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Congenital ureteropelvic junction obstruction

Laurence S Baskin, MD, FAAP
Section Editor
Duncan Wilcox, MD
Deputy Editor
Melanie S Kim, MD


Ureteropelvic junction (UPJ) obstruction is a partial or intermittent total blockage of the flow of urine that occurs where the ureter enters the kidney. The etiology of UPJ obstruction includes both congenital and acquired conditions. UPJ obstruction is the most common pathologic cause of antenatally detected hydronephrosis.

The epidemiology, pathophysiology, clinical features, and management of congenital UPJ obstruction will be reviewed here.


The reported incidence of UPJ obstruction is 1 in 500 live births screened by routine antenatal ultrasound; however, not all cases require surgical intervention [1,2]. UPJ obstruction is the most common anatomical cause of antenatal hydronephrosis.

Boys are affected with UPJ obstruction more commonly than are girls [3,4]. Lesions are found more frequently on the left than on the right side. The reported rate of bilateral involvement is approximately 10 percent [1,4].


Congenital UPJ obstruction is caused by anatomic lesions or functional disturbances that restrict urinary flow across the UPJ, resulting in hydronephrosis (figure 1 and picture 1) [1]. Most cases are thought to be due to partial obstruction, because complete obstruction results in rapid destruction of the kidney. In some cases, partial obstruction may also lead to progressive deterioration of renal function. However, in many infants, an equilibrium state may develop in which renal function remains stable.

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Literature review current through: Nov 2017. | This topic last updated: Oct 04, 2017.
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  1. Koff SA, Mutabagani KH. Anomalies of the kidney. In: Adult and Pediatric Urology, 4th ed, Gillenwater JY, Grayhack JT, Howards SS, Mitchell ME (Eds), Lippincott Williams and Wilkins, Philadelphia 2002. p.2129.
  2. Liang CC, Cheng PJ, Lin CJ, et al. Outcome of prenatally diagnosed fetal hydronephrosis. J Reprod Med 2002; 47:27.
  3. Morin L, Cendron M, Crombleholme TM, et al. Minimal hydronephrosis in the fetus: clinical significance and implications for management. J Urol 1996; 155:2047.
  4. Duong HP, Piepsz A, Collier F, et al. Predicting the clinical outcome of antenatally detected unilateral pelviureteric junction stenosis. Urology 2013; 82:691.
  5. Shulam PG. Ureteropelvic junction obstruction. Available at: http://kidney.niddk.nih.gov/statistics/uda/Ureteropelvic_Junction_Obstruction-Chapter09.pdf (Accessed on April 22, 2010).
  6. González R, Schimke CM. Ureteropelvic junction obstruction in infants and children. Pediatr Clin North Am 2001; 48:1505.
  7. McAleer IM, Kaplan GW, LoSasso BE. Congenital urinary tract anomalies in pediatric renal trauma patients. J Urol 2002; 168:1808.
  8. Tekin A, Tekgul S, Atsu N, et al. Ureteropelvic junction obstruction and coexisting renal calculi in children: role of metabolic abnormalities. Urology 2001; 57:542.
  9. de Waard D, Dik P, Lilien MR, et al. Hypertension is an indication for surgery in children with ureteropelvic junction obstruction. J Urol 2008; 179:1976.
  10. Cascio S, Sweeney B, Granata C, et al. Vesicoureteral reflux and ureteropelvic junction obstruction in children with horseshoe kidney: treatment and outcome. J Urol 2002; 167:2566.
  11. Ragan DC, Casale AJ, Rink RC, et al. Genitourinary anomalies in the CHARGE association. J Urol 1999; 161:622.
  12. McMann LP, Kirsch AJ, Scherz HC, et al. Magnetic resonance urography in the evaluation of prenatally diagnosed hydronephrosis and renal dysgenesis. J Urol 2006; 176:1786.
  13. Jones RA, Easley K, Little SB, et al. Dynamic contrast-enhanced MR urography in the evaluation of pediatric hydronephrosis: Part 1, functional assessment. AJR Am J Roentgenol 2005; 185:1598.
  14. McDaniel BB, Jones RA, Scherz H, et al. Dynamic contrast-enhanced MR urography in the evaluation of pediatric hydronephrosis: Part 2, anatomic and functional assessment of ureteropelvic junction obstruction [corrected]. AJR Am J Roentgenol 2005; 185:1608.
  15. Flake AW, Harrison MR, Sauer L, et al. Ureteropelvic junction obstruction in the fetus. J Pediatr Surg 1986; 21:1058.
  16. Drake DP, Stevens PS, Eckstein HB. Hydronephrosis secondary to ureteropelvic obstruction in children: a review of 14 years of experience. J Urol 1978; 119:649.
  17. Heinlen JE, Manatt CS, Bright BC, et al. Operative versus nonoperative management of ureteropelvic junction obstruction in children. Urology 2009; 73:521.
  18. Koff SA. Postnatal management of antenatal hydronephrosis using an observational approach. Urology 2000; 55:609.
  19. Josephson S. Antenatally detected pelvi-ureteric junction obstruction: concerns about conservative management. BJU Int 2000; 85:973.
  20. Ulman I, Jayanthi VR, Koff SA. The long-term followup of newborns with severe unilateral hydronephrosis initially treated nonoperatively. J Urol 2000; 164:1101.
  21. Moslehi J, Herndon CD, McKenna PH. Posterior urethral valves presented at birth despite normal prenatal ultrasound scans. Urology 2001; 57:1178.
  22. Song SH, Park S, Chae SY, et al. Predictors of Renal Functional Improvement After Pyeloplasty in Ureteropelvic Junction Obstruction: Clinical Value of Visually Assessed Renal Tissue Tracer Transit in (99m)Tc-mercaptoacetyltriglycine Renography. Urology 2017; 108:149.
  23. Roth CC, Hubanks JM, Bright BC, et al. Occurrence of urinary tract infection in children with significant upper urinary tract obstruction. Urology 2009; 73:74.
  24. Islek A, Güven AG, Koyun M, et al. Probability of urinary tract infection in infants with ureteropelvic junction obstruction: is antibacterial prophylaxis really needed? Pediatr Nephrol 2011; 26:1837.
  25. Sutherland RW, Chung SK, Roth DR, Gonzales ET. Pediatric pyeloplasty: outcome analysis based on patient age and surgical technique. Urology 1997; 50:963.
  26. Baek M, Park K, Choi H. Long-term outcomes of dismembered pyeloplasty for midline-crossing giant hydronephrosis caused by ureteropelvic junction obstruction in children. Urology 2010; 76:1463.
  27. Yeung CK, Tam YH, Sihoe JD, et al. Retroperitoneoscopic dismembered pyeloplasty for pelvi-ureteric junction obstruction in infants and children. BJU Int 2001; 87:509.
  28. Piaggio LA, Franc-Guimond J, Noh PH, 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.
  29. Tanaka ST, Grantham JA, Thomas JC, et al. A comparison of open vs laparoscopic pediatric pyeloplasty using the pediatric health information system database--do benefits of laparoscopic approach recede at younger ages? J Urol 2008; 180:1479.
  30. Vemulakonda VM, Cowan CA, Lendvay TS, et al. Surgical management of congenital ureteropelvic junction obstruction: a Pediatric Health Information System database study. J Urol 2008; 180:1689.
  31. Penn HA, Gatti JM, Hoestje SM, et al. Laparoscopic versus open pyeloplasty in children: preliminary report of a prospective randomized trial. J Urol 2010; 184:690.
  32. Turner RM 2nd, Fox JA, Tomaszewski JJ, et al. Laparoscopic pyeloplasty for ureteropelvic junction obstruction in infants. J Urol 2013; 189:1503.
  33. Blanc T, Muller C, Abdoul H, et al. Retroperitoneal laparoscopic pyeloplasty in children: long-term outcome and critical analysis of 10-year experience in a teaching center. Eur Urol 2013; 63:565.
  34. Varda BK, Johnson EK, Clark C, et al. National trends of perioperative outcomes and costs for open, laparoscopic and robotic pediatric pyeloplasty. J Urol 2014; 191:1090.
  35. Riachy E, Cost NG, Defoor WR, et al. Pediatric standard and robot-assisted laparoscopic pyeloplasty: a comparative single institution study. J Urol 2013; 189:283.
  36. Monn MF, Bahler CD, Schneider EB, et al. Trends in robot-assisted laparoscopic pyeloplasty in pediatric patients. Urology 2013; 81:1336.
  37. Dangle PP, Kearns J, Anderson B, Gundeti MS. Outcomes of infants undergoing robot-assisted laparoscopic pyeloplasty compared to open repair. J Urol 2013; 190:2221.
  38. Yiee JH, Baskin LS. Use of internal stent, external transanastomotic stent or no stent during pediatric pyeloplasty: a decision tree cost-effectiveness analysis. J Urol 2011; 185:673.
  39. Parente A, Angulo JM, Romero RM, et al. Management of ureteropelvic junction obstruction with high-pressure balloon dilatation: long-term outcome in 50 children under 18 months of age. Urology 2013; 82:1138.
  40. Tan HL, Najmaldin A, Webb DR. Endopyelotomy for pelvi-ureteric junction obstruction in children. Eur Urol 1993; 24:84.
  41. Romao RL, Koyle MA, Pippi Salle JL, et al. Failed pyeloplasty in children: revisiting the unknown. Urology 2013; 82:1145.
  42. Sukumar S, Djahangirian O, Sood A, et al. Minimally invasive vs open pyeloplasty in children: the differential effect of procedure volume on operative outcomes. Urology 2014; 84:180.
  43. Chertin B, Pollack A, Koulikov D, et al. Conservative treatment of ureteropelvic junction obstruction in children with antenatal diagnosis of hydronephrosis: lessons learned after 16 years of follow-up. Eur Urol 2006; 49:734.
  44. Almodhen F, Jednak R, Capolicchio JP, et al. Is routine renography required after pyeloplasty? J Urol 2010; 184:1128.
  45. Chertin B, Pollack A, Koulikov 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.
  46. Braga LH, Lorenzo AJ, Bägli DJ, et al. Risk factors for recurrent ureteropelvic junction obstruction after open pyeloplasty in a large pediatric cohort. J Urol 2008; 180:1684.