A Shafik1. 1. Department of Surgery and Experimental Research, Faculty of Medicine, Cairo University, Egypt.
Abstract
OBJECTIVES: To study the electromechanical activity of the normal ureter in 5 men and 4 women (mean age 39.4 +/- 10.8 years) scheduled for rectopexy due to rectal prolapse. The results of urinary tract investigations were normal. METHODS: During anesthesia for rectopexy, rectal mobilization necessitates ureteral exposure for protective reasons. One electrode was applied to each of the upper, middle, and lower third of the right ureter, and signals were registered for 30 minutes. Simultaneous recording of intraureteral pressure was performed. RESULTS: Slow waves, or pacesetter potentials (PPs), were recorded from the three electrodes. Identical readings for frequency, amplitude, and velocity of conduction were obtained from the three electrodes in the same ureter. Action potentials (APs) followed the PPs and were inconsistent and were associated with an intraureteral pressure increase (P < 0.001). No pressure elevation occurred with PPs. CONCLUSIONS: In contrast to PPs, APs seem to have a role in ureteral mechanical activity and might initiate ureteral peristalsis. The function of the PPs is unknown; they might pace the APs in terms of direction and frequency. The present study could characterize an electroureterographic pattern for the normal ureter. It is suggested that this pattern is changed in the various ureteral pathologic conditions and, thus, the electroureterogram be considered a useful investigative tool in ureteral disorders. However, the procedure in its present from is not applicable to clinical practice. Nevertheless, the present study might be of significance in explaining the mechanisms of ureteral motility and urinary bolus transport.
OBJECTIVES: To study the electromechanical activity of the normal ureter in 5 men and 4 women (mean age 39.4 +/- 10.8 years) scheduled for rectopexy due to rectal prolapse. The results of urinary tract investigations were normal. METHODS: During anesthesia for rectopexy, rectal mobilization necessitates ureteral exposure for protective reasons. One electrode was applied to each of the upper, middle, and lower third of the right ureter, and signals were registered for 30 minutes. Simultaneous recording of intraureteral pressure was performed. RESULTS: Slow waves, or pacesetter potentials (PPs), were recorded from the three electrodes. Identical readings for frequency, amplitude, and velocity of conduction were obtained from the three electrodes in the same ureter. Action potentials (APs) followed the PPs and were inconsistent and were associated with an intraureteral pressure increase (P < 0.001). No pressure elevation occurred with PPs. CONCLUSIONS: In contrast to PPs, APs seem to have a role in ureteral mechanical activity and might initiate ureteral peristalsis. The function of the PPs is unknown; they might pace the APs in terms of direction and frequency. The present study could characterize an electroureterographic pattern for the normal ureter. It is suggested that this pattern is changed in the various ureteral pathologic conditions and, thus, the electroureterogram be considered a useful investigative tool in ureteral disorders. However, the procedure in its present from is not applicable to clinical practice. Nevertheless, the present study might be of significance in explaining the mechanisms of ureteral motility and urinary bolus transport.