Haemodynamical stress in mouse aortic arch with atherosclerotic plaques: Preliminary study of plaque progression.

Atherosclerotic plaques develop at particular sites in the arterial tree, and this regional localisation depends largely on haemodynamic parameters (such as wall shear stress; WSS) as described in the literature. Plaque rupture can result in heart attack or stroke and hence understanding the development and vulnerability of atherosclerotic plaques is critically important. The purpose of this study is to characterise the haemodynamics of blood flow in the mouse aortic arch using numerical modelling. The geometries are digitalised from synchrotron imaging and realistic pulsatile blood flow is considered under rigid wall assumptions. Two cases are considered; arteries with and without plaque. Mice that are fed under fat diet present plaques in the aortic arch whose size is dependent on the number of weeks under the diet. The plaque distribution in the region is however relatively constant through the different samples. This result underlines the influence of the geometry and consequently of the wall shear stresses for plaque formation with plaques growing in region of relative low shear stresses. A discussion of the flow field in real geometry in the presence and absence of plaques is conducted. The presence of plaques was shown to alter the blood flow and hence WSS distribution, with regions of localised high WSS, mainly on the wall of the brachiocephalic artery where luminal narrowing is most pronounced. In addition, arch plaques are shown to induce recirculation in the blood flow, a phenomenon with potential influence on the progression of the plaques. The oscillatory shear index and the relative residence time have been calculated on the geometry with plaques to show the presence of this recirculation in the arch, an approach that may be useful for future studies on plaque progression.

Alcoholic liver disease: a clinical series in an Australian private practice.

BACKGROUND AND AIM: The published literature on alcoholic liver disease (ALD) in Australia lacks a large clinical series out of private practice as distinct from hospital-based hepatology referral units. This series describes the presentation and clinical features of ALD in a consecutive series out of metropolitan private practice in Australia. METHODS: A retrospective descriptive study by case-note review found 297 cases of ALD at a Brisbane practice over 20 years. The main outcome measures were: clinical features and stage at presentation, reasons for referral, and the predictive value of aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio. RESULTS: Most patients (57.9%) had no symptoms of liver disease and 29 patients (9.8%) had neither symptoms nor signs. Cirrhosis was found in 41% of patients and hepatitis-fibrosis was found in 26% of patients. The male to female (M : F) ratio was 4.7:1. The AST/ALT ratio was not reliably predictive of ALD stage. The average reported daily alcohol intake was 131 g. Females drank less on average and presented a more vigorous clinical picture. CONCLUSIONS: This series presents the spectrum of ALD in a metropolitan Australian private practice. Many patients are asymptomatic on presentation. All heavy drinkers should be targeted for early investigation without waiting for volunteered symptoms or abnormal physical signs. The male to female ratio in ALD is higher than hitherto reported. The AST/ALT ratio is not generally applicable in the staging of ALD. The differences from hospital series data suggest the demography and epidemiology of ALD in Australia are incomplete, and further study is warranted.

Elective end-to-side portacaval shunt: results in 64 cases.

In a series of 64 cases of elective end-to-side portacaval shunts performed for liver disease the success rate-in that the patient survived with a patent shunt, free of subsequent haemorrhage and severe encephalopathy-was 48%.The early postoperative death rate was 12.5% and the five-year survival 65%. Bleeding from oesophagogastric varices after blockage of the shunt was responsible for at least half of the early postoperative deaths, and most late deaths were due to liver failure. A decreased chance of late survival was associated with age over 40 years, active chronic hepatitis, and with a preoperative history of hepatocellular jaundice.Shunt blockage occurred in 16% of patients, and all bled again from oesophagogastric varices. Shunt block is more likely if the portal vein is calcified or thrombosed, and may be more likely if the portal vein diameter, as shown by splenic venography, is 1.5 cm or less.In survivors with a patent shunt the most serious late complication was chronic, severe portal-systemic encephalopathy, which occurred in 38%. Severe encephalopathy was associated with age over 40 years, a preoperative history of any degree of encephalopathy, diabetes mellitus, and with continued drinking in the alcoholic. Most patients who had portal-systemic encephalopathy in the first year postoperatively developed chronic disabling encephalopathy.A preoperative history of transient mild or moderate ascites did not seem adversely to influence the outcome.

Radiographic demonstration of gastric variceal bleeding.

A case is reported where emergency percutaneous splenoportography demonstrated an actively bleeding gastric varix. The radiographic appearance is described and the indications for this procedure are discussed.