Top-down approach for evaluation of urinary tract infection.

c a anagement of vesicoureteral reflux (VUR) involves as uch controversy as management of prostate cancer. magine if there was an easily available serum or radioraphic test that could definitively determine whether a an with prostate cancer would have any local spread of he disease, and whether it would ever cause any sympoms. Would not that test replace prostate-specific antien (PSA) or any other marker as the gold standard for hether patients should be offered treatment? In VUR, e already have such a test: the dimercaptosuccinic acid DMSA) scan. We can tell whether renal injury has ccurred after a febrile urinary tract infection (UTI). The resence of VUR is only an imperfect marker (like PSA) or the real endpoint of renal parenchymal injury. The top-down” approach gives us the ability to pick out hose children who are at risk for renal injury, and to anage the remainder without performing a voiding cysourethrogram (VCUG). More importantly, it reminds s that our goalpost is not just successful correction of UR, but decreasing the rate of renal injury regardless of hether VUR is present. There are obstacles to the broader acceptance of the op-down approach, some of which may be specific to this ide of the Atlantic, because the urological group of reat Ormond Street Hospital, London has been leading he charge for the DMSA scan. Some obstacles are ractical: DMSA is intermittently not available, it inolves exposure to ionizing radiation (1 mSv compared ith 1.6 for VCUG) and some parents may perceive he invasion of intravenous access as worse than urethral atheterization. Other measures of renal parenchyma reain relatively invasive (magnetic resonance imaging equires sedation or general anesthesia for young chilren, as does DMSA with single photon emitted colliated tomography) or insufficiently sensitive (ultrasound enal length). A positive DMSA obtained early in the ourse of pyelonephritis is not predictive of subsequent carring, because only 40% of children develop renal carring after an episode of pyelonephritis, and early scan