Obstruction

Question 1

What are causes of ureteric obstruction

Answer 1

Intraluminal -
stones, sloughed papilla, clots

Intramural
Pelvi-ureteric junction obstruction (PUJO)
Upper tract transitional cell carcinoma (TCC)
Benign strictures (TB, surgical injury)

Question 2

Descirb uh obstruction

Answer 2

Ss for image

Question 3

What are extraluminal causes of ureteric obstruction

Answer 3

Retroperitoneal malignancy - lymph node mets from breakfast, gynae, prostate, other malig

Direct obstruction rom tumours
- bladder cancer (obstruction at vesicoureteric junction)- locally advanced prostate cancer

Retroperitoneal fibrosis - scraping in retroperitoneum which causes obstruction

Question 4

What is acute ureteric obstruction

Answer 4

Renal colic

• flank pain, radiates to groin
• can be colicky or continuous
• usually caused by a calculus, but can be bloodclots (clot colic) or sloughed papilla

Usually unilateral

If there is super added infection: pyonephrosis or infected obstructed system

Question 5

What is chronic ureteric obstruction

Answer 5

Generally painless (Pujo is an exception)

Can be unilateral or bilateral

Clinical presentations

• incidental finding on imaging
• renal failure (obstructive uropathy)
• pyonephrosis

Question 6

What are obstructive causs of real impairment

Answer 6

Renal impairment due to

• Bilateral ureteric obstruction
• unilateral ureteric obstruction where there is a solitary kidney
• high pressure chronic retention

Post renal aki
Beware hyperkalaemia -

Question 7

How to treat obstructed kidney

Answer 7

The infected obstructed kidney is a urological emergency

Allure to promptly decompress May lead to death from sepsis, or permanent loss of renal function
irreversible injury

initial management as per any septic patient but involve a senior urologist early

Question 8

What is the imaging for upper tract obstruction

Answer 8

Ct and uss -can show stones
Vt and uss show structure not function - static tests but not functional studies
- non obstructive hydronephrosis seen in VUR and pregnancy (progesterone - sm relaxation - compliant and relax leading to hydronephrosis but most don’t have renal obstruction)

Question 9

What is the diagnosis for upper tract obstruction

Answer 9

Test to conform if functionally obstructed
Diuretic renography - radio labelled tracer - use a gamma camera to track tracer. Kidney starts to excrete tracer - level drops. When given diuretic - process of learning tracker accelerates
If obstructive, tracer accumulates in pelvis - unable to get down ureter. Found goes up. Diuretic makes this even worse. In image, right kidney obstructed

Question 10

What are ways in which kidneys can be drained

Answer 10

Bilateral obstruction - renal failure - get kidneys draining again. 2 ways

1) JJ stent - facilitates drainage of urine into bladder
2) nephrostomy - out of kidney into drainage bag

Stents put in by urologists, nephrostomy by radiologists.
Stands good if nephrotic problem bc dont want to damage kidney, nice bc no bag.
Nephrostomy good if don’t want to give general anaesthetic.- can give local anaesthetic - eg sepsis -

Question 11

What is pujo

Answer 11

Big dilated renal pelvis, dilatation of calyces but not the ureters. Congenital condition
Can present with antenatal hydronephrosis on uss
May resent at any stage in life
Can be asymptomtic (incidents inding)
Classic presentation - loin pain, worse after heavy fluid intake or alcohol (diuretic). Intermittent obstruction . Blood vessel running over puj - filling pelvis kinks over vessel, pressure gets worse, causes pain
Definitieve treatment is pyeloplasty (laparoscopic) - cut out puj and refashion it in front of vessel if the vessel is present.

Question 12

What is retroperitoneal fibrosis

Answer 12

Fibrotic tissue/scaring in retroperitoneum. Grey material. Ureters drawin into fibrosis. Interesting with peristalsis - causes fibrosis

Question 13

What are the cases and treatment for retroperitoneal fibrosis

Answer 13

• idiopathic
• malignant (breat lung stomach etc)
• auto immune (ig-g4 disease - autoimmune pancreatitis)
• drugs
• aaa

Treatment id decompression, exclusion o malignancy (may need biopsy), ad steroids/immunosupression or ureterolysis

Question 14

What is infravesical obstruction

Answer 14

Acute urinary retention
Chronic urincary retention - high pressure
- low pressure

Question 15

Compare acute vc chronic urinary retention

Answer 15

Acute - wilful inability to void
- residual volume 300-1500ml

Chronic - often painless

• may still be voicing
• residual volume 300-400(0?)ml

Question 16

What are causes o urinary retention

Answer 16

Much more common in men due to prostate
BPh, prostate cancer, urethral structures
Women - urethrala stenosis , pelvic masses eg gynae cancer

Uti, constipation, neurological dysfunction eg cauda equina syndrome, recent surgery, drugs,

Question 17

How si acute urinary retention managed

Answer 17

• catheterise and record residual volume (how much comes out of catheter)
• history
• exam (abdo, ext genitalia, dre)
• ruined drip, u+e
• rest any obvious causes (eg constipation)
• alpha blocker in men (relaxes prostate sm)
• trial without cathethe in 102 weeks on a blocker
• if fails: TURP

Question 18

What is a turp

Answer 18

Heated electrical loop to trim away parts of prostate

Question 19

Compare high vs low pressure chronic urinary retention

Answer 19

High pressure -

• abnormal u+Es
• hydronephrosis

Low pressure (big floppy bladder)

• normal renal function
• no hydronephrosis

Question 20

Ow is chronic urinary retention manage

Answer 20

• catheterise and record residual volume
• history
• exam
• urine dip, u+Es
• monitor for post-obstructive diuresis (usually admit overnight)

Question 21

Describe post structure diuresis

Answer 21

Ss