Ureteral peristalsis in pediatric urology

The review is based upon more than 300 pediatric studies from 6 years. Ureteral motility has been assessed in routine renography with I-123-hippuran and Tc-99m-DTPA. Normal ureters were studied with Tc-99m-MDP as by-product to bone scans. In a few cases the radioisotope was injected or infused into the renal pelvis via a Sober loop or a catheter. Ureteral motility information is compressed, similar to the M-mode in sonograhy, by a space time matrix approach, which was introduced in 1978. The clinical applications focussed upon vesico-ureteral reflux, megureter motility, and ureteral stenosis. Concerning vesico-ureteral reflux, the method revealed the clinical and diagnostic interference of retroperistalsis and reflux: (I) Retroperistalsis supports the backflow mechanism. (II) Retroperistalsis may be a symptom of a refluxive ureter, even if there is no actual reflux documented. (III) Discrepancies between direct and indirect tests for reflux are explained partly by the occurrence of retroperistaltic transport of prevesical urine during indirect testing, simulating vesico-ureteral valve dysfunction. Concerning megaureters, the preoperative motility is known to be of prognostic value. Early ureteral stenosis may be judged from peristalitic frequency, either in the basic study or after frusemide. The method became reliable, when the absence of motility could be distinguished frommore » the absence of information on motility, due to a low isotope input into the ureter. In conclusion, the method is now available as routine tool.« less