Interpretation of a marked drop in distal segmental pressures compared with proximal segments?

• A. A hemodynamically significant distal lesion in the runoff pathway
• B. No significant lesion
• C. Distal vascular spasm only
• D. Systemic hypertension effect on limb pressures

Answer: (B)

A marked drop in distal segmental pressures compared with proximal segments points to a block farther down the arterial runoff. In a healthy limb, pressures at different levels are fairly aligned; a substantial decline as you measure more distally means the flow has to push through a narrowed or occluded segment in the runoff vessels (tibial/femoral runoff paths). This creates a pressure gradient where distal sites show much lower pressures than proximal sites, indicating a hemodynamically significant distal lesion. Distal vasospasm can cause temporary lowering of distal pressures but usually presents differently and responds to vasodilators, while systemic hypertension would raise pressures more uniformly across segments. So the pattern described most consistently reflects downstream disease in the runoff pathway.