Epidemiology
- Common; Prevalence 3%
- ♂ > ♀
- Common in summer months
- 90% urinary stones radio-opaque
Location
- Pelviureteric junction
- Pelvic brim
- Vesicoureteric junction
Associated factors
- Dehydration
- Hypercalcaemia: 1° Hyperparathyroidism, immobilisation
- Urinary tract infection
- Hyperuricaemia
- Drugs: Furosemide, Thiazide
- ↑ Oxalate excretion: tea, strawberries
Types of stones:
- Calcium oxalate (75%)
- Radio-opaque
- Calcium ammonium phosphate or triple/struvite phosphate (15%)
- Radio-opaque
- Large; causes staghorn stone
- UTI (especially proteus causing)
- Urate (5%)
- Radio-lucent
- Caused by hyperuricaemia
- Smooth and brown
- Hydroxyapatite (5%)
- Cystine (1%)
- Semi-opaque ‘ground-glass’ appearance
- Caused by renal tubular defect
- Associated with Falconi syndrome
- Calcium phosphate
- Radio-opaque
Presentation
- Ureteric/Renal colic
- Loin to groin pain ± N&V ± often cannot lie still (differentiates from peritonitis)
- Loin pain between 12 rib and lateral edge of lumbar muscles —> suggest renal obstruction
- Obstruction of the lower ureter
- May lead to symptoms of bladder irritability and pain in scrotum, penile tip, or labia major
- Obstruction in bladder or urethra
- Pelvic pain ± dysuria (painful or difficulty urinating) ± stangury (desire but inability to void) ± interrupted flow
- Other features
- On dipstick: Haematuria, proteinuria, sterile pyuria (↑ WCC but culture negative)
- Anuria
- UTI
- Pyelonephritis: fever, rigors, loin pain, nausea, vomiting
- Pyonephrosis: Infective hydronephrosis
Investigation
- FBC
- U&Es
- Bone profile (calcium, phosphate, bicarbonate)
- Urate
- Urine dipstick (protein, blood, nitrites etc) à send for MC&S
- Further test for aetiology
- Urine pH
- 24 h urine collection (sieve stone and send for testing)
- Check urine composition of biochemical
Imaging
- X-ray KUB (Kidney, Ureter, Bladder)- 90% stones radio-opaque
- CT KUB without contrast (replaced IV urogram)- Gold standard imaging
- Renal US for hydronephrosis
- Renal ultrasonography
- Pregnant women
- Children
- Follow-up
- MRI
- Pregnant women
- Children
Management
Initial management
- Pain management and antiemetic
- Diclofenac (NSAIDS) 75mg IV or IM or 100mg PR ± Metoclopramide
- IV fluid
- If ↓PO intake
- Antibiotics
- If evidence of infection (cefuroxime5g/8h IV, or gentamicin)
Conservative
- Expectant management if <5mm in lower ureter as most will pass spontaneously
Medical Expulsive Therapy
If >5mm and pain not resolving
- Nifedipine (calcium antagonist, vasodilator) 10mg/8h PO
- Tamsulosin (alpha blockers) 0.4mg/day
- Start medical expulsive therapy at presentation
- Most pass within 48 hours (>80% in 30 days)
Active stone removal
- Indication
- Ureteric obstruction + infection = surgical emergency
- more than 10mm stone burden
- Infection
- Unresolving obstruction
- Renal insufficiency
| Size | Renal stone | Ureteric stone |
|---|---|---|
| <5mm and asymptomatic | Expectant management | Expectant management |
| 5-10mm | ESWL | ESWL |
| 5-10mm and pregnant or AAA | Ureteroscopy | Ureteroscopy |
| 10-20mm | ESWL or Ureteroscopy | ESWL or Ureteroscopy |
| >20mm | PCNL | Ureteroscpy |
- Surgical emergency
- Ureteric obstruction + infection
- aim is to decompress the system
- Nephrostomy tube or Ureteric stent aka JJ stent aka Double J stent
- Exracorporeal shockwave lithrotripsy (ESWL)
- external shockwave cause stone fragmentation by cavitation bubbles and mechanical stress
- uncomfortbale for patient
- CI: Pregnancy, AAA
- Ureteroscopy
- Ureteroscope passed retrograde through urethra and bladder into ureter
- Stone fragmented by laser or pneumatic fragmentation
- Stent can be placed
- Percutaneous Nephrolithotomy (PCNL)
- accessed the renal system percutaneously
- Stone fragmented and removed