The clinical significance of detecting renal urinary proteins through nephrostomy tube in children with extremely severe hydronephrosis

Abstract

Objective To explore the change of urine proteins from nephrostomy tube and renal function in patients with very severe hydronephrosis after nephrostomy in order to determine the treatment strategy of either renal preservation or resection. Methods Retrospective analysis of clinical data from March 2015 to March 2017 of 28 cases with congenital unilateral severe hydronephrosis in children's hospital affiliated to Zhejiang University, including 19 boys and 9 girls, with 20 cases on the left and 8 on the right, an average age of 26.6 (0.3 to 122.0) months at the first consultation and 2 cases of urinary biochemical abnormalities. Front to rear diameter for puncture were between 5.7 and 7.6 cm, with an average of 6.7 cm, and the differential renal function (DRF) for the affected kidneys were 6.98 %-9.89 % (average 8.65 %) before puncture. The children underwent percutaneous renal perforation fistula. According to the recovery of renal function after perforation fistula, those who underwent nephrectomy were recruited as a nephrectomy group and the children whose kidney were preserved as kidney preservation group. Comparison 24 hours before and 3 months after puncture was made beteween groups regarding the proportion of urine, pH of the renal pelvis urine, α1 microglobulin (α1-MG), albumin (Alb), β2 microglobulin (β2-MG), immunoglobulin G (IgG), transferrin (TRF), and the recovery of the damaged renal function (direnal function DRF). Results Twenty-eight cases of percutaneous nephrolithotomy were successful without puncture complications, with 10 cases in the nephrectomy group and 18 cases in the renal preservation group. The difference of renal pelvis urine from the affected kidney of the nephrectomy group showed no statistical significance 24 hours before and 3 months after the procedure when comparing the following parameters, including urinary specific gravity (1.006±0.007 vs. 1.009±0.005), pH value (7.74±0.41 vs. 7.70±0.32), urine creatinine value [(462.20 ±158.01)μmol/L and (449.20±143.41) μmol/L], α1 microglobulin [(14.03±4.360) mg/L vs. (13.84±2.55) mg/L], β2 microglobulin [(0.76±0.28) mg/L vs. (0.65±0.14) mg/L], immunoglobulin G [(1 292.20±303.50) mg/L vs. (1 175.33±376.67) mg/L], and kidney function (DRF) [(8.86±0.67) % vs. (9.90±1.26)%]. While microalbumin [(8 644.40±829.54) mg/L vs. (3 145.10±1 445.02) mg/L] and transferrin [(445.70±46.71) mg/L vs. (214.30±40.13) mg/L, P 0.05). The creatinine value of 3 months after the procedure was significantly increased than that 24 hours within the procedure [(654.50±154.52μmol/L) vs. (423.94±172.74)μmol/L], and the urine pH (7.28±0.32 vs. 7.91±0.56), α1 microglobulin [(5.85±0.38)mg/L vs. (12.58±3.40)mg/L], microalbumin [(571.50±167.14)mg/L vs. (2 343.28±576.22)mg/L], β2 microglobulin [(0.14±0.05)mg/L vs. (0.53±0.13) mg/L], immunoglobulin G [(247.38±75.29)mg/L vs. (1 026.44±245.42)mg/L], and transferrin [(67.64±16.34)mg/L vs. (249.17±78.62) mg/L] were significantly decreased 3 months after than 24 hours before the procedure. The renal function was higher 3 months after than 24 hours within the procedure [(8.53±0.80)% vs. (20.50±7.87)%, P<0.05]. Conclusions The increase of creatinine value and the decrease of urine pH, α1 microglobulin, microalbumin, β2 microglobulin, immunoglobulin G and transferrin in renal pelvis urine suggested that renal function recovered after renal puncture, which is important for next-step plan of treatment strategy. Key words: Hydronephrosis, severe; Urine protein; Children; Percutaneous nephrostomy