[Pathophysiology of primary renal pelvis outflow stenosis]

Ureteral peristalsis originates in the most proximal parts of the caliceal system. It is then conducted to the ureter by way of myogenic excitation conduction. In the pyeloureteral region, however, there seems to be some sort of physiological blockade and modulation of activity. It depends on the level of diuresis whether only a few or all contractions of the renal pelvis reach the ureter. Morphological and functional investigations show that the pathophysiological disturbance in cases of primary stenosis of the pyeloureteral junction seems to be a complete blockade of myogenic excitation conduction. The principle of open surgical corrections (dismembered pyeloureteroplasty) is not only to create a widely open connection between renal pelvis and ureter but also to remove the misfunctioning pyeloureteral segment and to substitute it by a region of improved myogenic excitation conduction.