The role of computed tomography for the prediction of esophageal variceal bleeding: Current status and future perspectives.

Esophageal variceal bleeding (EVB) is one of the most common and severe complications related to portal hypertension (PH). Despite marked advances in its management during the last three decades, EVB is still associated with significant morbidity and mortality. The risk of first EVB is related to the severity of both PH and liver disease, and to the size and endoscopic appearance of esophageal varices. Indeed, hepatic venous pressure gradient (HVPG) and esophagogastroduodenoscopy (EGD) are currently recognized as the "gold standard" and the diagnostic reference standard for the prediction of EVB, respectively. However, HVPG is an invasive, expensive, and technically complex procedure, not widely available in clinical practice, whereas EGD is mainly limited by its invasive nature. In this scenario, computed tomography (CT) has been recently proposed as a promising modality for the non-invasive prediction of EVB. Although CT is only a diagnostic modality, thus being not capable of supplanting EGD or HVPG in providing therapeutic and physiological data, it could potentially assist liver disease scores, HVPG, and EGD in a more effective prediction of EVB. However, to date, evidence concerning the role of CT in this setting is still lacking. Our review aimed to summarize and discuss the current evidence concerning the role of CT in predicting the risk of EVB.

Nitric oxide metabolites, nitrative stress, and paraoxonase activity in hepatopulmonary syndrome.

AIM: To investigate possible abnormalities of vasoactive compounds, nitrative stress, and antioxidant activity of paraoxonase (PONa) in human hepatopulmonary syndrome (HPS), we determined endothelin-1 (ET), nitric oxide (NOx) metabolites, PONa alongside crude plasma nitrotyrosine (NT) as surrogate marker of nitrative stress. MATERIAL AND METHODS: Liver cirrhosis (LC) patients with HPS (n = 12) were matched by age, sex, and Child-Pugh score to LC patients without HPS (n = 15) and to healthy controls (CTR) (n = 15); plasma NO2(-) (nitrite) (vascular metabolite), NO3(-) (nitrate) (inflammatory metabolite), and PONa were determined by a colorimetric assay, ET, and NT by immunoassays. RESULTS: HPS patients showed higher level of ET (p = 0.0002), NO2(-) (p = 0.002), NO3(-) (p = 0.0001), NT (p < 0.0001), and lower PONa (p = 0.0004) than CTR; post-hoc analysis revealed greater ET (p < 0.05) and NO3(-) (p < 0.005) in LC patients with HPS than in LC patients without HPS. NT correlated to Child-Pugh score within HPS (p = 0.04) and LC (p = 0.02). CONCLUSION: Our HPS patients are characterized by elevated plasma levels of ET and NOx metabolites and lower PONa. Reduced PONa alongside elevated NO3(-) and NT suggests that defective antioxidation may favor nitrative stress and both may be implicated in the pathogenesis of HPS.