| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 2996839 | Journal of Vascular Surgery | 2007 | 5 Pages |
PurposeThis study was conducted to clarify the effect of the direction of pressure measurement on the pressure readout in fibrinous thrombus of the abdominal aortic aneurysm.MethodsThree weights of 468 g (weight 1), 578 g (weight 2), and 675 g (weight 3) were molded. A specimen of human fibrinous thrombus was positioned under the weights. Because the surface area of the weights and the thrombus was 400 mm2, weights 1, 2, and 3 caused pressures of 88, 108, and 127 mm Hg, respectively. Pressure measurements were performed at different angles between the sensor and the applied force (0°, 22.5°, 30°, 45°, 60°, 67.5°, 90°) Thrombi of 10 different patients were analyzed. Pressure measurements in the thrombi at different angles were statistically compared by a linear mixed model analysis.ResultsThe measurements at 90° differed statistically from the measurements at 0°, 22.5°, 30°, 45°, 60°, and 67.5° (P < .001). The pressure readout was only similar to the applied pressure when the pressure sensor was positioned at 90° to the applied force. Pressure measurements in other sensor positions resulted in lower pressure measurements. Pressure changes were detected in all sensor positions. There appeared to be no significant difference between the pressure measurements taken at same angles in the 10 thrombi (P > .05).ConclusionIn fibrinous thrombus of abdominal aortic aneurysm, the direction of pressure measurement influenced the pressure readout.
Clinical relevanceEndovascular aneurysm repair (EVAR) aims reducing the pressure in the aneurysm sac; therefore, it seems attractive to use pressure monitoring in the aneurysm sac as a follow-up after EVAR. This study contributes to the development of the rationale of pressure monitoring in the aneurysm sac as a follow-up method after EVAR. The sensor position in fluids is not relevant for pressure measurement because the forces at a given point in a fluid are identical in all directions. This is not the case in solid materials. The aneurysm sac is filled with solid fibrinous thrombus. To interpret pressure measurements, we have to learn about the effect of the direction of pressure measurement in fibrinous thrombus on the pressure readout.
