Procoagulant phenotype of virus-infected pericytes is associated with portal thrombosis and intrapulmonary vascular dilations in fatal COVID-19.

BACKGROUND & AIMS: Mechanisms and clinical impact of portal microthrombosis featuring severe COVID-19 are unknown. Intrapulmonary vascular dilation (IPVD)-related hypoxia has been described in severe liver diseases. We hypothesized that portal microthrombosis is associated with IPVD and fatal respiratory failure in COVID-19. METHODS: Ninety-three patients who died from COVID-19, were analysed for portal microvascular damage (histology), IPVD (histology and chest-computed tomography, CT), and hypoxemia (arterial blood gas). Seventeen patients who died from COVID-19-unrelated pneumonia served as controls. Vascular lesions and microthrombi were phenotyped for endothelial (vWF) and pericyte (αSMA/PDGFR-ß) markers, tissue factor (TF), viral spike-protein and nucleoprotein (SP, NP), fibrinogen, platelets (CD41a). Viral particles in vascular cells were assessed by transmission electron microscopy (TEM). Cultured pericytes were infected with SARS-CoV-2 to measure TF expression and tubulisation of human pulmonary microvascular endothelial cells (HPMEC) was assessed upon vWF treatment. RESULTS: IPVD was present in 16/66 COVID-19 patients with both liver and lung histology, with a younger age (62 vs 78yo), longer illness (25 vs 14 days), worsening hypoxemia (PaO2/FiO2 from 209 to 89), and more ventilatory support (63 vs 22%) compared to COVID-19/Non-IPVD. IPVD, absent in controls, were confirmed by chest-CT. COVID-19/IPVD liver histology showed portal microthrombosis in >82.5% of portal areas, with a thicker wall of αSMA/PDGFR-ß+/ SP+/NP+ pericytes compared with COVID-19/Non-IPVD. Thrombosed portal venules correlated with αSMA+ area, whereas infected SP+/NP+ pericytes expressed TF. SARS-CoV-2 viral particles were observed in portal pericytes. In-vitro SARS-CoV-2 infection of pericytes up-regulated TF and induced endothelial cells to overexpress vWF, which expanded HPMEC tubules. CONCLUSIONS: SARS-CoV-2 infection of liver pericytes elicits a local procoagulant response associated with extensive portal microthrombosis, IPVD and worsening respiratory failure in fatal COVID-19. IMPACT AND IMPLICATIONS: Vascular involvement of the liver represents a serious complication of COVID-19 infection that must be considered in the work-up of patients with long-lasting and progressively worsening respiratory failure, as it may associate with the development of intrapulmonary vascular dilations. This clinical picture is associated with a pro-coagulant phenotype of portal venule pericytes, which is induced by SARS-CoV-2 infection of pericytes. Both observations provide a model that may apply, at least in part, to other vascular disorders of the liver, featuring obliterative portal venopathy, similarly characterized at the clinical level by development of hypoxemia and at the histological level, by phlebosclerosis and reduced caliber of the portal vein branches in the absence of cirrhosis. Moreover, our findings bring light to an as yet overlooked player of thrombosis pathophysiology, i.e. pericytes, which may provide novel therapeutic tools to halt prothrombotic mechanisms.

Diffusion-weighted imaging (DWI) in diagnosis, staging, and treatment response assessment of multiple myeloma: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the role of diffusion-weighted imaging (DWI) in the initial diagnosis, staging, and assessment of treatment response in patients with multiple myeloma (MM). MATERIALS AND METHODS: A systematic literature review was conducted in PubMed, the Cochrane Library, EMBASE, Scopus, and Web of Science databases. The primary endpoints were defined as the diagnostic performance of DWI for disease detection, staging of MM, and assessing response to treatment in these patients. RESULTS: Of 5881 initially reviewed publications, 33 were included in the final qualitative and quantitative meta-analysis. The diagnostic performance of DWI in the detection of patients with MM revealed pooled sensitivity and specificity of 86% (95% CI: 84-89) and 63% (95% CI: 56-70), respectively, with a diagnostic odds ratio (OR) of 14.98 (95% CI: 4.24-52.91). The pooled risk difference of 0.19 (95% CI: - 0.04-0.42) was reported in favor of upstaging with DWI compared to conventional MRI (P value = 0.1). Treatment response evaluation and ADCmean value changes across different studies showed sensitivity and specificity of approximately 78% (95% CI: 72-83) and 73% (95% CI: 61-83), respectively, with a diagnostic OR of 7.21 in distinguishing responders from non-responders. CONCLUSIONS: DWI is not only a promising tool for the diagnosis of MM, but it is also useful in the initial staging and re-staging of the disease and treatment response assessment. This can aid clinicians with earlier initiation or change in treatment strategy, which could have prognostic significance for patients.

US-guided percutaneous thrombin injection to treat non-femoral artery pseudoaneurysms: preliminary experience and review of the literature.

PURPOSE: To evaluate the clinical outcome of US-guided percutaneous thrombin injection in the treatment of non-femoral artery pseudoaneurysms (NFAP). MATERIALS AND METHODS: Among all pseudoaneurysms treated in our institution, we retrospectively collected NFAP embolized with percutaneous thrombin injections from January 1, 2015, to December 31, 2021. The embolization was prompted for an ongoing antiaggregating/anticoagulation therapy, NFAP optimal US visibility, or high surgery-related risks. Causes, location, size and neck of NFAP, complications, number of repeated treatments, clinical success and patients clinical conditions at discharge were annotated. The endpoint for clinical success was the resolution of NFAP at postprocedural imaging, with no resort to surgery. RESULTS: Eight consecutive patients (5 females, median age 73 years, range 46-84) underwent 16 procedures. Arterial damage was due to catheterization (3), CVC mispositioning (2), trauma, hemorrhagic diathesis and endoprosthesis endoleak. We treated humeral (2), subclavian (2), thyrocervical, anterior tibial, radial and pancreaticoduodenal arteries. Median pseudoaneurysm size was 530 mm2 (range 32-2400 mm2), with a thin (7/8) or non-visible (1/8) neck. No complications occurred. Clinical success was obtained in 7/8 patients (88%), with a single treatment in 4, multiple in 3 cases (4 embolizations, 3 and 2, respectively). One patient underwent surgical suture after the second failed attempt of percutaneous embolization. Seven patients were discharged in good clinical conditions; one died during hospitalization, due to the worsening of the underlying cardiac disease. CONCLUSIONS: Percutaneous US-guided thrombin injection to treat NFAP is feasible in selected cases, with rare complications. Clinical success is often reached, also by repeated injections.

Biliary complications in pediatric liver transplantation: findings of percutaneous transhepatic cholangiography in a large single-center cohort.

BACKGROUND: Although biliary complications after orthotopic liver transplantation represent a common source of morbidity and mortality, decreasing graft survival, consensus is lacking on their management in the pediatric population. OBJECTIVE: The aim of this study was to present the prevalence of such biliary complications and their interventional radiologic management with representative images. MATERIALS AND METHODS: This retrospective study reports our experience with percutaneous transhepatic cholangiography in the management of biliary complications after orthotopic liver transplantation in pediatric patients. This study enrolled all pediatric patients (<18 years old) who underwent percutaneous transhepatic cholangiography for the management of biliary complications after orthotopic liver transplantation at a tertiary care center between January 2010 and December 2020. Diagnosis of biliary complications and indication to perform percutaneous transhepatic cholangiography were based on clinical, laboratory or radiologic data. RESULTS: Among the 301 orthotopic liver transplantations, 78 (26%) developed biliary complications that were managed by interventional radiology: these included 52 (17.3%) biliary strictures, 19 (6.3%) bile leaks, 5 (1.7%) biliary stones, 1 (0.3%) iatrogenic biliary obstruction and 1 (0.3%) vanishing syndrome. The median time interval between orthotopic liver transplantation and the diagnosis of biliary complications was 6.0 years (interquartile range [IQR] 8.2 years). Percutaneous transhepatic cholangiography and biliary duct catheterization were successful in all cases, with low rates of complications that were variable among subgroups. CONCLUSION: A wide spectrum of biliary complications can occur after pediatric orthotopic liver transplantation. In this large single-center experience, we highlight the value of percutaneous transhepatic cholangiography in their diagnosis and management. Percutaneous treatments in pediatric patients are safe and effective, providing resolution or serving as a bridge to surgery, including re-transplantation.

Chest X-ray for predicting mortality and the need for ventilatory support in COVID-19 patients presenting to the emergency department.

OBJECTIVES: To evaluate the inter-rater agreement of chest X-ray (CXR) findings in coronavirus disease 2019 (COVID-19) and to determine the value of initial CXR along with demographic, clinical, and laboratory data at emergency department (ED) presentation for predicting mortality and the need for ventilatory support. METHODS: A total of 340 COVID-19 patients who underwent CXR in the ED setting (March 1-13, 2020) were retrospectively included. Two reviewers independently assessed CXR abnormalities, including ground-glass opacities (GGOs) and consolidation. Two scoring systems (Brixia score and percentage of lung involvement) were applied. Inter-rater agreement was assessed by weighted Cohen's kappa (κ) or intraclass correlation coefficient (ICC). Predictors of death and respiratory support were identified by logistic or Poisson regression. RESULTS: GGO admixed with consolidation (n = 235, 69%) was the most common CXR finding. The inter-rater agreement was almost perfect for type of parenchymal opacity (κ = 0.90), Brixia score (ICC = 0.91), and percentage of lung involvement (ICC = 0.95). The Brixia score (OR: 1.19; 95% CI: 1.06, 1.34; p = 0.003), age (OR: 1.16; 95% CI: 1.11, 1.22; p < 0.001), PaO2/FiO2 ratio (OR: 0.99; 95% CI: 0.98, 1; p = 0.002), and cardiovascular diseases (OR: 3.21; 95% CI: 1.28, 8.39; p = 0.014) predicted death. Percentage of lung involvement (OR: 1.02; 95% CI: 1.01, 1.03; p = 0.001) and PaO2/FiO2 ratio (OR: 0.99; 95% CI: 0.99, 1.00; p < 0.001) were significant predictors of the need for ventilatory support. CONCLUSIONS: CXR is a reproducible tool for assessing COVID-19 and integrates with patient history, PaO2/FiO2 ratio, and SpO2 values to early predict mortality and the need for ventilatory support. KEY POINTS: • Chest X-ray is a reproducible tool for assessing COVID-19 pneumonia. • The Brixia score and percentage of lung involvement on chest X-ray integrate with patient history, PaO2/FIO2 ratio, and SpO2 values to early predict mortality and the need for ventilatory support in COVID-19 patients presenting to the emergency department.

Surviving COVID-19 in Bergamo province: a post-acute outpatient re-evaluation.

Bergamo province was badly hit by the coronavirus disease 2019 (COVID-19) epidemic. We organised a public-funded, multidisciplinary follow-up programme for COVID-19 patients discharged from the emergency department or from the inpatient wards of 'Papa Giovanni XXIII' Hospital, the largest public hospital in the area. As of 31 July, the first 767 patients had completed the first post-discharge multidisciplinary assessment. Patients entered our programme at a median time of 81 days after discharge. Among them, 51.4% still complained of symptoms, most commonly fatigue and exertional dyspnoea, and 30.5% were still experiencing post-traumatic psychological consequences. Impaired lung diffusion was found in 19%. Seventeen per cent had D-dimer values two times above the threshold for diagnosis of pulmonary embolism (two unexpected and clinically silent pulmonary thrombosis were discovered by investigating striking D-dimer elevation). Survivors of COVID-19 exhibit a complex array of symptoms, whose common underlying pathology, if any, has still to be elucidated: a multidisciplinary approach is fundamental, to address the different problems and to look for effective solutions.

External validation of a combined PET and MRI radiomics model for prediction of recurrence in cervical cancer patients treated with chemoradiotherapy.

PURPOSE: The aim of this study was to validate previously developed radiomics models relying on just two radiomics features from 18F-fluorodeoxyglucose positron emission tomography (PET) and magnetic resonance imaging (MRI) images for prediction of disease free survival (DFS) and locoregional control (LRC) in locally advanced cervical cancer (LACC). METHODS: Patients with LACC receiving chemoradiotherapy were enrolled in two French and one Canadian center. Pre-treatment imaging was performed for each patient. Multicentric harmonization of the two radiomics features was performed with the ComBat method. The models for DFS (using the feature from apparent diffusion coefficient (ADC) MRI) and LRC (adding one PET feature to the DFS model) were tuned using one of the French cohorts (n = 112) and applied to the other French (n = 50) and the Canadian (n = 28) external validation cohorts. RESULTS: The DFS model reached an accuracy of 90% (95% CI [79-98%]) (sensitivity 92-93%, specificity 87-89%) in both the French and the Canadian cohorts. The LRC model reached an accuracy of 98% (95% CI [90-99%]) (sensitivity 86%, specificity 100%) in the French cohort and 96% (95% CI [80-99%]) (sensitivity 83%, specificity 100%) in the Canadian cohort. Accuracy was significantly lower without ComBat harmonization (82-85% and 71-86% for DFS and LRC, respectively). The best prediction using standard clinical variables was 56-60% only. CONCLUSIONS: The previously developed PET/MRI radiomics predictive models were successfully validated in two independent external cohorts. A proposed flowchart for improved management of patients based on these models should now be confirmed in future larger prospective studies.

Intraobserver and Interobserver Agreement in the Evaluation of Tumor Vascularization With Computed Tomography Perfusion in Cirrhotic Patients With Hepatocellular Carcinoma.

OBJECTIVES: To evaluate intrareader and inter-reader agreement in CT perfusion (Perf) measurements in cirrhotic patients with hepatocellular carcinoma (HCC) lesions. METHODS: Sixteen patients with HCC (9 untreated, 5 recurrence/residual disease after transarterial chemoembolization, and 2 after radiofrequency ablation treatment) underwent standard CT examination and a Perf study; a quantitative map of arterial and portal Perf by means of a color scale was generated. With dedicated Perf software, the following parameters were calculated on untreated and treated HCC lesions and on cirrhotic parenchyma: hepatic Perf, tissue blood volume, hepatic perfusion index, arterial perfusion, and time to peak. Intraobserver and interobserver agreements were assessed for 2 readers with Bland-Altman plots, intraclass correlation coefficients (ICCs), coefficients of variation, and repeatability. RESULTS: In HCC lesions, agreement analysis demonstrated higher intra-agreement values in comparison with interagreement (range of ICC values, 0.26-0.59 between readers and 0.67-0.94 between readings). Lower interagreement was found for treated HCC lesions in comparison with untreated lesions (range of ICC values, respectively, 0.12-0.54 and 0.31-0.89). CONCLUSIONS: For all Perf parameters intra-agreement was higher than interagreement, even though a relatively wide range of 95% limits of agreement was found in both cases.

Abnormal Uterine Bleeding: A Pictorial Review on Differential Diagnosis and Not-So-Common Cases of Interventional Radiology Management.

Abnormal uterine bleeding (AUB) poses a multifaceted challenge in women's health, necessitating an integrated approach that addresses its diverse etiologies and clinical presentations. The International Federation of Gynecology and Obstetrics PALM-COEIN classification system provides a systematic approach to the diagnosis of AUB in non-pregnant women, based on clinical and imaging-based categorization of causes into structural (Polyps, Adenomyosis, Leiomyomas and Malignancy; PALM), and non-structural causes (Coagulopathies, Ovulatory disorders, primary Endometrial disorders, Iatrogenic and Not otherwise classified; COEIN). On the other hand, placental disorders, uterine rupture, ectopic pregnancy and retained products of conceptions are the main causes of uterine bleeding during pregnancy and in the peripartum period. Ultrasound is usually the first-line imaging technique for the differential diagnosis of causes of AUB. Computed Tomography may be useful if ultrasound findings are unclear, especially in emergency settings. Magnetic resonance imaging, when indicated, is an excellent second-line diagnostic tool for a better non-invasive characterization of the underlying cause of AUB. This pictorial review aims to illustrate the main causes of AUB from the point of view of diagnostic imaging and to show not-so-common cases that can be treated by means of interventional radiology.

Viable residual tumor tissue after radiofrequency ablation treatment in hepatocellular carcinoma: evaluation with CT perfusion.

PURPOSE: To assess the role of CT perfusion technique in detection of blood flow changes related to the therapeutic effects in HCC lesion treated with RFA. METHODS: 14 cirrhotic patients with known HCC underwent a perfusion study about 4 months (range 1-13 months) after RFA on a 16-slice MDCT scanner (Brilliance, Philips). Dynamic CT was performed acquiring 8 dynamic slice/scan, after injection of 50 mL of contrast media. In treated lesion, surrounding parenchyma and hypervascular tissue suspicious for residual disease/recurrence, the following perfusion parameters were analyzed: perfusion (P, mL/100 g min); arterial perfusion (AP, mL/min); blood volume (BV, mL/100 mg); hepatic perfusion index (HPI, %), and time to peak (TTP, s). Univariate Wilcoxon signed rank test was used for statistical analysis. RESULTS: In patients with residual disease (8/14) values of perfusion parameters measured within tumor were: P, median = 45.2; AP, median = 48.2; BV, median = 18.9; HPI, median = 35.8; and TTP, median = 19.4. The values calculated in ablated area were: P, median = 10.9; AP, median = 9.6; BV, median = 5.5; HPI, median = 14.6; TTP, median = 39.6. The parameters calculated in the surrounding parenchyma were: P, median = 15.8; AP, median = 14.2; BV, median = 12.0; HPI, median = 17.9; TTP, median = 43.2. A significant difference (P < 0.05) was observed in mean values of P, AP, and HPI, calculated between treated lesions with residual tumor and those successfully treated. CONCLUSION: Perfusion CT enables assessment of HCC vascularity after RFA treatment, by adding quantitative information about the presence of residual arterial vessels within the viable residual neoplastic tissue.

Current Status and Future of Artificial Intelligence in MM Imaging: A Systematic Review.

Artificial intelligence (AI) has attracted increasing attention as a tool for the detection and management of several medical conditions. Multiple myeloma (MM), a malignancy characterized by uncontrolled proliferation of plasma cells, is one of the most common hematologic malignancies, which relies on imaging for diagnosis and management. We aimed to review the current literature and trends in AI research of MM imaging. This study was performed according to the PRISMA guidelines. Three main concepts were used in the search algorithm, including "artificial intelligence" in "radiologic examinations" of patients with "multiple myeloma". The algorithm was used to search the PubMed, Embase, and Web of Science databases. Articles were screened based on the inclusion and exclusion criteria. In the end, we used the checklist for Artificial Intelligence in Medical Imaging (CLAIM) criteria to evaluate the manuscripts. We provided the percentage of studies that were compliant with each criterion as a measure of the quality of AI research on MM. The initial search yielded 977 results. After reviewing them, 14 final studies were selected. The studies used a wide array of imaging modalities. Radiomics analysis and segmentation tasks were the most popular studies (10/14 studies). The common purposes of radiomics studies included the differentiation of MM bone lesions from other lesions and the prediction of relapse. The goal of the segmentation studies was to develop algorithms for the automatic segmentation of important structures in MM. Dice score was the most common assessment tool in segmentation studies, which ranged from 0.80 to 0.97. These studies show that imaging is a valuable data source for medical AI models and plays an even greater role in the management of MM.

Liver involvement in patients with COVID-19 infection: A comprehensive overview of diagnostic imaging features.

During the first wave of the pandemic, coronavirus disease 2019 (COVID-19) infection has been considered mainly as a pulmonary infection. However, different clinical and radiological manifestations were observed over time, including involvement of abdominal organs. Nowadays, the liver is considered one of the main affected abdominal organs. Hepatic involvement may be caused by either a direct damage by the virus or an indirect damage related to COVID-19 induced thrombosis or to the use of different drugs. After clinical assessment, radiology plays a key role in the evaluation of liver involvement. Ultrasonography (US), computed tomography (CT) and magnetic resonance imaging (MRI) may be used to evaluate liver involvement. US is widely available and it is considered the first-line technique to assess liver involvement in COVID-19 infection, in particular liver steatosis and portal-vein thrombosis. CT and MRI are used as second- and third-line techniques, respectively, considering their higher sensitivity and specificity compared to US for assessment of both parenchyma and vascularization. This review aims to the spectrum of COVID-19 liver involvement and the most common imaging features of COVID-19 liver damage.

Towards the Definition of Radiomic Features and Clinical Indices to Enhance the Diagnosis of Clinically Significant Cancers in PI-RADS 4 and 5 Lesions.

Prostate cancer (PC) is the most frequently diagnosed cancer among adult men, and its incidence is increasing worldwide [...].

Chest X-ray at Emergency Admission and Potential Association with Barotrauma in Mechanically Ventilated Patients: Experience from the Italian Core of the First Pandemic Peak.

Barotrauma occurs in a significant number of patients with COVID-19 interstitial pneumonia undergoing mechanical ventilation. The aim of the current study was to investigate whether the Brixia score (BS) calculated on chest-X-rays acquired at the Emergency Room was associated with barotrauma. We retrospectively evaluated 117 SARS-CoV-2 patients presented to the Emergency Department (ED) and then admitted to the intensive care unit (ICU) for mechanical ventilation between February and April 2020. Subjects were divided into two groups according to the occurrence of barotrauma during their hospitalization. CXRs performed at ED admittance were assessed using the Brixia score. Distribution of barotrauma (pneumomediastinum, pneumothorax, subcutaneous emphysema) was identified in chest CT scans. Thirty-eight subjects (32.5%) developed barotrauma (25 pneumomediastinum, 24 pneumothorax, 24 subcutaneous emphysema). In the barotrauma group we observed higher Brixia score values compared to the non-barotrauma group (mean value 12.18 vs. 9.28), and logistic regression analysis confirmed that Brixia score is associated with the risk of barotrauma. In this work, we also evaluated the relationship between barotrauma and clinical and ventilatory parameters: SOFA score calculated at ICU admittance and number of days of non-invasive ventilation (NIV) prior to intubation emerged as other potential predictors of barotrauma.

Pneumonia-related pneumatoceles in infants: CT assessment and image-guided treatment.

Lung pneumatoceles represent a potential life-threatening complication of pneumonia in infants, especially when they do not spontaneously reabsorb. In this category of patients, scientific literature lacks and no consensus guidelines for management have been proposed. Imaging plays a key role in the diagnosis, characterization, and follow-up of pneumatoceles. Image-guided percutaneous drainage can be considered a safe and effective treatment in children, although it is not widely recognized in newborns and infants. The aim of this case series review is to describe the main CT features of complicated or persistent pneumatoceles in infants and to highlight the potential role of image-guided percutaneous drainage as an effective approach for their treatment. Successful management of four infants affected by pneumonia-related pneumatoceles with percutaneous drainage is presented.

Accuracy of Inflow Inversion Recovery (IFIR) for Upper Abdominal Arteries Evaluation: Comparison with Contrast-Enhanced MR and CTA.

Background: Inflow-sensitive inversion recovery (IFIR) is a recently introduced technique to perform unenhanced magnetic resonance angiography (MRA). The purpose of our study is to determine the accuracy of IFIR-MRA in the evaluation of upper abdominal arteries, compared to standard MRA and computed tomography angiography (CTA). Materials and Methods: Seventy patients undergoing upper abdomen Magnetic Resonance Imaging (MRI) in different clinical settings were enrolled. The MRI protocol included an IFIR-MRA sequence that was intra-individually compared by using a qualitative 4-point scale in the same patients who underwent concomitant or close MRA (n = 65) and/or CTA (n = 44). Celiac trunk (CA), common-proper-left-right hepatic artery (C-P-L-R-HA), left gastric artery (LGA), gastroduodenal artery (GDA), splenic artery (SA), renal arteries (RA) and superior mesenteric artery (SMA) were assessed. Results: IFIR-MRA images were better rated in comparison with MRA. Particularly, all arteries obtained a statistically significant higher qualitative rating value (all p < 0.05). IFIR-MRA and MRA exhibited acceptable intraclass correlation coefficients (ICC) values for CA, C-L-R-HA, and SMA (ICC 0.507, 0.591, 0.615, 0.570, 0.525). IFIR-MRA and CTA showed significant correlations in C-P-L-R-HA (τ = 0.362, 0.261, 0.308, 0.307, respectively; p < 0.05), and in RA (τ = 0.279, p < 0.05). Conclusions: Compared to MRA, IFIR-MRA demonstrated a higher image quality in the majority of upper abdomen arterial vessels assessment. LHA and RHA branches could be better visualized with IFIR sequences, when visualizable. Based on these findings, we suggest to routinely integrate IFIR sequences in upper abdomen MRI studies.

A New Biodegradable Stent to Improve the Management of Biliary Strictures in Pediatric Split Liver Transplantation.

PURPOSE: Cholestasis due to benign biliary strictures is the most common biliary complication after pediatric split liver transplantation (SLT), decreasing graft survival, but consensus about its management lacks. Percutaneous transhepatic cholangiography, bilioplasty and internal-external biliary drainage (IEBD) are standard treatments. The aim of this report is to present the preliminary experience with a new biodegradable biliary stent in the management of post-SLT biliary strictures. MATERIALS AND METHODS: Between September 2020 and April 2021, SLT patients with a single anastomotic benign biliary stricture underwent percutaneous transhepatic implantation of an innovative 10F helical-shaped biodegradable biliary stent, featuring a slow degradation profile, in addition to the standard treatment with bilioplasty and IEBD. The device is unique and the first to be CE-marked for the use in this indication. RESULTS: Six pediatric patients (4 males; median age 8.6 years, interquartile range 3.7 years) underwent percutaneous stent implantation, without complications nor clinical cholestasis during a median follow-up of 271 days (IQR 120.25). Stent dislodgement occurred in one case. CONCLUSION: Preliminary data suggest that implantation of a new biodegradable biliary stent may be considered in the management of post-SLT cholestasis in pediatric patients. Some technical tips are useful during implantation. This device may prolong biliary drainage, potentially relieving the discomfort of long-term IEBD.

Ischemic and hemorrhagic abdominal complications in COVID-19 patients: experience from the first Italian wave.

PURPOSE: To report ischemic and haemorrhagic abdominal complications in a series of COVID-19 patients. To correlate these complications with lung involvement, laboratory tests, comorbidities, and anticoagulant treatment. METHODS: We retrospectively included 30 COVID-19 patients who undergone abdomen CECT for abdominal pain, between March 16 and May 19, 2020. Ischemic and haemorrhagic complications were compared with lung involvement (early, progressive, peak or absorption stage), blood coagulation values, anticoagulant therapy, comorbidities, and presence of pulmonary embolism (PE). RESULTS: Ischemic complications were documented in 10 patients (7 receiving anticoagulant therapy, 70%): 6/10 small bowel ischemia (1 concomitant obstruction, 1 perforation) and 4/10 ischemic colitis. Main mesenteric vessels were patent except for 1 superior mesenteric vein thrombosis. Two ischemia cases also presented splenic infarctions. Bleeding complications were found in 20 patients (all receiving anticoagulant treatments), half with active bleeding: hematomas in soft tissues (15) and retroperitoneum (2) and gastro-intestinal bleeding (3). Platelet and lymphocyte were within the normal range. D-Dimer was significantly higher in ischemic cases (p < 0.001). Most of the patients had severe lung disease (45% peak, 29% absorption), two patients PE. CONCLUSIONS: Ischemic and haemorrhagic abdominal complications may occur in COVID-19 patients, particularly associated to extended lung disease. CT plays a key role in the diagnosis of these potentially life- threatening conditions.

Superb Microvascular Imaging (SMI) Compared with Color Doppler Ultrasound for the Assessment of Hepatic Artery in Pediatric Liver Transplants: A Feasibility Study.

(1) Background: Despite progression in surgical techniques and immunological treatments, hepatic artery (HA) thrombosis and stenosis still develop as an early or late liver transplant (LT) complication. We aimed to compare superb microvascular imaging (SMI) with conventional Doppler imaging (CDI) in the assessment of HA in a cohort of pediatric patients undergoing follow-up ultrasound (US) for LT. (2) Methods: This prospective, observational study included 73 pediatric LT recipients (median age, 7 years; IQR, 5.8 years; 35 females) who underwent US during LT follow-up from March to December 2019. For each examination, CDI and SMI were separately assessed in terms of HA visibility and spectral waveform morphology (SWM). The former was scored based on HA discrimination from the blooming signal of the surrounding vessels, as follows: 0, not visible; 1, majority course hardly distinguishable; and 2, majority course clearly distinguishable. The latter was scored on a two-point scale: 0, combined venous and arterial SWM, and 1, pure arterial SWM. The patient's overall score was finally calculated by adding the two individual scores. (3) Results: Both the absolute scores and frequency of overall scores equal to 3 (maximum global score) were higher using SMI compared with CDI. The median overall score was 3 for SMI and 2 for CDI (p = 0.011; IQR = 1). An overall score equal to 3 was obtained in 74% and 49.3% of the study population using SMI and CDI, respectively (p = 0.002). This was attributable to a better score in HA visibility (p = 0.007). (4) Conclusions: SMI has shown promise for assessing HA in pediatric LT recipients, possibly serving as a complementary non-invasive tool of CDI in everyday practice.