Sun, 09/12/2010 - 06:43 | by admin


Long Term consequences

Reflux of urine into the ureters, and into the kidneys, will exacerbate any UTI, facilitating progression of the infection into the upper urinary tract.

Infections of the upper urinary tract are associated with higher morbidity than infections occurring lower in the urinary tract. A diagnosis of VUR is usually made after the child has presented with repeated UTIs, and between 29% and 50% of children presenting with UTIs will be diagnosed with VUR.1, 2  

Renal Damage

Reflux of infected urine, particularly in more severe cases, increases the risk of pyelonephritis – an inflammation of the kidneys – which can have longer-term consequences. Recurrent pyelonephritic infections can lead to damage within the renal unit and tissue scarring. Permanent renal damage has been reported in 73% of children with recurrent UTIs,4 and significantly more children with VUR were found to have permanent renal damage than those free from VUR (72% versus 52%, p<0.0001)3.

Tissue scarring occurring postnatally is, therefore, a secondary effect of persistent infections within the urinary tract and is more likely to occur in patients with VUR. Renal scarring also seems to worsen with recurrent UTIs, especially in young patients.6

It should be noted that reflux in the absence of a UTI is unlikely to lead directly to renal damage.5, 6 This is supported by a study that observed that reflux of sterile urine caused no new tissue scarring.1 However, renal scarring can occur without infection of the urinary tract in children where VUR is present before birth (prenatally).

Long-term consequences of renal scarring

Scarring of the renal unit can have long-term serious consequences, including:

  • An increased risk of developing pre-eclampsia during pregnancy
  • The possibility of developing reduced renal function
  • End-stage renal disease (ESRD)
  • Hypertension7, 8

In a study of 294 patients over the age of 15 years with VUR, who had suffered renal damage, 24% had reduced kidney function and 38% had developed hypertension.7

“The renal scarring seems to get worse with recurrent
urine infections especially in the young”.6

 

There is some evidence that treatment of VUR using either antibiotic prophylaxis or open surgery does not affect the long-term outcome with respect to the risk of ESRD.9-12 The damage to the renal unit may have already occurred in many children prior to VUR diagnosis and treatment.13 However, treatment of VUR has been shown to reduce the incidence of febrile UTIs.14

The aim of VUR treatment, therefore, is to reduce the risk associated with UTI, particularly febrile UTIs within the upper urinary tract and pyelonephritis, thus decreasing morbidity. Treatment may also lessen the risk of further damage to a renal unit that has already been weakened, though further data are required to establish the effect of both medical and surgical treatment on long-term renal function.

 

  1. International Reflux Study Committee. Medical versus surgical treatment of primary vesicoureteral reflux. Report of the International Reflux Study Committee. Pediatrics 1981; 67: 392-400.
  2. Puri P, Chertin B, Velayudham M, et al. Treatment of vesicoureteral reflux by endoscopic injection of dextranomer/hyaluronic acid copolymer: preliminary results. J Urol 2003; 170: 1541-4.
  3. Orellana P, Baquedano P, Rangarajan V, et al. Relationship between acute pyelonephritis, renal scarring, and vesicoureteral reflux. Results of a coordinated research project. Pediatr Nephrol 2004; 19: 1122–1126.
  4. Orellana P, Baquedano P, Rangarajan V, et al. Relationship between acute pyelonephritis, renal scarring, and vesicoureteral reflux: results of a coordinated research project. Pediatr Nephrol 2004; 19: 1122-6.
  5. Ylinen E, Ala-Houhala M, Wikstrom S. Risk of renal scarring in vesicoureteral reflux detected either antenatally or during the neonatal period. Urology 2003; 61: 1238-42.
  6. Goonasekera CD, Abeysekera CK. Vesicoureteric reflux and reflux nephropathy. Indian J Pediatr 2003; 70: 241-9.
  7. Zhang Y, Bailey RR. A long-term follow-up of adults with reflux nephropathy. N Z Med J 1995; 108: 142-4.
  8. McGladdery SL, Aparicio S, Verrier-Jones K, et al. Outcome of pregnancy in an Oxford-Cardiff cohort of women with previous bacteriuria. Q J Med 1992; 83: 533-9.
  9. Craig JC, Irwig LM, Knight JF, et al. Does treatment of vesicoureteric reflux in childhood prevent end-stage renal disease attributable to reflux nephropathy? Pediatrics 2000; 105: 1236-41.
  10. Wheeler D, Vimalachandra D, Hodson EM, et al. Antibiotics and surgery for vesicoureteric reflux: a meta-analysis of randomized controlled trials. Arch Dis Child 2003; 88: 688-94.
  11. Olbing H, Hirche H, Koskimies O, et al. Renal growth in children with severe vesicoureteral reflux: 10-year prospective study of medical and surgical treatment: the International Reflux Study in Children (European branch). Radiology 2000; 216: 731-7.
  12. Smellie JM, Barratt TM, Chantler C, et al. Medical versus surgical treatment in children with severe bilateral vesicoureteric reflux and bilateral nephropathy: a randomized trial. Lancet 2001; 357: 1329-33.
  13. Lama G, Russo M, De Rosa E, et al. Primary vesicoureteric reflux and renal damage in the first year of life. Pediatr Nephrol 2000; 15: 205-10.
  14. Wheeler D, Vimalachandra D, Hodson E, et al. Interventions for  primary vesicoureteric reflux. Cochrane Database Syst Rev 2004; 3: CD001532.