Congenital midureteral obstructions

Congenital midureteral obstruction caused by a ureteral stricture, valve, or an adynamic segment, is an exceedingly rare entity. When encountered, it is generally misdiagnosed as megaureter or ureteropelvic junction obstruction. Two children with midureteral obstructions were seen over the last two years. One of these had an anatomical defecta midureteral stricture; the other had a physiological abnormality­ midureteral adynamic segment. In one of the cases, the midureteral obstruction was missed initially; the patient underwent ipsilateral ureteroneocystostomy for vesicoureteral reflux. Later, midureteral stricture was diagnosed; excision of the lesion with primary anastomosis was done, with successful salvage of the renal unit. The other patient was pre-operatively diagnosed to have midureteral stricture; intra-operatively an adynamic midureteral segment of 4 cms was found, which was resected, and ureteral anastomosis was done. Pathological examination revealed probe-patent ureter with muscular disarray, suggesting functional obstruction. Neither of the patients had contralateral renal abnormality. A high index of suspicion is required to make a correct pre-operative diagnosis. Antegrade or retrograde urography would clinch the diagnosis. Over-reliance on radionucleotide scans to diagnosis the level of ureteral obstructions could be misleading occasionally, as happened in one of our cases.