Authors
1 Department of Pediatric Nephrology, Isfahan Kidney Diseases Research Center, Isfahan Child Growth and Development Research Center, Isfahan, Iran
2 Department of Physiology, Water and Electrolytes Research Center, Kidney Diseases Research Center, Isfahan, Iran
3 Department of pediatrics, Isfahan Kidney Diseases Research Center, Isfahan Child Growth and Development Research Center, Isfahan University of medical sciences, Isfahan, Iran
4 Department of Urology, Isfahan Urology and Kidney Transplantation Research Centre, Isfahan, Iran
Abstract
Background: Renal maldevelopment, interstitial fibrosis, ischemic atrophy, decreased glomerular filtration rate (GFR), and renal blood flow (RBF) are inevitable consequences of chronic kidney obstruction that only partially improve after early intervention. There are only few studies that evaluated urine osmolality in affected kidney and its correlation with short-term outcome.
Materials and Methods: Thirty patients (age<1 year) with unilateral ureteropelvic junction obstruction (UUPJO) were enrolled in this study. UUPJO was confirmed using Technetium 99 isotope scans and the patients were indicated to be operated afterward. Urine and blood samples were obtained before, 24, 48, and 72 h after the surgery. The serum level of blood urea nitrogen, creatinine, and glucose were measured. GFR, urine osmolality (measured and calculated), and urine specific gravity were determined too.
Results: Cortical thickness of hydronephrotic kidney was significantly increased 6 months after the surgery. GFR was significantly increased 72-h postsurgery compared to before operation.
Neither means of calculated nor of measured urine osmolalities were significantly different in various stages. The last calculated urine osmolality (72 h) had significant correlation with the last measured osmolality (72 h); r0=0.962, P=0.0001. The last GFR (72 h) had positive significant correlation with GFR before the surgery and GFRs at 24 and 48 h postsurgery.
Using regression tests, only the before surgery GFR was the predictor of the last GFR(72 h).
Conclusion: In UUPJO the measured and calculated urine osmolality of the affected kidney did not differ.
In addition, GFR before surgery should be considered as the predictor of the GFR shortly after repair.
Keywords
1. | Liu BD. Antenatal Hydronephrosis. Available from: http://www.emedicine.medscape.com/article/1016305-overview. [Last accessed on 2011 Nov 22]. |
2. | Thomas DF. Fetal uropathy. Br J Urol 1990;66:225-31. |
3. | Chevalier RL, Chung KH, Smith CD, Ficenec M, Gomez RA. Renal apoptosis and clusterin following ureteral obstruction: The role of maturation. J Urol 1996;156:1474-9. |
4. | Chevalier RL, Gomez RA, Jones CE. Developmental determinants of recovery after relief of partial ureteral obstruction. Kidney Int 1988;33:775-81. |
5. | Josephson S. Suspected pyelo-ureteral junction obstruction in the fetus: When to do what? II. Experimental viewpoints. Eur Urol 1991;19:132-8. |
6. | Madarikan BA, Hayward C, Roberts GM, Lari J. Clinical outcome of fetal uropathy. Arch Dis Child 1988;63:961-3. |
7. | Reznik VM, Murphy JL, Mendoza SA, Griswold WR, Packer MG, Kaplan GW. Follow-up of infants with obstructive uropathy detected in utero and treated surgically post-natally. J Pediatr Surg 1989;24:1289-92. |
8. | Mesrobian HG. The value of newborn urinary proteome analysis in the evaluation and management of ureteropelvic junction obstruction: A cost-effectiveness study. World J Urol 2009;27:379-83. |
9. | Mesrobian HG, Mitchell ME, See WA, Halligan BD, Carlson BE, Greene AS, et al. Candidate Urinary Biomarker Discovery in Ureteropelvic Junction Obstruction: A Proteomic Approach. J Urol 2010;184:709-14. |
10. | Drube J, Zürbig P, Schiffer E, Lau E, Ure B, Glüer S, et al. Urinary proteome analysis identifies infants but not older children requiring pyeloplasty. Pediatr Nephrol 2010;25:1673-8. |
11. | Edelmann CM Jr, Barnett HL, Stark H, Boichis H, Soriano JR. A standardized test of renal concentrating capacity in children. Am J Dis Child 1976;114:639-44. |
12. | Schwartz GJ, Haycock GB, Edelmann CM Jr, Spitzer A. A simple estimate of glomerular filtration rate in children derived from body length and plasma creatinine. Pediatrics 1976;58:259-63. |
13. | Klahr S. Pathophysiology of obstructive nephropathy. Kidney Int 1983;23:414-26. |
14. | Mustonen S, Ala-Houhala I, Tammela TL. Proteinuria and renal function during and after acute urinary retention. J Urol 1999;161:1781-4. |
15. | Nayyar R, Sarda AK, Kaza RC, Anand VJ. The obstructed kidney. Indian J Surg 2005;67:21-8. |
16. | Walsh PC, Retnik AB, Vaughan ED, Wein AJ. Pathophysiology of urinary tract obstruction. In: Campbell′s Urology. 7th ed. Philadelphia: W.B. Saunders Company; 1998. p. 343-60. |
17. | Klahr S. Obstructive nephropathy. Kidney Int 1988;54:286-300. |
18. | Klahr S, Morrissey JJ. The role of growth factors, cytokines, and vasoactive compounds in obstructive nephropathy. Semin Nephrol 1998;18:622-32. |
19. | Truong LD, Sheikh-Hamad D, Chakraborty S, Suki WN. Cell apoptosis and proliferation in obstructive uropathy Semin Nephrol 1998;18:641-51. |
20. | Topcu SO, Nørregaard R, Pedersen M, Wang G, Jørgensen TM, Frøkiær J. Regulation of aquaporins and sodium transporter proteins in the solitary kidney in response to partial ureteral obstruction in neonatal rats. Urol Int 2011;87:94-104. |
21. | MacLellan DL, Mataija D, Doucette A, Huang W, Langlois C, Trottier G, et al. Alterations in urinary metabolites due to unilateral ureteral obstruction in a rodent model. Mol Biosyst 2011;7:2181-8. |
22. | Buerkert J, Martin D, Head M. Effect of acute ureteral obstruction on terminal collecting duct function in the weanling rat. Am J Physiol 1979;236:F260-7. |
23. | Li ZQ, Zhang Y, Li Q, Wu SH, Sun CY, Yu ZJ. Alteration of renal cyclo-oxygenase expression due to partial unilateral ureteral obstruction in neonatal. Can Urol Assoc J 2012;2:1-6. |
24. | Chevalier RL, Kim A, Thornhill BA, Wolstenholme JT. Recovery following relief of unilateral ureteral obstruction in the neonatal rat. Kidney Int 1999;55:793-807. |
25. | Chertin B, Pollack A, Koulikov D, Rabinowitz R, Shen O, Hain D, et al. Does renal function remain stable after puberty in children with prenatal hydronephrosis and improved renal function after pyeloplasty?. J Urol 2009;182:1845-8. |
26. | Herndon CD, Kitchens DM. The Management of Ureteropelvic Junction Obstruction Presenting with Prenatal Hydronephrosis. Scientific World Journal 2009;9:400-3. |
27. | Klein J, Gonzalez J, Miravete M, Caubet C, Chaaya R, Decramer S, et al. Congenital ureteropelvic junction obstruction: Human disease and animal models. Int J Exp Path 2011;92:168-92. |
28. | Elder JS, O′Grady JP, Ashmead G, Duckett JW, Philipson E. Evaluation of fetal renal function: Unreliability of fetal urinary electrolytes. J Urol 1990;144:574-8; discussion 593-4. |
29. | Piaggio LA, Franc-Guimond J, Noh PH, Wehry M, Figueroa TE, Barthold J, et al. Transperitoneal laparoscopic pyeloplasty for primary repair of ureteropelvic junction obstruction in infants and children: Comparison with open surgery. J Urol 2007;178:1579-83. |
30. | Neheman A, Noh PH, Brenn R, González R. Laparoscopic urinary tract surgery in infants weighing 6 kg or less: Perioperative considerations and comparison to open surgery. J Urol 2008;179:1534-8. |
31. | Neheman A, Noh PH, Piaggio L, González R. The role of laparoscopic surgery for urinary tract reconstruction in infants weighing less than 10 kg: A comparison with open surgery. J Pediatr Urol 2008;4:192-6. |