Kidney Stones
Stones in the urinary tract are a common cause of pain when the stones move from where they are formed in the kidney and cause obstruction of the ureter or parts of the kidney itself.
Risk Factors for kidney stones include:
- 1. family history
- 2. diet ( see the dietary guides for patients with uric acid stones and oxalate stones
- 3. inadequate hydration
- 4. small bowel disease such Crohn’s
- 5. medical conditions causing excessive calcium in the urine eg hyperparathyroidism
Sudden obstruction of ureter will cause severe colic, pain in the flank referred to genitalia (loin to groin), nausea, vomiting may be misleading and look like gastrointestinal problem. Microscopic blood in urine likely chronic or longstanding stones tends to be associated with large or multiple stones. There can be little or no pain. Patients may have impaired renal function, anemia or even weight loss and concomitant infection is more likely.
Urine analysis (expect to see microscopic blood in the urine), stones may cause infection.
KUB (Xray) (expect to see a calcification but 5% of stones are not seen on Xray
Ultrasound can be useful but is not specific enough CT scan is the most accurate and useful test.
Pain control
Pain with kidney stones may be severe and require drugs including paracetomol, non steroidals such as indocid suppositories and opiod drugs such as codeine containing drugs and morphine.
Small ureteral stones
These small stone have good chance of passage (<5 mm have 80% chance of passing over a few weeks). We generally allow time for these to pass (2-4 weeks) and thus allow the patient to avoid a procedure.
Larger stones or stones which are not moving
Lower ureteric stones may require ureteroscopic stone removal. Mid to upper ureteric stones may be treated with ureteroscopy and laser with or without prior stent insertion or less commonly, shock wave treatment. Shock wave treatment uses a focused pulse of sound waves to break up kidney stones. It is only suitable for certain stone types and locations.
Incidentally found stones in the kidney which are > 5mm in size have a 50% risk of becoming symptomatic. They may be observed with periodic imaging or treated with ureteroscopy and laser or shock wave lithotripsy. Kidney stones may have implications for travel insurance eligibility.
Ureteroscopic Stone Removal
Percutaneous Nephrolithotomy
Shockwave Lithotripsy
