Liver Stiffness Measurement Allows Early Diagnosis of Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome in Adult Patients Who Undergo Hematopoietic Stem Cell Transplantation: Results from a Monocentric Prospective Study

Hepatic Sinusoidal Disorders

Hepatic sinusoids are highly specialized microcirculatory conduits within the hepatic lobules that facilitate liver functions. The sinusoids can be affected by various disorders, including sinusoidal dilatation, sinusoidal obstruction syndrome (SOS), sinusoidal cellular infiltration, perisinusoidal infiltration, and endothelial neoplasms, such as hemangioendothelioma and angiosarcoma. While these disorders, particularly SOS and neoplasms, can be life threatening, their clinical manifestation is often nonspecific. Patients may present with right upper quadrant pain, jaundice, hepatomegaly, ascites, splenomegaly, and unexplained weight gain, although the exact manifestation depends on the cause, severity, and duration of the disease. Ultimately, invasive tests may be necessary to establish the diagnosis. A comprehensive understanding of imaging manifestations of various sinusoidal disorders contributes to early diagnosis and can help radiologists detect subclinical disease. Additionally, specific imaging features may assist in identifying the cause of the disorder, leading to a more focused and quicker workup. For example, a mosaic pattern of enhancement of the liver parenchyma is suggestive of sinusoidal dilatation; peripheral and patchy reticular hypointensity of the liver parenchyma on hepatobiliary MR images is characteristic of SOS; and associated diffuse multiple hyperintensities on diffusion-weighted images may be specific for malignant sinusoidal cellular infiltration. The authors provide an overview of the pathogenesis, clinical features, and imaging appearances of various hepatic sinusoidal disorders, with a special emphasis on SOS. ©RSNA, 2024 Supplemental material is available for this article.

WFUMB Guideline/Guidance on Liver Multiparametric Ultrasound: Part 1. Update to 2018 Guidelines on Liver Ultrasound Elastography

The World Federation for Ultrasound in Medicine and Biology (WFUMB) endorsed the development of this document on multiparametric ultrasound. Part 1 is an update to the WFUMB Liver Elastography Guidelines Update released in 2018 and provides new evidence on the role of ultrasound elastography in chronic liver disease. The recommendations in this update were made and graded using the Oxford classification, including level of evidence (LoE), grade of recommendation (GoR) and proportion of agreement (Oxford Centre for Evidence-Based Medicine [OCEBM] 2009). The guidelines are clinically oriented, and the role of shear wave elastography in both fibrosis staging and prognostication in different etiologies of liver disease is discussed, highlighting advantages and limitations. A comprehensive section is devoted to the assessment of portal hypertension, with specific recommendations for the interpretation of liver and spleen stiffness measurements in this setting.

Liver stiffness measurements predict Sinusoidal Obstructive Syndrome after hematopoietic stem cell transplantation

Sinusoidal Obstructive Syndrome (SOS) is a life-threatening complication after hematopoietic stem-cell transplantation (HSCT), characterized by post-sinusoidal portal hypertension. FibroScan is used to assess portal hypertension non-invasively. We assessed transient elastography (TE) applicability in diagnosing SOS. The study included 27 adult patients, 11 underwent TE for high SOS risk pre-HSCT, 17 underwent TE post-HSCT due to bilirubin ≥2 mg/dl with no definite diagnosis of SOS. The first group had median Liver Stiffness Measurement (LSM) of 7.4 kPa (range, 3.3-22.5). Based on LSM results, conditioning regimen was modified for six patients and two of them developed SOS. Only one patient who did not have protocol adjustment experienced SOS. No patient with LSM < 7 kPa developed SOS. The second group had median LSM of 7.7 kPa (4.4-31.5). Median LSM after HSCT was significantly higher in patients who subsequently developed established SOS (n = 10) compared to patients who did not (n = 8), with values of 10.7 kPa (5.6-31.5) and 5.9 kPa (4.4-13.8), respectively (p = 0.02). An LSM cut-off of 7.5 kPa had a sensitivity and specificity of 75 and 80% for diagnosing SOS. In conclusion, pre-HSCT LSM can help adjustment of conditioning regimen in patients with high-risk for SOS. Post-HSCT LSM can help in early diagnosis of SOS.

Review of imaging findings in hepatic veno-occlusive disease

Hepatic veno-occlusive disease (VOD), also known as sinusoidal obstruction syndrome (SOS), is a potentially life-threatening complication of hematopoietic stem cell transplantation. Patients present with right upper-quadrant abdominal pain, jaundice, weight gain, and conjugated hyperbilirubinemia. Early diagnosis of VOD is essential to promptly initiate defibrotide therapy, which has been demonstrated to enhance survival and achieve complete resolution of disease in some patients. Historically, VOD was diagnosed by the modified Seattle or Baltimore criteria, which are both based on clinical symptoms. Alongside advancements in medical imaging over the last 40 years, the diagnosis of VOD has evolved to include the use of ultrasound, elastography, cross-sectional imaging, and image guided biopsy. Identification and interpretation of findings of VOD across imaging modalities is now a critical aspect of post-HSCT care. This review will outline the imaging findings and recommendations for the use of imaging in the management of VOD including gray-scale, color and spectral Doppler ultrasound, ultrasound elastography, CT, MRI, and liver biopsy.

Shear wave elastography and dispersion imaging for hepatic veno-occlusive disease prediction after pediatric hematopoietic stem cell transplantation: a feasibility study

BACKGROUND

Non-invasive imaging modalities are warranted for diagnosing and monitoring veno-occlusive disease because early diagnosis and treatment improve the prognosis.

OBJECTIVE

To evaluate the usefulness of liver shear wave elastography (SWE) and shear wave dispersion (SWD) imaging in diagnosing and monitoring veno-occlusive disease in pediatric patients.

MATERIALS AND METHODS

We conducted a prospective cohort study at a single tertiary hospital from March 2021 to April 2022. The study protocol included four ultrasound (US) sessions: a baseline US and three follow-up US after hematopoietic stem cell transplantation. Clinical criteria, including the European Society for Blood and Marrow Transplantation criteria, were used to diagnose veno-occlusive disease. We compared clinical factors and US parameters between the veno-occlusive disease and non-veno-occlusive disease groups. The diagnostic performance of US parameters for veno-occlusive disease was assessed by plotting receiver operating characteristic (ROC) curves. We describe temporal changes in US parameters before and after veno-occlusive disease diagnosis.

RESULTS

Among the 38 participants (mean age 10.7 years), eight developed veno-occlusive disease occurring 17.0 ± 5.2 days after hematopoietic stem cell transplantation. Liver stiffness, as measured by SWE (15.0 ± 6.2 kPa vs. 5.8 ± 1.8 kPa; P<0.001), and viscosity, as assessed with SWD (17.7 ± 3.1 m/s/kHz vs. 14.3 ± 2.8 m/s/kHz; P=0.015), were significantly higher in the veno-occlusive disease group compared to the non-veno-occlusive disease group at the time of diagnosis. Liver stiffness demonstrated the highest area under the ROC (AUROC) curves at 0.960, with an optimal predictive value of >6.5 kPa, resulting in sensitivity and specificity of 100% and 83.3%, respectively. Viscosity demonstrated an AUROC of 0.783, with an optimal cutoff value of 13.9 m/s/kHz for predicting veno-occlusive disease, with a sensitivity of 100% and specificity of 53.3%, respectively. Liver stiffness increased with disease severity and decreased during post-treatment follow-up.

CONCLUSION

SWE may be a promising technique for early diagnosis and severity prediction of veno-occlusive disease. Furthermore, liver viscosity assessed by SWD may serve as an additional marker of veno-occlusive disease.

Utility of the refined EBMT diagnostic and severity criteria 2023 for sinusoidal obstruction syndrome/veno-occlusive disease

Sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) is a life-threatening complication of hematopoietic stem cell transplantation (HSCT). Early diagnosis of SOS/VOD is associated with improved clinical outcomes. In 2023, the refined European Society for Blood and Marrow Transplantation diagnostic and severity criteria (refined EBMT criteria 2023) have been advocated. The revision has introduced new diagnostic categories, namely; probable, clinical, and proven SOS/VOD. In addition, the Sequential Organ Failure Assessment (SOFA) score has been newly incorporated into the SOS/VOD severity grading. We performed a retrospective analysis to evaluate the utility of these criteria. We analyzed 161 cases who underwent allogeneic HSCT. We identified 53 probable, 23 clinical, and 4 proven SOS/VOD cases. Probable SOS/VOD was diagnosed a median of 5.0 days earlier (interquartile range: 2-13 days, P < 0.001) than that of clinical SOS/VOD. The development of probable SOS/VOD alone was associated with a significantly inferior survival proportion compared to non-SOS/VOD (100-day survival, 86.2% vs. 94.3%, P = 0.012). The SOFA score contributed to the prediction of prognosis. Consequently, the refined EBMT criteria 2023 demonstrated the utility of SOS/VOD diagnosis and severity grading. Further investigations and improvements in these criteria are warranted.

Utility of liver stiffness measurement in the diagnosis of sinusoidal obstruction syndrome/veno-occlusive disease after hematopoietic stem cell transplantation

PURPOSE

We aimed to assess the role of liver stiffness measurement (LSM), evaluated using transient elastography (TE), for the diagnosis of sinusoidal obstruction syndrome (SOS)/veno-occlusive disease (VOD), a complication of hematopoietic stem cell transplantation (HSCT).

METHODS

In this retrospective study, ultrasonography (US) and LSM were performed on 86 adult patients (55 men and 31 women) undergoing HSCT between January 2016 and December 2022. Characteristics and changes in liver stiffness (LS) were compared between patients with and without SOS/VOD.

RESULTS

Of the 86 patients, 14 were diagnosed with SOS/VOD. A significant increase in LS (ranging from 12.6 to 55.1 kPa, median 23.8 kPa) compared to pre-HSCT values was observed in all patients who developed SOS/VOD. The area under the receiver operating characteristic curve (AUROC) for the diagnosis of SOS/VOD was 0.9663 (0.933-0.995) for LS ≥ 17.4 kPa after HSCT. Post-transplant LS exceeded 17.4 kPa in all 14 patients in the SOS/VOD group (100%) and in seven patients in the non-SOS/VOD group (9.7%). The sensitivity and specificity were 100% and 90.3%, respectively. AUROC for the diagnosis of SOS/VOD was 0.973 (0.943-1.000) for LS increase ≥  + 12.6 kPa from baseline after HSCT. The change of ≥  + 12.6 kPa from baseline was observed in all 14 patients in the SOS/VOD group (100%) and in four patients in the non-SOS/VOD group (5.6%). The sensitivity and specificity were 100% and 94.4%, respectively.

CONCLUSION

LSM using TE may contribute to establishing the diagnosis of SOS/VOD after HSCT.

Primary Budd-Chiari syndrome versus sinusoidal obstruction syndrome: a review

Budd-Chiari syndrome (BCS) and sinusoidal obstruction syndrome (SOS) are two major vascular disorders of the liver, of which both can cause portal hypertension related complications, but their locations of obstruction are different. BCS refers to the obstruction from the hepatic vein to the junction between the inferior vena cava and right atrium, which is the major etiology of post-sinusoidal portal hypertension; by comparison, SOS is characterized as the obstruction at the level of hepatic sinusoids and terminal venulae, which is a cause of sinusoidal portal hypertension. Both of them can cause hepatic congestion with life-threatening complications, especially acute liver failure and chronic portal hypertension, and share some similar features in terms of imaging and clinical presentations, but they have heterogeneous risk factors, management strategy, and prognosis. Herein, this paper reviews the current evidence and then summarizes the difference between primary BCS and SOS in terms of risk factors, clinical features, diagnosis, and treatment.

Assessment of hepatic veno-occlusive disease/sinusoidal obstruction syndrome using different scanning approaches for the ultrasonographic evaluation of portal vein blood flow and hepatic artery resistive index in hematopoietic stem cell transplant recipients

PURPOSE

Sinusoidal obstruction syndrome (SOS) is a fatal complication of hematopoietic stem cell transplantation (HSCT). Previously, we established a scoring system (Hokkaido ultrasound-based scoring system-10; HokUS-10) comprising 10 ultrasound parameters for SOS diagnosis. In HokUS-10, the portal vein time-averaged flow velocity (PV TAV) and hepatic artery resistive index (HA RI) are measured using subcostal scanning. However, measurement errors and delineation difficulties occur. Therefore, we aimed to prospectively evaluate PV TAV and HA RI measurements obtained via intercostal scanning as an alternative method to subcostal scanning and determine their cutoff values.

METHODS

HokUS-10 was administered before and after HSCT. PV TAV and HA RI were measured on subcostal and right intercostal scans.

RESULTS

We performed 366 scans on 74 patients. The median value (range) of PV TAV in the main and right portal veins was 15.0 cm/s (2.2-49.6 cm/s) and 10.5 cm/s (1.6-22.0 cm/s), respectively. A low correlation was observed between the two values (r = 0.39, p < 0.01). The highest diagnostic value of the right portal vein was less than 8.0 cm/s. The median value (range) of HA RI in the proper and right hepatic arteries was 0.72 (0.52-1.00) and 0.70 (0.51-1.00), respectively. A strong correlation was observed between the two values (r = 0.65, p < 0.01). The highest diagnostic value of the right HA RI was 0.72 or higher.

CONCLUSION

Quantitative measurement of PV TAV and HA RI using intercostal scanning can be appropriately performed as an alternative method to using subcostal scanning.

Liver Pathology After Hematopoietic Stem Cell Transplantation

Hematopoietic stem cell transplantation is used to treat a variety of hematologic malignancies and autoimmune conditions. The immunosuppressive medications as well as other therapies used both before and after transplantation leave patients susceptible to a wide spectrum of complications, including liver injury. Causes for liver damage associated with stem cell transplantation include sinusoidal obstruction syndrome, graft-versus-host disease, iron overload, and opportunistic infection. Here, the authors review the clinical and pathological findings of these etiologies of liver injury and provide a framework for diagnosis.

Diagnosis and severity criteria for sinusoidal obstruction syndrome/veno-occlusive disease in adult patients: a refined classification from the European society for blood and marrow transplantation (EBMT)

Sinusoidal obstruction syndrome, also known as veno-occlusive disease (SOS/VOD), is a potentially life-threatening complication that can develop after hematopoietic cell transplantation (HCT). A new definition for diagnosis, and a severity grading system for SOS/VOD in adult patients, was reported a few years ago on behalf of the European Society for Blood and Marrow Transplantation (EBMT). The aim of this work is to update knowledge regarding diagnosis and severity assessment of SOS/VOD in adult patients, and also its pathophysiology and treatment. In particular, we now propose to refine the previous classification and distinguish probable, clinical and proven SOS/VOD at diagnosis. We also provide an accurate definition of multiorgan dysfunction (MOD) for SOS/VOD severity grading based on Sequential Organ Failure Assessment (SOFA) score.

Imaging of pediatric hematopoietic stem cell transplant recipients: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Imaging in hematopoietic stem cell transplantation patients is not targeted at evaluating the transplant per se. Rather, imaging is largely confined to evaluating peri-procedural and post-procedural complications. Alternatively, imaging may be performed to establish a baseline study for comparison should the patient develop certain post-procedural complications. This article looks to describe the various imaging modalities available with recommendations for which imaging study should be performed in specific complications. We also provide select imaging protocols for different indications and modalities for the purpose of establishing a set minimal standard for imaging in these complex patients.

Prognostic Biomarkers for Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome in Myeloablative Allogeneic Hematopoietic Cell Transplantation: Results from the Blood and Marrow Transplant Clinical Trials Network 1202 Study

Hepatic veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation (HCT). This study aimed to determine a blood biomarker signature early post-HCT that identifies patients at high risk for VOD/SOS. A set of 23 plasma biomarkers, selected from the VOD/SOS literature, was measured on days 0, 7, and 14 after myeloablative HCT using blood samples from patients enrolled in the Blood and Marrow Transplant Clinical Trials Network (BMT CTN) Protocol 1202. Eligible cases were diagnosed with VOD/SOS in BMT CTN 1202 using the Baltimore criteria. Controls (without VOD/SOS) were matched to cases for conditioning regimen and age. Significant biomarkers were identified using the Bonferroni-adjusted Wilcoxon rank-sum test (P ≤ .002). Thirty-three patients with mild or severe VOD/SOS were identified (cases) and matched to 107 controls. Two, 8, and 5 biomarkers measured from the plasma of these patients were significantly associated with the development of VOD/SOS at days 0, 7, and 14, respectively, with the strongest associations on days 7 and 14. Biomarker associations were stronger for severe VOD/SOS risk and were stronger prognostic markers for VOD/SOS cases occurring within 28 days of HCT. Hyaluronan was most strongly associated with VOD/SOS risk, with an area under the receiver operating characteristic curve (AUC) of .81 on day 7 and .79 on day 14. Multivariate models of up to 5 biomarkers generated AUCs ranging from .82 to .85. All associations with VOD/SOS risk were independent of clinical risk factors. This study confirms previously identified biomarkers of VOD/SOS risk and identified novel prognostic biomarker signatures that identify patients at risk for VOD/SOS shortly after HCT. Multivariate analysis suggests that a combination of up to 5 of these protein biomarkers may provide a prognostic tool for identifying patients at risk for VOD/SOS.

Utility of Doppler-Ultrasound and Liver Elastography in the Evaluation of Patients with Suspected Pregnancy-Related Liver Disease

Grayscale abdomen ultrasound (US) is routinely performed in pregnant women with suspected pregnancy-related liver dysfunction, but its diagnostic yield is very low. We aimed to investigate the association between Doppler-US findings, liver stiffness measurement (LSM) and different causes of pregnancy-related liver dysfunction. This is a prospective cohort study of pregnant women referred to our tertiary center for any suspected gastrointestinal disease between 2017 and 2019 and undergoing Doppler-US and liver elastography. Patients with previous liver disease were excluded from the analysis. For group comparisons of categorical and continuous variables, the chi-square test or Mann-Whitney test, and the McNemar test were used, as appropriate. A total of 112 patients were included in the final analysis, of whom 41 (36.6%) presented with suspected liver disease: 23 intrahepatic cholestasis of pregnancy (ICP), six with gestational hypertensive disorders and 12 cases with undetermined causes of elevated liver enzymes. Values of LSM were higher and significantly associated with a diagnosis of gestational hypertensive disorder (AUROC = 0.815). No significant differences at Doppler-US or LSM were found between ICP patients and controls. Patients with undetermined causes of hypertransaminasemia showed higher hepatic and splenic resistive indexes than controls, suggesting splanchnic congestion. The evaluation of Doppler-US and liver elastography is clinically useful in patients with suspected liver dysfunction during pregnancy. Liver stiffness represents a promising non-invasive tool for the assessment of patients with gestational hypertensive disorders.

Predictive factors of collateral vessel development induced by oxaliplatin-based chemotherapy

BACKGROUND AND AIM

Oxaliplatin can lead to hepatic sinusoidal injury, called hepatic sinusoidal obstruction syndrome (SOS), resulting in portal hypertension-related complications. This could worsen the clinical course of the patients treated with oxaliplatin. Early diagnosis is challenging. We explored predictive markers of oxaliplatin-induced collateral vessels.

METHODS

Patients who received oxaliplatin-based chemotherapy were retrospectively screened. We evaluated their laboratory findings and spleen size on computed tomography immediately before oxaliplatin-based chemotherapy and after 6 months of treatment. The primary outcome was collateral vessel development, as a surrogate marker for oxaliplatin-induced SOS in patients who underwent oxaliplatin-based chemotherapy. The secondary outcome was the identification of factors that predicted the development of collateral vessels.

RESULTS

We enrolled 161 patients who received oxaliplatin-based chemotherapy. They had a median age of 69 years, and 63.3% were men. Collateral vessels developed in nine (5.6%) patients during the study period. After oxaliplatin-based chemotherapy, the spleen size increased in 104 patients (64.6%), with a ≥ 30% increase in 19.4% of the patients. Univariate analysis showed that the Fibrosis-4 (FIB-4) index (≥ 1.76; OR 9.17), aspartate aminotransferase:platelet ratio index (APRI) (≥ 0.193; OR 9.62), cumulative dose of oxaliplatin (≥ 1000 mg; OR 8.43), and increase in spleen size (≥ 30%; OR 6.01) were significant risk factors for collateral vessel development. Multivariate analysis after stepwise selection revealed that the FIB-4 index and spleen size were significant independent predictive factors.

CONCLUSION

A ≥ 1.76 increase in the FIB-4 index and a ≥ 30% increase in spleen size after 6 months of oxaliplatin-based chemotherapy were significant predictive markers for collateral vessel development.

Hepatic venous pressure gradient in sinusoidal obstruction syndrome: diagnostic value and link with histological lesions

Background & Aims

Liver sinusoidal obstruction syndrome (SOS) is a well-established complication of myeloablative conditioning regimens used in hematopoietic stem cell transplantation. Hepatic venous pressure gradient (HVPG) >10 mmHg was described as an accurate diagnostic tool for SOS in the 1990s. However, epidemiology and presentation of SOS have dramatically changed. Moreover, elementary histological lesions influencing HVPG are unknown.

Methods

We retrospectively analyzed the charts of all patients who underwent transjugular liver biopsy with HVPG measurement for a clinical suspicion of SOS at our center. Two expert pathologists unaware of the presence or absence of SOS reviewed all liver samples and graded elementary histological lesions according to a semi-quantitative scoring defined a priori.

Results

Out of the 77 included patients, the 30 patients with SOS had higher HVPG than the 47 patients without SOS (median 14 mmHg [IQR 10-18], vs. 6 mmHg [3-9], respectively p <0.001). HVPG >10 mmHg had a specificity of 78% and a positive predictive value of 66% for the diagnosis of SOS. However, almost 40% of the patients with SOS had an HVPG ≤10 mmHg. HVPG correlated with sinusoidal congestion (r = 0.57; p = 0.001) and hepatocyte necrosis (r = 0.42; p = 0.02), but not with other lesions.

Conclusion

Even though HVPG is higher in patients with SOS, low HVPG values do not rule out SOS. Thus, HVPG cannot be used alone, and should be combined with transjugular liver biopsy, for the diagnosis of SOS.

Lay summary

Hepatic venous pressure gradient >10 mmHg has been described as an accurate tool for the diagnosis of liver sinusoidal obstruction syndrome after hematopoietic stem cell transplantation. This study shows that the sensitivity and specificity of hepatic venous pressure gradient measurement for sinusoidal obstruction syndrome are insufficient, so that liver pressure measurement should be combined with a liver biopsy in this setting.

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HVPG is significantly higher in patients with sinusoidal obstruction syndrome than in those with other liver injuries.

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A 10 mmHg threshold is associated with low PPV (66%) and low sensitivity (63%).

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HVPG measurement should be combined with transjugular liver biopsy when sinusoidal obstruction syndrome is suspected.

Early diagnostic value of liver stiffness measurement in hepatic sinusoidal obstruction syndrome induced by hematopoietic stem cell transplantation

Hematopoietic stem cell transplantation (HSCT)-sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease, is a clinical syndrome characterized by symptoms, such as right upper quadrant pain, jaundice, fluid retention, and hepatomegaly, and is caused by pre-treatment-related hepatotoxicity during the early stages after HSCT. Clinical diagnosis of HSCT-SOS is based on the revised Seattle or Baltimore standards. The revised standard by the European Society for Bone Marrow Transplantation in 2016 has good practicability and can be used in combination with these two standards. Eight studies have shown the value of liver stiffness measurement (LSM) in the early diagnosis of HSCT-SOS. Four studies investigated LSM specificity and sensitivity for the early diagnosis of HSCT-SOS. LSM can distinguish SOS from other post-HSCT complications, enabling a clear differential diagnosis. It has been shown that median LSM of patients with SOS is significantly higher than that of patients with other treatment-related liver complications (e.g., acute cholecystitis, cholangitis, antifungal drug-related liver injury, liver graft-versus-host disease, isolated liver biochemical changes, and fulminant Epstein Barr virus related hepatitis reactivation). Therefore, the above data confirmed the utility of LSM and strongly suggested that LSM improves the positive predictive value of the SOS diagnostic clinical score after allogeneic HSCT. Early diagnosis of SOS is beneficial in preventing severe HSCT complications.

Multiparametric MRI with MR elastography findings in patients with sinusoidal obstruction syndrome after oxaliplatin-based chemotherapy

Objective

To evaluate the magnetic resonance elastography (MRE)-derived liver stiffness measurement (LSM), T1 and T2 relaxation times, and hepatobiliary phase images in patients, who developed sinusoidal obstruction syndrome (SOS) after oxaliplatin-based chemotherapy.

Methods

Thirty-four patients (M/F:22/12) who underwent liver MRI-MRE and received oxaliplatin for colorectal, gastric, and pancreas cancer were included in the study. SOS was diagnosed by Gd-EOB-DTPA-enhanced MRI in 18 patients. MRE-LSM and T1–T2 maps were evaluated. Patients with SOS were grouped according to the amount of reticular hypointensity on the hepatobiliary phase images.

Results

The mean MRE-LSM in the patients with SOS was 3.14 ± 0.45 kPa, and the control group was 2.6 ± 0.5 kPa (p = 0.01). The mean-corrected T1 (cT1) relaxation time was 1181 ± 151 ms in the SOS group and 1032 ± 129 ms in the control group (p = 0.005). The mean T2 relaxation time was 50.29 ± 3.6 ms in the SOS group and 44 ± 3.9 ms in the control group (p = 0.01). Parenchymal stiffness values were 2.8 ± 0.22 kPa, 3 ± 0.33 kPa, and 3.65 ± 0.28 kPa in patients with mild, moderate, and advanced SOS findings, respectively (p = 0.002). Although cT1 and T2 relaxation times increased with increasing SOS severity, no statistical significance was found.

Conclusions

We observed increased MRE-LSM in patients with SOS after chemotherapy compared to control group. T1 and T2 relaxation times were also useful in diagnosing SOS but were found inadequate in determining SOS severity. MRE is effective in diagnosing SOS and determining SOS severity in patients who cannot receive contrast agents, and it may be useful in the follow-up evaluation of these patients.

Retrospective Application of Sinusoidal Obstruction Syndrome/Veno-occlusive Disease Diagnostic Criteria in a Pediatric Hematopoietic Stem Cell Transplant Cohort

Sinusoidal obstruction syndrome/veno-occlusive disease (SOS/VOD) posthematopoietic stem cell transplantation (HSCT) is often diagnosed using the modified Seattle (MS) or European Society for Blood and Marrow Transplantation (EBMT) criteria. We hypothesized that strict application of these criteria could affect the timing of diagnosis and incidence of SOS/VOD. We collected data on 215 transplants performed in 184 patients at a single pediatric hematopoietic stem cell transplantation center, which were divided into 3 cohorts. Clinical diagnosis and treatment of SOS/VOD was documented in 13% of transplants (cohort 1). On retrospective review, 49% of transplant events met either MS and/or EBMT criteria, however, were not diagnosed with SOS/VOD (cohort 2); remaining 38% of transplant events did not meet MS or EBMT criteria and were not diagnosed with SOS/VOD (cohort 3). Day+100 overall survival was significantly inferior for cohort 1 (78%) compared with cohorts 2 or 3 (92% and 95%, P=0.01) with no difference between cohorts 2 and 3 (P=0.5). Patients diagnosed with SOS/VOD >day+13 had worse day+100 overall survival when compared with those diagnosed ≤day13 (64.3% and 100%, respectively, P=0.02). This study highlights the value of careful clinical assessment to guide diagnosis and the need to refine diagnostic criteria for SOS/VOD in children.

Prevalence and outcomes of patients with sinusoidal obstruction syndrome after liver transplantation: A ten year's experience of a third-level Centre in Japan

BACKGROUND

Sinusoidal obstruction syndrome (SOS) after liver transplantation (LT) is a rare and potentially lethal complication. We retrospectively reviewed the outcomes of patients with post-transplant SOS.

METHODS

Between May 2001 and December 2019, of 332 patients who underwent LT, 5 (1.5%) developed SOS. The median age at LT was 1.7 years (range 0.1-66.5). SOS was histopathologically diagnosed and classified as early-onset (<1 month) or late-onset.

RESULTS

The median time to diagnosis of SOS was one month after LT. All patients developed acute cellular rejection before SOS, and the cause of SOS was acute cellular rejection in four patients and unknown in one. The treatment of SOS included conversion to tacrolimus from cyclosporine, intrahepatic hepatic vein stent placement, strengthening of immunosuppression, and plasma exchange. The 5-year graft survival rates in patients with and without SOS were 53.0% and 92.5%, respectively (p < 0.001). Of three patients with early-onset SOS, two patients improved and are doing well, and one patient died of graft failure four months after LT.

CONCLUSIONS

The cause and treatment of post-transplant SOS are not yet defined. The poor outcomes in patients with early-onset SOS may be improved by strengthening of immunosuppression. Patients with late-onset SOS are ultimately treated by repeat LT.

Hepatic venoocclusive disease/sinusoidal obstruction syndrome with normal portal vein flow mimicking aggravated chronic hepatic GVHD following inotuzumab ozogamicin salvage therapy: a case report of pathologic-radiologic discrepancy

Inotuzumab ozogamicin (INO) showed improved treatment outcomes for relapsed or refractory B-cell precursor acute lymphoblastic leukemia (BCP-ALL) but can induce hepatotoxic adverse events. Hepatic venoocclusive disease/sinusoidal obstruction syndrome (VOD/SOS) frequently develops after allogeneic hematopoietic cell transplantation (allo-HCT), and INO is a strong pretransplant risk factor. However, VOD/SOS can occur just after INO therapy. Here, we describe a BCP-ALL patient treated with INO for isolated extramedullary relapse after allo-HCT. The patient experienced elevated liver enzymes with ascites at 21 days from the last INO dose. Although she met the criteria for VOD/SOS, the diagnosis was challenging because of her ongoing hepatic graft-versus-host disease (GVHD) and normal portal vein flow on Doppler sonogram. The radiologist suggested liver cirrhosis based on computed tomography, with VOD/SOS, liver cirrhosis, and GVHD assumed to be differential diagnoses. She received supportive care with GVHD management; however, due to progressive hepatic failure, we conducted emergent deceased-donor liver transplantation, and the pathologic findings indicated VOD/SOS. Her leukemia was stable, but she died of sepsis after 3 months. INO use is a high-risk factor for VOD/SOS, but an accurate diagnosis can be challenging due to various hepatic complications. Early diagnosis and proper management for VOD/SOS is important for improved outcomes.

Imaging features of hepatic sinusoidal obstruction syndrome or veno-occlusive disease in children

Hepatic sinusoidal obstruction syndrome, also known as veno-occlusive disease, can occur as a complication of myeloablative chemotherapy, as a result of low-intensity chemotherapy-related liver toxicity or radiotherapy of the liver. Symptoms of sinusoidal obstruction syndrome can range from asymptomatic to liver dysfunction or severe disease with life-threatening acute multi-organ failure. Imaging features can suggest or support this clinical diagnosis. Familiarity with the imaging spectrum of sinusoidal obstruction syndrome is therefore important for both radiologists and clinical oncologists. Here, multi-modality radiologic appearances of sinusoidal obstruction syndrome in pediatric patients are illustrated, including outcome after follow-up.

Comparison Between Liver Stiffness Measurement by Fibroscan and Splenic Volume Index as NonInvasive Tools for the Early Detection of Oxaliplatin-induced Hepatotoxicity

Background

Oxaliplatin remains an essential component of many chemotherapy protocols for gastrointestinal cancers; however, neurotoxicity and hepatotoxicity may be dose-limiting. The gold standard for the diagnosis of oxaliplatin-induced hepatotoxicity is liver biopsy, which is invasive and costly. Splenomegaly has also been used as a surrogate for liver biopsy in detecting oxaliplatin-induced sinusoidal obstruction syndrome (SOS), but splenic measurement is not routine and can be inaccurate and complex. We investigated the correlation between increased liver elasticity assessed by Fibroscan and the increase in spleen volume on cross-sectional imaging after oxaliplatin as a noninvasive technique to assess liver stiffness associated with oxaliplatin-induced SOS.

Methods

Forty-six patients diagnosed with gastrointestinal cancers and planned to take oxaliplatin containing regimens were included in this prospective study at the American University of Beirut Medical Center (AUBMC). Measurement of spleen volume using cross-sectional imaging and of liver elasticity using Fibroscan was performed at baseline, 3 and 6 months after starting oxaliplatin. Mean liver elasticity measurements were compared between patients stratified by the development of splenomegaly using the Student t-test. Splenomegaly was defined as 50% increase in spleen size compared with baseline.

Results

Patients who developed splenomegaly after oxaliplatin use had significantly higher mean elasticity measurements as reported by Fibroscan at 3 (16.2 vs. 7.8 kPa, P = 0.036) and 6 (9.3 vs. 6.7 kPa, P = 0.03) months.

Conclusion

Measurement of elasticity using Fibroscan could be potentially used in the future as a noninvasive test for predicting oxaliplatin-induced hepatotoxicity.

Assessment of liver stiffness measurement and ultrasound findings change during inotuzumab ozogamicin cycles for relapsed or refractory acute lymphoblastic leukemia

In adult patients, acute lymphoblastic leukemia (ALL) is a rare hematological cancer with a cure rate below 50% and frequent relapses. With traditional therapies, patients with relapsed or refractory (R/R) ALL have a survival that may be measured in months; in these patients, inotuzumab ozogamicin (IO) is an effective therapy. IO was linked to increased risk of veno-occlusive disease/sinusoid obstruction syndrome (VOD/SOS), liver injury, and various grade of liver-related complications during clinical trials and real-life settings; however, hepatologic monitoring protocol is not established in this population. In our institution, 21 patients who received IO (median of 6 doses of IO administered) for R/R ALL were prospectively followed for hepatologic surveillance, including clinical evaluation, ultrasonography, and liver stiffness measurement (LSM) biochemistry. After a median follow-up of 17.2 months, two SOS events were reported (both after allogeneic transplant) as IO potentially related clinically relevant adverse event. Mild alterations were reported in almost the totality of patients and moderate-severe liver biochemical alterations in a quarter of patients. Within biochemicals value, AST and ALP showed an augment related to IO administration. LSM linearly augmented for each IO course administered. Baseline LSM was related to liver-related changes, especially with the severity of portal hypertension (PH)-related complications. Pre-transplant LSM was higher in patients receiving IO when compared with a control cohort. PH-related complications were discovered in nearly 77% of patients, with clinically significant PH occurrence and development of ascites in 38% and 14%, respectively. This prospective experience constitutes the rationale to design a hepatologic monitoring program in patients receiving IO. LSM may be of pivotal importance in this program, constituting a rapid and effective screening that quantitatively correlates with liver alterations.

Utility of Hepatic 2D Shear-Wave Elastography in Monitoring Response to Image-Guided Intervention in Children With Chronic Budd-Chiari Syndrome: A Prospective Study

Background: Image-guided interventions for Budd-Chiari syndrome (BCS) reduce hepatic congestion, thereby reducing liver stiffness. Liver stiffness measurements (LSM) by ultrasound may provide a noninvasive marker for assessing treatment response. Objective: To assess the utility of 2D shear-wave elastography (SWE) for monitoring response to image-guided intervention in children with BCS, with attention to changes in LSM in patients with disease recurrence. Materials and Methods: This prospective study included children with chronic BCS and planned image-guided intervention. Color Doppler ultrasound (CDUS) and 2D SWE were performed at baseline; at 24 hours, one month, and three months after intervention; and thereafter every three months or at the time of clinically suspected recurrence. Eighteen children underwent liver biopsy at the time of intervention for fibrosis staging using METAVIR criteria. Disease recurrence was diagnosed by CDUS. Statistical evaluation was performed using non-parametric tests. Results: A total of 32 children (28 boys, 4 girls; mean age: 9.0 years; range: 3-14 years) were included. Median LSM was at baseline 43.7 kPa [interquartile range (IQR): 33.0-65.4), at 24 hours 22.5 kPa (IQR: 16.8-32.0), at one month 18.7 kPa (IQR: 14.2-32.0), and at three months 16.7 kPa (IQR: 11.5-22.5) (p<.05 for all post-intervention time points vs baseline). Nine (28.1%) patients developed recurrence after intervention at mean of 4.4 months. In one patient with recurrence, LSM was higher at 24 hours (52.3 kPa) than at baseline (44.2 kPa). In the remaining eight patients with recurrence, LSM increased at the time of recurrence compared with the prior post-intervention LSM measurement [median absolute increase of 11.0 kPa (IQR: 6.1-24.4 kPa)]. Fibrosis stage was not significantly correlated with baseline LSM (r=0.11, 95% CI: -0.37, 0.54; p=.51) or 24-hour post-intervention LSM (r=0.39, 95% CI: -0.11, 0.73; p=.11). Conclusion: LSM decreased significantly after image-guided intervention for chronic BCS in children, showing a maximal decrease at 24 hours post-intervention. Disease recurrence was typically associated with an increase in LSM compared with the patient's prior measurement. Clinical Impact: LSM obtained by 2D SWE may serve as a useful quantitative adjunct to CDUS in monitoring children with chronic BCS for disease recurrence after percutaneous interventional treatment.

Elastography improves accuracy of early hepato-biliary complications diagnosis after allogeneic stem cell transplantation

Significant morbidity and mortality have been associated with liver complications after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Causes and consequences of these hepato-biliary complications are various and might be life-threatening. A high misdiagnosis rate has been reported because of a weak correlation between clinical, laboratory and imaging data. Liver elastography, a liver stiffness measure, is able to assess liver fibrosis and portal hypertension in most liver diseases, but data after allo-HSCT are scarce. Our aim was to determine the interest of sequential liver stiffness measurements for the diagnosis of early hepatic complications after allo-HSCT. Over a 2-year time period, 161 consecutive adult patients were included and 146 were analyzed. Ultrasonography and elastography measurements were performed before transplantation, at day+7 and day+14 by three different experienced radiologists unaware of the patients’ clinical status. Eightyone (55%) patients had liver involvements within the first 100 days after allo-HSCT. Baseline elastography was not predictive for the occurrence of overall liver abnormalities. A significant increase in two-dimensional real-time shearwave elastography (2D-SWE) was found in patients with sinusoidal obstruction syndrome (SOS). Fifteen patients (10%) fulfilled European Society for Blood and Marrow Transplantation (EBMT) score criteria and twelve (8%) reached Baltimore criteria for SOS diagnosis, but only six (4%) had a confirmed SOS. 2D-SWE at day+14 allowed early detection of SOS (AUROC=0.84, P=0.004) and improved sensibility (75%), specificity (99%) and positive predictive value (60%) over the Seattle, Baltimore or EBMT scores. A 2D-SWE measurement above 8.1 kPa at day+14 after allo-HSCT seems a promising, non-invasive, and reproducible tool for early and accurate diagnosis of SOS.

Shear Wave Elastography in the Detection of Sinusoidal Obstruction Syndrome in Adult Patients Undergoing Allogenic Hematopoietic Stem Cell Transplantation

Hepatic sinusoidal obstruction syndrome (SOS), also known as veno-occlusive disease (VOD) can be a life-threatening complication after hematopoietic stem cell transplantation (HSCT). Diagnosis is often difficult and traditionally based on clinical parameters. Shear wave elastography (SWE) is a modern non-invasive liver stiffness measurement technique using ultrasound. In this monocentric study, we evaluated the role of SWE in diagnosing SOS/VOD in 63 adult patients undergoing HSCT from February 2020 to August 2020 in real world settings. Three patients developed SOS/VOD. This was accompanied by an increase in shear wave velocity in all three patients, indicating that this method may contribute to establishing the diagnosis SOS/VOD after HSCT.

Veno-occlusive Disease in HSCT Patients: Consensus-based Recommendations for Risk Assessment, Diagnosis, and Management by the GITMO Group

Variation in clinical practice affects veno-occlusive disease management, mainly in patients who undergo allogeneic hematopoietic stem cell transplantation. Disputes about diagnostic criteria, treatment, and prophylaxis, due to the lack of high-quality data, are at the base of this variability. With the aim of limiting inconsistency in clinical care, thus improving both patient outcomes and data collection reliability, the Italian Society of Stem cell transplant (Gruppo Italiano Trapianto Midollo Osseo e Terapia Cellulare) launched a collaborative effort to formulate recommendations based on integration of available evidence and expert's consensus. A systematic method, according to US National Institute of Health guidelines and Italian National System for Guidelines, was used. Twenty-nine recommendations were approved with a strong (20) or weak (9) level of agreement, while 26 were rejected. In particular, the panel pointed out the need to achieve an early diagnosis, encouraging the adoption of European Society for Blood and Marrow Transplantation criteria and the prompt use of ultrasonography. Moreover, our experts strongly recommended in favor of prophylactic use of ursodeoxycholic acid. As soon as a veno-occlusive disease diagnosis is established, treatment with defibrotide should be started for at least 21 days. A number of areas of uncertainty, particularly concerning risk stratification and use of diagnostic tools such as elastography has been identified and discussed.

Analysis of determinant factors of liver fibrosis progression in ex-thalassemic patients

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) potentially renders thalassemia patients disease-free with presumably cessation of associated complications. This study analyzes the liver fibrosis status and the determinants of its progression in ex-thalassemic patients. The liver fibrosis status of 108 pediatric transfusion-dependent β-thalassemia major patients was evaluated before and one year after allo-HSCT using transient elastography (TE). All patients achieved normal hematopoiesis. In univariate analyses, not in all, but in patients developing significant post-HSCT iron overload or hepatic graft-versus-host disease (GvHD), as well as recipients of bone marrow stem cells (BMSC), significant TE increment occurred. In multivariable analyses, through a model with large effect size (Adj.R² = 26%, F_(3,104) = 13.53, P < 0.001), post-HSCT serum ferritin and hepatic GvHD were ascertained as independent determinants of significant TE increase, and the effect of stem cell graft source approached the level of significance. Excluding the patients with intermediate/high Lucarelli risk classes, the TE increase was significantly greater only in BMSC recipients (P = 0.033). Although the risk impact of allograft source on liver fibrosis progression requires further evaluation; hepatic status of ex-thalassemic patients can be preserved after HSCT, if hepatic GvHD is controlled and adequate post-transplantation iron depletion is ensured.

Sinusoidal obstruction syndrome

Sinusoidal obstruction syndrome (SOS), previously known as veno-occlusive disease, is characterized by concentric and non-thrombotic obstruction of the sinusoid and central vein lumen with no identified primitive or thrombotic hepatic vein lesions. The initial lesion is a result of endothelial denudation, corresponding to the migration of damaged sinusoidal cells to the central veins of the hepatic lobules, leading to sinusoidal and veno-occlusive congestive obstruction. SOS may be associated with other lesions such as centrilobular perisinusoidal fibrosis, peliosis, or nodular regenerative hyperplasia. The first cases of SOS were documented in 1920 in South Africa, after ingestion of food sources contaminated by pyrrolizidine alkaloids. SOS is a well-known complication of hematopoietic stem cell transplantation (HSCT). Numerous toxins and drugs have been associated with SOS, mainly chemotherapies and immunosuppressive therapies, as well as total body or liver irradiation and ABO mismatch platelet transfusion. The pathogenesis of this entity remains unknown.

Noninvasive Diagnostics for Portal Hypertension: A Comprehensive Review

Noninvasive diagnostics for portal hypertension include imaging and functional tests, as well as blood-based biomarkers, and capture different features of the portal hypertensive syndrome. Definitive conclusions regarding their clinical utility require assessment of their diagnostic value in specific clinical settings (i.e., diagnosing a particular hemodynamic condition within a well-defined target population). Several noninvasive methods are predictive of clinically significant portal hypertension (CSPH; hepatic venous pressure gradient [HVPG] ≥ 10 mm Hg; the threshold for complications of portal hypertension); however, only a minority of them have been evaluated in compensated advanced chronic liver disease (i.e., the target population). Importantly, most methods correlate only weakly with HVPG at high values (i.e., in patients with CSPH). Nevertheless, selected methods show promise for diagnosing HVPG ≥ 16 mm Hg (the cut-off for increased risks of hepatic decompensation and mortality) and monitoring HVPG changes in response to nonselective beta-blockers or etiological treatments. Finally, we review established and potential future clinical applications of noninvasive methods.

Ultrasound liver elastography beyond liver fibrosis assessment

Several guidelines have indicated that liver stiffness (LS) assessed by means of shear wave elastography (SWE) can safely replace liver biopsy in several clinical scenarios, particularly in patients with chronic viral hepatitis. However, an increase of LS may be due to some other clinical conditions not related to fibrosis, such as liver inflammation, acute hepatitis, obstructive cholestasis, liver congestion, infiltrative liver diseases. This review analyzes the role that SWE can play in cases of liver congestion due to right-sided heart failure, congenital heart diseases or valvular diseases. In patients with heart failure LS seems directly influenced by central venous pressure and can be used as a prognostic marker to predict cardiac events. The potential role of LS in evaluating liver disease beyond the stage of liver fibrosis has been investigated also in the hepatic sinusoidal obstruction syndrome (SOS) and in the Budd-Chiari syndrome. In the hepatic SOS, an increase of LS is observed some days before the clinical manifestations; therefore, it could allow an early diagnosis to timely start an effective treatment. Moreover, it has been reported that patients that were successfully treated showed a LS decrease, that reached pre-transplantation value within two to four weeks. It has been reported that, in patients with Budd-Chiari syndrome, LS values can be used to monitor short and long-term outcome after angioplasty.

Imaging in Hepatic Veno-Occlusive Disease/Sinusoidal Obstruction Syndrome

Veno-occlusive disease/sinusoidal obstruction syndrome (VOD/SOS) is a potentially life-threatening complication of hematopoietic cell transplantation. Early diagnosis and, subsequently, earlier intervention have been shown to be beneficial to clinical outcomes. Diagnostic criteria from the European Society for Blood and Marrow Transplantation include recommendations on the use of imaging for diagnosis. This review discusses evidence on the use of imaging in the management of VOD/SOS and how imaging biomarkers can contribute to earlier diagnosis/treatment.

Diagnosis and Treatment of VOD/SOS After Allogeneic Hematopoietic Stem Cell Transplantation

Hepatic veno-occlusive disease (VOD) or sinusoidal obstruction syndrome (SOS) is a rare complication characterized by hepatomegaly, right-upper quadrant pain, jaundice, and ascites, occurring after high-dose chemotherapy, hematopoietic stem cell transplantation (HSCT) and, less commonly, other conditions. We review pathogenesis, clinical appearance and diagnostic criteria, risk factors, prophylaxis, and treatment of the VOD occurring post-HSCT. The injury of the sinusoidal endothelial cells with loss of wall integrity and sinusoidal obstruction is the basis of development of postsinusoidal portal hypertension responsible for clinical syndrome. Risk factors associated with the onset of VOD and diagnostic tools have been recently updated both in the pediatric and adult settings and here are reported. Treatment includes supportive care, intensive management, and specific drug therapy with defibrotide. Because of its severity, particularly in VOD with associated multiorgan disease, prophylaxis approaches are under investigation. During the last years, decreased mortality associated to VOD/SOS has been reported being it attributable to a better intensive and multidisciplinary approach.

Liver stiffness and perfusion changes for hepatic sinusoidal obstruction syndrome in rabbit model

BACKGROUND

Hepatic sinusoidal obstruction syndrome (SOS) is caused by damage to hepatic sinusoidal endothelial cells that results in fibrous obliteration of intrahepatic venules and necrosis of hepatocytes. Currently the diagnosis is primarily based on nonspecific clinical features and invasive liver biopsy. Therefore, noninvasive imaging methods are required for the early diagnosis and severity assessment of hepatic SOS.

AIM

To determine the effectiveness of supersonic shear wave imaging (SSI) and dual energy computed tomography (DECT) for diagnosing hepatic SOS using a rabbit model.

METHODS

Among nine New Zealand white rabbits (3-4 kg, male), three in control group ingested normal saline for 20 d and six in the SOS group ingested 6-thioguanine (5 mg/kg/d) for 20 d. Liver stiffness was measured using SSI on days 0, 3, 10, and 20. On the same days, liver perfusion was evaluated from virtual monochromatic images of 55 keV and iodine map using DECT. Morphologic changes in the liver were assessed using CT. Final pathology scores were compared between the two groups. Liver stiffness and perfusion parameters were compared according to the groups, days, and pathology scores.

RESULTS

Final pathology scores were significantly higher in the SOS than the control group (median 22 vs 2, P = 0.024). No gross morphologic changes were seen in livers. Liver stiffness, Hounsfield Unit values, and iodine concentrations were higher in the SOS compared to the control group on days 10 and 20 (all, P ≤ 0.007). Compared to day 0, liver stiffness and perfusion parameters were higher on day 20 in the SOS group (all, P ≤ 0.001). Correlation coefficients for liver stiffness (r = 0.635), Hounsfield Unit values (r = 0.587), and iodine concentration (r = 0.611) with final pathology scores were positive without significance (all, P > 0.05).

CONCLUSION

Liver stiffness and perfusion parameters were significantly increased in the livers of a rabbit SOS model. SSI and DECT might aid in early diagnosis of hepatic SOS.

Diagnosis, grading, and treatment recommendations for children, adolescents, and young adults with sinusoidal obstructive syndrome: an international expert position statement

Sinusoidal obstructive syndrome, also known as hepatic veno-occlusive disease, is a potentially life-threatening complication that occurs in children undergoing haemopoietic stem-cell transplantation (HSCT). Differences in the incidence of genetic predisposition and clinical presentation of sinusoidal obstructive syndrome between children and adults have rendered the historical Baltimore and Seattle diagnostic criteria insufficient for children. In 2017, the European Society for Blood and Marrow Transplantation (EBMT) proposed the first paediatric diagnostic and severity grading guidelines for sinusoidal obstructive syndrome, intended for implementation across European centres. However, universally accepted paediatric criteria are needed to ensure prompt diagnosis, definitive treatment, and improved outcomes for children, adolescents, and young adults with sinusoidal obstructive syndrome, and to facilitate international clinical research collaboration. We convened an international panel of multidisciplinary experts including physicians with expertise in HSCT, paediatric intensive care, nephrology, hepatology, radiology, pathology, and transfusion medicine; HSCT advanced-practice providers and medical trainees; pharmacists; and translational and basic science researchers from the Pediatric Acute Lung Injury and Sepsis Investigators Network, the EBMT, the Pediatric Blood and Marrow Transplant Consortia, and several other institutions with extensive experience in sinusoidal obstructive syndrome. Panellists convened at The University of Texas, MD Anderson Cancer Center (Houston, TX, USA) in February, 2019, to evaluate the available evidence. In this expert position statement paper, we provide consensus recommendations for the international implementation of guidelines for the diagnosis, severity grading, and treatment of sinusoidal obstructive syndrome among children, adolescents, and young adults. We endorse universal adoption of paediatric diagnostic guidelines for sinusoidal obstruction syndrome as proposed by the EBMT, and provide implementation guidance for standardisation across centres; we have further proposed adjunctive use of age-appropriate organ-specific toxicity criteria for severity grading and provided prophylaxis and treatment considerations among children and adolescent and young adult patients. Key recommendations include: (1) liver biopsy, portal venous wedge pressure, and reversal of portal venous flow on Doppler ultrasonography should not be used for the routine diagnosis of sinusoidal obstructive syndrome in children, adolescents, and young adults; (2) platelet refractoriness can be defined as a corrected count increment of less than 5000-7500 following at least two sequential ABO-compatible fresh platelet transfusions; (3) hepatomegaly is best defined as an absolute increase of at least 1 cm in liver length at the midclavicular line; and if a baseline measurement is not available, hepatomegaly can be defined as greater than 2 SDs above normal for age; and (4) the presence and volume of ascites can be categorised as mild (minimal fluid by liver, spleen, or pelvis), moderate (<1 cm fluid), or severe (fluid in all three regions with >1 cm fluid in at least two regions).

Noninvasive imaging diagnosis of sinusoidal obstruction syndrome: a pictorial review

Sinusoidal obstruction syndrome (SOS) is a rare liver disorder due to hepatic vascular injury. Its rapid and accurate diagnosis is crucial for patient survival. SOS is often established clinically, based on Baltimore, modified Seattle, or European Society for Blood and Marrow Transplantation (EBMT) criteria. Unfortunately, such criteria are not highly specificity and fail to provide a timely, reliable differential diagnosis. The use of noninvasive imaging techniques, such as ultrasound (US), computed tomography (CT), magnetic resonance imaging (MRI), and fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT), has recently grown in this setting, some key imaging features offering diagnostic improvement. This review provides a synopsis of current noninvasive imaging techniques used for this purpose, summarizing accurate and reliable diagnostic features of SOS.

Drop of Butyrylcholinesterase Activity after Cyclophosphamide Conditioning as a Predictive Marker of Liver Transplant-Related Complications and Its Correlation with Transplant-Related Mortality in Pediatric Hematopoietic Stem Cell Recipients

Transplant-related liver complications are a potentially fatal condition of hematopoietic stem cell transplantation (HSCT) in pediatric patients, actually representing one of the main factors involved in transplant-related mortality (TRM). The search for a specific marker capable of predicting the development of this condition is a relevant clinical issue. We have observed a variable reduction in serum butyrylcholinesterase (BChE) activity after a cyclophosphamide-containing conditioning regimen. This study aims to determine the cutoff of BChE activity reduction that might be a specific prognostic marker for liver complications after HSCT. Our results show that the reduction of BChE values below 2000 U/L the day before the transplantation is an indicator strongly associated with the transplant-related liver complications (p < 0.0001). The incidence of overall survival at 1 year was significantly higher in the BChE > 2000 U/L group compared to the BChE < 2000 U/L group (84.7% versus 58.5%, p < 0.001), while the TRM rate was significantly lower (8.1% versus 23.1%, p < 0.05). None of the patients undergoing prophylaxis with defibrotide developed severe liver complications. Starting defibrotide treatment at the first signs of hepatic dysfunction in patients with particularly low BChE activity levels reduces severe liver transplant-related complications.

Role of imaging techniques in liver veno-occlusive disease diagnosis: recent advances and literature review

Veno-occlusive-disease (VOD), known also as sinusoidal-obstruction-syndrome (SOS), is one of the main complications of haematopoietic stem cell transplantation and is related to the treatment with pyrrolizidine alkaloids or other toxic agents (chemotherapy for liver-metastasis). Clinical diagnosis using the recent criteria from the European Society for Blood and Marrow Transplantation, is the reference for VOD/SOS diagnosis. However, increasing evidence suggests the emerging role of several imaging methods that could help the clinician in VOD/SOS assessment. Areas covered: This review evaluates the current literature on the various imaging techniques used in VOD/SOS diagnosis in several clinical scenarios. Literature searches were performed using several keywords on MEDLINE/Ovid/In-Process/Cochrane Library/EMBASE and PubMed up to July 2018. Expert commentary: Hepatic-gradient-measurement (HVPG) and contextual transjugular-liver-biopsy are invasive and should always be considered in unclear cases. The main studies revolve around ultrasound with Doppler evaluation, identifying numerous findings suggestive of VOD/SOS. However, their accuracy and validation are still suboptimal and controversial. CT-Scan and MRI have shown encouraging data in other contexts in which VOD/SOS can develop, but studies on the post-HSCT patient are lacking. Elastography techniques measuring liver stiffness (LSM) represent the most recent and promising approach for an accurate and early diagnosis of VOD/SOS. In our view, a multidisciplinary approach to the VOD/SOS diagnosis should be highly encouraged.