Topographic Distribution Pattern in Hepatic Amyloidosis Presenting with Portal Hypertension

Background/aims

The liver is often involved in both primary and secondary forms of amyloidosis. Significant clinical evidence of portal hypertension is relatively uncommon and seems to be related to the reduced sinusoidal lumen and increased resistance to blood flow due to massive perisinusoidal amyloid deposits. The relationships between the pattern and extent of amyloid deposition in patients presenting with portal hypertension have not yet been clearly demonstrated. This study is focusing on the topographic distribution of amyloidosis in patients presenting with portal hypertension.

Methods

The study included biopsy-proven cases of hepatic amyloidosis. The clinical, biochemical, and serological data, involvement of the extrahepatic organs, and HVPG values were recorded. Tissue sections were re-evaluated for the distribution patterns of amyloid deposits.

Results

We had 41 patients with hepatic amyloidosis, of which, 32 were male. A mixed pattern (sinusoidal and vascular) was the most common (32/41; 78%). Hepatic venous pressure gradient was available in 21 cases. Portal hypertension was found in 14 patients (14/21; 67%). Cases of portal hypertension were found to have a sinusoidal pattern (3/14; 21.4%), vascular pattern (1/14; 7.1%), or a mixed sinusoidal and vascular pattern (10/14; 71.4%). Those not having portal hypertension showed hepatic artery (HA) involvement in 6/7 (85.7%) cases. A comparative analysis between portal hypertension (PTH) and non-PTH groups showed that HA amyloid deposition was dominant in the non-PTH group (6/7; 85.7%) and sinusoidal deposition in the PTH group (13/14; 92.8%). The difference was found to be significant (P < 0.05).

Conclusion

We found that portal hypertension was noted in cases with diffuse sinusoidal deposition or mixed sinusoidal with portal vein deposition. In the non-PHT group, the deposition was mainly in HA alone.

Percutaneous transsplenic venous embolization of elevated jejunal varices after pancreaticoduodenectomy: A case report

Recent advances in chemotherapy and radiotherapy have led to an increase in the number of long-term survivors of pancreatic cancer. However, this has also increased the number of patients suffering from ectopic varices and bleeding owing to left-sided portal hypertension and thrombocytopenia caused by splenomegaly after pancreaticoduodenectomy combined with resection of the splenic vein. A 65-year-old woman with varices of the elevated jejunum due to left sided portal hypertension after pancreaticoduodenectomy had repeated melena, which started about 1 year before admission. We describe the first reported case of percutaneous transsplenic venous embolization using metallic coils, which successfully achieved hemostasis of refractory bleeding from the elevated jejunal varices after pancreaticoduodenectomy.

Portal Vein Thrombosis in Cirrhosis

Patients with cirrhosis of the liver are at high risk of developing portal vein thrombosis (PVT), which has a complex, multifactorial cause. The condition may present with a myriad of symptoms and can occasionally cause severe complications. Contrast-enhanced computed tomography (CT) is the gold standard for the diagnosis of PVT. There are uncertainties regarding the effect on PVT and its treatment outcome in patients with cirrhosis. The main challenge for managing PVT in cirrhosis is analyzing the risk of hemorrhage compared to the risk of thrombus extension leading to complications. All current knowledge regarding non-tumor PVT in cirrhosis, including epidemiology, risk factors, classification, clinical presentation, diagnosis, impact on natural history, and treatment, is discussed in the present article.

Single-cell RNA sequencing of human liver reveals hepatic stellate cell heterogeneity

Background & Aims

The multiple vital functions of the human liver are performed by highly specialised parenchymal and non-parenchymal cells organised in complex collaborative sinusoidal units. Although crucial for homeostasis, the cellular make-up of the human liver remains to be fully elucidated. Here, single-cell RNA-sequencing was used to unravel the heterogeneity of human liver cells, in particular of hepatocytes (HEPs) and hepatic stellate cells (HSCs).

Method

The transcriptome of ~25,000 freshly isolated human liver cells was profiled using droplet-based RNA-sequencing. Recently published data sets and RNA in situ hybridisation were integrated to validate and locate newly identified cell populations.

Results

In total, 22 cell populations were annotated that reflected the heterogeneity of human parenchymal and non-parenchymal liver cells. More than 20,000 HEPs were ordered along the portocentral axis to confirm known, and reveal previously undescribed, zonated liver functions. The existence of 2 subpopulations of human HSCs with unique gene expression signatures and distinct intralobular localisation was revealed (i.e. portal and central vein-concentrated GPC3⁺ HSCs and perisinusoidally located DBH⁺ HSCs). In particular, these data suggest that, although both subpopulations collaborate in the production and organisation of extracellular matrix, GPC3⁺ HSCs specifically express genes involved in the metabolism of glycosaminoglycans, whereas DBH⁺ HSCs display a gene signature that is reminiscent of antigen-presenting cells.

Conclusions

This study highlights metabolic zonation as a key determinant of HEP transcriptomic heterogeneity and, for the first time, outlines the existence of heterogeneous HSC subpopulations in the human liver. These findings call for further research on the functional implications of liver cell heterogeneity in health and disease.

Lay summary

This study resolves the cellular landscape of the human liver in an unbiased manner and at high resolution to provide new insights into human liver cell biology. The results highlight the physiological heterogeneity of human hepatic stellate cells.

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A cell atlas from the near-native transcriptome of >25,000 human liver cells is presented.

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Hepatocytes were ordered along the portocentral axis to reveal previously undescribed gene expression patterns and zonated liver functions.

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Two subpopulations of human hepatic stellate cells (HSCs) are reported, characterised by different spatial distribution in the native tissue.

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Characteristic gene signatures of HSC subpopulations are suggestive of far-reaching functional differences.

Constitutive androstane receptor induced-hepatomegaly and liver regeneration is partially via yes-associated protein activation

The constitutive androstane receptor (CAR, NR3I1) belongs to nuclear receptor superfamily. It was reported that CAR agonist TCPOBOP induces hepatomegaly but the underlying mechanism remains largely unknown. Yes-associated protein (YAP) is a potent regulator of organ size. The aim of this study is to explore the role of YAP in CAR activation-induced hepatomegaly and liver regeneration. TCPOBOP-induced CAR activation on hepatomegaly and liver regeneration was evaluated in wild-type (WT) mice, liver-specific YAP-deficient mice, and partial hepatectomy (PHx) mice. The results demonstrate that TCPOBOP can increase the liver-to-body weight ratio in wild-type mice and PHx mice. Hepatocytes enlargement around central vein (CV) area was observed, meanwhile hepatocytes proliferation was promoted as evidenced by the increased number of KI67⁺ cells around portal vein (PV) area. The protein levels of YAP and its downstream targets were upregulated in TCPOBOP-treated mice and YAP translocation can be induced by CAR activation. Co-immunoprecipitation results suggested a potential protein–protein interaction of CAR and YAP. However, CAR activation-induced hepatomegaly can still be observed in liver-specific YAP-deficient (Yap^–/–) mice. In summary, CAR activation promotes hepatomegaly and liver regeneration partially by inducing YAP translocation and interaction with YAP signaling pathway, which provides new insights to further understand the physiological functions of CAR.

The Use of a 3D Printing Model in Planning a Donor Hepatectomy for Living Donor Liver Transplantation: First in India

INTRODUCTION

Three-dimensional (3D) anatomical relationships between the hepatic veins and portal structures can serve as a guide to plan resections in donor hepatectomy during living donor liver transplantation. We present the first case report from India on the use of a 3D printed liver model, as an assist to living donor liver transplantation.

METHODS

A 3D model of the donor liver with hepatic venous structures printed within it was prepared using image acquisition data. The model was used for a simulated cut preoperatively, to mimic the donor hepatectomy based on the venous structures seen through the transparent material used for making the liver model. The volume of the graft measured by volume displacement in the actual surgery was compared with the volume of the model after the simulated cut.

RESULTS

The calculated volume of the graft was 359 ml as per the preoperative simulation, and the observed weight/volume was 380 gm/310 ml.

CONCLUSION

Three-dimensional printing of liver models using imaging data can help predict the actual size of the graft after donor hepatectomy, in patients undergoing living donor liver transplantation.

Where does TIPS fit in the management of patients with cirrhosis?

In this review, we summarise the current knowledge on the indications and contraindications of transjugular intrahepatic portosystemic shunt (TIPS) placement for the treatment of the complications of portal hypertension in cirrhosis, specifically variceal haemorrhage and ascites. Moreover, we discuss the role of TIPS for the treatment of portal vein thrombosis (PVT) and the prevention of complications after extrahepatic surgery ('preoperative TIPS') in patients with cirrhosis. The position of TIPS in the treatment hierarchy depends on the clinical setting and on patient characteristics. In acute variceal haemorrhage, preemptive TIPS is indicated in patients at a high risk of failing standard therapy, that is those with a Child-Pugh score of 10-13 points or Child-Pugh B with active bleeding at endoscopy, although the survival benefit in the latter group still remains to be established. Non-preemptive TIPS is a second-line therapy for the prevention of recurrent variceal haemorrhage and for the treatment of ascites. Of note, TIPS may also improve sarcopenia. Contraindications to TIPS placement, independent of clinical setting, include very advanced disease (Child-Pugh >13 points), episodes of recurrent overt hepatic encephalopathy without an identifiable precipitating factor, heart failure, and pulmonary hypertension. In patients with PVT, TIPS placement not only controls complications of portal hypertension, but also promotes portal vein recanalisation. Although the severity of portal hypertension correlates with poor outcomes after extrahepatic surgery, there is no evidence to recommend preoperative TIPS placement.

EUS-guided portal pressure gradient measurement with a simple novel device: a human pilot study

BACKGROUND AND AIMS

Portal hypertension is a serious adverse event of liver cirrhosis. Recently, we developed a simple novel technique for EUS-guided portal pressure gradient (PPG) measurement (PPGM). Our animal studies showed excellent correlation between EUS-PPGM and interventional radiology-acquired PPGM. In this video we demonstrate the results of the first human pilot study of EUS-PPGM in patients with liver disease.

METHODS

EUS-PPGM was performed by experienced endosonographers using a linear echoendoscope, a 25-gauge FNA needle, and a novel compact manometer. The portal vein and hepatic vein (or inferior vena cava) were targeted by use of a transgastric or transduodenal approach. Feasibility was defined as successful PPGM in each patient. Safety was based on adverse events captured in a postprocedural interview.

RESULTS

Twenty-eight patients underwent EUS-PPGM with 100% technical success and no adverse events. PPG ranged from 1.5 to 19 mm Hg and had excellent correlation with clinical parameters of portal hypertension, including the presence of varices (P = .0002), PH gastropathy (P = .007), and thrombocytopenia (P = .036).

CONCLUSION

This novel technique of EUS-PPGM using a 25-gauge needle and compact manometer is feasible and appears safe. Given the availability of EUS and the simplicity of the manometry setup, EUS-guided PPG may represent a promising breakthrough for procuring indispensable information in the management of patients with liver disease.

Toxicological evaluation of a novel cooling compound: 2-(4-methylphenoxy)-N-(1H-pyrazol-3-yl)-N-(2-thienylmethyl)acetamide

A toxicological evaluation of a novel cooling agent, 2-(4-methylphenoxy)-N-(1H-pyrazol-3-yl)-N-(2-thienylmethyl) acetamide (S2227; CAS 1374760-95-8), was completed for the purpose of assessing its safety for use in food and beverage applications. S2227 undergoes rapid oxidative metabolism in vitro, and in rat and dog pharmacokinetic studies is rapidly converted to its component carboxylic acid and secondary amine. S2227 was not found to be mutagenic or clastogenic in vitro, and did not induce micronuclei in polychromatic erythrocytes in vivo. The secondary amine hydrolysis product, N-(2-thienylmethyl)-1H-pyrazol-3-amine (M179), was also evaluated for genotoxicity. In subchronic oral toxicity studies in rats, the no-observed-adverse-effect-level (NOAEL) for S2227 was 100 mg/kg/day (highest dose tested) when administered by oral gavage for 90 consecutive days. Furthermore, S2227 demonstrated a lack of maternal toxicity, as well as adverse effects on fetal morphology at the highest dose tested, providing a NOAEL of 1000 mg/kg/day for both maternal toxicity and embryo/fetal development when administered orally during gestation to pregnant rats.

Portal vein thrombosis

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

Endoscopic retrograde cholangiography in portal cavernoma cholangiopathy - results from different studies and proposal for uniform terminology

Portal cavernoma cholangiopathy (PCC) refers to a constellation of secondary changes in the biliary tree in patients with chronic portal vein (PV) thrombosis and portal cavernoma formation. These findings of PCC are seen in the extra-hepatic bile duct(s), with or without involvement of the 1st or 2nd degree intra-hepatic bile ducts. Of all patients with chronic PV thrombosis, cholangiographic features of PCC are found in 80%-100%. The biliary changes are symptomatic in a smaller proportion of 5%-38% patients. Choledocholithiasis and hepatolithiasis occur in 5%-20%, independent of the occurrence of cholelithiasis. We review the published literature on cholangiographic description of PCC. We also propose standardized nomenclature for the cholangiographic findings, namely: extrinsic impressions/indentations, shallow impressions, irregular ductal contour, stricture (s), upstream dilatation, filling defects, bile duct angulation, and ectasia.

Collateral pathways in portal hypertension

Presence of portosystemic collateral veins (PSCV) is common in portal hypertension due to cirrhosis. Physiologically, normal portosystemic anastomoses exist which exhibit hepatofugal flow. With the development of portal hypertension, transmission of backpressure leads to increased flow in these patent normal portosystemic anastomoses. In extrahepatic portal vein obstruction collateral circulation develops in a hepatopetal direction and portoportal pathways are frequently found. The objective of this review is to illustrate the various PSCV and portoportal collateral vein pathways pertinent to portal hypertension in liver cirrhosis and EHPVO.

Identification of Perforators in Patients with Duodenal Varices by Endoscopic Ultrasound-A Case Series [with video]

BACKGROUND/AIMS

Duodenal varices (DV) are ectopic varices which can cause massive gastrointestinal bleeding. The diagnosis of DV may be difficult; sometimes they can be hidden behind duodenal folds. The aim of the study was to evaluate DV by endoscopic ultrasound.

METHODS

Endoscopic ultrasound was done in patients detected or suspected to be having DV. The para duodenal varices were identified and subsequently hemodynamic evaluation of DV was done.

RESULTS

Endoscopic ultrasound identified perforators in seven cases of DV.

CONCLUSION

The endoscopic ultrasound can help in detection of DV underlying thickened folds. It can also help in hemodynamic evaluation of DV.

Bleeding after endoscopic biliary sphincterotomy

Bleeding during endoscopic sphincterotomy is a common complication. Sometimes bleeding occurs as a late complication after endoscopic retrograde cholangiopancreatography (ERCP). We describe a case in which bleeding happened during ERCP but detection was done after the completion of the procedure. The detection of bleeding allowed further evaluation and detection of hemobilia in this case. The removal of blood clots from inside common bile duct by repeat ERCP however led to an uneventful recovery without any morbidity.