The use of a biological model for comparing two techniques of fluoroscopy-guided percutaneous puncture: A randomised cross-over study

OBJECTIVES: To develop a new and inexpensive model for training in fluoroscopic puncture into the pelvicalyceal system, and to use this model to compare the learning curve of two fluoroscopic techniques, the ‘eye of the needle’ (EN) and triangulation techniques. MATERIALS AND METHODS: For the trial we used a commercial plastic model (a shop-window mannequin) in which a bovine kidney, embedded in sponge with a spatial orientation similar to the human, was inserted into the model. The ureter of the animal kidney was connected to contrast fluid. Ten residents and interns were randomised into two groups; group A started the puncture using the EN technique, each member making five attempts, and then five attempts using the triangulation technique, and group B started with triangulation and then used the EN technique. RESULTS: There was no statistically significant difference between the techniques for the mean (SD) number of trials to make a correct puncture, at 2.68 (1.00) in the EN technique and 2.86 (1.05) in the triangulation technique, or for the duration of each trial, at 523 (189) s for the EN technique and 578 (175) s for the triangulation technique. The fluoroscopy time was less in the EN technique, at 113.9 (48.9) s than for the triangulation method, at 135.8 (42.4) (P < 0.005). CONCLUSIONS: The model was easy to construct and feasible for training. Both techniques had a similar learning curve, with higher fluoroscopy exposure for the triangulation technique.