Urology: Urinary Tract Obstruction Flashcards
where can this obstruction damage?
from the renal calyces to the urethral meatus
classification of a urinary tract obstruction
- partial/complete
- unilateral/bilateral
what are the types of obstructing lesions?
- luminal
- mural
- extra-mural
what happens if there is an obstruction?
- the tract proximal to the obstruction dilates
- dilatation of the renal pelvis and calyces is hydronephrosis
what are the luminal causes of obstruction?
- calculus
- blood clot
- sloughed papilla
- tumour of the renal pelvis or ureter bladder tumour
what are mural causes of obstruction?
- pelviureteric neuromuscular dysfunction
- ureteric stricture
- ureterovesical stricture
- congenital megaureter
- congenital bladder neck obstruction
- neuropathic bladder
- urethral stricture
- congenital urethral valve
- pin-hole meatus
what are extramural causes of obstruction?
- pelviureteric compression
- tumours of surrounding organs
- diverticulitis
- aortic aneurysm
- retroperitoneal fibrosis
- accidental ligation of the ureter
- retrocaval ureter
- prostatic obstruction
- phimosis
in which population is renal tract obstruction more common?
elderly men due to the frequency of bladder outflow obstruction due to prostatic disease
unilateral causes of hydronephrosis
- pelviureteric junction obstruction
- congenital pelviureteric junction obstruction
- aberrant renal vessels
- calculus
- tumours of the renal pelvis
- ureteric obstruction: calculus, ureteric invasion, iatrogenic
bilateral causes of hydronephrosis
- urethral valves
- urethral or meatal stenosis
- prostatic enlargement
- extensive bladder tumours
- retroperitoneal fibrosis
pathophysiology of an urinary tract obstruction
- if urine is still being produced, there is an increase in the intraluminal pressure, a dilatation proximal to the obstruction site, compression of the renal parenchyma, eventually reducing it to a thin rim and resulting in a decrease in the size of the kidney
- acute obstruction is followed by transient renal arterial vasodilatation succeeded by vasoconstriction
symptoms of upper tract obstruction
- loin pain (dull/sharp)
- exacerbated by a high urine volume, diuretics, distension
- loin tenderness (in acute obstruction)
- chronic obstruction: flank pain, renal failure, superimposed infection, polyuria
what happens in bilateral obstruction?
complete anuria
symptoms of bladder outflow obstruction
- hesistancy
- diminished force of the urinary stream
- terminal dribbling
- sense of an incomplete bladder
- if infection occurs: increased frequency, urgency, urge incontinence, dysuria, passage of cloudy smelly urine
signs of renal obstruction
- loin tenderness
- palpable enlarged hydronephrotic kidney
- enlarged bladder can be felt if there is retention, dull to percussion
- examination of genitalia is essential
