Presented by: Belén Giménez MD
Universidad de Chile

Introduction

Percutaneous nephrolithotomy (PNL) is considered the treatment of choice for large and staghorn renal stones. Stone fragmentation can be performed using lithotripters, where Lithoclast Master (LM) and Trilogy (LT) stand out. The surgical approach for PNL can be performed prone or supine, with debate on the optimal position. Our aim was to compare the physical and mental fatigue produced by PNL in the urologist when the patient is in the prone vs. supine position, comparing the use of both lithotripters, through an ergonomic analysis of the procedure.

Materials

Urologists experts in endourology were evaluated when performing simulated PNL in 4 different conditions that combined each of the approaches (prone or supine) with each of the lithotripters (LM or LT). Muscular fatigue was measured by electromyography and assessed by the mean percentage of muscular activation using root mean square method. Heart rate was used to analyze emotional fatigue. Besides, a surgical workload measure questionnaire, Surgery Task Load Index (SURG-TLX), was applied for each condition, comparing physical and temporal demands, situational stress, task complexity and distractions. Data was analyzed using STATA 11.

Results

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Four urologists were recruited for the study. The analysis of fatigue did not show relevant overall differences in the evaluated muscles in the 4 conditions, despite the existence of differences in specific muscles. In the analysis of emotional fatigue, a greater increase in heart rate was observed when LM was used in both positions. The SURG-TLX questionnaire analysis highlighted higher physical demand, temporal demand, task complexity, and distraction for prone position compared to the supine position, mainly when using LT. The higher score for distraction was observed when using LM, in the supine position. Regarding mental demand and situational stress, there were no major differences between both approaches or lithotripters.

 

Conclusion

This study provides the first analysis of physical and emotional fatigue in different PNL approaches. The overall findings indicate no significant differences in terms of physical fatigue between the two lithotripters and approaches. However, variations in emotional fatigue were observed across the different conditions. These findings should be taken into consideration when selecting the appropriate surgical technique for urologists.

Funding

None

Lead Authors

Juan Fulla, MD, MsC
Universidad de Chile

Co-Authors

Diego González, MD
Universidad de Chile

Tomás Gatica, MD
Universidad Finis Terrae

Pablo Chamorro, Medical Intern
Universidad de Chile

Nicolás Urnía, Medicla Intern
Universidad de Desarrollo

Sebastián Arroyo, Medical Intern
Universidad de Chile

José Salvado, MD
Universidad Finis Terrae

Felipe Pauchard, MD
Universidad de Valparaíso

Gastón Astroza, MD
Pontificia Universidad Católica de Chile

Sofía Astorga, MD
Universidad de Chile

Catherine Sanchez, DVM, PhD
Clinica las Condes