Post-renal causes of kidney damage Flashcards
How is post-renal kidney damage caused?
By the obstruction of urinary flow anywhere along the route of urine
What route does urine take?
Collecting duct -> ureter -> bladder -> urethra
What happens once the passage of urine is obstructed?
Increased pressure behind the obstruction backing into the kidney causes hydronephrosis
What are the two types of obstruction that leads to post-renal kidney disease?
Unilateral obstruction - only one kidney is obstructed
Bilateral obstruction - both kidneys are obstructed
Why are unilateral obstructions normally asymptomatic?
Normal kidney replaces the function of the abnormal kidney
Overall kidney function might not obviously be impaired
Can cause significant injury if the other kidney is damaged or missing
What are causes of upper tract obstruction?
Obstructing stones - kidney stones, not all lead to kidney injury
Lesions on the urotherial wall - tumour
Extrinsic compression - more common
Developmental abnormalities - born
What are examples of extrinsic compression that leads to post-renal kidney injury?
Compressing lymph nodes - pelvic malignancy
Locally spreading cancer
Inflammatory masses
Post surgical or radiation fibrosis (inflammatory)
What is the most common cause of post-renal kidney injury in women?
Gynecological tumours
What are the most common causes of post-renal kidney injury in men?
Happen lower down in the urinary tract compared to women
Prostatic hyperplasia - ploriferation of cellular elements of the prostate
What are the symptoms of post-renal kidney injury?
Urinary retention
Renal insufficiency
Recurrent UTIs
How do you relieve obstruction of post-renal kidney injury?
Stent
Nephrostomy
Bladder catheter
How does a stent relieve post-renal kidney injury?
This is a flexible stent
Passed down the ureter through the bladder all the way up into the kidney
Allows urine to flow down
How does a nephrostomy relieve post-renal kidney injury?
Stent is directly placed into the kidney
Catheter perforates the skin and passes through the body wall and renal parenchyma
Catheter maintains passageway
Terminates in renal pelvis and passes into the collecting duct
How does a bladder catheter relieve post-renal kidney injury?
Tube is passed into the bladder
Urine passes through the flexible tube and collects in an urine bag
Balloon is inflated to prevent it from moving
Definitive procedures can then be pursued to remove obstruction
