Obstruction, Retention

Question 1

Causes of urinary tract obstruction

Answer 1

1. Luminal
2. Mural
3. Extramural

Question 2

Luminal causes of obstruction

Answer 2

Stones

Blood clots

Sloughed papilla

Question 3

Mural causes of obstruction

Answer 3

Stricture

Tumour

Neuromuscular dysfunction

Question 4

Extramutal causes of obstruction

Answer 4

Prostatic enlargement

Abdo / pelvic mass / tumour

Retroperitoneal fibrosis

Question 5

Upper urinary tract obstruction sx

Answer 5

Flank plain

Renal failure

Question 6

Lower urinary tract obstruction

Answer 6

Voiding sx

Distended, palpable bladder ± large prostate on PR

Question 7

Upper tract obstruction rx

Answer 7

Nephrostomy or

Ureteric stent

Question 8

Lower tract obstruction rx

Answer 8

catheter

Question 9

Ureteric stent complications

Answer 9

Infection/inflammation

Haematuria

Encrustation

Obstruction

Ureteric rupture

Stent migration

Question 10

Urethral stricture causes

Answer 10

Trauma

Infection: e.g. gonorrhoea

Chemotherapy

Balantitis xerotica obliterans

Question 11

Presentation of urethral stricture

Answer 11

Voiding sx

Question 12

Examination for urethral stricture

Answer 12

PR

Palpate urethra through penis

Examine meatus

Question 13

Investigations for urethral stricture

Answer 13

1. Urodynamics
2. Urethroscopy and cystoscopy
3. Retrograde urethrogram

Question 14

Urodynamic testing results of a urethral stricture

Answer 14

↓ peak flow rate

↑ micturition time

Question 15

Treatment of urethral stricture

Answer 15

Internal urethrotomy

DilatationStent

Question 16

Chronic urinary retention classification

Answer 16

1. High Pressure High detrusor pressure at end of micturition Typically bladder outflow obstruction Bilateral hydronephrosis and ↓ renal function
2. Low Pressure Low detrusor pressure at end of micturition Large volume retention, very compliant bladder Kidney able to excrete urine No hydronephrosis - normal renal function

Question 17

High pressure urinary retention features

Answer 17

High detrusor pressure at end of micturition

Typically bladder outflow obstruction

Bilateral hydronephrosis and ↓ renal function

Question 18

Low pressure urinary retention features

Answer 18

Low detrusor pressure at end of micturition

Large volume retention, very compliant bladder

Kidney able to excrete urine

No hydronephrosis - normal renal function

Question 19

Treatment of high pressure chronic urinary retention

Answer 19

Catheterise and consider TURP

Question 20

Treatment of low pressure chronic urinary retention

Answer 20

Avoid catheters

Early TURP

Question 21

Contraindications of suprapubic catheterisation

Answer 21

Known or suspected bladder carcinoma

Undiagnosed haematuria

Previous lower abdominal surgery - adhesions of small bowel

Question 22

Clean Intermittent Self-Catheterisation (CISC)

Answer 22

Alternative to permenant catheter

Useful in patients with failure to void after TURP