Unveiling the Forces of Ureteroscopy: Investigating Urologists' Impact on Ureteral Injury Presentation - Seyed Amiryaghoub M. Lavasani

May 22, 2023

Seyed Amiryaghoub M Lavasani presents on the forces exerted during ureteroscopy, a study that aimed to investigate the force applied by urologists when placing ureteral access sheets. Forces below six newtons showed no ureteral injury, while forces above eight led to severe ureteral injuries.


Seyed Amiryaghoub M. Lavasani, Department of Urology, University of California, Irvine, CA

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Seyed Amiryaghoub M. Lavasani: Dear viewers, our previous porcine and clinical studies show that during ureteroscopy, forces under six newtons resulted in no injury to the ureter, while forces greater than eight newtons resulted in high grade ureteral injuries. Based off these endeavors, we sought to investigate the amount of force urologists exert on placing ureteral access sheets. During the 2022 American Urological Association Conference in New Orleans, and the 2022 World Congress of Endourology and Uro-Technology Conference in San Diego, we invited urologists and urological residents in training to interact with our genitourinary model that contained a hidden force sensor. Participants were instructed to pass three ureteral access sheets from 12 to 16 French in sequential order into the draped model. Participants were told they were being evaluated on the decision-making process when encountering resistance during the passage of a ureteral access sheet. There was no mentioning of force or of a force sensor to the participants, as they were unaware of the true measure of the study.

After the passage of all three ureteral access sheets, participants filled up a demographic survey. 45 and 32% of participants exerted forces greater than six and eight newtons respectively, with a 16 French ureteral access sheet. There was a significant difference for years of practice, age, and number of ureteroscopies within the six newton group. Among the eight newton group. There was a significant difference for years of practice and age only. When taking a deeper look, the multivariate analysis showed that only years of practice and ureteroscopies per month were of significance. The likelihood of exceeding six newtons was directly related to the years of practice and inversely proportional to the number of ureteroscopies per month. Only years of practice was directly related to the likelihood of exceeding eight newtons. In conclusion, 45% of urologists surpassed six newtons. Years of practice was positively correlated with exceeding the six newton and eight newton thresholds. The ureteroscopies per month parameter was negatively correlated with the passage of the six newton threshold.