Assessment of difficult renal stones
Foo, K.T.
Singapore Medical Journal 27(6): 507-511
1986
ISSN/ISBN: 0037-5675 PMID: 3589721 Document Number: 273283
The difficult renal stones are the Staghorn stones, stones which cause calculous anuria and acute infections, the recurrent stones and the uric stones. It is emphasised that the Staghorn stones if left untreated eventually will destroy the kidney but usually over a period 5 to 10 years. In relatively young and fit patient therefore all Staghorn Stones should be removed, though asymptomatic stones in older and unfit patients can be left alone. In patient with acute infection due to stone; blood culture is more reliable than urine culture. In our local population, there is relatively a higher incidence of abnormal uric acid metabolism than abnormal calcium metabolism. Patient with uric acid abnormally can be treated with allopurinol and pure uric acid stones can be dissolved with alkalinisation of urine without surgery. Intravenous urogram (IVU) is the most important radiological assessment. In acute obstruction, excretion may be poor, even in delayed film, however, a repeat IVU in a week or two would delineate the site and degree of obstruction without the need for retrograde pyelogram. Ultrasound is useful in assessing uraemic patient with calculus anuria to detect hydronephrosis. Percutaneous nephrostomy can be used to relieve the acute obstruction and hence treat the final failure without the need for dialysis, before definitive procedure.