Which is the preferred modality of renal access for a trainee urologist: ultrasonography or fluoroscopy? Results of a prospective randomized trial.

Objective: In percutaneous nephrolithotomy (PCNL), placement of the access tract into the kidney is an important aspect of the procedure and is responsible for the steep learning curve associated with the operation. The aim of the current prospective randomized trial was to assess the duration of radiation exposure along with the safety and efficacy of PCNL done by a trainee, utilizing either ultrasonography (US) or fluoroscopic guidance to obtain access.

Methods: Sixty-four patients with ≤3 cm renal calculi undergoing single-tract PCNL by trainee urologists (experience of <25 PCNL's) were randomized into US- and fluoroscopic-guided access groups (32 in each). In Group 1 (US guided), puncture was done using a 3.5/5 MHz US probe with a puncture attachment, whereas the triangulation technique with biplanar C-arm fluoroscopy was utilized in group 2 (fluoroscopic guided). Patient demographics, stone parameters, intraoperative characteristics, fluoroscopy durations, and postoperative outcomes were analyzed.

Results: Both groups were comparable as far as patient and stone characteristics were concerned. The fluoroscopy exposure during the puncture phase (T2) and overall (T) was significantly lower in the US group at 9.0±20.8 vs 43.8±34.8, (p<0.0001) and 204.3±84 vs 239.9±77.5, (p=0.04). Six patients in group1 required fluoroscopic adjustment (p=0.03). All other intra- and postoperative parameters were similar in both the groups.

Conclusions: Both ultrasound and fluoroscopic guidance for renal access are equally safe and feasible in the hands of a trainee urologist. Total fluoroscopy duration and exposure time during puncture were both significantly less in the ultrasound group. Expertise in fluoroscopic-guided access is essential for a novice to effectively achieve access in all possible situations.