Functional outcome after pyeloplasty for unilateral symptomatic hydronephrosis.

The functional outcome and factors influencing improvement after pyeloplasty for ureteropelvic junction (UPJ) obstruction are still debated. This retrospective study was aimed at evaluating the factors associated with functional improvement in symptomatic unilateral hydronephrosis (HDN). Patients (n = 68) who underwent successful pyeloplasty for unilateral symptomatic UPJ obstruction without any other associated urological abnormality were included. Preoperative evaluation included a diuretic renogram (DR) to confirm obstruction and assess the split renal function (SRF). A follow-up DR was obtained 3 months and 1, 2, and 5 years postoperatively. An absolute increase in the differential function of the operated kidney by over 5% was considered significant; such kidneys were classified as improved (group A) and the others as unimproved (group B). The difference between the preoperative and 3-month SRF was highly significant (P < 0.001). Significant (P < 0.01) improvement in SRF continued until 1 year after pyeloplasty. Patients who presented with a mass had significantly greater improvement (P < 0.05) than those who presented with other clinical features. In group A, a significantly higher number of patients presented with a mass. It was also evident that patients aged less than 1 year showed significantly greater (P < 0.01) improvement in SRF than older patients. Thus, in unilateral symptomatic HDN with impaired function, patients who present with a mass or those in whom pyeloplasty was performed before 1 year of age showed significantly greater improvement.