酸性尿酸アンモニウム結石の1例

Abstract

18歳女.13歳時, 両側II度膀胱尿管逆流に対し両側膀胱尿管逆流防止術を施行されていた.また, 17歳頃よりダイエットを行ない, 1年間で24kgの体重減少があった.今回, 発熱を主訴とし, 膿尿と腹部超音波で左腎結石を指摘され, 両側腎結石と腎盂腎炎と診断した.抗生剤IPM/CS1g/dayの点滴静注による腎盂腎炎治療を先行させ, 左腎結石に対し, 体外衝撃波結石破砕(ESWL)を施行した.結石成分は酸性尿酸アンモニウム98%以上であった.DIPで完全排石を確認し, 退院した.本邦における尿酸アンモニウム結石の報告は12例を数えるに過ぎず, 稀な結石であると考えられる.本例では, ダイエットによる低栄養と緩下剤の常用が結石形成の原因となっていたと思われた

An 18-year-old female, who had undergone antireflux surgery for bilateral vesicoureteral reflux 5 years ago, was admitted to our department with complaints of fever and left-sided back pain. Bilateral renal stones and pyelonephritis were diagnosed after roentgenography, ultrasonography and urinalysis. Pyelonephritis was successfully treated with antibiotics and the left renal stone was completely disintegrated with extracorporeal shock wave lithotripsy. Spectrophotometric analysis revealed that the stone was composed of pure ammonium urate (AU). The patient had not experienced any episodes of urinary tract infection from the antireflux surgery until the present event, but had lost 20 kg in body weight during the last year due to a low-caloric diet and laxative abuse. AU urinary stones have been infrequently reported in Japan, and they are supposed to be associated with a low-caloric diet, laxative abuse, and anorexia nervosa.