Renal tract calculi

Question 1

What is the medical term for renal tract stones?

Answer 1

Urolithiasis

Question 2

What is urolithiasis?

Answer 2

Renal tract stones

Question 3

What are most urinary tract stones made up of?

Answer 3

Calcium (80%)

• as calcium oxalate, calcium phosphate or mixed

Question 4

What is the most common pathophysiology for urinary tract stones?

Answer 4

Over-saturation of urine

• certain stone types are linked to underlying pathologies

Question 5

What can different urinary tract stones be made of?

Answer 5

Calcium - oxalate or phosphate
Urate
Cystine
Struvite

Question 6

What can cause urate stones to form?

Answer 6

High levels of purine in blood due to

• diet (e.g. red meats)
• haematological disorders

Question 7

Name the three points where ureteric stones are most likely to impact

Answer 7

PUJ - pelviureteric junction
Crossing pelvic brim - where iliac vessels go across the ureter
VUJ - Vesicoureteric junction

Question 8

How do ureteric stones commonly present?

Answer 8

Ureteric colic pain
- sudden onset, severe + radiating from flank to pelvis
Nausea + vomiting
Haematuria - typically non visible
Tenderness on examination

Question 9

What are some differentials for flank pain?

Answer 9

Renal tract calculi
Pyelonephritis
Ruptured AAA
Biliary pathology
Bowel obstruction
Lower lobe pneumonia
MSK pain

Question 10

What investigations can be done for renal stones?

Answer 10

Bloods
non- contrast CT scan (gold standard)
Abdo xray
Ultrasound scan - also can assess if any hydronephrosis - not good for finding the stones
Urine dipstick - to look for blood / any infection

Question 11

Why are X-RAYs not as good as CT for renal stones?

Answer 11

As some stones are radio-lucent - so can’t be seen

Question 12

How are renal calculi initially managed?

Answer 12

• rehydration / fluid resus
• analgesia
• antibiotics if any signs of infections

Many will pass spontaneously without the need for further intervention

Question 13

How can renal calculi be treated?

Answer 13

Extracorporeal shock wave lithotripsy - for small stones
Percutaneous nephrolithotomy - for renal stones
Flexible uretero-renoscopy - scope is inserted then laser therapy + fragments removed

Question 14

How can signs of obstructive nephropathy from renal stones be temporarily managed?

Answer 14

Retrograde stent insertion

Nephrostomy

Question 15

What is a nephrostomy?

Answer 15

When an opening is made between the renal pelvis of the kidney and the skin. This allows drainage of blocked urine.

Question 16

What are some complications of renal tract calculi?

Answer 16

Infection
Post renal AKI
Recurrent = scarring + decline in renal function

Question 17

What condition can cause calcium stones to form?

Answer 17

Primary hyperparathyroidism - check PTH levels

Question 18

What familial condition can cause cystine stones?

Answer 18

Homocystinuria (go over this)

Question 19

What can cause bladder stones?

Answer 19

Urine stasis - chronic urinary retention
Secondary to infections such as schistosomiasis
Passed ureteric stones

Question 20

How are bladder stones treated?

Answer 20

Cystoscopy - with lithotripsy if needed

Question 21

What can chronic irritation of the bladder epithelium from bladder stones lead to?

Answer 21

Predisposition to squamous cell carcinoma bladder cancer

Question 22

Which bloods should be done for urinary colic?

Answer 22

Xx

Question 23

Why is diclofenac a good option of analgesia for renal tract calculi?

Answer 23

As it is an antispasmodic