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Ultrasonographic measurement of intima-media thickness of radial artery in pre-dialysis uraemic patients: comparison with histological examination.

BACKGROUND
Increased intima-media thickness (IMT) of the radial artery is associated with early failure of radiocephalic arteriovenous fistula (AVF) in haemodialysis patients. Therefore, non-invasive measurements of radial artery IMT before AVF operations are very important in predicting AVF patency. This study was designed to evaluate the accuracy of high-resolution ultrasonography in measuring radial artery IMT in pre-dialysis uraemic patients.


METHODS
This study enrolled 43 pre-dialysis uraemic patients awaiting radiocephalic AVF operations for the first time. In this study, 17 age- and sex-matched uncomplicated hypertensive patients and 15 healthy subjects were included as a control. We measured the internal diameter (ID) and IMT of the radial artery using high-resolution ultrasonography on the wrists of uraemic patients as well as the control group before the AVF operation. We obtained specimens of the radial artery during the AVF operation and directly measured the IMT by histological examination.


RESULTS
The radial artery IMT of the uraemic patients (0.41 +/- 0.09 mm) was significantly thicker, compared to both those of the hypertensive (0.33 +/- 0.05 mm, P < 0.001) and the healthy patients (0.25 +/- 0.04 mm, P = 0.002). In contrast, the radial artery ID in the uraemic patients (1.85 +/- 0.48 mm) was smaller than both that of the hypertensive patients (2.08 +/- 0.31 mm, P = 0.023) and the healthy persons (2.34 +/- 0.37 mm, P = 0.001). Radial artery IMT had a negative correlation with radial artery ID in a total of 73 subjects (r = -0.290, P = 0.012). The value of the radial arterial IMT measured by sonographic examination correlated significantly with that by histological examination in 43 uraemic patients (r = 0.786, P < 0.001) and it correlated significantly with early AVF failure (r = 0.358, P = 0.027).


CONCLUSION
Our data suggest that high-resolution ultrasonography is an effective tool in measuring radial artery IMT in uraemic patients before AVF operation.