The vascular diseases including aneurysm, occlusion, and thromboses in the mesenteric lesions could cause severe symptoms and appropriate diagnosis and treatment are essential for managing patients. With the development and improvement of imaging modalities, diagnostic frequency of these vascular diseases in abdominal lesions is increasing even with the small changes in the vasculatures. Among various vascular diseases, fibromuscular dysplasia (FMD) and segmental arterial mediolysis (SAM) are noninflammatory, nonatherosclerotic arterial diseases which need to be diagnosed urgently because these diseases could affect various organs and be lethal if the appropriate management is not provided. However, because FMD and SAM are rare, the cause, prevalence, clinical characteristics including the symptoms, findings in the imaging studies, pathological findings, management, and prognoses have not been systematically summarized. Therefore, there have been neither standard diagnostic criteria nor therapeutic methodologies established, to date. To systematically summarize the information and to compare these disease entities, we have summarized the characteristics of FMD and SAM in the gastroenterological regions by reviewing the cases reported thus far. The information summarized will be helpful for physicians treating these patients in an emergency care unit and for the differential diagnosis of other diseases showing severe abdominal pain.

Fibromuscular dysplasia (FMD) and segmental arterial mediolysis (SAM) are noninflammatory, nonatherosclerotic arterial diseases that cause aneurysm, occlusion, and thromboses. These diseases are rarely seen in mesenteric arterial lesions; however, as they can be lethal if appropriate management is not provided, the accumulation of clinical information from cases is essential. We herein report the cases of a 57-year-old man diagnosed with FMD and a 63-year-old man diagnosed with SAM. We conclude that an early diagnosis with imaging modalities and clinical information followed by the appropriate treatment improves the prognosis of these arterial diseases.

Abstract. Percutaneous transhepatic obliteration (PTO) and percutaneous transhepatic sclerotherapy (PTS) are widely performed as an emergency measure in cases of variceal hemorrhage and intractable hepatic encephalopathy. The PTO/PTS technique is capable of directly blocking the blood supply in cases in which balloon-occluded retrograde transvenous obliteration (B-RTO) is not effective, or in cases with complicated collateral flow. Although PTO/PTS is not currently the first choice due to the invasiveness of transhepatic puncture, this procedure can modify the blood flow in an antegrade manner. The present study examined the changes in hepatic function reserve following PTO/PTS for intractable hepatic encephalopathy and/or gastric varices. In total, the study included 37 patients (mean age, 61.75±12.77 years; age range, 32-88 years; male to female ratio, 23:14) with a variety of gastrorenal shunts, or B-RTO-intractable hepatic encephalopathy and gastric varices without gastrorenal shunts. The patients underwent PTO/PTS by embolizing a microcoil or injection of a sclerosing agent (5% ethanolamine oleate iopamidol). Alterations in hepatic function reserve prior to and following the procedure were compared. The patients were treated for hepatic encephalopathy in 11 patients, gastric varices in 19 patients, and both conditions in 7 patients. The results indicated that the blood ammonia level improved from 135.76±75.23 mg/dl to 88.00±42.16 and 61.81±33.75 mg/dl at 3 and 6 months after therapy, respectively. In addition, the Child-Pugh score improved from 8.48±2.01 prior to therapy to 7.70±1.84 and 7.22±2.01 at 3 and 6 months after the procedure, respectively. Although there was a concern that PTO/PTS may cause complications due to an increase in portal venous pressure (PVP) arising from shunt occlusion, no severe complications were observed. In conclusion, for patients with various gastrorenal shunts or those with B-RTO-intractable hepatic encephalopathy and gastric varices without gastrorenal shunts, PTO/PTS can improve the antegrade blood flow to the liver, as demonstrated by improvement in the hepatic function reserve.

Background The correlation of the growth hormone (GH) and insulin‐like growth factor‐1 (IGF‐1) with non‐alcoholic fatty liver disease (NAFLD) has been reported in epidemiological studies. However, the mechanisms of molecular and inter‐organ systems that render these factors to influence on NAFLD have not been elucidated. In this study, we examined the induction of ghrelin which is the GH‐releasing hormone and IGF‐1, and involvement of autonomic neural circuits, in the pathogenesis of NAFLD. Methods The expression of gastric and hypothalamic ghrelin, neural activation in the brain, and serum IGF‐1 were examined in NAFLD models of choline‐deficient defined l‐amino‐acid diet‐fed, melanocortin 4 receptor knockout mice, and partial hepatectomy mice with or without the blockades of autonomic nerves to test the contribution of neural circuits connecting the brain, liver, and stomach. Key Results The fatty changes in the liver increased the expression of gastric ghrelin through the autonomic pathways which sends the neural signals to the arcuate nucleus in the hypothalamus through the afferent vagal nerve which reached the pituitary gland to release GH and then stimulate the IGF‐1 release from the liver. In addition, high levels of ghrelin expression in the arcuate nucleus were correlated with NAFLD progression regardless of the circuits. Conclusions Our study demonstrated that the fatty liver stimulates the autonomic nervous signal circuits which suppress the progression of the disease by activating the gastric ghrelin expression, the neural signal transduction in the brain, and the release of IGF‐1 from the liver.

The etiology of non-alcoholic fatty liver disease (NAFLD) consists of various factors, including neural signal pathways. However, the molecular mechanisms of the autonomic neural signals influencing NAFLD progression have not been elucidated. Therefore, we examined the involvement of the gut-liver neural axis in NAFLD development and tested the therapeutic effect of modulation of this axis in this study. To test the contribution of the gut-liver neural axis, we examined NAFLD progression with respect to body weight, hepatic steatosis, fibrosis, intestinal tight junction, microbiota and short-chain fatty acids in NAFLD models of choline-deficient defined L-amino-acid and high-fat diet-fed mice with or without blockades of autonomic nerves from the liver. Blockade of the neural signal from the liver to the gut in these NAFLD mice models ameliorated the progression of liver weight, hepatic steatosis and fibrosis by modulating serotonin expression in the small intestine. It was related to the severity of the liver pathology, the tight junction protein expression, microbiota diversity and short-chain fatty acids. These effects were reproduced by administrating serotonin antagonist, which ameliorated the NAFLD progression in the NAFLD mice models. Our study demonstrated that the gut-liver neural axis is involved in the etiologies of NAFLD progression and that serotonin expression through this signaling network is the key factor of this axis. Therefore, modulation of the gut-liver neural axis and serotonin antagonist ameliorates fatty and fibrotic changes in non-alcoholic fatty liver, and can be a potential therapeutic target of NAFLD.This article has an associated First Person interview with the first author of the paper.