Clinical features of extrahepatic portal vein obstruction: Myeloproliferative neoplasms eliminate hypersplenic hematologic changes in extrahepatic portal vein obstruction.

Extrahepatic portal vein obstruction (EHPVO) is a rare disease. Most EHPVO patients are usually referred to a gastroenterologist for intestinal bleeding and hypersplenic thrombocytopenia; however, hypercoagulative diseases may be occult in these patients and require anticoagulation. The purpose of this study was to elucidate the clinical characteristics of EHPVO. We conducted a retrospective analysis of the hospital database, evaluating the medical records of 15 patients (7 males, 8 females, mean age of onset 42.0 years, range 5-74 years). Thirteen of 15 EHPVO patients (86.7%) had intestinal varices. These included 10 esophageal (66.7%), 12 gastric (80.0%), and 6 ectopic varices (40.0%). Nine (60.0%) of 15 had a history of intestinal bleeding. Regarding comorbidities, 5 of 15 (33.3%) suffered from vascular diseases, including acute myocardial infarction, cerebral infarction, pulmonary embolism, Budd-Chiari syndrome, and mesenteric vein thrombosis. The former 3 vascular commodities manifested at less than 32 years of age. Four patients (26.7%) with JAK2V617F mutation were diagnosed as myeloproliferative neoplasm (MPN). 72.3% of EHPVO patients without MPN experienced thrombocytopenic state. No EHPVO patients with MPN experienced thrombo-leukocytopenia. The elevation of white blood cell and platelet counts, and decrease of protein S were seen in EHPVO with MPN, compared with EHPVO without MPN. EHPVO is frequently associated with underlying hypercoagulative factors, causing a dilemma between thrombotic complications and portal hypertensive bleeding. Most EHPVO patients experience an evident thrombocytopenic state due to severe hypersplenism; however, hypersplenic hematologic changes are eliminated in EHPVO with MPN. MPN should be suspected in EHPVO patients negative for thrombo-leukocytopenia.

Safety and effectiveness of SARS-CoV-2 vaccines for patients with intractable hepatobiliary diseases: A multicenter, questionnaire-based, cross-sectional study.

AIM: There are few data regarding the safety and effectiveness of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccines in patients with intractable hepatobiliary diseases. We conducted a multicenter, questionnaire-based, cross-sectional study to determine the safety and effectiveness of the SARS-CoV-2 vaccines in Japanese patients with intractable hepatobiliary disease. METHODS: Patients aged ≥18 years with autoimmune hepatitis (AIH), primary biliary cholangitis, primary sclerosing cholangitis, Budd-Chiari syndrome, idiopathic portal hypertension, and extrahepatic portal vein obstruction at each center were consecutively invited to join the study. Participants were asked to complete a questionnaire regarding their characteristics, vaccination status, post-vaccination adverse effects, and SARS-CoV-2 infection. Additionally, liver disease status, treatment regimens, and liver function test values pre- and post-vaccination were collected. RESULTS: The survey was conducted from September 2021 to May 2022, and 528 patients (220 AIH, 251 primary biliary cholangitis, 6 AIH- primary biliary cholangitis/primary sclerosing cholangitis overlap, 39 primary sclerosing cholangitis, 4 Budd-Chiari syndrome, 5 idiopathic portal hypertension, and 3 extrahepatic portal vein obstruction) participated in the study. Post-vaccination adverse effects were comparable to those observed in the general population. Post-vaccination liver injuries classified as grade 1 or higher were observed in 83 cases (16%), whereas grades 2 and 3 were observed in only six cases (1.1%); AIH-like liver injury requiring treatment was not observed. Overall, 12 patients (2.3%) were infected with SARS-CoV-2, and only one patient was infected 6 months after the second vaccination. CONCLUSION: SARS-CoV-2 vaccines demonstrated satisfactory safety and effectiveness in Japanese patients with intractable hepatobiliary diseases.

Stenting of Inferior Right Hepatic Vein in a Patient with Budd-Chiari Syndrome: A Case Report.

A Japanese man in his 20s was referred to our hospital with a two-month history of abdominal fullness and leg edema. Abdominal computed tomography revealing massive ascites and ostial blockage of the main hepatic veins, and angiographic evaluation demonstrating obstruction of the main hepatic veins yielded a diagnosis of Budd-Chiari syndrome (BCS). Diuretic agents were prescribed for the ascites but failed to provide relief. The patient was referred to our department for further evaluation and treatment. Angiography showed ostial obstruction of the main hepatic veins, with most of the portal hepatic flow draining from an inferior right hepatic vein (IRHV) into the inferior vena cava (IVC) thorough an intrahepatic portal venous and venovenous shunt. Access between the main hepatic veins and IVC was impossible, but cannulation between the IRHV and IVC was achieved. Because of the venovenous connection between the main hepatic vein and the IRHV, metallic stents were placed into two IRHVs to decrease congestion in the hepatic venous outflow. After stent placement followed by balloon expansion, the gradient pressure between the hepatic vein and IVC improved remarkably. The ascites and lower leg edema improved postoperatively, and long-term stent patency (6 years) was achieved.

Safety and Feasibility of Laparoscopic Liver Resection with the Clamp-Crush Method Using the BiSect.

BACKGROUND: Various energy devices are available for resection of the liver parenchyma during laparoscopic liver resection (LLR). We have historically performed liver resections using the Cavitron Ultrasonic Surgical Aspirator (CUSA). More recently, we have used new bipolar forceps (BiSect; Erbe Elektromedizin GmbH, Tübingen, Germany) to perform clamp-crush dissection with good results. The BiSect is a reusable bipolar forceps with a laparoscopic dissecting forceps tip and both an incision mode and coagulation mode. We evaluated the perioperative clinical course of patients who underwent LLR using the clamp-crush method with the BiSect compared with the CUSA. METHODS: This single-center case control study involved patients with liver metastasis from colorectal cancer who underwent LLR using either the BiSect or CUSA at our hospital from January 2019 to December 2022. We performed the LLR using CUSA from January 2019 to early October 2020. After introduction of the BiSect in late October 2020, we used BiSect for the LLR. Before surgery, the three-dimensional liver was constructed based on computed tomography images, and a preoperative simulation was performed. We evaluated the results of LLR using the BiSect versus the CUSA and assessed the short-term results of LLR. RESULTS: During the study period, we performed partial liver resection using the BiSect in 26 patients and the CUSA in 16 patients. In the BiSect group, the median bleeding volume was 55 mL, the median operation time was 227 minutes, and the median postoperative length of hospital stay was 9 days. In the CUSA group, the median bleeding volume was 87 mL, the median operation time was 305 minutes, and the median postoperative length of hospital stay was 10 days. There were no statistically significant differences in the clinical course including bile leakage, bile duct stenosis, and post operative hospital stay between the two groups. CONCLUSIONS: Compared with LLR using the CUSA, the clamp-crush method using the BiSect in LLR is a safe and useful liver transection technique. Further study should be conducted to clarify whether BiSect is safe and useful in LLR for patients with other tumor types and patients who undergo other procedures.

Distribution of Splenic Arterial Flow and Segmental Spleen Volume for Partial Splenic Arterial Embolization.

INTRODUCTION: The spleen is a lymphatic organ that manages immune surveillance of the blood, produces blood cells, and helps filter the blood, remove old blood cells, and fight infection. The normal splenic weight is approximately 65-265 g. This study evaluated spleen volume and segmental volume. METHODS: 121 patients who underwent enhanced CT at our center were analyzed. The spleen was divided into upper, middle, and lower segments according to arterial flow area, and the volume of each segment was measured. Patients were classified into two groups as those with and without liver cirrhosis, and differences in the distribution of the segments in these groups was evaluated. RESULTS: The mean upper, middle, and lower spleen segmental volume ratios were 35.4%, 37.0%, and 27.6%, respectively. In the liver cirrhosis group, the segmental splenic volume ratios for the upper, middle, and lower segments were 34.5%, 38.5%, and 28.0%, respectively, indicating that these ratios remain similar regardless of liver cirrhosis status. CONCLUSION: The present findings on segmental spleen volume are useful for estimating infarction volume in cases of partial splenic arterial embolization.

Esophagogastric varix caused by extrahepatic portal vein obstruction with essential thrombocythemia: A case report.

Extrahepatic portal vein obstruction (EHPVO) is a very rare disease-causing portal hypertension. Myeloproliferative neoplasm (MPN) including essential thrombocythemia (ET) is reported as a risk factor for EHPVO due to underlying persistent thrombophilia.A Japanese woman in her 40s was referred to our hospital with a one-month history of gastric variceal bleeding due to EHPVO. Laboratory investigation demonstrated thrombocytosis despite portal hypertension. She had a mutation of clonal marker JAK2V617F with EHPVO, which prompted us to consult a hematologist. Bone marrow biopsy revealed megakaryocyte lineage proliferation, leading to a diagnosis of ET.Esophagogastroduodenoscopy indicated esophagogastric varices (LsF2CbRC2, Lg-cF1RC1). Abdominal Computed Tomography and angiography revealed splenomegaly and portal vein thrombosis with cavernous transformation. These radiologic findings suggested EHPVO.The patient had a history of ruptured esophagogastric varices and required prophylaxis against further variceal bleeding prior to anti-thrombotic therapy for EHPVO with ET. We performed laparoscopic Hassab's operation followed by endoscopic variceal ligation (EVL) and hematological cytoreduction therapy.Laparoscopic Hassab's operation and three bi-monthly EVL improved the esophagogastric varix (LmF0RC0, Lg-f F0RC0) at 6 months after surgery. Platelet count decreased to 60.1 x104 /uL by cytoreduction therapy. She was very healthy at 7 months after surgery.Patients with EHPVO are traditionally referred to the gastroenterologist for abdominal pain, intestinal bleeding, or refractory ascites; however, hypercoagulative disease may be occult in such patients and require the attention of a hematologist. When encountering the patients with splanchnic thrombosis caused by EHPVO, the gastroenterologists should screen for hematological disease, including MPN.

Evaluation of splenic infarction ratio and platelet increase ratio after partial splenic artery embolization.

OBJECTIVE: The spleen is part of the lymphatic system and is one of the least understood organs of the human body. It is involved in the production of blood cells and helps filter the blood, remove old blood cells, and fight infection. Partial splenic artery embolization (PSE) is widely used to treat pancytopenia and portal hypertension. The efficacy of PSE for improving thrombocytopenia has been well demonstrated. In this study, we evaluated the splenic infarction ratio and platelet increase ratio after PSE. METHODS: Forty-five consecutive patients underwent PSE from January 2014 to August 2022. We retrospectively evaluated the splenic infarction volume and ratio after PSE and analyzed the relationship between the splenic infarction ratio and platelet increase ratio after PSE. RESULTS: The platelet increase ratio was correlated with the splenic infarction ratio after PSE. The cutoff value for the splenic infarction ratio with a two-fold platelet increase was 63.0%. CONCLUSION: We suggest performance of PSE in patients with a splenic infarction ratio of 63% to double the expected platelet count.

Causes and Management of Endoscopic Retrograde Cholangiopancreatography-Related Perforation: A Retrospective Study.

BACKGROUND: Endoscopic retrograde cholangiopancreatography (ERCP) is essential for diagnosing and treating biliopancreatic disease. Because ERCP-related perforation can result in death, therapeutic decisions are important. The aim of this study was to determine the cause of ERCP-related perforation and suggest appropriate management. METHODS: Between January 1999 and August 2022, 7,896 ERCPs were performed in our hospital. We experienced 15 cases (0.18%) of ERCP-related perforation and conducted a retrospective review. RESULTS: Of the 15 patients, 6 were female and 9 were male, and the mean age was 77.1 years. According to Stapfer's classification, the 15 cases of ERCP-related perforation comprised 3 type I (duodenum), 3 type II (periampullary), 9 type III (distal bile duct or pancreatic duct), and no type IV cases. Fourteen of 15 (92.6%) were diagnosed during ERCP. The main cause of perforation was scope-induced damage, endoscopic sphincterotomy, and instrumentation penetration in type I, II, and III cases, respectively. Four patients with severe abdominal pain and extraluminal fluid collection underwent emergency surgery for repair and drainage. One type III patient with distal bile duct cancer underwent pancreaticoduodenectomy on day 6. Three type III patients with only retroperitoneal gas on computed tomography (CT) performed immediately after ERCP had no symptoms and needed no additional treatment. Seven of the 15 patents were treated by endoscopic nasobiliary drainage (n=5) or CT-guided drainage (n=2). There were no deaths, and all patients were discharged after treatment. CONCLUSIONS: Early diagnosis and appropriate treatment are important in managing ERCP-related perforation.

Structure and mechanism of oxalate transporter OxlT in an oxalate-degrading bacterium in the gut microbiota.

An oxalate-degrading bacterium in the gut microbiota absorbs food-derived oxalate to use this as a carbon and energy source, thereby reducing the risk of kidney stone formation in host animals. The bacterial oxalate transporter OxlT selectively uptakes oxalate from the gut to bacterial cells with a strict discrimination from other nutrient carboxylates. Here, we present crystal structures of oxalate-bound and ligand-free OxlT in two distinct conformations, occluded and outward-facing states. The ligand-binding pocket contains basic residues that form salt bridges with oxalate while preventing the conformational switch to the occluded state without an acidic substrate. The occluded pocket can accommodate oxalate but not larger dicarboxylates, such as metabolic intermediates. The permeation pathways from the pocket are completely blocked by extensive interdomain interactions, which can be opened solely by a flip of a single side chain neighbouring the substrate. This study shows the structural basis underlying metabolic interactions enabling favourable symbiosis.

The Role of the Spleen in Portal Hypertension.

As liver disease progresses, intrahepatic vascular resistance increases (backward flow theory of portal hypertension) and collateral veins develop. Adequate portal hypertension is required to maintain portal flow into the liver through an increase in blood flow into the portal venous system (forward flow theory of portal hypertension). The splenic artery resistance index is significantly and selectively elevated in cirrhotic patients. In portal hypertension, a local hyperdynamic state occurs around the spleen. Splenomegaly is associated with a poor prognosis in cirrhosis and is caused by spleen congestion and by enlargement and hyperactivation of splenic lymphoid tissue. Hypersplenism can lead to thrombocytopenia caused by increased sequestering and breakdown of platelets in the spleen. The close relationship between the spleen and liver is reflected in the concept of the hepatosplenic axis. The spleen is a regulatory organ that maintains portal flow into the liver and is the key organ in the forward flow theory of portal hypertension. This review summarizes the literature on the role of the spleen in portal hypertension.

Cauda Equina Atrophy in Amyotrophic Lateral Sclerosis on Routine Lumbar Magnetic Resonance Imaging.

OBJECTIVE: The aim of the study was to evaluate the cross-sectional area of the cauda equina in amyotrophic lateral sclerosis (ALS) on routine lumbar magnetic resonance imaging and investigate the diagnostic accuracy in comparison with age- and sex-matched non-ALS controls. METHODS: This retrospective study included 15 ALS patients and 15 age- and sex-matched non-ALS controls. Two independent neuroradiologists measured and compared the total cross-sectional area of the cauda equina of ALS patients and the non-ALS controls at the level of the L3 and L4 using axial T2-weighted images. The cutoff value, sensitivity, specificity, and area under the curve were measured. The interobserver reproducibility of the 2 independently obtained measurements was evaluated. RESULTS: The total cross-sectional area of the cauda equina in the ALS group was significantly smaller than that in the non-ALS group (L3: median, 66.73 vs 90.19 mm 2 , P < 0.001; L4: median, 52.9 vs 67.63 mm 2 , P < 0.001). The cutoff values at L3 and L4 were 76.95 and 61.04 mm 2 with a sensitivity and specificity of 1 and 0.87 and 0.8 and 0.87, respectively. The area under the curve at L3 and L4 were high at 0.96 and 0.94, respectively. The interobserver reproducibility was 0.88 at L3 and 0.89 at L4. CONCLUSIONS: The ALS patients showed significant atrophy of the cauda equina compared with non-ALS patients.

GFAP variant p. Tyr366Cys demonstrated widespread brain cavitation in neonatal Alexander disease.

Alexander disease is a rare form of leukodystrophy caused by heterozygous mutations in the gene encoding glial fibrillary acidic protein (GFAP). Brain cavitation in the white matter, predominantly distributed in the frontal periventricular area, has been described in some cases. Here, we present a case of a 1-year-old boy with neonatal Alexander disease caused by the p. Tyr366Cys GFAP variant, with rapid and widespread white matter cavitation. This case broadens the radiological spectrum of Alexander disease and suggests a possible genotype-phenotype correlation between the p. Tyr366Cys variant and cavitation.

Medical Treatment for Hepatocellular Carcinoma in Japan.

Liver cancer, including hepatocellular carcinoma (HCC), is the fifth most common cause of cancer deaths in Japan. The main treatment options for HCC are surgical resection, liver transplantation, radiofrequency ablation (RFA), transarterial chemoembolization (TACE), and systemic chemotherapy. Here, recent medical treatments for HCC, including surgery, percutaneous ablation, transcatheter arterial chemoembolization/transcatheter arterial embolization, and drug therapy, are reviewed with a focus on Japan.

Management of Simple Hepatic Cyst.

Simple hepatic cysts are typically saccular, thin-walled masses with fluid-filled epithelial lined cavities. They arise from aberrant bile duct cells that develop during embryonic development. With the development of diagnostic modalities such as ultrasonography (US), CT, and MRI, simple hepatic cysts are frequently detected in clinical examinations. US is the most useful and noninvasive tool for diagnosis of simple hepatic cysts and can usually differentiate simple hepatic cysts from abscesses, hemangiomas, and malignancies. Cysts with irregular walls, septations, calcifications, or daughter cysts on US should be evaluated with enhanced CT or MRI, to differentiate simple hepatic cysts from cystic neoplasms or hydatid cysts. Growth and compression of hepatic cysts cause abdominal discomfort, pain, distension, and dietary symptoms such as nausea, vomiting, a feeling of fullness, and early satiety. Complications of simple hepatic cysts include infection, spontaneous hemorrhage, rupture, and external compression of biliary tree or major vessels. Asymptomatic simple hepatic cysts do not require treatment. Treatment for symptomatic simple hepatic cysts includes percutaneous aspiration, aspiration followed by sclerotherapy, and surgery. The American College of Gastroenterology clinical guidelines recommend laparoscopic fenestration because of its high success rate and low invasiveness. Percutaneous procedures for treatment of simple hepatic cysts are particularly effective for immediate palliation of patient symptoms; however, they are not generally recommended because of the high rate of recurrence. Management of simple hepatic cysts requires correct differentiation from neoplasms and infections, and selection of a reliable treatment.

Short-term Outcomes of Liver Resection in Patients With Hemodialysis.

BACKGROUND: The number of patients with hemodialysis is increasing increased yearly. Few reports are available on hepatobiliary and gastrointestinal surgery in these patients. PATIENTS AND METHODS: A total of 222 patients who underwent partial liver resection or segmentectomy in our hospital between January 2015 and September 2019 were included in this study. Patients were divided into the hemodialysis group (n=9) and non-hemodialysis group (n=213). RESULTS: No significant difference was observed in postoperative complications between the hemodialysis and non-hemodialysis group. The hemodialysis group had a significantly higher infectious complication rates than the non-hemodialysis group (33.3% vs. 8.0%, p=0.009). In logistic regression analysis, hemodialysis was only a significant risk factor for postoperative infectious complications (OR=5.61, 95% CI=1.12-28.20, p=0.036). CONCLUSION: Liver resections, at least segmentectomy or smaller, is acceptable in patients on hemodialysis. However, these patients may have a higher risk of postoperative infectious complications than other patients.

Physiological pseudo-thickened cauda equina associated with dural sac dilatation on magnetic resonance imaging.

OBJECTIVES: In daily clinical practice, the assessment of the thickness of the cauda equina on lumbar spine magnetic resonance imaging is an important parameter. However, its relevance to the size of the dural sac in non-pathological conditions is unknown. To examine the relationship between the size of the dural sac and the apparent thickness of the cauda equina nerve root using lumbar spine magnetic resonance imaging in non-pathological conditions. METHODS: We retrospectively measured the dural sac diameter and vertebral body diameter, counted the apparent number, and calculated total cross-sectional area of the cauda equina, dural sac ratio and the area of one apparent nerve root of cauda equina in 100 cases. Spearman's rank correlation coefficient (ρ) was used. RESULTS: Dural sac ratio and diameter were positively correlated with the area of one apparent nerve root (ρ=0.77, P<0.001; ρ=0.74, P<0.001; respectively) and negatively correlated with the apparent number of cauda equina in a single cross-section (ρ=-0.63, P<0.001; ρ=-0.52, P<0.001; respectively). CONCLUSIONS: A larger dural sac ratio and diameter was associated with an apparently thicker cauda equina and lower visible number. In a larger dural sac, the physiologically clumped and apparently thicker cauda equina should not be misdiagnosed as pathological.

Management of portal hypertension based on portal hemodynamics.

Portal hypertension is most commonly caused by chronic liver disease. As liver damage progresses, portal pressure gradually elevates and hemodynamics of the portal system gradually change. In normal liver, venous returns from visceral organs join the portal trunk and flow into the liver (hepatopetal blood flow). As portal pressure increases due to liver damage, congestion of some veins of the visceral organ occurs (blood flow to and from). Finally, the direction of some veins (the left gastric vein in particular) of the visceral organ change (hepatofugal blood flow) and develop as collateral veins (portosystemic shunt) to reduce portal pressure. Therefore, esophagogastric varices serve as drainage veins for the portal venous system to reduce the portal pressure. In chronic liver disease, as intrahepatic vascular resistance is increased (backward flow theory) and collateral veins develop, adequate portal hypertension is required to maintain portal flow into the liver through an increase of blood flow into the portal venous system (forward flow theory). Splanchnic and systemic arterial vasodilatations increase the blood flow into the portal venous system (hyperdynamic state) and lead to portal hypertension and collateral formation. Hyperdynamic state, especially around the spleen, is detected in patients with portal hypertension. The spleen is a regulatory organ that maintains portal flow into the liver. In this review, surgical treatment, interventional radiology, endoscopic treatment, and pharmacotherapy for portal hypertension (esophagogastric varices in particular) are described based on the portal hemodynamics using schema.

Three cases of follicular pancreatitis: association between radiological findings and pathological features.

Follicular pancreatitis (FP) is characterized by nodular mass composed of lymphoid hyperplasia and fibrosis. We here present radiological and pathological features of three cases of FP. The three patients were middle- or old-aged men, and nodular mass was pointed out at health examination. Computed tomography failed to demonstrate a mass. Magnetic resonance imaging demonstrated a mass in each case. 18F-fluorodeoxyglucose positron-emission tomography (FDG-PET) demonstrated two nodular masses with high standardized uptake value (SUV) in two cases and single mass in one case. The pathological examination disclosed two lesions with fibrosis and hyperplastic lymphoid follicles in two cases and one lesion in one case. Masses with high SUV appeared to correspond with the lesions of FP. Compared with the features of FDG-PET images of pancreatic ductal carcinoma, multiple lesions with high SUV favor a diagnosis of FP rather than pancreatic cancer. FDG-PET is useful for the diagnosis of FP.