Lecture 23 - Urinary tract obstruction

Question 1

Causes of ureteric obstruction

Answer 1

Intraluminal:
Stones
Sloughed papilla
Clots

Intramural:

• PUJ obstruction
• TCC upper tract
• Benign strictures

Extraluminal:

• Metastases e.g. breast and prostate
• Retroperitoneal malignancy

Question 2

Renal colic pain

Answer 2

Renal stone obstructs ureter

• Acute severe flank plain radiating to the groin
• Nausea and vomiting

Question 3

Clot colic pain

Answer 3

Clot obstructing the ureter

Question 4

Pyonephrosis

Answer 4

Super added infection as well as obstruction in kidney

Swinging temperature and sepsis

Must decompress immediately as rapid irreversible destruction to nephrons

Question 5

Chronic ureteric obstruction

Answer 5

Generally painless
except PUJ obstruction
More commonly bilateral

Question 6

Obstructive uropathy

Answer 6

Post renal AKI
Can cause hyperkalaemia and metabolic acidosis

• Due to obstruction

Question 7

Non - obstructive hydronephrosis

Answer 7

Vesico-ureteric reflux seen in children

Question 8

MAG3

Answer 8

Radiocative tracer picked up by gamma camera to see kidney function

Initial rapid uptake as taken up in blood and then cleared gradually

Question 9

Treatments for upper tract drainage in obstructions

Answer 9

JJ stent - dilates ureters and urine goes around obstruction

Nephrostomy - drain urine in external bag

Question 10

Pelvicureteric junction obstruction

Answer 10

Loin pain
Worse after heavy fluid intake or alcohol

Treatment: pyeloplasty

Question 11

Dietl’s crisis

Answer 11

Flank pain

Question 12

Pyeloplasty

Answer 12

Disconnect ureters and renal pelvis and reconnect at different site

Question 13

Retroperitoneal fibrosis causes

Answer 13

Idiopathic
Malignant 
Auto immune - IgG4 disease
(causes pancreatitis)
Drugs
Abdominal aorta aneurysm

Question 14

Retroperitoneal fibrosis treatment

Answer 14

Decompression
Steroids
Immunosuppresion - IGG4
Ureterolysis

Question 15

Acute urinary retention

Answer 15

Painful inability to void

Question 16

Chronic urinary retention

Answer 16

Painless
Can still void
Not fully emptying

Question 17

Causes of urinary retention

Answer 17

More common in men due to prostate:

• BPH
• Prostate cancer

Others:

• UTI
• Drugs
• Urethral stricture
• Recent surgery
• Constipation

Question 18

Management of urinary retention

Answer 18

catheterise - record residual volume

History
Abdo exam
DRE
External genitalia

Urine dip - UTI
U + E - renal function

Treat obvious causes e.g. constipation (alpha blocker)

Trial without catherterisation with alpha blocker

Transurethral resection of prostate if TWOC fails

Question 19

High pressure chronic urinary retention

Answer 19

Stiff
Non compliant
Full bladder

Abnormal U+E
Bilateral hydronephrosis as kidneys can’t empty

Question 20

Low pressure chronic urinary retention

Answer 20

Compliant kidneys
Does not fully empty

Normal U+Es
No hydronephrosis

Question 21

Management of chronic urinary retention

Answer 21

Same as acute but monitor post obstructive diuresis - admit overnight

High pressure: Can’t do TWOC without transurethral resection of prostate (TURP)

Low pressure: TURP but only 50% void again - decreased contraction
Use catheter or intermittent catheter

Question 22

Post obstructive diuresis

Answer 22

When obstruction removed e.g. with catheter - diuresis due to off loading of accumulated salt and water during high pressure chronic retention

Can be excessive due to decreased sensitivity to ADH and cause dehydration

Give IV saline and oral fluid replacement