-escalation of care in a high proportion of patients, thereby decreasing disease burden.
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•Post-treatment LSM/platelet count can be used to estimate the probability of CSPH and predict clinical outcomes in cACLD.•Patients with cACLD and LSM <12 kPa & PLT >150 G/L (CSPH-excluded; no decompensation risk) may not require portal hypertension surveillance.•Patients with cACLD and LSM ≥25 kPa require surveillance/treatment (CSPH-ruled-in; increased decompensation risk).
Background & Aims
: A 50% dysfunction rate at 1 year is one of the main drawbacks of the transjugular intrahepatic portosystemic shunt procedure. Preliminary experimental and clinical studies suggest ...that the use of stents covered with polytetrafluoroethylene could tremendously decrease this risk.
Methods
: Eighty patients with cirrhosis and uncontrolled bleeding (n = 23), recurrent bleeding (n = 25), or refractory ascites (n = 32) were randomized to be treated by transjugular intrahepatic portosystemic shunts with either a polytetrafluoroethylene-covered stent (group 1; 39 patients) or a usual uncovered prosthesis (group 2; 41 patients). Follow-up Doppler ultrasound was scheduled at day 7, at 1 month, and then every 3 months for 2 years. Angiography and portosystemic pressure gradient measurements were performed 6, 12, and 24 months after the transjugular intrahepatic portosystemic shunt procedure and whenever dysfunction was suspected. Dysfunction was defined as a >50% reduction of the lumen of the shunt at angiography or a portosystemic pressure gradient >12 mm Hg.
Results
: After a median follow-up of 300 days, 5 patients (13%) in group 1 and 18 (44%) in group 2 experienced shunt dysfunction (
P < 0.001). Clinical relapse occurred in 3 patients (8%) in group 1 and 12 (29%) in group 2 (
P < 0.05). Actuarial rates of encephalopathy were 21% in group 1 and 41% in group 2 at 1 year (not significant). Estimated probabilities of survival were 71% and 60% at 1 year and 65% and 41% at 2 years in groups 1 and 2, respectively (not significant).
Conclusions
: The use of polytetrafluoroethylene-covered prostheses improves transjugular intrahepatic portosystemic shunt patency and decreases the number of clinical relapses and reinterventions without increasing the risk of encephalopathy.
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