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Endoscopic Doppler Ultrasound for Measurement of Azygos Blood Flow: Validation against Thermodilution and Assessment of Pharmacological Effects of Terlipressin in Portal Hypertension

2001, Vol. 36, No. 3 , Pages 318-325 (doi:10.1080/00365520120159)
PDF (198 KB) PDF Plus (199 KB) ReprintsPermissionsE. F. Hansen, F. Bendtsen, K. Brinch, S. Møller, J. H. Henriksen, U. Becker
Depts. of Medical Gastroenterology and Clinical Physiology and Nuclear Medicine, Hvidovre Hospital, University of Copenhagen, Denmark




Background: Endoscopic ultrasound (EUS) is a new modality allowing real-time flow measurements by means of the Doppler technique. The aim of the study was to evaluate azygos blood flow measurements by endoscopic ultrasound. Methods: Measurements of azygos blood flow by EUS and by the thermodilution technique were compared in 20 patients with portal hypertension. The ability of EUS flowmetry to detect changes in the azygos and portal venous flow after an intravenous dose of 2 mg of terlipressin was evaluated in 13 of the patients in a double-blind, randomized, placebo-controlled, cross-over design. Results: The EUS Doppler and thermodilution measurements correlated significantly (R = 0.81, P < 0.001). The azygos blood flow was found to be 14% higher by the EUS method than by thermodilution. The coefficient of variation of the EUS Doppler measurements of the azygos blood flow was 14.8%. After administration of terlipressin, the azygos blood flow, as measured by EUS Doppler, decreased significantly by 23% from 915 to 704 ml/min (P = 0.014) and the portal venous flow decreased by 28% from 1170 to 789 ml/min (P = 0.03). No effects of placebo were detected. Conclusions: These results show that EUS measurement of the azygos blood flow correlate strongly to the measurements by the thermodilution technique, and EUS is moreover well tolerated by the patients. The method is applicable for monitoring pharmacological effects on the superior porto-systemic collateral circulation and portal venous flow in patients with portal hypertension.




Read More: http://informahealthcare.com/doi/abs/10 ... alCode=gas

Discussion: Azygos vein enlargement is defined as an azygos vein measuring greater than 7 mm diameter on an upright chest radiograph. It can be secondary to a number of different disease states involving two primary categories: a need for collateral circulation and engorgement due to right atrial hypertension. The azygos vein becomes a collateral vessel in the following states: portal hypertension, SVC obstruction/compression below the azygos vein, IVC obstruction/compression, interrupted IVC with azygos continuation, and partial anomalous venous return. Azygos enlargement is seen with right atrial hypertension in right-sided heart failure, constrictive pericarditis, and large pericardial effusion.

The patient in this case had incidental azygos vein enlargement secondary to pulmonary arterial hypertension and right-sided heart failure.

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Canadians may be screwed at the moment (and for the last two years) but with the federal trials beginning, it is not going to last forever.

Researchers of controversial MS theory facing series of hurdles
CARLY WEEKS
From Tuesday's Globe and Mail
Published Monday, Jul. 18, 2011 7:26PM EDT
Last updated Monday, Jul. 18, 2011 8:10PM EDT

North American researchers investigating the controversial Zamboni theory of multiple sclerosis are running into a host of problems with their trials that threaten to delay meaningful results.

The problems, documented in a new progress report, call into question the timing of Ottawa’s decision last month to announce support for formal clinical trials of the vein-widening treatment in Canada.

Problems with the trials include difficulty recruiting study participants, challenges figuring out how to properly identify and diagnose venous problems and trouble obtaining ethics approval to conduct research.

'If you think we're wax-works,' he said, 'you ought to pay, you know. Wax-works weren't made to be looked at for nothing. Nohow.'

'Contrariwise,' added the one marked "DEE", 'if you think we're alive, you ought to speak.'

'I'm sure I'm very sorry,' was all Aglukkaq could say; for the words of the old song kept ringing through her head like the ticking of a clock, and she could hardly help saying them out loud:

Tweedledum the Neurologist and Tweedledee the Phlebologist
Agreed to have a battle!
For Tweedledum said Tweedledee
Had spoiled his nice old rattle.

Just then flew down a monstrous crowd of sick people,
As black as a tar-barrel!
Which frightened both the heroes so,
They quite forgot their quarrel.'

'I know what you're thinking about,' said Tweedledum; 'but it isn't so, nohow.'

'Contrariwise,' continued Tweedledee, 'if it was so, it might be; and if it were so, it would be; but as it isn't, it ain't. That's logic.'

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'But it certainly was funny,' (Aglukkaq said afterwards, when she was telling her sister the history of all this), 'to find myself singing "Here we go round the mulberry bush." I don't know when I began it, but somehow I felt as if I'd been singing it a long long time!'