New ex vivo organ model for percutaneous renal surgery using a laparoendoscopic training box: the sandwich model.

PURPOSE: Percutaneous renal surgery (PRS) is a challenging procedure for urologic surgeons and requires a large variety of different skills. Our objective was to improve the preexisting porcine kidney-training model for percutaneous renal access and PRS.
METHODS: For our biologic training model, we use porcine kidneys with preserved ureter. The ureter was dissected, stones were placed into the collecting system using a 16, 5F Amplatz sheath, and a 12Ch indwelling catheter was placed in the ureter for further irrigation with blue-dyed saline. The kidney was placed between two porcine full-thickness skin lobes in an existing laparoscopy trainer (SITUS Box). The kidney was punctured with ultrasound guidance, and minimally invasive percutaneous nephrolithotomy (MIP) was then performed as previously described. The model was evaluated in MIP training courses, which are regularly held at the Hannover Medical School.
RESULTS: All trainees were urologists with experience in endourologic surgery. Eleven participants were trained in this model. Percutaneous puncture under ultrasonographic guidance and following intrarenal surgery was successful in all 11 (100 %) cases. Therefore, all participants rated the model useful for simulating percutaneous renal surgery.
CONCLUSION: Compared to recently published models, this new porcine kidney model is easy to prepare and is cost-effective by using standard material. Moreover, it provides realistic and reproducible practice for PRS in the laboratory. Unfavorably, the described organ model requires an existing laparoscopy training system. Comprehensively, the presented organ model approximates the natural retroperitoneal circumstances precisely by using the two full-thickness skin flaps with the fatty subcutaneous tissue.