[Long-term follow-up of antegrade endopyelotomy. Factors that influence the outcome]

To find out the outcomes of endopyelotomy alter a long-term follow-up and determine the variables that may influence the results.

We review the results obtained in 77 patients that underwent antegrade endopyelotomy with ureteropelvic junction obstruction, after 10-year follow-up. We used the Kaplan-Meier curve in order to determine the probable failure rate at a certain point. We took measurements of the pyelocalix area and studied its shape to find out the influence of hydronephrosis in the outcomes. Other variables, such as renal function, previous surgery, lithiasis and renal malformation associated, were analysed.

Mean follow-up was 149.26 months. Faliure rate probability was 26.9, 34.5 and 36.8% a year, 5 years and 10 years later, respectively. Major failure concentration occurred in the first 20 months. Mean pyelocalix area success was 19.70 +/- 8.32 cm2 vs 30.19 +/- 11.07 cm2 of failure, (p=0,018). There were no differences between the values of the shape factor in either success and failure. (0,87 vs 0.88, p= 0.135, respectively). Renal function (45.1% success vs 40,9% failure, p=0,625), previous surgery (62% success after previous surgery vs 64.7% first procedure, p=0.843), and lithiasis associated (69.3% success through lithiasis vs 61.1% without lithiasis, p=0.541) did not affect the outcomes. Concomitance of hydronephrosis and renal malformation affected the outcomes negatively.

Endopyelotomy success rate reduces long-term follow-up, however, after the fifth year it becomes stable. Selecting cases to apply this technique according to the value of hydronephrosis area could improve the results.