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Factors determining fluoroscopy time during ureteroscopy.

PURPOSE
The aim of this study was to prospectively identify predictors of radiation exposure during ureteroscopy.


PATIENTS AND METHODS
Eighty-five consecutive patients who presented for ureteroscopies and laser lithotripsy were considered. Fluoroscopy time (FT) was obtained from radiology reports for each patient, and clinical data were obtained from chart review. Nine patients were excluded (three unconfirmed FTs, four staghorn calculi, one ectopic kidney, and one multiple ureteral strictures). Seventy-six patients were included in the study. Univariate and multivariate linear regression were used to identify factors that determined FT.


RESULTS
The patient cohort was 65.8% male with a mean age of 52.7 years. Mean FT was 183 s, and mean surgical time was 68.4±29 minutes. Mean stone size was 10±5 mm in the greatest dimension. A large proportion of patients (50%) had renal stones, multiple stones were present in 31.6% of cases, and 22.3% of stones were radiolucent. Cases were equally distributed between surgeons A and B, and 46% of patients had preoperative stents. On multivariate analysis, increased FT was independently associated with surgeon A (104 additional seconds per case, P<0.001), longer duration of surgery (14 s per 10 minutes, P<0.001), and male patients (54 s per procedure, P=0.02). Age, stone characteristics, presence of ureteral stent, and stone-free status did not correlate with FT.


CONCLUSIONS
Surgeon behavior, longer duration of surgery, and male gender were significant predictors of FT and, hence, radiation exposure during ureteroscopy. In the present study, stone characteristics were not found to be predictors of FT.