Assessment of ureteric jets as a supportive diagnostic modality for unilateral pelvi-ureteric junction obstruction and its utility in follow-up: A pilot study

Abstract

Pelvi-Ureteric Junction Obstruction (PUJO) is a common cause of hydronephrosis (HDN) in children. While ultrasonography (USG) is useful for initial assessment and grading of hydronephrosis, it cannot differentiate obstructive from non-obstructive cases. Renal Dynamic Scintigraphy (RDS) confirms the diagnosis but involves ionizing radiation exposure. Ureteric jets using colour Doppler USG have been proposed for diagnosing obstructive HDN. Our study aimed to evaluate Ureteric Jet Frequency (UJF) and Relative Jet Frequency (RJF) in unilateral PUJO before and after furosemide (Lasix) administration, assessing their diagnostic and post-operative utility. Children (<14 years) with unilateral HDN underwent USG and RDS for PUJO diagnosis. Pyeloplasty was performed based on standard criteria. UJF and RJF were assessed before and after furosemide administration (0.5mg/kg) by colour Doppler USG. The non-obstructed side was taken as the control. Follow-up included repeat RDS and ureteric jet assessment. Fifty-two cases were included. UJF (pre- and post-Lasix) was significantly lower in the obstructed side compared to the non-obstructed side at baseline and post-pyeloplasty (p<0.0001). However, the baseline UJF difference between cases and controls was not significant (p>0.05). UJF and RJF (pre- and post-Lasix) increased postoperatively. The UJF difference decreased postoperatively (p<0.05). (attached Table) CONCLUSION: UJF and RJF are useful for diagnosing and monitoring unilateral PUJO. The effect of furosemide on UJF needs to be assessed using additional studies with larger sample sizes to understand if it can affect UJF in a way similar to that noted in diuretic scintigraphy.