Ureteroscopy-assisted retrograde nephrostomy for a large and obstructive renal pelvic stone: a case report.

<bold>Introduction: </bold>We have previously described the use of ureteroscopy-assisted retrograde nephrostomy. However, reaching the target calyx with the ureteroscope is difficult in patients with obstructive renal pelvic stones.<bold>Case Presentation: </bold>A 53-year-old Japanese woman was referred to our department for the treatment of a right renal stone. She was admitted to our department for percutaneous nephrolithotomy of a right renal stone located at her ureteropelvic junction. A Lawson retrograde nephrostomy puncture wire was subsequently inserted into the flexible ureteroscope, and we successfully punctured the calyx from the target spot to the skin. The nephrostomy was dilated, and the stone fragments were obtained and removed.<bold>Conclusions: </bold>We here report the case of a large and obstructive renal stone successfully treated with percutaneous nephrolithotomy using the ureteroscopy-assisted retrograde nephrostomy technique. [ABSTRACT FROM AUTHOR]