Stones < 5-mm and distal ureteral stones, will most likely spontaneously pass within 4 weeks, without the need for urologic intervention. Stones 5-10mm stones may be helped to pass with MET. Usually Tamsulosin 400 microgram OD.
- Common worldwide especially hot climates
- Seen in 10% population. Males > Females 2:1
- Chemicals come out of solution
- High urinary calcium (High PTH, Sarcoid, Vitamin D)
- High urinary oxalates, cystine
- Infection, renal tubular acidosis, polycystic kidneys
- Medullary sponge kidney
- Uric acid stones with ileostomies due to loss of bicarbonate
- Calcium oxalate/phosphate 65%
- Calcium phosphate alone 15%
- Magnesium ammonium phosphate 10%
- Uric acid 5% and Cystine 2%
- Severe pain or dull ache
- Concentrated urine in dry environment
- Renal stones, renal colic
- UTIs, urinary tract obstruction
- Ureteric obstruction
- Renal/Ureteric colic
- Leaking AAA should be considered - will be seen on CT
- U&E, LFTS, Ca, PO4, PTH, Urate
- Urinalysis: 90% have blood
- MSSU for culture
- CXR, ACEI if sarcoid suspected
- Plain AXR (KUB) sensitive in 44-77% and specific in 80-87%
- Renal USS but not so good for ureteric stones. Small less than 5 mm stones unlikely to be symptomatic.
- CT Renal sensitive in 94-100% and specific in 92-100%. If acute stones: within 24 hours of presentation) low-dose non-contrast CT to adults with suspected renal colic. If a woman is pregnant, offer an ultrasound instead of CT.
- Chemical analysis of the stone is useful
- Diagnostic uncertainty ? AAA
- Need for pain control
- Significant fever - surgical emergency
- Solitary kidney
- Worsening renal function
- Good hydration to encourage diuresis at least 2 L/day. No benefit of high volume. Antibiotics if urosepsis. If not causing any issues incidental stones can be ignored or monitored with X-rays. Analgesia for colic: Paracetamol and Diclofenac 75 mg IV infusion. If urosepsis: Treat as an emergency. Urology referral and admission, Intravenous antibiotics, Decompression with stent vs. nephrostomy
- After renal/ureteric it would be unusual to have urgent surgery unless associated renal infection - pyonephrosis and blocked ureter. This would mean a percutaneous nephrostomy or a ureteric stent to decompress and drain an obstructed kidney
- Treatment will vary according to the size and position of the stone or stones, and the facilities available locally. If the stone is small and in the lower ureter Medical Expulsive Therapy (MET) is used. Either Tamsulosin once a day) or occasionally calcium antagonists. MET is best for stones in the distal ureter greater than 5 mm.
- Ureteroscopy is the most frequently used surgical treatment for stones in the ureter that have not passed, or are not likely to pass, by themselves. The stones can be broken up. Often a stent is left in the ureter at the end of ureteroscopy, though this will be avoided if possible. Stents are temporary plastic tubes that keep the kidney draining. They can cause symptoms of cystitis and sometimes discomfort in the kidney while you are passing urine. They need to be removed at a later stage, usually by using a fine telescope into the bladder to grasp the stent and slide it out.
- Sometimes lithotripsy (ESWL see below) is used for ureteric stones. When the stone is in the kidney, the options are ureteroscopy (usually for stones up to 1-2cm, but sometimes larger), and may include flexible ureteroscopy, keyhole surgery or lithotripsy (ESWL). Keyhole surgery - percutaneous nephrolithotomy (PCNL) tends to be reserved for larger or harder-to-reach stones.
ESWL works best for smaller stones that are sited in the upper parts of the kidney, though it can work for virtually any stone. The procedure is carried out with analgesia. A 'shock head' is placed on the side of the abdomen or back, next to the kidney. The stone is then hit by focused sound waves, usually once or twice a second for up to about 3000 pulses per session. This breaks the stone into pieces that are small enough to be passed spontaneously with the urine. ESWL often needs to be repeated after a few days or weeks
- Long term avoid Berr which acidifies urine and increases uric acid excretion. Also, avoid soft drinks e.g. coke acidified by phosphoric acid rather than citric acid. Lemon and orange good and raise the pH of urine. Mineral water with bicarbonate is good.