[A case of stone formation in the Mainz pouch using appendix as the efferent limb: a case report].

A large calculus (6.0 x 4.5 x 7.0 cm sized) in the continent urinary pouch was detected incidentally by computed tomography in a 7-year-old man with a gall bladder stone. He underwent a total cystectomy and Mainz pouch formation using appendix as the efferent limb for bladder cancer 7 years ago. Urine culture showed Proteus mirabilis and Escherichia coli, and urine pH was 8.5. The stone was removed successfully through a pouchotomy and composed mainly of struvite. The stone analysis was MAP; 88% and CaCO3; 12%. Convalescence was uneventful. This is the first case of in Mainz pouch using appendix as the efferent limb.