Renal parenchymal thickness and urinary protein levels in patients with ureteropelvic junction obstruction after nephrostomy placement

Abstract

Objective: To assess recovery of renal parenchymal thickness and urinary protein levels in patients with severely hydronephrotic kidneys after nephrostomy placement. Methods: Fourteen patients (median age 1 year, range 6 months-7 years) who underwent nephrostomy placement for unilateral ureteropelvic junction obstruction at our hospital between May 2007 and January 2009 were included in a retrospective analysis. All patients had severe hydronephrosis, with a median parenchymal thickness of 1.8 mm (range 1-2.5 mm). Kidney morphology was examined by ultrasound before the procedure and 1, 2, 3, 4, 6 and 8 weeks after. Urinary proteins (including albumin, immunoglobulin [IgG], a2-macroglobulin, a1-microglobulin, b2-microglobulin [b2-MG] and kappa chain) and creatinine levels were also tested during these follow-up visits. Fifteen healthy children were assessed for urinary protein levels as well and made up the control group. Results: Parenchymal thickness increased within 4 weeks of nephrostomy placement. Kidney volumes were significantly decreased within 2 weeks. No further changes in morphology were detected after 4 weeks. Urinary a1-microglobulin and b2-MG levels decreased to baseline within 1 and 4 weeks, respectively. Urinary albumin, IgG, a2-macroglobulin and kappa chain levels decreased gradually after nephrostomy, but did not return to baseline within 8 weeks. Conclusions: After nephrostomy placement, parenchymal thickness increases within 4 weeks, tubular function returns to normal earlier than glomerular function and glomerular membrane repair is inversely correlated with the severity of damage.

Full blown nephrotic syndrome due to unilateral obstruction of the uretero‐pelvic junction

“…It was suggested that persistent obstruction is associated with severe glomerular membrane damage, resulting in lower leakage of larger proteins, yet, higher leakage of smaller proteins. However, nephrotic syndrome was not reported in these children . In conclusion, unilateral partial UPJ obstruction can be a cause of full‐blown nephrotic syndrome.…”

“…However, nephrotic syndrome was not reported in these children. 2 In conclusion, unilateral partial UPJ obstruction can be a cause of full-blown nephrotic syndrome.…”

To Save or not to Save the Kidney: Relieving Unilateral Obstruction May Significantly Improve an Initially Low Split Renal Creatinine Clearance

“…In the literature, there are some studies reporting that a 4-week follow-up might be sufficient to evaluate the recovery of renal functions. Deng et al (22) evaluated improvement of renal function in patients with ureteropelvic junction obstruction after insertion of nephrostomy and reported that paranchymal thickness increases in 4 weeks and tubular function returns to nearly normal levels in this period. In another study, Shokeir et al (20) evaluated renal resistive index and reported that at the first week of relief of obstruction, the mean resistive index significantly decreased and stabilized till to the 4 th week.…”

Excessive urinary tract dilatation and proteinuria in pregnancy: a common and overlooked association?

“…The possibility that urinary tract obstruction may occasionally cause proteinuria outside of pregnancy is well known, even if not frequently reported [9-11]; its degree is usually sub-nephrotic and its pathogenesis is usually related to increased pressure in the renal pelvis, leading to a diuretic response from the contralateral kidney. Proteinuria caused by kidney obstruction is usually mild and considered of tubular origin, although different mechanisms may be operating [12,13].…”