Does endoscopic sclerotherapy in filarial chyluria affect renal function and morphology? A prospective study using dimercaptosuccinic acid renal scan

Objective: To look for change in relative renal function and document renal scarring following endoscopic renal pelvic instillation sclerotherapy (RPIS) in patients with chyluria by dimercaptosuccinic acid (DMSA) renal scan.

Methods: A prospective study was performed between November 2015 and September 2016. All patients with biochemically documented chyluria who underwent RPIS using either 1%-silver nitrate or 0.1%-povidine iodine were included. Patients received either 3-, 6- or 9-doses. DMSA renal scan was performed before and 2-3 months after sclerotherapy.

Results: Of the 34 patients, 22 were males. Mean age was 41.08 ± 16.64 years (range, 15-70 years). Thirty-two patients (94.1%) responded to therapy while two did not respond even after 9-doses. Average follow-up was 8.94 ± 3.70 months. The mean relative renal function (pre-instillation) of normal kidney was 50.76% ± 3.55% while that of affected renal unit (side of instillation) was 49.20% ± 3.44% (range, 43.0%-61.0%). After instillation therapy, the mean relative renal function of normal side was 52.26% ± 3.57% while that of affected renal unit was 47.50% ± 3.56% (range, 41.0%-54.0%). The relative renal function did not change >5% from the baseline value in any patient except one (in which the differential function increased paradoxically by 12%). Two patients developed renal scar in post-instillation renal scan.

Conclusion: Endoscopic sclerotherapy in chyluria is safe and effective. The relative renal function does not deteriorate by more than 5%. There is a small risk of development of renal scar. More studies involving larger number of patients are needed to answer this dilemma.