Risk Factors for Recurrent Ureteropelvic Junction Obstruction After Open Pyeloplasty in a Large Pediatric Cohort

PURPOSE: Recurrent ureteropelvic junction obstruction after open pyeloplasty is a serious complication for which treatment remains challenging. We identified risk factors for persistent obstruction. MATERIALS AND METHODS: We retrospectively reviewed the charts of 401 children who underwent open dismembered pyeloplasty between 1997 and 2005. Of these children 21 (5.2%) experienced recurrent ureteropelvic junction obstruction. Age, prenatal diagnosis, hydronephrosis grade, differential renal function, incision location (flank or dorsal lumbotomy), retrograde pyelography and stent placement were analyzed. Univariate and multivariate analyses were performed to identify risk factors for pyeloplasty failure. RESULTS: Median age at surgery was 21 months and median followup was 36 months. Of the 401 patients dorsal lumbotomy was performed in 171 (42.6%) and a flank incision was used in 230 (57.4%). Retrograde pyelography was done in 195 patients (48.6%) and stents were used in 352 (87%). Age, prenatal diagnosis, degree of hydronephrosis, differential renal function and stent placement did not have an impact on pyeloplasty outcome on univariate analysis. Recurrent ureteropelvic junction obstruction developed in 14 of 171 patients who had originally undergone dorsal lumbotomy vs 7 of 230 who had originally undergone a flank incision (8.1% vs 3.1%, p = 0.02) as well as in 17 of 206 who did not undergo initial retrograde pyelography vs 4 of 195 who did (8.3% vs 2.1%, p = 0.005). On multivariate analysis incision type and lack of retrograde pyelography showed significant association with pyeloplasty failure despite adjustment for other risk factors (p <0.05, OR 3.2 and 4.4, respectively). CONCLUSIONS: In this series lack of retrograde pyelography and dorsal lumbotomy were independently associated with a higher risk of recurrent ureteropelvic junction obstruction. While retrograde pyelography or a flank approach could not be directly shown to prevent recurrent ureteropelvic junction obstruction, electing to perform retrograde pyelography may be a proxy for better perioperative planning, including the choice of incision, and it may ultimately increase the chances of successful pyeloplasty.