Is there a best alternative to treating the obstructed upper pole?

We addressed whether salvage of upper pole renal units in comparison to partial nephrectomy affects differential renal function in patients with a duplicated obstructed upper pole.

We retrospectively reviewed the records of all children who underwent surgery for a unilateral obstructed duplicated kidney at our institution from 1988 to 1995. Patients were evaluated with respect to postoperative complications, reoperation rate and percent change in differential renal function of the obstructed duplicated kidney, as determined by nuclear renography.

We identified 46 patients with a unilateral obstructed upper pole of a duplicated kidney who were divided into 2 groups. Group 1 (12 patients) underwent an upper pole salvage procedure, that is ureteropyelostomy or ureteroureterostomy, and group 2 (31 patients) underwent partial nephrectomy. Three reoperations (25%) were performed in group 1 and 1 (4%) was done in group 2. Postoperative symptomatic urinary tract infections were diagnosed in 3 group 1 patients (25%) and in 2 (8%) in group 2. Average change in ipsilateral renal function in the 8 patients who underwent upper pole salvage procedures was 2.25 +/- 2.34% (range -6 to 12). In the 8 patients who underwent upper pole nephrectomy and who also had postoperative renal scans average change in function was -1.25 +/- 4.51% (range -23 to +16).

There was no statistically significant loss of relative renal function in patients treated with partial nephrectomy and no significant gain in relative renal function in those treated with an upper pole salvage procedure. The reoperation rate was higher in the upper pole salvage than in the partial nephrectomy group (25 versus 4%). While not statistically significant, we believe that this rate is clinically important. We think that partial nephrectomy should remain the preferred treatment for most patients with obstructed duplicated kidneys.