Training in percutaneous nephrolithotomy--a critical review.

Aim: To study factors influencing training and maintaining skills in performing percutaneous nephrolithotomy (PCNL).

Methods: We matched key words, throughout Medline, MeSH, and Cochrane databases including: renal stone, percutaneous, nephrostomy, endourology, educational, training, learning curve, expertise, skill, residency, practice, survey, simulator, and robotics. For this topic we defined, if possible, levels of evidence based on International Consultation on Urological Diseases (ICUD) and World Health Organization recommendations.

Results: Obtaining renal access is one of the most important factors in training for PCNL. A resident has to perform about 24 PCNL procedures to obtain a good proficiency during the residence period. Competence at performing PCNL is reached after 60 cases and excellence is obtained at >100 cases. Stone centers providing all the endoscopic treatment options seem to provide the best conditions to ensure a sufficient volume of patients recruited. Virtual reality simulators may have a potential in training for PCNL. To maintain one's expertise, participation in continuing educational programs is recommended.

Conclusion: PCNL is currently the most complicated stone surgery technique to teach. The steep learning curve is mainly related to obtaining renal access. The traditional method of acquiring surgical skills is by apprenticeship in the absence of validated virtual simulators. Given the complexity of the treatment of renal stones, one may consider a centralized renal stone treatment in dedicated stone centers.