UVJ obstruction

Both UPJ and UVJ obstruction may coexist. UVJ obstruction may evolve unrecognized, especially on IVU, up to the surgical correction of the UPJ obstruction (Fig. 5.17) only thereafter will the lower obstruction be detected and eventually corrected. The condition might be easier to diagnose on MR urography (McGrath et al. 1987). 

Differential diagnosis of UPJ obstruction should include multicystic dysplastic kidney (MDK), infundibular stenosis, and UVJ obstruction. This differential diagnosis is easy in most cases. In IVIDK, no... 

Fig. 5. 23. Coexisting UVJ obstruction and VUR post-void film of a VCU there is bilateral VUR. On the left, VUR has occurred in a dilated collecting system...

Fig. 5.51. UVJ obstruction on the upper and lower moieties displayed by MR urography (inversion-recovery sequence with MIP reconstruction)...

Reflux and UPJ Obstruction 221 Reflux and UVJ Obstruction 222 Reflux and Lithiasis 222 Reflux Into an Unused Ureter 222 Yo-Yo Reflux 222... 

Contralateral VUR may be present in about 10%-20% of patients with multicystic dysplastic kidney (Fig. 11.29). VUR is also present in a significant number of other uropathies, i.e., horseshoe kidney, crossed fused kidney, UPJ, and UVJ obstruction. Therefore, in any anomaly of this type, a VCU should be advised for a complete workup (Atiyeh et al. 1992 Ring et al. 1993 Song et al. 1995 Avni et al. 1997 Cascio et al. 1999). 

Fig. 13.9. Right UVJ obstruction. 3rd trimester. Transverse scan of the fetal abdomen. A circonvoluted dilated ureter (12 mm between the crosses) is visible. K, kidney B, bladder...

Like VUR, UVJ obstruction has shown great potential for spontaneous resolution, probably because of the maturation of the UVJ (Fig. 13.22). Therefore, after completion of the workup a prophylactic antibiotic therapy should be started and the urinary tract monitored by US and eventually isotopes. US may underestimate the dilatation, especially since the renal pelvis may not be dilated. Therefore, before confirming complete resolution, morphological assessment of the urinary tract may be necessary (best by MR urography) (Baskin et al. 1994 Liu et al. 1994 Avni et al. 1992 Avni et al. 2000). 

Fig. 26.7. a A 19-year-old patient with a UVJ obstruction and secondary hydronephrosis and hydroureter, b A coned-down view of the UVJ confirms the site of obstruction, c Treatment with a universal drain was effective... 

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