Renal stones

Question 1

Where are renal stones most likely to deposit?

Answer 1

• Pelviureteric junction
• Pelvic brims
• Vesicoureteric junction

Question 2

What are the different types of renal stones, their causes and appearance?

Answer 2

=> Calcium Oxalate: - MOST COMMON:

• Metabolic or Idiopathic
• Spiky, karge, radio-opaque

=> Calcium Phosphate:

• Metabolic or Idiopathic
• Smooth, large, radio-opaque

=> Cystine:

• Renal tubular effect
• Yellow, crystalline, semi-opaque

=> Urate:

• Hyperuricaemia
• Small, brown, radiolucent

=> Struvite:

• Bacterial cause
• Formed of Mg, Ammonium and Phosphate
• Slightly radio-opaque

Question 3

What are the risk factors of Renal Stone formation?

Answer 3

• Dehydration
• Hypercalciuria, Hyperparathyroidism, Hypercalcaemia
• Cystinuria
• High dietary oxalate
• Renal tubular acidosis
• Medially Sponge Kidney
• Polycystic Kidney Disease
• Beryllium or Cadmium exposure

Question 4

What are the causes of Renal stones?

Answer 4

• Occur due to high levels of Ca in urine (hypercalciuria)

These parents typically do NOT have hypercalcaemia

=> Possible causes of hypercalciuria:

• Absorptive hypercalciuria
• Renal hypercalciuria
• Hypercalcaemia

Question 5

What is the clinical presentation of Renal Stones?

Answer 5

• Nausea and vomiting
• Ureteric colic (sudden onset of pain originating from loins going to groin. On and off comes in waves)
• Haematuria
• Dysuria
• Recurrent UTIs

Question 6

What are the complications of urinary tract obstruction?

Answer 6

• Pyelonephritis
• Medium to long term complication is hydroureter and hydronephrosis
• Long term complication is hypertension

Question 7

What are the investigations in suspected Renal Stones?

Answer 7

=> Bloods

=> Urinanlysis
- Haematuria

=> 24 hour urine - Ca, oxalate, rate, citrate, Na, creatinine

=> AXR
Staghorn Calculi

=> Non-contrast CT
Preferred choice of investigation, helps exclude acute abdomen

=> Ultrasound
- In cases of hydronephrosis or hydrourter

Question 8

What is the management of Renal stones?

Answer 8

=> Management of Renal Colic (the pain):

• NSAID Diclofenac + IV fluids
• Antibiotis for infection
• Ca blocker Nifidipne or alpha blocker Tamsulosin to promote expulsion of stone if < 5mm

=> Management if < 5mm:

• Passes spontaneously
• Increase fluid intake
• Lithotripsy or Nephrolithotomy in severe cases

=> Management if > 5mm:

• Extacorporeal Shockwave Lithotripsy
• Uteroscopy
• Percutaneous Nephrolithotomy

Question 9

What is the immediate emergency management of Renal stones and when is it indicated?

Answer 9

=> Indicated when obstruction + infection

=> Options include:

• Nephrostomy tube replacement
• Ureteric stent
• Ureteric catheters