Hereditary hemorrhagic telangiectasia involving portal venous system: A case report and review of the literature

BACKGROUND

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant genetic disorder with an incidence of approximately 1 in 5000 in the general population. It is characterized by vasodilation, which affects specific organs, such as the skin, mucous membranes, brain, lungs, gastrointestinal tract, liver, and others. However, HHT rarely involves the portal venous system to cause serious clinical complications.

CASE SUMMARY

A 68-year-old woman was admitted to the emergency department due to four consecutive days of abdominal pain and bloody stool and was subsequently diagnosed with HHT. Computed tomography angiography confirmed the presence of an arteriovenous fistula (AVFs). Considering this specific manifestation, whole exome sequencing was performed. After a comprehensive evaluation, a selective superior mesenteric artery embolization was prioritized to avoid intestinal ischemia. The postoperative symptoms of the patient were quickly relieved. Unfortunately, two months post-procedure the patient died from intestinal necrosis and abdominal infection related to remaining AVFs.

CONCLUSION

For patients with diffuse superior mesenteric AVFs, selective mesenteric arterial embolization may lead to positive short-term outcomes.

Incidence of Extrahepatic Portal Vein Anatomic Variations and Their Clinical Implications in Daily Practice

Anatomical variations of the portal vein are relatively common and can affect the outcomes of hepatic resections, transplantations and interventional radiological procedures. The aim of this study was to review the literature regarding extrahepatic portal vein anomalies. Two main databases were searched for suitable articles, and results concerning more than 3,700 patients were included in the analysis. The most common anatomical variations of the portal vein were trifurcation and having a right posterior portal vein as the first branch of the main portal vein; these anomalies were found in 11.7% and 10.8% of cases, respectively.

History of hypothalamic research: "The spring of primitive existence"

The central brain region of interest for neuroendocrinology is the hypothalamus, a name coined by Wilhelm His in 1893. Neuroendocrinology is the discipline that studies hormone production by neurons, the sensitivity of neurons for hormones, as well as the dynamic, bidirectional interactions between neurons and endocrine glands. These interactions do not only occur through hormones, but are also partly accomplished by the autonomic nervous system that is regulated by the hypothalamus and that innervates the endocrine glands. A special characteristic of the hypothalamus is that it contains neuroendocrine neurons projecting either to the neurohypophysis or to the portal vessels of the anterior lobe of the pituitary in the median eminence, where they release their neuropeptides or other neuroactive compounds into the bloodstream, which subsequently act as neurohormones. In the 1970s it was found that vasopressin and oxytocin not only are released as hormones in the circulation but that their neurons project to other neurons within and outside the hypothalamus and function as neurotransmitters or neuromodulators that regulate central functions, including the autonomic innervation of all our body organs. Recently magnocellular oxytocin neurons were shown to send not only an axon to the neurohypophysis, but also axon collaterals of the same neuroendocrine neuron to a multitude of brain areas. In this way, the hypothalamus acts as a central integrator for endocrine, autonomic, and higher brain functions. The history of neuroendocrinology is described in this chapter from the descriptions in De humani corporis fabrica by Vesalius (1537) to the present, with a timeline of the scientists and their findings.

Can we differentiate HIV-associated obliterative portopathy from liver cirrhosis using MRI?

AIM

To describe the magnetic resonance imaging (MRI) features of HIV-associated obliterative portopathy (HIV-OP) and determine the most indicative appearance of this condition on MRI by using a retrospective case-control study.

METHODS

MRI examinations of 24 patients with HIV-OP (16 men, 8 women; mean age = 48 ± 6.6 [SD] years; age range, 35-71 years) were analyzed by two blinded observers and compared with those obtained in 18 HIV-infected patients with hepatic cirrhosis (14 men, 4 women; mean age = 51 ± 3.4 [SD] years; age range, 35-60 years). Images were qualitatively and quantitatively analyzed with respect to imaging presentation. Comparisons were performed using uni- and multivariate analyses.

RESULTS

Regular liver contours had the highest accuracy for the diagnosis of HIV-OP (83%, 35 of 42; 95% confidence interval [CI], 69-93%) and was the most discriminating independent variable for the diagnosis of HIV-OP (odds ratio, 51; 95%CI, 4.96-1272%) (p < 0.0001). At multivariate analysis, the width of segment 4 in millimeters (OR = 1.23 [95%CI, 1.05-1.44%]; p = 0.011) and the presence of regular liver contours (OR = 7.69 [95%CI, 1.48-39.92%]; p = 0.015) were the variables independently associated with the diagnosis of HIV-OP.

CONCLUSIONS

Regular liver contours are the most discriminating independent variable for the diagnosis of HIV-OP but have limited accuracy. Familiarity with this finding may help differentiate HIV-OP from cirrhosis in HIV-infected patients.

KEY POINTS

• Regular liver contour is the most discriminating independent variable for the diagnosis of HIV-OP (odds ratio = 51) with 83% accuracy. • At multivariate analysis, the width of segment 4 in millimeters and the presence of regular liver contours are the variables independently associated with the diagnosis of HIV-OP. • MRI helps diagnose HIV-OP in the presence of several categorical findings, which are more frequently observed in HIV-OP patients than in HIV patients with cirrhosis.

A hypothesis on paradoxical privileged portal vein metastasis of hepatocellular carcinoma. Can organ evolution shed light on patterns of human pathology, and vice versa?

Unlike other carcinomas, hepatocellular carcinoma (HCC) metastasizes to distant organs relatively rarely. In contrast, it routinely metastasizes to liver vasculature/liver, affecting portal veins 3-10 times more often than hepatic veins. This portal metastatic predominance is traditionally rationalized within the model of a reverse portal flow, due to accompanying liver cirrhosis. However, this intuitive model is not coherent with facts: 1) reverse portal flow occurs in fewer than 10% of cirrhotic patients, while portal metastasis occurs in 30-100% of HCC cases, and 2) portal vein prevalence of HCC metastasis is also characteristic of HCC in non-cirrhotic livers. Therefore, we must assume that the route for HCC metastatic dissemination is the same as for other carcinomas: systemic dissemination via the draining vessel, i.e., via the hepatic vein. In this light, portal prevalence versus hepatic vein of HCC metastasis appears as a puzzling pattern, particularly in cases when portal HCC metastases have appeared as the sole manifestation of HCC. Considering that other GI carcinomas (colorectal, pancreatic, gastric and small bowel) invariably disseminate via portal vein, but very rarely form portal metastasis, portal prevalence of HCC metastasis appears as a paradox. However, nature does not contradict itself; it is rather our wrong assumptions that create paradoxes. The 'portal paradox' becomes a logical event within the hypothesis that the formation of the unique portal venous system preceded the appearance of liver in evolution of chordates. The analysis suggests that the appearance of the portal venous system, supplying hormones and growth factors of pancreatic family, which includes insulin, glucagon, somatostatin, and pancreatic polypeptide (HGFPF) to midgut diverticulum in the early evolution of chordates (in an Amphioxus-like ancestral animal), promoted differentiation of enterocytes into hepatocytes and their further evolution to the liver of vertebrates. These promotional-dependent interactions are conserved in the vertebrate lineage. I hypothesize that selective homing and proliferation of malignant hepatocytes (i.e., HCC cells) in the portal vein environment are due to a uniquely high concentration of HGFPF in portal blood. HGFPF are also necessary for liver function and renewal and are significantly extracted by hepatocytes from passing blood, creating a concentration gradient of HGFPF between the portal blood and hepatic vein outflow, making post-liver vasculature and remote organs less favorable spaces for HCC growth. It also suggested that the portal vein environment (i.e., HGFPF) promotes the differentiation of more aggressive HCC clones from already-seeded portal metastases, explaining the worse outcome of HCC with the portal metastatic pattern. The analysis also offers new hypothesis on the phylogenetic origin of the hepatic diverticulum of cephalochordates, with certain implications for the modeling of the chordate phylogeny.

All about portal vein: a pictorial display to anatomy, variants and physiopathology

The portal vein (PV) is the main vessel of the portal venous system (PVS), which drains the blood from the gastrointestinal tract, gallbladder, pancreas, and spleen to the liver. There are several variants affecting the PV, and quite a number of congenital and acquired pathologies.

In this pictorial review, we assess the embryological development and normal anatomy of the PVS, displaying selected cases consisting of normal variants, congenital anomalies, and a large and heterogeneous group of acquired conditions that may affect the PV.

Hepatic portal venous gas after colonoscopy: A case report and review

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Here we reported a rare case of hepatic portal venous gas with a relevant review of literature.

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Actually the mechanism of HPVG is still unknown.

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The case present in literature are few and the mortality, generally caused by complications like necrotizing enterocolitis, is still high.

Introduction

Hepatic portal venous gas (HPVG) is a rare radiological finding in which gas enters the portal venous system and it is associated in case of necrotizing colitis with a mortality of 75%. We report a case of iatrogenic HPVG with a review of literature.

Presentation of case

A 41 years old patient underwent total colectomy and ileal pouch- anal anastomosis with derivative ileostomy for a familiar adenomatous polyposis coli in June 2008. A stenosis of the pouch-anal anastomosis developed. The patient underwent several endoscopic dilations. A recurrence of the stenosis was observed. The patient underwent to several endoscopic procedure. After the last colonoscopy the patient showed a fever with abdominal pain. A CT scan showed little peri-anastomotic collections and massive hepatic portal venous gas.

Discussion

The management of HPVG varied from surgical intervention to non-operative procedure. The surgical approach it's reserved to clinically unstable patients or those with evidence of peritonitis or bowel perforation. Stable patients, like those with an HPVG consequence of an endoscopic procedure, can be treated with non- operative management.

Conclusion

Our experience confirm that hepatic portal venous gas can be related to endoscopic procedure; thus, it can be managed on the basis of patient's general clinical conditions, and in selected cases it will disappear without therapeutic interventions with a good outcome.

The concept of portal system obstruction in Avicenna's canon of medicine

Historical literature on portal hypertension is mainly focused on the contemporary advances in therapeutic methods, especially surgical ones. However, it seems that the origin of the human knowledge on the portal system, its association with the caval system, obstructive pathologies in this system and the gastrointestinal bleeding due to hepatic diseases might be much older than previously believed. Avicenna provided a detailed anatomy of the portal venous system and its feeding branches in the Canon of Medicine. Soddat al-Kabed va al-Masarigha (liver and mesenteric occlusion) is also a disease presented by Avicenna with clinical, etiological and therapeutic descriptions suggesting the fact that Soddat al-Kabed va al-Masarigha has multiple similarities with the currently identified concept of "portal hypertension". He presented sense of heaviness in the liver area with or without mild pain, anemia, pale and inappropriate body color, and loose stool which can be complicated with ascites, infection, fever and abdominal pain as clinical manifestations of this disease. He has also suggested therapeutic approaches including laxative and diuretic herbs to help excreting the obstructive material into stool or urine.

The Bacteriophage Head-to-Tail Interface

Many icosahedral viruses use a specialized portal vertex for genome encapsidation in the viral capsid (or head). This structure then controls release of the viral genetic information to the host cell at the beginning of infection. In tailed bacteriophages, the portal system is connected to a tail device that delivers their genome to the bacterial cytoplasm. The head-to-tail interface is a multiprotein complex that locks the viral DNA inside the phage capsid correctly positioned for egress and that controls its ejection when the viral particle interacts with the host cell receptor. Here we review the molecular mechanisms how this interface is assembled and how it carries out those two critical steps in the life cycle of tailed phages.

Evaluation of the rabbit liver by direct portography and contrast-enhanced computed tomography: anatomical variations of the portal system and hepatic volume quantification

Background

The study was aimed at: (1) describing the incidence of anatomic variations of the portal system in the rabbit using direct portography; and (2) estimating the liver volume and caudate lobe volume by using contrast-enhanced computed tomography (CECT) in the same animal model.

Methods

Forty-six New Zealand white rabbits were included. All of them underwent direct portography and unenhanced CECT. Conventional liver rabbit portal system anatomy (type 1) consisted of the bifurcation of the main portal vein (MPV) into the right portal vein (RPV) and left portal vein (LPV), which subsequently divided into medial left portal vein and lateral left portal vein. Trifurcation of the LPV was considered type 2. The LPV that divides into four smaller branches was classified as type 3. Other configurations of the portal system, including particular cases of MPV branching, were grouped as type 4. Liver lobes were manually segmented.

Results

The incidence of each type of portal system anatomy was: type 1, 67.4%; type 2, 15.2%; type 3, 13.0%); and type 4, 4.3%. The mean volume of the caudate lobe was 19.1 ml ± 5.7 ml and of the cranial lobes it was 66.7 ml ± 13.7 ml, and the total liver volume was 85.7 ml ± 16.7 ml.

Conclusions

In New Zealand white rabbits, type 1 is the prevalent type of portal system, liver volume is about 86 ml, and the caudate and cranial lobes are separated. This information could be important when planning experimental rabbit liver procedures.

Developmental anatomy of the liver from computerized three-dimensional reconstructions of four human embryos (from Carnegie stage 14 to 23)

BACKGROUND & AIM

Some aspects of human embryogenesis and organogenesis remain unclear, especially concerning the development of the liver and its vasculature. The purpose of this study was to investigate, from a descriptive standpoint, the evolutionary morphogenesis of the human liver and its vasculature by computerized three-dimensional reconstructions of human embryos.

MATERIAL & METHODS

Serial histological sections of four human embryos at successive stages of development belonging to three prestigious French historical collections were digitized and reconstructed in 3D using software commonly used in medical radiology. Manual segmentation of the hepatic anatomical regions of interest was performed section by section.

RESULTS

In this study, human liver organogenesis was examined at Carnegie stages 14, 18, 21 and 23. Using a descriptive and an analytical method, we showed that these stages correspond to the implementation of the large hepatic vascular patterns (the portal system, the hepatic artery and the hepatic venous system) and the biliary system.

CONCLUSION

To our knowledge, our work is the first descriptive morphological study using 3D computerized reconstructions from serial histological sections of the embryonic development of the human liver between Carnegie stages 14 and 23.

CT/99mTc-GSA SPECT fusion images demonstrate functional differences between the liver lobes

AIM: To evaluate the functional differences between the 2 liver lobes in non-cirrhotic patients by using computed tomography/^99mTc-galactosyl human serum albumin (CT/^99mTc-GSA) single-photon emission computed tomography (SPECT) fusion images.

METHODS: Between December 2008 and March 2012, 264 non-cirrhotic patients underwent preoperative liver function assessment using CT/^99mTc-GSA SPECT fusion images. Of these, 30 patients, in whom the influence of a tumor on the liver parenchyma was estimated to be negligible, were selected. Specifically, the selected patients were required to meet either of the following criteria: (1) the presence of an extrahepatic tumor; or (2) presence of a single small intrahepatic tumor. These 30 patients were retrospectively analyzed to calculate the percentage volume (%Volume) and the percentage function (%Function) of each lobe. The ratio between the %Function and %Volume (function-to-volume ratio) of each lobe was also calculated, and the ratios were compared between the 2 lobes. Furthermore, the correlations between the function-to-volume ratio and each of 2 liver parameters [lobe volume and diameter ratio of the left portal vein to the right portal vein (LPV-to-RPV diameter ratio)] were investigated.

RESULTS: The median values of %Volume and %Function were 62.6% and 67.1% in the right lobe, with %Function being significantly higher than %Volume (P < 0.01). The median values of %Volume and %Function were 31.0% and 28.7% in the left lobe, with %Function being significantly lower than %Volume (P < 0.01). The function-to-volume ratios of the right lobe (1.04-1.14) were significantly higher than those of the left lobe (0.74-0.99) (P < 0.01). The function-to-volume ratio showed no significant correlation between the lobe volume in either lobe. In contrast, the function-to-volume ratio showed significant correlations with the LPV-to-RPV diameter ratio in both lobes (right lobe: negative correlation, r_s = -0.37, P = 0.048; left lobe: positive correlation, r_s = 0.71, P < 0.001). The function-to-volume ratio in the left lobe tended to be higher, and that in the right lobe tended to be lower, in accordance with the increase in the LPV-to-RPV diameter ratio.

CONCLUSION: CT/^99mTc-GSA SPECT fusion images demonstrated that the function of the left lobe was significantly decreased compared with that of the right lobe in non-cirrhotic livers.

Endotoxin receptor CD14 gene variants and histological features in chronic HCV infection

AIM: To analyze the correlation between CD14 rs2569190/C-159T single nucleotide polymorphism (SNP) and disease progression in chronic hepatitis C.

METHODS: Liver biopsy specimens from a total of 137 and 349 patients with chronic hepatitis C were separately evaluated with respect to necroinflammatory activity (grading) and architectural changes (staging). In one group, further histological lesions characteristic for hepatitis C, hepatitis C virus subtypes, and biochemical parameters of liver disease were also investigated. Samples of genomic DNA were genotyped for the respective SNP by 5’-nuclease assays using fluorescent dye-labeled allele-specific probes.

RESULTS: Genotype distribution did not deviate from the Hardy-Weinberg equilibrium. In the first group, patients homozygous for the variant allele T were found to be younger than C allele carriers (39.6 ± 12.5 vs 45.7 ± 11.5, P = 0.008). Among the histological lesions studied, portal lymphoid aggregates were more frequently observed among TT homozygotes than among C carriers (21/37 vs 32/100, P = 0.008). The presence of portal lymphoid aggregates was closely correlated with hepatic inflammation (P = 0.003) and with bile duct damage (P < 0.001). The degree of fibrosis, in contrast, was not found to be related to the CD14 gene C-159T polymorphism.

CONCLUSION: The data suggest a possible relationship between CD14 C-159T polymorphism and the formation of portal lymphoid aggregates, but not liver fibrosis progression in chronic hepatitis C.