Does Diversion in Poorly Functioning Obstructed Kidneys in Adults Favors Reconstructive Surgeries Over Ablative Procedures? A Prospective Study

Objective In obstructed poorly functioning kidneys, management depends on the recovery potential of the kidney. Some kidneys have good recovery capability and diversion may unfold the real condition of the kidney. This study evaluated whether pre-operative drainage for six weeks results in improvement of renal function in unilateral obstructed poorly functioning kidney with split renal function (SRF) less than 20%. Methods This was a prospective interventional study conducted between March 2013 and December 2015. All patients between 15 and 65 years, with unilaterally obstructed kidney with SRF ≤20% underwent percutaneous nephrostomy (PCN) drainage for six weeks. Patients having post-drainage SRF of ≥15% and per day urine output from PCN > 400 ml were considered for the reconstructive procedure. Nephrectomy was performed in cases with SRF <15% after considering patient preferences. Results Twelve of 17 patients had improvement in SRF; four had no change while one had a decrease in SRF after drainage. The mean improvement in glomerular filtration rate (GFR) and SRF was 1.4 ml/min and 3%, respectively (P = 0.08). Three out of seven patients with SRF of ≥15% showed an improvement of 5% or more while none of the patients with SRF <15% had such an improvement. Eight patients had final SRF <15% and underwent nephrectomy. Factors such as pre-existing SRF, duration of symptoms, kidney size, transverse pelvic diameter, 24-hour urinary output, and etiology for obstruction were not significant in predicting functional improvement. Conclusion Diversion and decompression of poorly functioning kidneys do not result in a significant functional improvement in obstructed kidneys with SRF <15%.