The SimPORTAL fluoro-less C-arm trainer: an innovative device for percutaneous kidney access

Achieving proper renal access is arguably the most challenging component of percutaneous nephrolithotomy. A core skill required during this procedure is the use of C-arm fluoroscopic imaging and parallax techniques for proper needle insertion into a predetermined calyceal papilla. The trainers available for these skills include virtual reality (VR) simulators and physical models requiring actual fluoroscopy and radiation exposure precautions. In this study we present the successful proof-of-concept of a low-cost physical fluoro-less C-arm trainer (CAT) for training percutaneous renal access.

The SimPORTAL CAT includes a mini C-arm for simulating fluoroscopic imaging and a silicon flank simulation model for needle insertion. The C-arm has two mounted video cameras and is jointed to tilt and rainbow. The flank model contains an anatomically accurate cast of the upper urinary tract, including the ureter, calyces, and the renal pelvis, with an overlay of ribs to visually and tactically simulate the 10th-12th ribs. The simulated fluoroscopic imaging is viewed on a computer screen allowing for real-time visualization. Preliminary surveys were completed by participants (n=14) at a training course that took place in Hemel Hampsted to obtain information on the acceptability of version 2.1 of the model.

We have successfully created a fluoro-less CAT that achieves the goals of training percutaneous access of the kidney. All participants (100%) considered the concept of avoiding radiation exposure during training as a highly valuable feature. About 92.8% of the enrolled participants considered the CAT of at least equal value to existing VR training models.

The fluoroscopy-less CAT is an economically feasible and accurate model for training parallax. It effectively replicates the functions of a C-arm X-ray system for percutaneous access to the kidney without any radiation exposure to the learner. Further studies will examine construct validity for training and assessing percutaneous access skills.