Medical Archive

Introduction

Macrovascular disease

Renal artery stenosis

• ?Renin secretion from affected kidney 
• Resultant hypertension 
  • Helps ?the decline in GFR in the affected kidney
  • Pressure natriuresis with ?sodium excretion in the unaffected kidney

Histology

• Stenotic kidney
  • Diffuse cortical thinning, tubular atrophy, interstitial fibrosis, and small crowded glomeruli.
  • Juxtaglomerular apparatus enlargement d/t chronic stimulation and increased renin release
• Nonstenotic kidney
  • Arteriolar wall thickening d/t hyaline arteriosclerosis 
  • Hyperplastic arteriolosclerosis; concentric smooth muscle cell proliferation in response to pressure “onion-skinning”

Management

• Aggressive risk factor reduction
  • Aspirin, DM/hyperlipidemia control, smoking cessation.
• ACEIs/ARBs
  • First-line. Have long-term nephroprotective effects
  • Higher risk of AKI -> renal function should be monitored closely.
• Revascularization
  • For those who are refractory.

Atheroembolic renal disease

Cholesterol crystal embolism

Risk factors

• Comorbid conditions (hypercholesterolemia, hypertension, NIDDM)
• Cardiac catheterization or vascular procedure

Clinical features

• Dermatologic (livedo reticularis, ulcers, gangrene, blue toe syndrome)
• Renal (acute or subacute kidney injury)
• CNS (stroke, amaurosis fugax)
• Ocular involvement (Hollenhorst plaques)
• Gastrointestinal (intestinal ischemia, pancreatitis)

Diagnosis

• Lab findings
  • ?Scr, eosinophilia, hypocomplementemia (d/t IL-5 activation)
• Urinalysis
  • Typically benign with few cells or casts, may have eosinophiluria
• Skin or renal biopsy
  • Biconvex, needle-shaped clefts within occluded vessels
  • Perivascular inflammation with eosinophils.

Thromboembolic renal disease

Thromboembolic disease
Mitral valve stenosis, atrial fibrillation? ?? ??.
Sudden onset flank pain – CT angiography? ??. 
Infarction ????? renin ?? ??? ???, ??? ?????.
e.g. ???? ????? liveido reticularis? ??? -> Statin? ???

Gross pathology – sharply demarcated, yellow-white, wedge-shaped infarcts surrounded by hyperemic tissue.

Management of arterial thrombosis of the kidney

Microvascular injury associated with hypertension

Arteriolonephrosclerosis

= “Hypertensive nephrosclerosis”

• Pathophysiology
  • Hyaline arteriolosclerosis
    • In response to chronic hypertension, renal arterioles undergo medial hypertrophy and intimal fibrosis, and subsequent endothelial damage
  • Glomerulosclerosis
    • The resultant luminal narrowing causes a progressive decrease in renal blood flow, leading to glomerular ischemia with glomerular and tubular fibrosis and atrophy.
• Clinical features
  • Elevated creatinine
  • Ultrasonographically small, atrophic kidneys
  • Bland urinalysis with mild proteinuria (<1g/day)
  • Azotemia – slowly progressive and irreversible.
  • Anemia

High pitched epigasatric bruit, Kidney Sono

Captopril renogram
?? ?? ?? ?? ??.

ACEi(?? ???? X) & BB. ?? ???? ??????

?? 
Indication
ACEI/ARB ??, Cr ??, ?? ??? HTN, recurrent volume overload 

Proximal – Stent; PTRA? ?? ???? ??!
Distal – Percutaneous Transluminal Renal Angioplasty (PTRA)