mindmap - renal vascular problems

Vascular Diseases of the Kidney

Diseases affecting

Renal Blood vessels

• Thrombotic Microangiopathies
  • general features
    • describe lesions seen in various clinical syndromes
    • common causes include
      • childhood Hemolytic Uremic Syndrome (HUS)
        TTP (Thrombotic Thrombocytopenic Purpura)
        Adult HUS
  • pahogenesis
    • HUS
      • endothelial injury and activation
      • intravascular thrombosis
    • TTP
      • acquired defect in proteolytic cleavage of vWF multimers
      • familial TTP
    • childhood HUS
      • 75% follow Shiga-toxin-producing E-coli
        Shigella dysentriae type 1
        renal glomerular endothelial
        cells is target of toxin
        
        
        • increased adhesion of leukocytes
        • increased endothelin production
        • loss of endothelial NO
        • endothelial damage
        thrombosis occurs
  • morphology
    • thrombotic microangiopathy
      fibrin thrombi
      widening of subendothelium
      lysis of mesangium
  • clinical course
    • Childhood HUS
      • sudden onset
      • after GI / Flulike prodromal episode
      • bleeding manifestations
        • hematemesis
        • melena
    • severe oligurea
    • hematuria
    • prominent neurologic changes
    • one of main causes of ARF in children
    • if dyalisis done properly in early stage, patient mostly recover in matter of weeks
    • long-term prognosis
      • 25% of children evantually develop renal insufficiency due to scarring
  benign Nephrosclerosis
  • general characteristics
    • always associated with hyaline arteriosclerosis
    • frequency and severeity increases with Hypertension / DM.
    • present at autopsy in many people >60 years (although benign)
  • pathogenesis
    • many renal diseases cause hypertension
       - which is in turn associated with nephrosclerosis
      often seen superimposed to other renal other primary kidney lesions
  • morphology
    • gross
      • 
        symmetrically atrophic
        diffuse fine granularity that resembles grain leather
    • microscopic
      • 
      • hyaline arteriosclerosis
      • pink hyaline thickening at expence of basal lumina
      • loss of cellular detail
      • narrowing of lumen
  • clinical course
    • rarely cause any problems
      however some population susceptible
      • African americans
      • may lead to uremia and death
      all person with the lesion usually
      show some level of functional impairment
      • loss of concentration of urine
      • diminished GFR
      • Mild proeinuria
  Malignant Hypertension
  Malignant Nephrosclerosis
  • general features
    • less common in US
    • only happen in 5% of people with high BP
    • may arise de novo or appear in a person with mild Hypertension
    • happens more frequently in less developed countries
  • pahogenesis
    • some form of vascular damage to kidneys
    • long standing benign hypertension
    • evantual injury to arteriolar walls
      • increeased permeability
        of small vessels to
        • fibrinogen
        • other plasma proteins
        increased endothelial injury
        platelet depots.
  • morphology
    • gross
      • pinpoint petechial hemorrhages
      • flea-bitten appearance
    • microscopic
      • fibrinoid necrosis of arterioles
        homogeneous, granular eosinophilic vessel walls
        onion-skin appearance - hyperplastic arteriosclerosis
  • clinical course
    • medical emergency
    • early symptoms related more to ICP increase
      • headache
      • nausea
      • vomiting
      • visual impairment
      • scotomas
    • diastolic pressures >120 mmHg
    • papilledema
    • encephalopathy
    • renal failure
    • CVS abnormalities
    • proteinurea
    • micro/macroscopic hematurea
    • 50% survive for 5 years
    • 90% deaths made from uremia
    • 10% death from cerebral hemorrhage / Cardic failure