酸性尿酸アンモニウム結石の臨床的検討

Clinical study on ammonium acid urate urinary stones

　1988～2000年に当科で体外衝撃波砕石術を施行した上部尿路結石5,327例のうち，3,894例で結石分析可能で，酸性尿酸アンモニウム（AAU）の頻度は0.6％であった。カルテ検索できたAAU結石20例について，単一組成の6例と混合組成の14例を比較検討した。単一組成群は混合組成群よりも女性に多く，若年で，体格指数は低値であった。X線透過性結石は単一組成群の全例と混合組成群の6例であった。また，混合組成群とは異なる特徴として，単一組成群では血清電解質異常（5例），緩下剤常用（5例），心身症的背景（3例）が目立った。AAU結石は，単一組成群と混合組成群で異なる特徴を認めた。

　From 1988 to 2000,5,327 patients with upper urinary tract stones were treated by extracorporeal shock wave lithotripsy in our hospital. Ammonium acid urate（AAU）stone was 0.6％of 3,894 cases in which stone compositions were analyzed. The medical records of 20 cases of AAU stones（6 pure AAU and 14mixed AAU）were investigated. Pure AAU group tended to have young females with low body mass index compared with mixed AAU group. All of pure AAU group and 6 of mixed AAU group had radiolucent stones. Pure AAU group also had some distinctions such as abnormal serum electrolyte,laxative abuse,and inclination of psychosomatic ailment. Some differences were found out between pure AAU group and mixed one.