Informative title: Calyceal plication with Anderson-Hynes pyeloplasty in a 7-year-old boy with a giant hydronephrosis of the single right kidney Short title: Calyceal plication with pyeloplasty of a giant hydronephrotic kidney

A 7-year-old boy presented with distended abdomen without any other complaints. A plain abdominal radiograph demonstrated an extremely large soft tissue shadow that occupied right and part of the left hemiabdomen. Ultrasound revealed large hydronephrotic right kidney that occupied whole abdomial cavity without visualization of the left kidney. Dynamic scintigraphy confirmed extreme renal functional damage of the single right kidney. Operation was not indicated according to significant renal impairment. Percutaneous nephrostomy was made. After 9 months with slight functional renal improvement operation was indicated. At operation ureteropelvic junction obstruction was found and Anderson-Hynes pyeloplasty was made with calyceal plication of dilated calyces. Postoperative scintiscans and serial sonographies showed preservation of renal parenchyma with slight functional improvement. This modification of Anderson-Hynes pyeloplastys obviated the need for nephrectomy and was especially valuable in this patient with giant hydronephrosis of the single kidney when nephrectomy would inevitably lead to dialysis and subsequent renal transplantation.