A qualitative investigation of turbulence in flow through a model abdominal aortic aneurysm.

RATIONALE AND OBJECTIVES

As part of a general examination of the effect of blood flow patterns on the growth and risk of rupture of abdominal aortic aneurysms, the authors investigated the flow through an experimental model of a fusiform aneurysm.

MATERIALS AND METHODS

Aneurysms were simulated in polyvinyl chloride tubing. A steady flow of 450 mL/minute to 2 L/minute was investigated by color Doppler flow imaging.

RESULTS

Two types of flow patterns existed in the model aneurysm, depending on the overall flow rate through the model. At low velocity flow, this pattern is smooth, steady, and laminar, whereas at higher flows it is irregular and turbulent.

CONCLUSION

This finding corresponds to recent clinical observations. The onset of unsteadiness and irregularity in the flow through the model is related to flow velocity.