Objective: To study the predictive value of 6 ultrasonographic (USG) parameters for early detection of children at risk of recurrent obstruction.
Patients and methods: A prospective nonrandomized study included all patients who underwent pyeloplasty between 2010 and 2012. All of the patients had completed at least 6 months of follow-up and preoperative and postoperative USG imaging data were available. The primary outcome was the correlation between USG and diuretic scintigraphic parameters. The secondary outcome was the predictive ability of the pelvicalyceal system parameters, measured by USG, of parenchymal growth after surgery.
Results: Sixty-eight patients were evaluated. The mean age was 3.6 years (range 0.1-12). The mean (± standard deviation) differential renal function improved from 37.4 ± 11 ml/min to 37.7 ± 14 ml/min, which was a difference of no statistical significance. On the other hand, the mean (± SD) half-time (T1/2) significantly improved. After constructing a linear regression model of the 4 USG parameters and the parenchymal growth, the model explained 57.2% of the variance in parenchymal growth after pyeloplasty. The calyx-to-parenchyma ratio change was the largest unique contribution for explaining the variance in parenchymal growth, followed by anteroposterior diameter and calyceal dilatation.
Conclusion: We proved that calyx-to-parenchyma ratio, anteroposterior diameter and calyceal dilatation are independent predictors of early success after pyeloplasty.