Preoperative rapid growth of inferior vena cava tumor thrombus in renal cell carcinoma.

Introduction: We present the case of a rapidly growing inferior vena cava tumor thrombus in renal cell carcinoma. Case presentation: We present a case of a 66-year-old woman with right renal cell carcinoma with a tumor thrombus extending 2 cm into the inferior vena cava on an initial Imaging. Radical surgery was performed 6 weeks after the first visit. Intraoperatively, the tumor thrombus was confirmed to have grown near the diaphragm. The tumor was resected using an inferior vena cava clamping just below the diaphragm. The tumor thrombus and renal cell carcinoma were completely removed. There was no recurrence 6 months postoperatively. Conclusion: Inferior vena cava tumor thrombus in renal cell carcinoma can grow in a short period, suggesting that preoperative imaging evaluation at the appropriate time is important. Once inferior vena cava tumor thrombus of renal cell carcinoma occurs, surgery should not be delayed unless there is an urgent reason.

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.

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.

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.

Effects of half-body and foot baths on peripheral circulation in healthy adult males: a pilot study.

[Purpose] This study aimed to clarify the optimal conditions of warm-water bathing required to improve peripheral circulation. [Participants and Methods] Ten healthy males experienced three warm-water bathing depths (half-body, low-leg, and foot) on different days. Peripheral circulation (earlobe blood flow), tympanic temperature, pulse rate, and blood pressure were measured during each session and compared among the bathing conditions. [Results] In half-body bathing, the relative blood flow of participants increased steeply to a level 2.7-fold higher than the baseline during bathing and rapidly decreased after that. Conversely, the relative blood flow gradually and continuously increased to a level 1.7-fold higher than that at the baseline during low-leg bathing and maintained a similar level after that. The blood flow did not markedly change throughout the experiment in foot bathing. The pulse rate during foot bathing and that during low-leg bathing did not change throughout the observation period, but that of half-body bathing increased considerably. [Conclusion] Rapid changes in pulse rate or blood pressure associated with bathing are considered risky. We suggest that low-leg bathing, rather than the usually adopted half-body bathing, is appropriate for improving peripheral circulation in terms of effectiveness and safety.

Estimating colorectal polyp size with a virtual scale endoscope and visual estimation during colonoscopy: Prospective, preliminary comparison of accuracy.

The virtual scale endoscope (VSE) is a new endoscope that helps estimate the size of neoplasms in the gastrointestinal tract. We compared the accuracy of polyp size estimation by VSE with that of visual estimation. A dual center prospective study was conducted in two Japanese academic endoscopy units. Ten endoscopists (five trainees and five experts) estimated the size of 20 simulated polyps in four colon phantoms during colonoscopy by two methods: conventional visual estimation and estimation by VSE. The primary endpoint was the relative accuracy in relation to true polyp size according to visual estimation and VSE estimation during colonoscopy. The secondary endpoint was the required time (the time needed to measure in each procedure). The mean values of the primary end-point were 62.5% for visual estimation and 84.0% for VSE estimation; hence the result differed significantly (95% confidence interval 18.3-24.7; P < 0.001). The mean of required times was significantly longer for estimation by VSE (6.4 min) than that by visual estimation (2.9 min; P < 0.001). The accuracy of colorectal polyp size estimation was superior with VSE than with visual estimation during colonoscopy. In the future, VSE should be evaluated in actual clinical settings, including the time required for size estimation.

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.

Revealing scenarios of interzeolite conversion from FAU to AEI through the variation of starting materials.

Interzeolite conversion, which refers to the synthesis of zeolites using a pre-made zeolite as the starting material, has enabled promising outcomes that could not be easily achieved by the conventional synthesis from a mixture of amorphous aluminum and silicon sources. Understanding the mechanism of interzeolite conversion is of particular interest to exploit this synthesis route for the preparation of tailor-made zeolites as well as the discovery of new structures. It has been assumed that the structural similarity between the starting zeolite and the target one is crucial to a successful interzeolite conversion. Nevertheless, an image as to how one type of zeolite evolves into another one remains unclear. In this work, a series of dealuminated FAU zeolites were created through acid leaching and employed as the starting zeolites in the synthesis of AEI zeolite under various conditions. This experimental design allowed us to create a comprehensive diagram of the interzeolite conversion from FAU to AEI as well as to figure out the key factors that enable this kinetically favourable crystallization pathway. Our results revealed different scenarios of the interzeolite conversion from FAU to AEI and pinpointed the importance of the structure of the starting FAU in determining the synthesis outcomes. A prior dealumination was proven effective to modify the structure of the initial FAU zeolite and consequently facilitate its conversion to the AEI zeolite. In addition, this strategy allowed us to directly transfer the knowledge obtained from the interzeolite conversion to a successful synthesis of the AEI zeolite from dealuminated amorphous aluminosilicate precursors. These results offer new insights to the design and fabrication of zeolites via the interzeolite conversion as well as to the understandings of the crystallization mechanisms.

Virtual scale function of gastrointestinal endoscopy for accurate polyp size estimation in real-time: a preliminary study.

SIGNIFICANCE: Polyp size is important for selecting the surveillance interval or treatment policy. Nevertheless, it is challenging to accurately estimate the polyp size during endoscopy. An easy and cost-effective function to assist in polyp size estimation is required. AIM: To propose a virtual scale function for endoscopy and evaluate its performance and expected accuracy. APPROACH: An adaptive virtual scale behavior was demonstrated. The measurement error of the virtual scale along the distance between the tip of the endoscope and the object plane was evaluated using graph paper. The accuracy of polyp size estimation by an expert endoscopist was compared with the accuracy of the biopsy forceps method using phantom images. RESULTS: The measurement errors of the virtual scale were ≤ 0.7 mm when the distance to the graph paper, which faced the tip of the endoscope, varied from 4 to 30 mm. The accuracy with the virtual scale was significantly higher than that obtained with biopsy forceps (5.3 ± 5.5 % versus 11.9 ± 9.4 % , P < 0.001). CONCLUSIONS: The virtual scale function, which operates in real-time without any additional device, can be used to estimate polyp sizes easily and accurately with endoscopy.

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.

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.

Tracking the crystallization behavior of high-silica FAU during AEI-type zeolite synthesis using acid treated FAU-type zeolite.

During AEI zeolite synthesis using acid treated FAU (AcT-FAU), we found the recrystallization of high-silica FAU with high crystallinity and Si/Al ratio of 6.1 using N,N-dimethyl-3,5-dimethylpiperidinium hydroxide (DMDMPOH) after 2 h, followed by the crystallization of AEI via FAU-to-AEI interzeolite conversion at a longer synthesis time. In order to understand the formation mechanism of high-silica FAU and generalize its direct synthesis, we have investigated this synthesis process. An analysis of the short-range structure of AcT-FAU revealed that it has an ordered aluminosilicate structure having a large fraction of 4-rings despite its low crystallinity. The changes in the composition of the products obtained at different synthesis times suggested that DMDMP+ plays a certain role in the stabilization of the FAU zeolite framework. Moreover, the results of thermogravimetric analysis showed that the thermal stability of DMDMP+ changed with the zeolite conversion. To the best of our knowledge, this is the first study to clarify the structure-directing effect of DMDMP+ on FAU zeolite formation.

Complete mitochondrial DNA sequence of the parasitic honey bee mite Varroa destructor (Mesostigmata: Varroidae).

Varroa destructor is a parasite mite of the eastern honey bee Apis cerana, which is native to Asia. The European honey bee Apis mellifera was imported to Asia from Europe and the USA for apiculture in the 19th century. In a short period of time, V. destructor parasitized the artificially introduced honey bees. Varroa destructor was estimated to have spread around the world with A. mellifera when it was exported from Asia to locations worldwide about 50 years ago. The mitochondrial DNA of the parasitic honey bee mite V. destructor was analyzed using next-generation sequencing. The complete mitochondrial genome of V. destructor was identified as a 16,476-bp circular molecule containing 13 protein-coding genes (PCGs), 22 tRNA genes, two rRNA genes, and one AT-rich control region. The heavy strand was predicted to have nine PCGs and 13 tRNA genes, whereas the light strand was predicted to contain four PCGs, nine tRNA genes, and two rRNA genes. All PCGs began with ATA as the start codon, except COIII and CytB, which had ATG as the start codon. Stop codons were of two types: TAA for eight genes and TAG for five genes. Molecular phylogenetic analysis revealed that V. destructor from Japan was genetically distant from that of France. A high base substitution rate of 2.82% was also confirmed between the complete mitochondrial DNA sequences of V. destructor from Japan and the USA, suggesting that one Varroa mite strain found in the USA is not from Japan.

Reg3α and Reg3ß Expressions Followed by JAK2/STAT3 Activation Play a Pivotal Role in the Acceleration of Liver Hypertrophy in a Rat ALPPS Model.

To explore the underlying mechanism of rapid liver hypertrophy by liver partition in associating liver partition and portal vein ligation for staged hepatectomy (ALPPS), liver partition at different sites was investigated. Increased inflammatory cytokines owing to the liver partition have been reportedly responsible. If this were true, rapid liver hypertrophy should be achieved regardless of where the liver was split. A male Sprague-Dawley rat model was created, in which a liver split was placed inside the portal vein ligated lobe (PiLL), in addition to the ALPPS and portal vein ligation (PVL) models. Liver regeneration rate, inflammatory cytokine levels, activation status of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) pathway and expressions of regenerating islet-derived (Reg)3α and Reg3ß were investigated. The liver regeneration rate was significantly higher in the ALPPS group than in the PiLL group, whereas inflammatory cytokine levels were nearly equal. Additional volume increase in ALPPS group over PVL and PiLL groups was JAK2/STAT3-dependent. Reg3α and Reg3ß expressions were observed only in the ALPPS group. An increase in inflammatory cytokines was not enough to describe the mechanism of rapid liver hypertrophy in ALPPS. Expressions of Reg3α and Reg3ß could play an important role in conjunction with an activation of the JAK2/STAT3 pathway.