What is the primary pathological feature observed in kidneys affected by chronic hypertension?

In kidneys affected by chronic hypertension, the primary pathological feature observed is hyaline arteriosclerosis. This condition occurs due to the long-standing elevated blood pressure that leads to changes in small blood vessels, particularly the arterioles. The increased pressure results in a thickening of the vessel walls and the deposition of hyaline material, which is a glassy, homogeneous substance comprised of plasma proteins and other components.

This process ultimately narrows the lumen of the arterioles, reducing blood flow to the kidney tissues and contributing to ischemia and potential kidney damage. Over time, these changes can lead to chronic kidney disease as the renal function progressively declines due to the inadequate perfusion and nutrient delivery to the renal parenchyma.

The inclusion of other options helps to clarify this point. Hyperplastic arteriolitis is more characteristic of malignant hypertension and is associated with a specific pattern of fibrinoid necrosis and proliferation of smooth muscle cells. Giant cell arteritis is primarily an inflammatory process involving large vessels, not typically affecting the kidneys in the same way. Medial calcific sclerosis is related to aging or diabetes and typically doesn’t represent the arteriolar changes seen in chronic hypertension. Therefore, hyaline arteriosclerosis specifically captures the chronic changes