Endoluminal Isoproterenol Irrigation Decreases Renal Pelvic Pressure During Flexible Ureterorenoscopy: A Clinical Randomized, Controlled Study

ObjectivesIrrigation during ureterorenoscopic procedures causes increased pelvic pressure (PP), which may lead to intrarenal backflow with potential harmful consequences. This study aims to investigate PP response to intraluminal administration of isoproterenol (β-agonist; ISO) during flexible ureterorenoscopy.MethodsTwelve patients admitted for retrograde intrarenal stone surgery (RIRS) were included. Patients were randomized to (1) irrigation with saline (n = 6) or (2) irrigation with ISO 0.1 μg/mL (n = 6). Irrigation rate was standardized to 8 mL/min. A ureteral catheter was retrogradely placed in the renal pelvis for PP measurements. PP, heart rate (HR), and mean arterial pressure (MAP) were also measured.ResultsBaseline PP was 12.1 ± 4 mm Hg in the saline group and 10.3 ± 4 mm Hg in the ISO group (p = 0.44).In the saline group, PP increased to a mean 33 ± 12 mm Hg during ureterorenoscopy. In the ISO group, PP was a mean 19 ± 3 mm Hg (p = 0.029).During endoscopy, PP peaks as high as 328 mm Hg were noted during saline irrigation. The number of pressure peaks above 50 mm Hg was minimized dramatically during ISO irrigation (p = 0.035). No systemic side effects to ISO irrigation were observed.ConclusionFor the first time, a randomized, controlled human study demonstrates that pharmacologic modulation of the ureter is possible during upper urinary tract endoscopy. The ability to relax ureteral tone during endoscopy may have clinical advantages.