Factors Accountable for Unabated Obstruction Following Pyeloplasty

Area of Science:

• Pediatric Urology
• Nephrology
• Radiology

Background:

• Split renal function (SFR) and frusemide washout (FWO) assessed by DTPA renography are crucial for evaluating renal parenchymal function and obstruction in pelviureteric junction obstruction.
• Persistent abnormal SFR and FWO post-pyeloplasty can cause significant parental and physician distress, often misattributed to
• defective pyeloplasty
• .

Purpose of the Study:

• To differentiate between irreversible kidney damage and pyeloplasty restenosis as causes of poor outcomes after pyeloplasty.
• To assess the role of DTPA renography in evaluating renal function post-pyeloplasty.

Main Methods:

• A retrospective study of 69 patients who underwent pyeloplasty with a double "J" (DJ) stent for 8 weeks.
• DTPA scans were performed preoperatively, at 8 weeks post-surgery (stent in situ), and at 12 and 24 months post-stent removal.

Main Results:

• 65.2% of patients showed improvement in SRF or FWO (or both) after 8 weeks with the DJ stent.
• 34.8% of units showed no change in renal function with the DJ stent in place.
• 8.7% of units experienced a deterioration in renal function after DJ stent removal.

Conclusions:

• Lack of renal function improvement with a DJ stent suggests irreversible renal damage.
• Reversal of renal function in 65.2% of units indicates successful pyeloplasty and stenting.
• Deterioration of renal function post-stent removal in 8.7% of units points to restenosis.