Simplified biplanar (0-90°) fluoroscopic puncture technique for percutaneous nephrolithotomy: the learning curve

Purpose To evaluate the learning curve of the simplified fluoroscopic biplanar (0-90o) puncture technique for percutaneous nephrolithotomy. Methods We prospectively evaluated patients with renal stones treated with percutaneous nephrolithotomy by a single institution's fellows employing the simplified bi-planar (0-90o) fluoroscopic puncture technique for renal access. The learning curve was assessed with the fluoroscopic screening time and the percutaneous renal puncture time. Data obtained were compared to a subset of patients operated by a senior surgeon. Results Eighty-nine patients were included in the study. Forty patients were operated by fellow-1, 39 by fellow-2, and 10 patients by the senior surgeon. Demographic data of all patients between groups were homogeneous, with no difference in gender (p = 0.432), age (p = 0.92), stone volume (p = 0.78), puncture laterality (p = 0.755), and body mass index (p = 0.365). The mean puncture time was 7.5, 4, and 3.1 min for fellow-1, fellow-2, and expert, respectively. The mean fluoroscopic screening time for the puncture was 10, 11, and 5.1 s for fellow-1, fellow-2, and the expert, respectively. Stone cases, both fellows needed to complete 10 procedures to match the senior surgeon in the mean puncture time (p = 0.046); meanwhile, the fluoroscopic screening time was equal even before to complete 10 procedures. Conclusion This study suggests that with the simplified biplanar (0-90o) puncture technique, the fluoroscopic screening time used in the learning process is brief. A novice fellow could require to complete ten cases to flatten the learning curve treating complex stone cases, and a flat learning curve is seen since the beginning when treating simple renal stones.

Automated summary

The study suggests that the fluoroscopic screening time using the simplified biplanar (0-90o) puncture technique is brief during the learning process. A novice fellow may need to complete ten cases to match the senior surgeon's average puncture time for complex cases, while a flat learning curve is observed from the start when dealing with simple renal stones.