逸脱尿道ステントを核とした膀胱結石

Vesical stone formation around migrating urethral stent

　症例は96歳，男性。血膿尿を主訴に当科を受診した。KUBにて膀胱結石および膀胱内に逸脱した尿道ステントを核とした膀胱結石を認めた。経尿道的な摘出を試みたが摘出できず，膀胱高位切開術にて摘出を行った。結石成分は尿酸100％であった。

We recently experienced a case of vesical stone forma-tion around intraprostatic spiral stent composed of titan-ium nickel alloy with shape memory effect (Memokath,Engineers & Doctors A/S, Hornbaek, Denmark). We placed the Memokath in 1997 and soon after, we observed migration of the stent by X-ray, which he rejected to be replaced. He presented with hema-topyuria in Noveneber 1999 and we finally performed vesicolithotomy to remove Memokath surrounded with stone which was uric acid stone.