arterioliosclerosis

Arterioliosclerosis, more commonly referred to as arteriolosclerosis, is the thickening and stiffening of the walls of small arteries and arterioles. This degeneration leads to luminal narrowing and impaired perfusion of tissues supplied by these microvessels. The term encompasses several histologic patterns, most notably hyaline arteriolosclerosis and hyperplastic arteriolosclerosis, and it is a key feature of hypertensive and diabetic microangiopathy.

Hyaline arteriolosclerosis is the most frequent form. It results from plasma protein leakage into the vessel wall and an increase in smooth muscle cell matrix production, producing a homogeneous, pink, glassy thickening of arteriolar walls on histology. It is classically associated with long-standing essential hypertension and diabetes mellitus, and it contributes to chronic organ ischemia, especially in the kidneys.

Hyperplastic arteriolosclerosis is characterized by concentric, laminated (“onion-skin”) thickening of arteriolar walls due to smooth muscle cell proliferation and basement membrane reduplication. It commonly occurs in the setting of malignant or severely uncontrolled hypertension and can be accompanied by fibrinoid necrosis of the vessel wall, reflecting more acute vascular injury.

Organs frequently affected include the kidneys (nephrosclerosis), brain (microvascular ischemia and lacunar infarcts), and retina (retinopathy with arteriolar changes). Clinically, arteriolosclerosis may contribute to chronic kidney disease, stroke risk, and end-organ damage related to hypertension and diabetes.

Diagnosis is typically clinical, supported by histology when tissue is available (e.g., biopsy or autopsy). Management centers on treating underlying risk factors: strict blood pressure control, glycemic control in diabetes, lifestyle measures, and avoidance of tobacco use. The prognosis depends on the extent of microvascular disease and the surrounding comorbid conditions.