Surgical treatment and outcome of mega-hydronephrosis due to pelviureteric junction stenosis.

To study the surgical treatment and outcome of hydronephrosis secondary to pelviureteric junction obstruction (PUJS) that is so massive that the renal pelvis crosses over the vertebral column [mega-hydronephrosis (MH)]. Of the 40 cases of PUJS we treated over the past 5 years, 6 cases had MH secondary to PUJS (MH-PUJS) in 6 renal units and were reviewed. Incidence of MH was 15.0%. All had Anderson-Hynes dismembered pyeloplasty to treat obstructive renal pattern on technetium-99m diethylenetriaminepentaacetic acid (DTPA) scans in five and gait disturbance due to MH in one. The contralateral kidney was normal in five and dysplastic in one. Three had nephrostomy before pyeloplasty. Preoperative DTPA scans showed good renal function in four and poor in two. Plication of the entire dilated, lax renal parenchyma ("nephroplication") was performed in three to decrease the intra-renal pelvic cavity. Prenatal diagnosis was performed in three cases. Mean age at pyeloplasty was 3.5 years and mean duration of follow-up was 1.5 years. Postoperatively, two of the three who did not have nephroplication had prolonged but not obstructed renal pattern on DTPA scans, and the other case who did not have nephroplication had nephrectomy for non-functioning kidney caused by recurrent pyelonephritis 2 years after pyeloplasty. In the three who had nephroplication, DTPA scans showed acceptable to relatively good passage in all cases. The surgical treatment of MH-PUJS is challenging with no fixed guidelines. However, nephroplication may be useful during pyeloplasty to decrease the size of MH-PUJS.