A Low-Cost Gelatin-Based Model for Ultrasound- Guided Percutaneous Renal Access

Objective: The aim of this study was to develop and validate a low-cost and reproducible training model using gelatin that can be useful for acquiring the necessary skills for successful ultrasound-guided access in percutaneous nephrolithotomy without exposing patients to clinical risks.

Methods: A prospective and analytical study involving 12 urology residents was conducted to validate the model using content and construct validation systems. The study consisted of 2 parts: content validation through expert opinion surveys and construct validation through resident skill assessments before and after training on
the model. This model imitates the calyx to puncture and was developed using pitted olives in dense gelatin. The model was constructed for a total cost of $29.7 per unit with an easy and reproducible construction. Each model can be used to perform approximately 40 punctures before the image quality deteriorates.

Results: Globally, this training model increased skills. Puncture time decreased from 106 to 40.5 seconds after training (P = .002). The study found that the model was accepted by 71.4% of urologists as a safe training alternative and provided a risk-free environment for practicing the 2 skills required for a successful puncture: adjusting the ultrasound machine for an adequate image of the target and surrounding tissues and
needle-probe alignment.

Conclusion: This model is easy to build, reproducible, and cost-effective. It enhances the residents’ skills to increase success and safety when performing ultrasound-guided percutaneous access.

Cite this article as: Pulido-Contreras E, Gonzalez-Villegas H, Lopez-Hernandez JA, Medrano-Sanchez J, Angel M. A low-cost gelatin-based model for ultrasound-guided percutaneous renal access. Urol Res Pract.
2025;51(2):54-59.