Renal pathophysiology III PY3002

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Renal pathophysiology III PY3002

• Dr. Michael Scholz

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Overview

• Urinary obstructions
• Types
• Common causes of obstructions
• Effects of obstruction
• Examination of obstructions
• Treatment of obstructions

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Urinary tract obstruction
Obstructions in the urinary tract reduce the
urinary flow and impair the renal function A
frequent effect of a partial or complete
obstruction is a dilation of the renal pelvic
(hydronephrosis)
Obstructions of the urinary tract are painful
and need immediate treatment due to the fail of
renal function (reduced GFR)
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Obstructions of the urinary tract
Types and locations
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Types of obstruction

• Intramural
• Transitional cell cancer
• Fibrosis
• Inflammation
• Infection

• Extrinsic
• Trauma
• Tumour
• Inflammation
• Infection
• Haemorrhage
• Fibrosis

• Intraluminal
• Calculus
• Blood clot
• Renal papilla

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Renal Calculi
Causes of development

• Renal Calculi develop by precipitation of hardly
  soluble salts in the kidney or the subsequent
  tubule of the urinary tract
• The formation of calculi is related to
• impairment of the metabolism (overproduction
  of metabolites)
• ? filtration thresholds are exceeded!
• Impairment of renal filtration
• Impairment of renal re-absorption

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Renal Calculi
Types
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Consequences of urinary tract obstruction

• Reduced glomerular filtration rate
• Reduced renal blood flow (after initial rise)
• Impaired renal concentrating ability
• Impaired distal tubular function
• Nephrogenic diabetes insipidus
• Renal salt wasting
• Renal tubular acidosis
• Impaired potassium concentration
• Postobstructive diuresis

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Acute urinary tract obstruction
Functional consequences
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Acute urinary tract obstruction
Functional consequences
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Examination of obstructions
Imaging of the urinary tract is frequently used
to examine obstructions and differentiate between
renal disease
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Imaging of urinary tract
Examples
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Treatment of obstructions
Renal Calculi
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Treatment of obstructions
Relief of obstruction

• Stones with diameters less than 1 cm may pass
  spontaneous
• Larger stones require intervention
• Depending on size, position, shape and
  composition
• Lithotripsy (fragmentation of the stone
  i.e. ultrassonic)
• Endoluminal extraction (endoscopic)
• open surgical removal
• Combination of techniques
• Tumours, fibrosis or hypertrophy require surgical
  intervention

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Conclusion

• Obstructions of the urinary tract impair renal
  function by blocking the urinary flow
• Multiple causes like stones, fibrosis, tumours
  or hypertrophy etc
• Acute effect is the loss of renal function by
  decrease of GFR
• Calculi indicate a primary renal or metabolic
  imbalances leading to precipitation of unsoluble
  salts in the urinary tract
• Removal of obstruction is essential
• Different imaging techniques are used to examine
  renal obstructions and to differentiate from
  other renal disease