Intrarenal pressures during flexible ureteroscopy: an insight into safer endourology.

Abstract

To assess intrarenal pressures (IRPs) and complication rates after flexible ureteroscopy, and to assess factors that contribute to raised IRPs and post-operative complications. After informed consent underwent flexible ureteroscopy under general anaesthesia. The transducer of a 0.014" Comet II Pressure Guidewire® (Boston Scientific Corporation, Marlborough, Massachusetts, USA) was placed in the renal pelvis for live recording of IRPs. Flexible ureteroscopy procedures were performed in a routine manner under antibiotic cover with the aim of dusting the calculus to completion. The operating surgeon was blinded to the live recorded IRPs. 40 procedures were performed in 37 patients (26 male and 11 female). The mean age was 50.5 years. As a cohort, mean of average IRPs for is 34.8 mmHg and the mean of maximal IRPs is 128.8 mmHg. Pearson correlation showed significant inverse correlation between mean IRP versus age (r(38): -0.391, p=0.013). Three cases experienced post-operative deviations from uncomplicated recovery, with two being hypotension and one case being both hypotension and hypoxia. Three cases returned to the emergency department within 30 days of surgery, with two cases of flank pain and one case of urosepsis with positive urine cultures. The patient representing with urosepsis had exhibited IRPs exceeding the mean. IRPs change significantly from normal baseline levels during routine ureteroscopy. Mean IRP during ureteroscopy correlates with patient age, but not with other factors. IRP may be related to increased complication rates at ureteroscopy. Understanding factors that influence IRP will allow urologists to better manage this intraoperatively.