New drainage technique in the ureteropelvic junction obstructions. Side-to-side ureterocalicostomy (or ureterocaliceal by-pass) preserving renal pelvis and ureteropelvic junction.

We present a new ureterocalicostomy technique in a patient with intrarenal pelvis together with renal artery compression on the pelvis and ureteropelvic junction (UPJ). The patient had grade 4 hydronephrosis in the left kidney and angulation at the ureteropelvic junction. We performed side-to-side ureterocalicostomy between the ureter and lower calyx of the kidney.