Is decreased diameter of renal pelvis in prone position an indicator of successful pyeloplasty?

OBJECTIVE

To evaluate patients who had undergone pyeloplasty for pelviureteric junction obstruction, by measuring the anteroposterior diameter (APD) of the renal pelvis in supine and prone positions, and determine whether a decrease in APD in prone position can exclude obstruction in dilated renal system.

MATERIALS AND METHODS

From January 2012 to December 2013, patients who had undergone pyeloplasty were evaluated by ultrasound in two centers. The difference of APD of the renal pelvis in supine and prone positions was obtained. Correlation was made with the pre- and post-pyeloplasty renal function by radionuclide renogram.

RESULTS

There were 42 patients (31 males, 11 females; age range 5 months to 18 years). Residual hydronephrosis was detected in 41 patients of whom 35 patients (85%) showed decrease in APD by >10% in prone position. These patients and the one without hydronephrosis showed either no deterioration or improvement in renal function. Six patients (15%) showed either no change or increase in APD in prone position. Three patients (7.5%) were confirmed to have decrease in renal function indicating obstruction. Three patients (7.5%) showed no deterioration of renal function, but sluggish drainage on radionuclide renogram.

CONCLUSION

Demonstration of decreased APD of renal pelvis in prone position by ultrasound is useful to differentiate obstructed from non-obstructed dilated renal system, and it correctly identified 85% candidates with successful pyeloplasty. In patients with no decrease or increase in APD at prone position, further follow-up is recommended to rule out obstruction.

Crossing Vessel in Pelvi Ureteric Junction Obstruction: A Histopathological Analysis

OBJECTIVE

The aim of the study is to identify whether crossing vessel is a cause or an associated finding in Pelvi Ureteric Junction Obstruction.

MATERIAL AND METHODS

This is a prospective study of a total of 128 patients who underwent laparoscopic pyeloplasty from January 2016 to June 2020. All patients who underwent laparoscopic pyeloplasty and pelvi ureteric junction segments were sent for histopathological examination. The presence of crossing vessels is documented intraoperative and patients were divided into two groups, group 1 having pelvi ureteric junction obstruction with crossing vessel, and group 2, pelvi ureteric junction obstruction without crossing vessels. Histopathological examination findings of pelvi ureteric junction segment including inflammation, fibrosis, muscle hypertrophy, muscle disarray, and synaptophysin were recorded. Unpaired Student t-test was used for comparing differences between continuous normally distributed data from 2 samples and non-parametric tests were applied for continuous data.

RESULTS

Of the total 128 patients, crossing vessels were identified in 42 (32.8%), and 86 (67.2%) were without crossing vessels. The demographic profile of patients between the 2 groups was comparable. On histopathological examination, moderate-to-severe chronic inflammation was seen in 23.8% and 44.2% (P > .05) in group 1 and group 2, respectively; fibrosis and muscular hypertrophy were higher in group 2 but statistically insignificant (P > .05), and muscle disarray was higher in group 1 but statistically insignificant (P > .05). Synaptophysin was positive in 4.8% and 4.7% in group 1 and group 2, respectively.

CONCLUSION

The differences in histopathological examination between the 2 groups were not statistically significant. However, in patients with crossing vessels, there was a higher degree of inflammation, which may lead to early pelvi ureteric junction obstruction.