Bloody Bile and Rescue Intervention-A Case Series of Post-PTBD Hemorrhagic Complications With a Review of the Literature

Percutaneous transhepatic biliary drainage (PTBD) is a routinely performed interventional radiological procedure. A myriad of complications can occur after PTBD, the most important being hemorrhagic complications that require immediate attention. Hemorrhage following PTBD may result from arterial, portal, or hepatic venous injury. A catheter or pull-back cholangiogram often demonstrates the venous injury. A computed tomogram angiogram aids in identifying bleeding sources and procedural planning. Catheter repositioning, upsizing, or clamping often suffice for minor venous bleeding. However, major venous injury necessitates tract embolization, portal vein embolization, or stent grafting. Arterial injury may lead to significant blood loss unless treated expeditiously. Transarterial embolization is the treatment of choice in such cases. Adequate knowledge about the hemorrhagic complications of PTBD will allow an interventional radiologist to take necessary precautionary measures to reduce their incidence and take appropriate steps in their management. This article entails four different hemorrhagic complications of PTBD and their interventional management. It also discusses the various treatment options to manage different kinds of post-PTBD hemorrhagic complications.

Emergence of Long-Range Angular Correlations in Low-Multiplicity Proton-Proton Collisions

This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at sqrt[s]=13  TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of 1.4<|Δη|<1.8 and a transverse momentum of 1 Collapse

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First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production

The first measurement of the cross section for incoherent photonuclear production of J/ψ vector mesons as a function of the Mandelstam |t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |y|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02  TeV. This rapidity interval corresponds to a Bjorken-x range (0.3-1.4)×10^{-3}. Cross sections are given in five |t| intervals in the range 0.04<|t|<1  GeV^{2} and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |t| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.

Impact of nutritional status on the outcome of transjugular intrahepatic portosystemic shunt in patients with cirrhosis: a systematic review

OBJECTIVES

Malnutrition and sarcopenia have been reported to adversely affect the outcome of patients with cirrhosis of the liver. There is an emerging body of evidence suggesting malnutrition and sarcopenia increase the risk of hepatic encephalopathy (HE) and mortality after transjugular intrahepatic portosystemic shunt (TIPS). The current systematic review aims to determine whether the body of evidence supports an association between nutritional status and post-TIPS outcomes in patients with cirrhosis.

METHODS

Electronic databases of PubMed, Embase, and Scopus were searched from inception to June 3, 2023, for studies analysing the effect of nutritional status on post-TIPS outcomes in patients with cirrhosis.

RESULTS

A total of 22 studies were included in the systemic review. Assessment of sarcopenia was done by skeletal muscle index (SMI) at the L3 level, transversal psoas muscle thickness, psoas muscle density, malnutrition as per ICD, relative sarcopenia with excess adiposity, lipid profile, controlling nutritional status score, body composition analysis, hospital frailty risk score, and visceral and subcutaneous fat area index. Ten out of 12 studies in this systematic review showed a significant association with the incidence of post-TIPS HE. Thirteen out of 14 studies reported that the presence of malnutrition was associated with increased odds of mortality following TIPS. One study reported sarcopenia as an independent predictor of liver failure, and another study reported that Pre-TIPS SMI was an independent predictor of substantial improvement in post-TIPS SMI.

CONCLUSIONS

The current systematic review shows that the presence of pre-TIPS malnutrition or sarcopenia is an independent predictor of adverse outcomes after TIPS. Incorporating these parameters into present prediction models can provide additional prognostic information.

ADVANCES IN KNOWLEDGE

Nutritional assessment should be part of the evaluation of patients planned for TIPS for prediction of adverse events after the procedure.

Role of contrast-enhanced ultrasound for differentiation of benign vs. malignant portal vein thrombosis in hepatocellular carcinoma - A systematic review a meta-analysis

Introduction/Purpose

Patients with cirrhosis and hepatocellular carcinoma (HCC) can develop both benign and malignant portal vein thrombosis (PVT). Characterising the nature of PVT is important for planning an optimal therapeutic strategy. In the absence of typical findings or contraindications to computed tomography (CT) or magnetic resonance imaging (MRI), contrast-enhanced ultrasound (CEUS) could help in this differentiation. The present meta-analysis aimed to evaluate the performance of CEUS for characterising PVT in patients with HCC.

Methods

Electronic databases of PubMed, Embase and Scopus were searched from inception to 31 December 2022 for studies analysing the role of CEUS in the differentiation of benign and malignant PVT in HCC. Using the bivariate random effect model, pooled sensitivity and specificity were calculated, and the summary receiver operating characteristic (sROC) curve was plotted.

Results

A total of 12 studies with data from 712 patients were included in the meta-analysis. The pooled sensitivity and specificity of CEUS for the diagnosis of tumour in vein were 97.0% (95% CI: 93.0-98.7) and 96.8% (95% CI: 92.1-98.7), respectively, without significant heterogeneity. A sROC curve was plotted, and the area under the receiver operating characteristic was 0.99 (95% CI: 0.98-1.00). Despite the presence of publication bias, sensitivity analysis did not show any change in sensitivity and specificity.

Discussion

Our meta-analysis summarises the accuracy data from 12 studies, including >700 subjects. Contrast-enhanced ultrasound had excellent diagnostic accuracy with pooled sensitivity and specificity of 97.5% (95% CI: 93.5-99.1) and 98.2% (95% CI: 91.5-99.6), respectively, without any significant heterogeneity. Additionally, the pooled positive LR, negative LR and DOR were 54.6 (95% CI: 11.1-25.6), 0.02 (0.01-0.07) and 2186.8 (318.3-15022.2), respectively. A positive result increases the pretest probability of malignant PVT from 50% to 98%, whereas a negative result decreases it from 50% to 2%. Most of the studies included in our meta-analysis used identical techniques and 6-12-month follow-up scans to check for thrombus progression or regression. Our analysis showed no significant heterogeneity in the studies, and area under receiver operating characteristic curve (AUROC) with 95% CI was 1.00 (95% CI: 0.99-1.00). This critical meta-analysis thus propels CEUS to the forefront for differentiating benign from tumoural PVT and suggests routinely using CEUS in patients presenting with HCC and evidence of thrombus on greyscale ultrasound.

Conclusion

Contrast-enhanced ultrasound is an effective diagnostic modality differentiation of benign and malignant PVT in patients with HCC and can be an alternative modality to CT or MRI. Further studies are required to study the role of CEUS as initial diagnostic modality for the characterisation of PVT in HCC.

Role of Interventional Radiology (IR) in vascular emergencies among cirrhotic patients

Gastrointestinal hemorrhage remains one of the most common causes of morbidity and mortality among patients with liver cirrhosis. Mostly, these patients bleed from the gastroesophageal varices. However, nonvariceal bleeding is also more likely to occur in these patients. Because of frequent co-existing coagulopathy, cirrhotics are more prone to bleed from a minor vascular injury while performing percutaneous interventions. Ultrasound-guided bedside vascular access is an essential procedure in liver critical care units. Transjugular portosystemic shunts (TIPS) with/without variceal embolization is a life-saving measure in patients with refractory variceal bleeding. Whenever feasible, balloon-assisted retrograde transvenous obliteration (BRTO) is an alternative to TIPS in managing gastric variceal bleeding, but without a risk of hepatic encephalopathy. In cases of failed or unfeasible endotherapy, transarterial embolization using various embolic agents remains the cornerstone therapy in patients with nonvariceal bleeding such as ruptured hepatocellular carcinoma, gastroduodenal ulcer bleeding, and procedure-related hemorrhagic complications. Among various embolic agents, N-butyl cyanoacrylate (NBCA) enables better vascular occlusion in cirrhotics, even in coagulopathy, making it a more suitable embolic agent in an expert hand. This article briefly entails the different interventional radiological procedures in vascular emergencies among patients with liver cirrhosis.

ψ(2S) Suppression in Pb-Pb Collisions at the LHC

The production of the ψ(2S) charmonium state was measured with ALICE in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV, in the dimuon decay channel. A significant signal was observed for the first time at LHC energies down to zero transverse momentum, at forward rapidity (2.5 Collapse

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Measurements of Groomed-Jet Substructure of Charm Jets Tagged by D^{0} Mesons in Proton-Proton Collisions at sqrt[s]=13 TeV

Understanding the role of parton mass and Casimir color factors in the quantum chromodynamics parton shower represents an important step in characterizing the emission properties of heavy quarks. Recent experimental advances in jet substructure techniques have provided the opportunity to isolate and characterize gluon emissions from heavy quarks. In this Letter, the first direct experimental constraint on the charm-quark splitting function is presented, obtained via the measurement of the groomed shared momentum fraction of the first splitting in charm jets, tagged by a reconstructed D^{0} meson. The measurement is made in proton-proton collisions at sqrt[s]=13  TeV, in the low jet transverse-momentum interval of 15≤p_{T}^{jet ch}<30  GeV/c where the emission properties are sensitive to parton mass effects. In addition, the opening angle of the first perturbative emission of the charm quark, as well as the number of perturbative emissions it undergoes, is reported. Comparisons to measurements of an inclusive-jet sample show a steeper splitting function for charm quarks compared with gluons and light quarks. Charm quarks also undergo fewer perturbative emissions in the parton shower, with a reduced probability of large-angle emissions.

Hepatic Vascular Variants in Hereditary Haemorrhagic Telangiectasia: Imaging findings

Hereditary haemorrhagic telangiectasia (HHT) is an autosomal dominant disorder characterised by vascular dysplasia. Hepatic vascular malformations (VMs) range from small telangiectases to significant vascular shunting. Here we report two cases of HHT. Case 1 had diffuse ectasia of the hepatic artery along its intrahepatic and extrahepatic course with a hepatic arterial aneurysm. Case 2 presented with ileal and hepatic telangiectases. Knowledge of these vascular variants is indispensable for clinicians and radiologists in aiding diagnosis and surgical and interventional management.

Measurement of the Lifetime and Λ Separation Energy of _{Λ}^{3}H

The most precise measurements to date of the _{Λ}^{3}H lifetime τ and Λ separation energy B_{Λ} are obtained using the data sample of Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV collected by ALICE at the LHC. The _{Λ}^{3}H is reconstructed via its charged two-body mesonic decay channel (_{Λ}^{3}H→^{3}He+π^{-} and the charge-conjugate process). The measured values τ=[253±11(stat)±6(syst)]  ps and B_{Λ}=[102±63(stat)±67(syst)]  keV are compatible with predictions from effective field theories and confirm that the _{Λ}^{3}H structure is consistent with a weakly bound system.

Measurement of the J/ψ Polarization with Respect to the Event Plane in Pb-Pb Collisions at the LHC

We study the polarization of inclusive J/ψ produced in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC in the dimuon channel, via the measurement of the angular distribution of its decay products. We perform the study in the rapidity region 2.5 Collapse

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First Measurement of Antideuteron Number Fluctuations at Energies Available at the Large Hadron Collider

The first measurement of event-by-event antideuteron number fluctuations in high energy heavy-ion collisions is presented. The measurements are carried out at midrapidity (|η|<0.8) as a function of collision centrality in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV using the ALICE detector. A significant negative correlation between the produced antiprotons and antideuterons is observed in all collision centralities. The results are compared with a state-of-the-art coalescence calculation. While it describes the ratio of higher order cumulants of the antideuteron multiplicity distribution, it fails to describe quantitatively the magnitude of the correlation between antiproton and antideuteron production. On the other hand, thermal-statistical model calculations describe all the measured observables within uncertainties only for correlation volumes that are different with respect to those describing proton yields and a similar measurement of net-proton number fluctuations.

Enhanced Deuteron Coalescence Probability in Jets

The transverse-momentum (p_{T}) spectra and coalescence parameters B_{2} of (anti)deuterons are measured in p-p collisions at sqrt[s]=13  TeV for the first time in and out of jets. In this measurement, the direction of the leading particle with the highest p_{T} in the event (p_{T}^{lead}>5  GeV/c) is used as an approximation for the jet axis. The event is consequently divided into three azimuthal regions, and the jet signal is obtained as the difference between the toward region, that contains jet fragmentation products in addition to the underlying event (UE), and the transverse region, which is dominated by the UE. The coalescence parameter in the jet is found to be approximately a factor of 10 larger than that in the underlying event. This experimental observation is consistent with the coalescence picture and can be attributed to the smaller average phase-space distance between nucleons in the jet cone as compared with the underlying event. The results presented in this Letter are compared to predictions from a simple nucleon coalescence model, where the phase-space distributions of nucleons are generated using pythia8 with the Monash 2013 tuning, and to predictions from a deuteron production model based on ordinary nuclear reactions with parametrized energy-dependent cross sections tuned on data. The latter model is implemented in pythia8.3. Both models reproduce the observed large difference between in-jet and out-of-jet coalescence parameters, although the almost flat trend of the B_{2}^{Jet} is not reproduced by the models, which instead give a decreasing trend.

Noninvasive differentiation of porto-sinusoidal vascular disorder from cirrhosis: a systematic review

BACKGROUND

Porto-sinusoidal vascular disorder (PSVD) is one of the common causes of portal hypertension and has overlapping features with early cirrhosis. The differentiation of PSVD from cirrhosis requires a liver biopsy, which is invasive and has potential complications. This systematic review aimed at summarizing the current evidence on the performance of noninvasive modalities for differentiating PSVD from cirrhosis.

METHODS

A comprehensive search of electronic databases of MEDLINE, Embase, and Scopus was conducted from 2000 to October 2022 for the studies comparing the elastographic and radiological features of PSVD and cirrhosis, using liver biopsy as the gold standard.

RESULTS

A total of 12 studies were included in the systematic review. Transient elastography (TE) as a modality was studied in five studies, MR elastography (MRE) in two, contrast CT in two, Contrast CT and MRI in two, and ARFI in only one. Both TE and MRE showed a significantly lower liver stiffness measurement and a higher splenic stiffness measurement with a higher SSM/LSM ratio with PSVD, compared to cirrhosis. Among the radiological features, focal nodular hyperplasia-like lesions, portal vein abnormalities (intrahepatic and extrahepatic), and a larger spleen size favored a diagnosis of PSVD. In contrast, surface nodularity and atrophy of segment IV with a segment I hypertrophy favored a diagnosis of cirrhosis.

CONCLUSION

Elastography and cross-sectional imaging can help differentiate PSVD from early cirrhosis with good accuracy. Further studies are required to assess the diagnostic role of a combination of both modalities.

Lower extremity pseudoaneurysms and their interventional radiological management: a pictorial review

Lower extremity pseudoaneurysms (PsAs) are mostly developed after traumatic or iatrogenic injury to the arteries. Unless treated, they can be complicated by adjacent mass effects, distal embolism, secondary infection, and rupture. Imaging helps in the diagnosis and planning of therapeutic intervention. Ultrasonography (USG) is often diagnostic, while CT angiography aids in vascular mapping required for intervention. Image-guided therapy offers to manage these pseudoaneurysms in a minimally invasive approach, obviating the need for surgery. A smaller, superficial, and narrow-necked PsA can easily be managed with local USG-guided compression or thrombin injection. When the percutaneous approach is not a feasible option, PsA from expendable arteries can also be managed with coiling or glue injection. Wide-necked PsA from an unexpendable artery necessitates stent graft placement, although coiling of the neck may be a viable and cheaper alternative for a long- and narrow-necked PsA. Presently, vascular closure devices are also used to seal a small arterial rent through a direct percutaneous approach. This pictorial review entails various techniques to deal with lower extremity pseudoaneurysms. An idea about the various intervention radiological approaches will help in choosing appropriate methods to tackle lower extremity pseudoaneurysms.

Comparative outcome of transjugular intrahepatic portosystemic shunt with or without variceal obliteration: a systematic review and meta-analysis

BACKGROUND

Transjugular intrahepatic portosystemic shunt (TIPS) has been used for the secondary prevention of variceal bleeding. TIPS can be combined with variceal embolization (TIPS-VO), but its benefit remains controversial. The present systematic review and meta-analysis were conducted to compare the incidence of rebleeding, adverse events, and mortality among patients with TIPS alone and with TIPS-VO.

METHODS

A literature search from January 2000 to June 2022 was done for studies comparing the outcome of patients undergoing TIPS alone or TIPS-VO. A subgroup analysis was conducted for patients undergoing TIPS with covered stents.

RESULTS

A total of 11 studies with data from 1044 patients were included. The incidence of rebleeding was significantly higher in the TIPS alone group in both overall population OR 2.01 (1.42-2.83) and the subgroup (OR 1.92, 95% CI 1.21-3.04). There was no difference between the two groups concerning the risk of hepatic encephalopathy (OR 1.15, 95% CI 0.83-1.59), procedural adverse events (OR 0.86, 95% CI 0.54-1.39), shunt dysfunction (OR 1.20, 95% CI 0.82-1.75), overall mortality (OR 1.03, 95% CI 0.73-1.46), and mortality due to variceal rebleeding (OR 1.58, 95% CI 0.44-5.64). There was no significant heterogeneity or publication bias among the included studies. The certainty of evidence remains low for all the outcome expect for variceal rebleeding.

CONCLUSION

The present meta-analysis provides a moderate-quality evidence for the benefit of TIPS-VO in reducing the incidence of rebleeding. However, the decision for combining variceal embolization with TIPS should be made on a case-to-case basis.

Diagnostic outcome and safety of plugged liver biopsy in high-risk patients: a systematic review and meta-analysis

BACKGROUND

Percutaneous liver biopsy is the gold standard test for the assessment of liver disease. In patients with coagulopathy, ascites, post-transplantation, and hypervascular tumors, biopsy is associated with increased risk of adverse events (AEs). Transjugular liver biopsy (TJLB) is recommended in these conditions but is expensive and unavailable at many centers. Plugged liver biopsy (PLB) provides an alternate diagnostic modality in these high-risk cases.

PURPOSE

To analyze the pooled diagnostic outcome and safety of PLB in high-risk cases.

MATERIAL AND METHODS

A literature search of various databases from January 1990 to July 2022 was conducted for studies evaluating the outcome of PLB in high-risk cases. The primary outcomes were pooled sample adequacy and AEs. Pooled event rates across studies were expressed with summative statistics.

RESULTS

A total of 17 studies (2329 patients) were included in the meta-analysis. The pooled proportion of sample adequacy was 98.9% (95% confidence interval [CI]=98.2-99.6). Severe AEs, major bleeding, and minor AEs were seen in 0.7% (95% CI=0.1-1.3), 0.4% (95% CI=0.1-0.8), and 11.5% (95% CI=2.4-20.6) of the patients. There was only one reported mortality, giving a pooled incidence of 0.0002% (95% CI=0.0-0.0038). Compared to TJLB (5 studies, n = 336), there was no difference in either sample adequacy (odds ratio [OR]=2.34, 95% CI=0.83-6.58) or risk of serious AEs (OR=0.47, 95% CI=0.173-1.31).

CONCLUSION

PLB can be safely performed on patients with coagulopathy and/or ascites with high sample adequacy rates and low incidence of AEs and mortality.

Hypertriton Production in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The study of nuclei and antinuclei production has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. The first measurement of the production of _{Λ}^{3}H in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV is presented in this Letter. Its production yield measured in the rapidity interval -1<y<0 for the 40% highest-multiplicity p-Pb collisions is dN/dy=[6.3±1.8(stat)±1.2(syst)]×10^{-7}. The measurement is compared with the expectations of statistical hadronization and coalescence models, which describe the nucleosynthesis in hadronic collisions. These two models predict very different yields of the hypertriton in charged particle multiplicity environments relevant to small collision systems such as p-Pb, and therefore the measurement of dN/dy is crucial to distinguish between them. The precision of this measurement leads to the exclusion with a significance larger than 6.9σ of some configurations of the statistical hadronization model, thus constraining the theory behind the production of loosely bound states at hadron colliders.

Polarization of Λ and Λ[over ¯] Hyperons along the Beam Direction in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The polarization of the Λ and Λ[over ¯] hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded with ALICE at the Large Hadron Collider (LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle. We report the measurement of P_{z,s2} for different collision centralities and in the 30%-50% centrality interval as a function of the hyperon transverse momentum and rapidity. The P_{z,s2} is positive similarly as measured by the STAR Collaboration in Au-Au collisions at sqrt[s_{NN}]=200  GeV, with somewhat smaller amplitude in the semicentral collisions. This is the first experimental evidence of a nonzero hyperon P_{z} in Pb-Pb collisions at the LHC. The comparison of the measured P_{z,s2} with the hydrodynamic model calculations shows sensitivity to the competing contributions from thermal and the recently found shear-induced vorticity, as well as to whether the polarization is acquired at the quark-gluon plasma or the hadronic phase.

Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, z_{g}, and the (scaled) groomed jet radius, θ_{g}. Charged-particle jets are reconstructed at midrapidity using the anti-k_{T} algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θ_{g} distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the z_{g} distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.

Measurement of Prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) Production in Proton-Proton Collisions at sqrt[s]=13 TeV

The p_{T}-differential production cross sections of prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at sqrt[s]=13  TeV. This is the first measurement of Σ_{c}^{0,++} production in hadronic collisions. Assuming the same production yield for the three Σ_{c}^{0,+,++} isospin states, the baryon-to-meson cross section ratios Σ_{c}^{0,+,++}/D^{0} and Λ_{c}^{+}/D^{0} are calculated in the transverse momentum (p_{T}) intervals 2<p_{T}<12 and 1<p_{T}<24  GeV/c. Values significantly larger than in e^{+}e^{-} collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σ_{c}. The feed-down contribution to Λ_{c}^{+} production from Σ_{c}^{0,+,++} is also reported and is found to be larger than in e^{+}e^{-} collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.

A Modified Manual Compression Technique for the Treatment of Traumatic Pseudoaneurysm of Superficial Temporal Artery

Traumatic Pseudoaneurysm of Superficial temporal artery (STA) is an uncommon entity. Surgical management is the treatment of choice, and endovascular management is also equally feasible particularly for the proximal STA aneurysm. The manual compression for the treatment of STA aneurysm is also described, but it has a high chance of failure. We report a case of traumatic pseudoaneurysm of STA in a pregnant female, successfully treated with a modified manual compression technique.

Bleeding Stomal Varices and Their Interventional Management- A Series of Three Cases

Although stomal and parastomal varices are uncommon causes of variceal bleeding, the mortality rate might be as high as 40%. Timely intervention is essential for the management of these ectopic bleeding varices. Due to the rarity of such varices, no standard treatment guideline is available. We present three cases of bleeding stomal varices managed with an endovascular approach, one through percutaneous transhepatic and the other two through transjugular intrahepatic portosystemic shunt approach.

Measurement of the Cross Sections of Ξ_{c}^{0} and Ξ_{c}^{+} Baryons and of the Branching-Fraction Ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+}) in pp Collisions at sqrt[s]=13 TeV

The p_{T}-differential cross sections of prompt charm-strange baryons Ξ_{c}^{0} and Ξ_{c}^{+} were measured at midrapidity (|y|<0.5) in proton-proton (pp) collisions at a center-of-mass energy sqrt[s]=13  TeV with the ALICE detector at the LHC. The Ξ_{c}^{0} baryon was reconstructed via both the semileptonic decay (Ξ^{-}e^{+}ν_{e}) and the hadronic decay (Ξ^{-}π^{+}) channels. The Ξ_{c}^{+} baryon was reconstructed via the hadronic decay (Ξ^{-}π^{+}π^{+}) channel. The branching-fraction ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+})=1.38±0.14(stat)±0.22(syst) was measured with a total uncertainty reduced by a factor of about 3 with respect to the current world average reported by the Particle Data Group. The transverse momentum (p_{T}) dependence of the Ξ_{c}^{0}- and Ξ_{c}^{+}-baryon production relative to the D^{0} meson and to the Σ_{c}^{0,+,++}- and Λ_{c}^{+}-baryon production are reported. The baryon-to-meson ratio increases toward low p_{T} up to a value of approximately 0.3. The measurements are compared with various models that take different hadronization mechanisms into consideration. The results provide stringent constraints to these theoretical calculations and additional evidence that different processes are involved in charm hadronization in electron-positron (e^{+}e^{-}) and hadronic collisions.

Carotid blowout syndrome: endovascular management of a lesser known oncological emergency: case report

Background

Carotid blowout syndrome (CBS) refers to a fatal hemorrhagic complication of cervical carotid arteries that occurs due to rupture of the extracranial carotid artery or one of its major branches in patients treated for head and neck malignancy. In this article, we will discuss two different spectrum of CBS and endovascular approach.

Case presentation

Two cases of per oral bleeding presented in the emergency department. After patients were hemodynamically stabilized, CT angiography was done which showed type II CBS and type III CBS, respectively. This was followed by transfemoral supra-aortic digital subtraction angiogram coil embolization with scaffolding and anchoring technique, respectively, for the patients.

Conclusions

Early recognition of the predictors of CBS by a multidisciplinary team is critical. The endovascular treatment approach is relatively safe and effective with low rates of morbidity and mortality compared to surgical approach in CBS.

Abdominal Computed Tomography Findings among COVID-19 Patients with Index Gastrointestinal Manifestations: A Preliminary Single-center Experience

Background

About 20% of COVID-19 patients can have digestive symptoms, apart from the typical chest-related symptoms, and 10% of patients may have only gastrointestinal (GI) symptoms during their entire disease course.

Aim and objective

The purpose of this study was to describe the spectrum of abdominal computed tomographic (CT) findings in a cohort of 15 COVID-19 patients (confirmed on reverse transcription polymerase chain reaction (RT-PCR)) who presented with various GI presentations without preceding respiratory symptoms.

Materials and methods

A total of 93 patients with COVID-19 (confirmed on RT-PCR) who underwent CT imaging (between September 28, 2020 and March 20, 2021) in our center were retrospectively searched from the existing database. Among those, 15 patients having index presentation with abdominal symptoms and underwent CT abdomen were further evaluated.

Results

Biliary stasis in the form of distended gallbladder and wall thickening was the most common finding, seen in 66.7% (n = 10) patients, followed by bowel wall thickening. Small bowel and large bowel thickenings were seen in 26.7% (n = 4) and 20% (n = 3) patients, respectively. Other findings include fluid-filled colon (n = 1), mesenteric venous thrombosis (MVT) (n = 2), paper-thin bowel wall and pneumatosis (n = 1), acute pancreatitis (n = 1), and ascites (n = 2). One patient who presented with abdominal pain did not show any obvious imaging findings on CT.

Conclusion

Patients with COVID-19 can present with initial GI symptoms preceding typical respiratory symptoms. CT imaging helps in identifying the GI involvement, to rule out alternate etiologies, and also aids in appropriate management planning.

How to cite this article

Patel RK, Chandel K, Mittal S, et al. Abdominal Computed Tomography Findings among COVID-19 Patients with Index Gastrointestinal Manifestations: A Preliminary Single-center Experience. Euroasian J Hepato-Gastroenterol 2021;11(2):76–80.

Λ_{c}^{+} Production and Baryon-to-Meson Ratios in pp and p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV at the LHC

The prompt production of the charm baryon Λ_{c}^{+} and the Λ_{c}^{+}/D^{0} production ratios were measured at midrapidity with the ALICE detector in pp and p-Pb collisions at sqrt[s_{NN}]=5.02  TeV. These new measurements show a clear decrease of the Λ_{c}^{+}/D^{0} ratio with increasing transverse momentum (p_{T}) in both collision systems in the range 2<p_{T}<12  GeV/c, exhibiting similarities with the light-flavor baryon-to-meson ratios p/π and Λ/K_{S}^{0}. At low p_{T}, predictions that include additional color-reconnection mechanisms beyond the leading-color approximation, assume the existence of additional higher-mass charm-baryon states, or include hadronization via coalescence can describe the data, while predictions driven by charm-quark fragmentation processes measured in e^{+}e^{-} and e^{-}p collisions significantly underestimate the data. The results presented in this Letter provide significant evidence that the established assumption of universality (colliding-system independence) of parton-to-hadron fragmentation is not sufficient to describe charm-baryon production in hadronic collisions at LHC energies.

Experimental Evidence for an Attractive p-ϕ Interaction

This Letter presents the first experimental evidence of the attractive strong interaction between a proton and a ϕ meson. The result is obtained from two-particle correlations of combined p-ϕ⊕ p[over ¯]-ϕ pairs measured in high-multiplicity pp collisions at sqrt[s]=13  TeV by the ALICE Collaboration. The spin-averaged scattering length and effective range of the p-ϕ interaction are extracted from the fully corrected correlation function employing the Lednický-Lyuboshits approach. In particular, the imaginary part of the scattering length vanishes within uncertainties, indicating that inelastic processes do not play a prominent role for the p-ϕ interaction. These data demonstrate that the interaction is dominated by elastic p-ϕ scattering. Furthermore, an analysis employing phenomenological Gaussian- and Yukawa-type potentials is conducted. Under the assumption of the latter, the N-ϕ coupling constant is found to be g_{N-ϕ}=0.14±0.03(stat)±0.02(syst). This work provides valuable experimental input to accomplish a self-consistent description of the N-ϕ interaction, which is particularly relevant for the more fundamental studies on partial restoration of chiral symmetry in nuclear medium.

Multiharmonic Correlations of Different Flow Amplitudes in Pb-Pb Collisions at sqrt[s_{NN}]=2.76 TeV

The event-by-event correlations between three flow amplitudes are measured for the first time in Pb-Pb collisions, using higher-order symmetric cumulants. We find that different three-harmonic correlations develop during the collective evolution of the medium when compared to correlations that exist in the initial state. These new results cannot be interpreted in terms of previous lower-order flow measurements since contributions from two-harmonic correlations are explicitly removed in the new observables. A comparison to Monte Carlo simulations provides new and independent constraints for the initial conditions and system properties of nuclear matter created in heavy-ion collisions.

Soft-Dielectron Excess in Proton-Proton Collisions at sqrt[s]=13 TeV

A measurement of dielectron production in proton-proton (pp) collisions at sqrt[s]=13  TeV, recorded with the ALICE detector at the CERN LHC, is presented in this Letter. The data set was recorded with a reduced magnetic solenoid field. This enables the investigation of a kinematic domain at low dielectron (ee) invariant mass m_{ee} and pair transverse momentum p_{T,ee} that was previously inaccessible at the LHC. The cross section for dielectron production is studied as a function of m_{ee}, p_{T,ee}, and event multiplicity dN_{ch}/dη. The expected dielectron rate from hadron decays, called hadronic cocktail, utilizes a parametrization of the measured η/π^{0} ratio in pp and proton-nucleus collisions, assuming that this ratio shows no strong dependence on collision energy at low transverse momentum. Comparison of the measured dielectron yield to the hadronic cocktail at 0.15<m_{ee}<0.6  GeV/c^{2} and for p_{T,ee}<0.4  GeV/c indicates an enhancement of soft dielectrons, reminiscent of the "anomalous" soft-photon and soft-dilepton excess in hadron-hadron collisions reported by several experiments under different experimental conditions. The enhancement factor over the hadronic cocktail amounts to 1.61±0.13(stat)±0.17(syst,data)±0.34(syst,cocktail) in the ALICE acceptance. Acceptance-corrected excess spectra in m_{ee} and p_{T,ee} are extracted and compared with calculations of dielectron production from hadronic bremsstrahlung and thermal radiation within a hadronic many-body approach.

Elliptic Flow of Electrons from Beauty-Hadron Decays in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The elliptic flow of electrons from beauty hadron decays at midrapidity (|y|<0.8) is measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The azimuthal distribution of the particles produced in the collisions can be parametrized with a Fourier expansion, in which the second harmonic coefficient represents the elliptic flow, v_{2}. The v_{2} coefficient of electrons from beauty hadron decays is measured for the first time in the transverse momentum (p_{T}) range 1.3-6  GeV/c in the centrality class 30%-50%. The measurement of electrons from beauty-hadron decays exploits their larger mean proper decay length cτ≈500  μm compared to that of charm hadrons and most of the other background sources. The v_{2} of electrons from beauty hadron decays at midrapidity is found to be positive with a significance of 3.75  σ. The results provide insights into the degree of thermalization of beauty quarks in the medium. A model assuming full thermalization of beauty quarks is strongly disfavored by the measurement at high p_{T}, but is in agreement with the results at low p_{T}. Transport models including substantial interactions of beauty quarks with an expanding strongly interacting medium describe the measurement within uncertainties.

Measurement of the Low-Energy Antideuteron Inelastic Cross Section

In this Letter, we report the first measurement of the inelastic cross section for antideuteron-nucleus interactions at low particle momenta, covering a range of 0.3≤p<4  GeV/c. The measurement is carried out using p-Pb collisions at a center-of-mass energy per nucleon-nucleon pair of sqrt[s_{NN}]=5.02  TeV, recorded with the ALICE detector at the CERN LHC and utilizing the detector material as an absorber for antideuterons and antiprotons. The extracted raw primary antiparticle-to-particle ratios are compared to the results from detailed ALICE simulations based on the geant4 toolkit for the propagation of (anti)particles through the detector material. The analysis of the raw primary (anti)proton spectra serves as a benchmark for this study, since their hadronic interaction cross sections are well constrained experimentally. The first measurement of the inelastic cross section for antideuteron-nucleus interactions averaged over the ALICE detector material with atomic mass numbers ⟨A⟩=17.4 and 31.8 is obtained. The measured inelastic cross section points to a possible excess with respect to the Glauber model parametrization used in geant4 in the lowest momentum interval of 0.3≤p<0.47  GeV/c up to a factor 2.1. This result is relevant for the understanding of antimatter propagation and the contributions to antinuclei production from cosmic ray interactions within the interstellar medium. In addition, the momentum range covered by this measurement is of particular importance to evaluate signal predictions for indirect dark-matter searches.

Probing the Effects of Strong Electromagnetic Fields with Charge-Dependent Directed Flow in Pb-Pb Collisions at the LHC

The first measurement at the LHC of charge-dependent directed flow (v_{1}) relative to the spectator plane is presented for Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV. Results are reported for charged hadrons and D^{0} mesons for the transverse momentum intervals p_{T}>0.2  GeV/c and 3<p_{T}<6  GeV/c in the 5%-40% and 10%-40% centrality classes, respectively. The difference between the positively and negatively charged hadron v_{1} has a positive slope as a function of pseudorapidity η, dΔv_{1}/dη=[1.68±0.49(stat)±0.41(syst)]×10^{-4}. The same measurement for D^{0} and D[over ¯]^{0} mesons yields a positive value dΔv_{1}/dη=[4.9±1.7(stat)±0.6(syst)]×10^{-1}, which is about 3 orders of magnitude larger than the one of the charged hadrons. These measurements can provide new insights into the effects of the strong electromagnetic field and the initial tilt of matter created in noncentral heavy ion collisions on the dynamics of light (u, d, and s) and heavy (c) quarks. The large difference between the observed Δv_{1} of charged hadrons and D^{0} mesons may reflect different sensitivity of the charm and light quarks to the early time dynamics of a heavy ion collision. These observations challenge some recent theoretical calculations, which predicted a negative and an order of magnitude smaller value of dΔv_{1}/dη for both light flavor and charmed hadrons.

Evidence of Spin-Orbital Angular Momentum Interactions in Relativistic Heavy-Ion Collisions

The first evidence of spin alignment of vector mesons (K^{*0} and ϕ) in heavy-ion collisions at the Large Hadron Collider (LHC) is reported. The spin density matrix element ρ_{00} is measured at midrapidity (|y|<0.5) in Pb-Pb collisions at a center-of-mass energy (sqrt[s_{NN}]) of 2.76 TeV with the ALICE detector. ρ_{00} values are found to be less than 1/3 (1/3 implies no spin alignment) at low transverse momentum (p_{T}<2  GeV/c) for K^{*0} and ϕ at a level of 3σ and 2σ, respectively. No significant spin alignment is observed for the K_{S}^{0} meson (spin=0) in Pb-Pb collisions and for the vector mesons in pp collisions. The measured spin alignment is unexpectedly large but qualitatively consistent with the expectation from models which attribute it to a polarization of quarks in the presence of angular momentum in heavy-ion collisions and a subsequent hadronization by the process of recombination.

Scattering Studies with Low-Energy Kaon-Proton Femtoscopy in Proton-Proton Collisions at the LHC

The study of the strength and behavior of the antikaon-nucleon (K[over ¯]N) interaction constitutes one of the key focuses of the strangeness sector in low-energy quantum chromodynamics (QCD). In this Letter a unique high-precision measurement of the strong interaction between kaons and protons, close and above the kinematic threshold, is presented. The femtoscopic measurements of the correlation function at low pair-frame relative momentum of (K^{+}p⊕K^{-}p[over ¯]) and (K^{-}p⊕K^{+}p[over ¯]) pairs measured in pp collisions at sqrt[s]=5, 7, and 13 TeV are reported. A structure observed around a relative momentum of 58  MeV/c in the measured correlation function of (K^{-}p⊕K^{+}p[over ¯]) with a significance of 4.4σ constitutes the first experimental evidence for the opening of the (K[over ¯]^{0}n⊕K^{0}n[over ¯]) isospin breaking channel due to the mass difference between charged and neutral kaons. The measured correlation functions have been compared to Jülich and Kyoto models in addition to the Coulomb potential. The high-precision data at low relative momenta presented in this work prove femtoscopy to be a powerful complementary tool to scattering experiments and provide new constraints above the K[over ¯]N threshold for low-energy QCD chiral models.

Measurement of ϒ(1S) Elliptic Flow at Forward Rapidity in Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The first measurement of the ϒ(1S) elliptic flow coefficient (v_{2}) is performed at forward rapidity (2.5<y<4) in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector at the LHC. The results are obtained with the scalar product method and are reported as a function of transverse momentum (p_{T}) up to 15  GeV/c in the 5%-60% centrality interval. The measured ϒ(1S)v_{2} is consistent with 0 and with the small positive values predicted by transport models within uncertainties. The v_{2} coefficient in 2<p_{T}<15  GeV/c is lower than that of inclusive J/ψ mesons in the same p_{T} interval by 2.6 standard deviations. These results, combined with earlier suppression measurements, are in agreement with a scenario in which the ϒ(1S) production in Pb-Pb collisions at LHC energies is dominated by dissociation limited to the early stage of the collision, whereas in the J/ψ case there is substantial experimental evidence of an additional regeneration component.

Investigations of Anisotropic Flow Using Multiparticle Azimuthal Correlations in pp, p-Pb, Xe-Xe, and Pb-Pb Collisions at the LHC

Measurements of anisotropic flow coefficients (v_{n}) and their cross-correlations using two- and multiparticle cumulant methods are reported in collisions of pp at sqrt[s]=13  TeV, p-Pb at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02  TeV, Xe-Xe at sqrt[s_{NN}]=5.44  TeV, and Pb-Pb at sqrt[s_{NN}]=5.02  TeV recorded with the ALICE detector. The multiplicity dependence of v_{n} is studied in a very wide range from 20 to 3000 particles produced in the midrapidity region |η|<0.8 for the transverse momentum range 0.2<p_{T}<3.0  GeV/c. An ordering of the coefficients v_{2}>v_{3}>v_{4} is found in pp and p-Pb collisions, similar to that seen in large collision systems, while a weak v_{2} multiplicity dependence is observed relative to nucleus-nucleus collisions in the same multiplicity range. Using a novel subevent method, v_{2} measured with four-particle cumulants is found to be compatible with that from six-particle cumulants in pp and p-Pb collisions. The magnitude of the correlation between v_{n}^{2} and v_{m}^{2}, evaluated with the symmetric cumulants SC(m,n) is observed to be positive at all multiplicities for v_{2} and v_{4}, while for v_{2} and v_{3} it is negative and changes sign for multiplicities below 100, which may indicate a different v_{n} fluctuation pattern in this multiplicity range. The observed long-range multiparticle azimuthal correlations in high multiplicity pp and p-Pb collisions can neither be described by pythia 8 nor by impact-parameter-Glasma, music, and ultrarelativistic quantum molecular dynamics model calculations, and hence, provide new insights into the understanding of collective effects in small collision systems.

First Observation of an Attractive Interaction between a Proton and a Cascade Baryon

This Letter presents the first experimental observation of the attractive strong interaction between a proton and a multistrange baryon (hyperon) Ξ^{-}. The result is extracted from two-particle correlations of combined p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} pairs measured in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV at the LHC with ALICE. The measured correlation function is compared with the prediction obtained assuming only an attractive Coulomb interaction and a standard deviation in the range [3.6, 5.3] is found. Since the measured p-Ξ^{-}⊕p[over ¯]-Ξ[over ¯]^{+} correlation is significantly enhanced with respect to the Coulomb prediction, the presence of an additional, strong, attractive interaction is evident. The data are compatible with recent lattice calculations by the HAL-QCD Collaboration, with a standard deviation in the range [1.8, 3.7]. The lattice potential predicts a shallow repulsive Ξ^{-} interaction within pure neutron matter and this implies stiffer equations of state for neutron-rich matter including hyperons. Implications of the strong interaction for the modeling of neutron stars are discussed.

A challenging case of a large intraorbital foreign body perforating the nasal septum in a child

A 5 year old boy with a history of fall from a height of about 4 feet, presented after one week with swelling, watering and discharge of the right eye. He had severe conjunctival chemosis with superior displacement of the globe. Computed Tomography (CT) showed a linear low attenuation tract in the right orbit extending from the inferolateral wall up to the left uncinate process of the ethmoid bone with increasing Hounsfield unit after 10 days. The parents did not agree for early exploration. After 10 days an exploration was done and a large linear and irregular wooden foreign body (FB) measuring 4.5 x 1.5 cm² was removed from the right orbit and a smaller one from the nasal cavity. Four weeks post surgery, his vision was 6/9 in the right eye with the eyeball in the normal position. This case was challenging because of the late presentation, parents not agreeing for early exploration, difficulty in diagnosing by CT and a large and very deep penetrating FB.