Characteristics of patients with staghorn calculi in our experience.
OBJECTIVE
To elucidate the factors contributing to staghorn stone formation in patients.


METHODS
The records of 82 patients (44 men and 38 women) with complete staghorn calculi were reviewed retrospectively for clinical presentation, metabolic disturbances and anatomical abnormalities.


RESULTS
There were 79 unilateral and three bilateral cases. The patient performance of the activities of daily life was assessed with the modified Rankin scale (MRS) and it was found that 69 patients were functionally independent (84.1%, MRS 0-1) and 10 patients had a severe disability (12.2%, MRS 4-5). Seven patients had chronic indwelling catheters (8.5%). A positive urine culture was found in 24.4% of patients. Analysis of stone composition revealed magnesium ammonium phosphate and mixed calcium oxalate-phosphate were the most frequently identified types of stone (32.1% and 22.2%, respectively). Urinary pH was low in patients with uric acid stones (mean 5.4). Hyperuricemia, cystinuria and hypercalciuria were found in 14.6%, 2.4% and 37.8%, respectively. Hypercalciuria was found more frequently in calcium-stone cases. Eleven patients (13.4%) showed structural abnormalities of the kidney.


CONCLUSIONS
Our data show that the patients with severe disability, urinary tract infection and hypercalciuria could be recognized more frequently in staghorn calculi compared with common urolithiasis. However, in Western countries, the frequency of both urinary tract infection and struvite stones is much higher than in our data. Other Japanese authors have also reported the low frequency of struvite stones in staghorn calculi, suggesting that various factors other than urinary tract infection possibly contribute to the formation of staghorn calculi in Japan.
Akagashi
Keigo
K
Department of Urology, Sanjukai Hospital, Sapporo, Hokkaido, Japan. akagashi@sanjukai.or.jp
Tanda
Hitoshi
H
Kato
Shuji
S
Ohnishi
Shigeki
S
Nakajima
Hisao
H
Nanbu
Akihito
A
Nitta
Toshikazu
T
Koroku
Mikio
M
Sato
Yoshikazu
Y
Hanzawa
Tatsuo
T
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D002118:Calcium / Q000652:urine; D002129:Calcium Oxalate / Q000032:analysis; D002130:Calcium Phosphates / Q000032:analysis; D002408:Catheters, Indwelling; D003555:Cystinuria / Q000150:complications; D005260:Female; D006801:Humans; D006863:Hydrogen-Ion Concentration; D033461:Hyperuricemia / Q000150:complications; D007668:Kidney / Q000002:abnormalities; D007669:Kidney Calculi / Q000737:chemistry* / Q000150:complications* / Q000175:diagnosis / Q000628:therapy; D017616:Magnesium Compounds / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010710:Phosphates / Q000032:analysis; D012189:Retrospective Studies; D000069877:Struvite; D014527:Uric Acid / Q000032:analysis; D014552:Urinary Tract Infections / Q000209:etiology; D014556:Urine / Q000382:microbiology / Q000502:physiology
D002130:Calcium Phosphates; D017616:Magnesium Compounds; D010710:Phosphates; D002129:Calcium Oxalate; D014527:Uric Acid; D000069877:Struvite; D002118:Calcium