Large renal stones which occupy the renal pelvis, branching in to one or more calyces.
PCNL is the recommended first line treatment for staghorn calculi.
Exceptions – non-functioning/poorly functioning or XGP kidney may be better treated with nephrectomy – consider MAG3/split function before treatment.
Most commonly made of struvite (magnesium ammonium phosphate), associated with alkaline urine and urease producing bacteria. These need complete clearance ideally.
Occasionally uric acid or cystine.
Natural history
Papers from Blandy and Singh in the 70s argued all staghorn calculi should be treated surgically and that surveillance was associated with mortality of 28 %. Half of patients observed ended up needing nephrectomies for pyonephrosis. All others apparently developed symptoms – i.e. none remained asymptomatic.
Next large series (Teichman 1995) showed an overall renal deterioration in 28 %, most often seen in those who refused treatment, neurogenic bladders, single kidneys and those with previous stones.
Another recent series (Deutsch 2016) followed patients who were not fit for or declined surgery for a mean of 8 years – 14 % developed progressive renal failure, 9 % required dialysis, 9 % died related to stones (both had bilateral staghorns).
Approach to staghorn stones:
- History – fitness for surgery, co-morbidities, baseline renal function, UTIs, coagulopathies, symptoms (pain, infection, haematuria)
- Split function assessment – MAG3 or DMSA
- Urine culture for infection (?urease producing)
- CT and XR
- If fit for surgery -> PCNL
- If < 15 % function -> nephrectomy
- If not fit for surgery
- Anaesthesia / peri-op medical / renal physician reviews
- Renal physician referral for potential deterioration
- Antimicrobial prophylaxis if needed