An in vivo endoluminal ultrasonographic study of peristaltic activity in the distal porcine ureter.
OBJECTIVE
Experiments were performed to quantify the duration and frequency of ureteric peristaltic activity in the laparotomized and non-laparotomized pig in its virgin and postinstrumented states.


METHODS
Pigs (n = 10) in a steady state of hydration were studied under halothane anesthesia in two groups. The study was undertaken in two separate sessions at a week's interval. In group I laparotomy and vesicotomy were undertaken to obtain ELUS images. In group II, peristalsis was studied using an ELUS probe introduced through the working channel of a 22F rigid cystoscope. Peristalsis was visualized as a periodic diameter-change of ureter and recorded (for approx. 30 minutes) on videotape after an initial period of adaptation of approx. 30 minutes.


RESULTS
The ureter acts like a pump discharging urine into the bladder through peristaltic activity. ELUS imaging of ureteric peristalsis correlated well with "eyeballing" of the passage of peristalsis through a ureter (group I). The shortest peristaltic activity in group I was 6.0+/-2.0 seconds in the non-instrumented- and 5.1+/-1.4 seconds in the instrumented ureter. In group II it was 6.8+/-1.5 seconds in the non-instrumented- and 6.4+/-1.5 seconds in the instrumented ureter. Chronic dilatation of ureter led to decrease in peristalsis frequency. Interestingly, acute dilatation caused an increase in ureteric peristalsis frequency.


CONCLUSIONS
Ureteric peristalsis acts as a pump discharging urinary boluses (intraluminal fluid load) unidirectionally into the bladder. ELUS provides us an opportunity to quantify and study ureteric peristalsis.
Roshani
H
H
Department of Urology, Academic Medical Center, Faculty of Medicine, Amsterdam, The Netherlands.
Dabhoiwala
N F
NF
Dijkhuis
T
T
Kurth
K H
KH
Lamers
W H
WH
D000818:Animals; D005260:Female; D013552:Swine; D014463:Ultrasonography; D014513:Ureter / Q000000981:diagnostic imaging* / Q000502:physiology*