Abstract
The accuracy and reliability of a noninvasive pressure- sensitive capsule for the endoscopic measurement of esophageal varix pressure was evaluated. Capsule pressure was correlated with direct intraluminal pressure measurements. The influence o/vessel wall tension on capsule pressure was also assessed. In vitro studies demonstrated an excellent correlation (r ≥ 0.94; p < 0.001) between the pre~sure obtained with the capsule and intraluminal pressure over a range of vessel diameters and wall thicknesses. In vivo correlation of pressures obtained with the capsule with direct venous pressure measurements was excellent (r = 0.85). However, this correlation decreased with a decrease in vessel diameter (group 1 diameter ≥ 10 mm, r = 0.95; group 2 diameter ≥ 5 mm but < 10 mm, r = 0.75; group 3 diameter ≥ 3 mm but < 5 mm, r = 0.81). This decrease in accuracy was significant (p < 0.001) between group 1 and groups 2 and 3. In vitro and in vivo, capsule pressure variability was significantly greater (p < 0.001) in vessels of smaller diameter. Wall tension significantly influenced capsule pressure (p < 0.05), although this effect was only seen in large “vessels” with a diameter beyond a clinically relevant range. Therefore, despite obtaining technically acceptable capsule pressure measurements in ideal experimental conditions, the accuracy and variability of these measurements are limited by vessel size.
Original language | English |
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Pages (from-to) | 1109-1115 |
Number of pages | 7 |
Journal | Gastroenterology |
Volume | 92 |
Issue number | 5 |
DOIs | |
State | Published - 1 Jan 1987 |
Externally published | Yes |
Keywords
- CP
- EVP
- IP
- MVP
- capsule pressure
- esophageal varix pressure
- intraluminal pressure
- mesenteric vein pressure
ASJC Scopus subject areas
- Hepatology
- Gastroenterology