Irrigation with isoproterenol diminishes increases in pelvic pressure without side-effects during ureterorenoscopy: a randomized controlled study in a porcine model.

ABSTRACT

OBJECTIVE: Recently, we showed that endoluminally administered isoproterenol (ISO) inhibits muscle function of the pyeloureter in swine. This may be of value in managing increases in pelvic pressure during upper urinary tract endoscopy. The purpose of this study was to examine the effect of endoluminally administered ISO on increases in pelvic pressure and cardiovascular function during flexible ureterorenoscopy. MATERIAL AND METHODS: The study was performed in anaesthetized female pigs. In terms of endoscopic procedures, the pigs were randomized as follows Group 1, irrigation with 0.1 microg/ml ISO added to saline (n=12); and Group 2, irrigation with saline (n=10). A 5-Fr catheter was retrogradely placed in the renal pelvis and an 8-Fr catheter in the bladder for pressure measurements. Flexible ureterorenoscopy was performed with constant irrigation at a perfusion rate of 8 ml/min. Pelvic, bladder and blood pressure and heart rate were registered continuously. RESULTS: Mean baseline pelvic pressure was identical in both groups 12+/-2.3 mmHg in Group 1 and 14+/-3.6 mmHg in Group 2 (p=0.26). During ureterorenoscopy, mean pelvic pressure increased to 26+/-2.3 mmHg in Group 1 and to 38+/-3.1 mmHg in Group 2. Hence ISO reduced the pressure increase due to ureterorenoscopy by 42% (p<0.001). Pelvic pressure seemed to be independent of bladder pressure, which showed no difference between the two groups (p=0.067). Blood pressure and heart rate showed no significant differences between the two groups p=0.425 and p=0.166, respectively. CONCLUSIONS: ISO (0.1 microg/ml) added to irrigation fluid significantly reduces the increase in pelvic pressure during ureterorenoscopy in pigs, without concomitant side-effects.