What segmental pressure drop indicates significant obstruction between two consecutive levels?

A segmental pressure drop of 30 mmHg between two consecutive levels is generally considered to indicate significant obstruction. This threshold is based on the standards used in vascular studies to assess peripheral arterial disease. When there is a drop of 30 mmHg or more, it suggests that there is likely a hemodynamic significance associated with a stenosis or occlusion in the artery.

This drop reflects an inadequate blood supply to tissues beyond the obstruction due to a restriction in blood flow. Measurement of segmental pressures is utilized in non-invasive vascular testing to help evaluate the severity of arterial disease and to guide further diagnostic or therapeutic interventions. Understanding the significance of pressure gradients is crucial in identifying patients who may require more extensive evaluation or treatment.