Abstract

Although there are many studies in the literature, diagnostic evaluation, followup and optimal therapy of antenatal hydronephrosis is an ongoing challenge between different disciplines. Main discussion continues on indications for invasive diagnostics and surgery in infants with asymptomatic primary UPJ-type hydronephrosis. Due to the fact that the majority of UPJ-type hydronephrosis are temporary and physiologic, the vast majority of them resolve spontaneously without obstruction and renal damage. Therfore, many need only proper followup depending on the severity of hydronephrosis. However, a small number of neonatal UPJ type hydronephrosis persist and need prompt surgical correction do to renal damage.

AP diameter of renal pelvis, SFU hydronephrosis grading system and UTD classification have many disadvantages in determining the severity of hydronephrosis, and thus may cause unneccessary invasive diagnostics or even unneccessary surgery. On the other hand, Onen hydronephrosis grading system prevents the disadvantages of such grading systems; it is simple and safe for appropriate followup and timely prompt treatment of infants with severe obstructive UPJ type hydronephrosis.

The infanst with Onen-1 and 2 UPJ type hydronephrosis neither need invasive evaluation nor surgical treatment or antibiotic due to their benign nature; all they need is followup with ultrasound alone. However, Onen-3 (renal parenchyme, 3-7 mm) patients need close followup including renal scan and antibiotic because more than one-third of such children need pyeloplasty during followup. On the other hand, Onen-4 (renal parenchyme, <3 mm) patients need surgical correction after a short followup and evaluation.