What is observed at the exit of a stenosis?

At the exit of a stenosis, flow reversals, flow separation, and vortices are observed due to the abrupt changes in vessel diameter and flow dynamics that occur as the blood exits the narrowed area. When blood moves through a stenosis, it accelerates as it enters the narrowing, leading to an increase in velocity and a corresponding decrease in pressure according to the principles of fluid dynamics and Bernoulli's theorem.

As the flow exits the stenosis and transitions back into a wider vessel, the high-velocity flow can disrupt the regular laminar layers of blood flow, creating turbulent flow patterns. This turbulence is characterized by flow reversals (backward flow), separation of flow from the vessel wall, and the formation of vortices—small circular patterns of fluid motion. These phenomena are common hemodynamic consequences of a stenosis and are critical for understanding how vascular disease can affect blood flow and create complications.

The other options, such as regular laminar flow, higher pressure levels, or increased smooth flow, do not accurately describe the chaotic flow dynamics that occur after a stenosis. In fact, the presence of turbulence and flow disturbances is one of the key indicators of significant vascular narrowing or stenosis. Understanding these flow patterns is essential for interpreting