Kidney folding: the Y-plasty--a means of creating a dependent ureteropelvic junction in the child with giant hydronephrosis

PURPOSE: Occasionally, in the presence of severe dilatation and parenchymal thinning, postoperative obstruction or stasis may secondarily occur even after creation of a funneled ureteropelvic junction. Preferential filling of a severely dilated lower pole may kink or distort the ureteropelvic junction, causing this problem. MATERIALS AND METHODS: A requirement for renal folding is a large hydronephrotic kidney with severe mid renal parenchymal thinning. After pyeloplasty if it is apparent that secondary obstruction is a possibility, and simple lateral or posterior fixation of the lower pole to retroperitoneal fascia will not resolve the problem, the lower pole can be brought superiorly adjacent to the upper pole and fixed in position with 2 or 3, 2-zero or 3-zero polyglactin sutures, creating a "Y" configuration with the ureteropelvic junction dependent from all calices. We reviewed the records of 5 children who underwent this procedure. RESULTS: Five patients with severe upper tract dilatation were treated successfully. Four underwent primary pyeloplasty with concomitant renal folding, and 1 had persistent hydronephrosis with recurrent pyonephrosis before undergoing this procedure secondarily. All patients achieved excellent results with normal drainage postoperatively. CONCLUSIONS: Renal folding is a simple surgical maneuver that can be applied easily and successfully when the situation warrants. It allows creation of a dependent, funneled ureteropelvic junction in the presence of giant hydronephrosis.