UC Irvine

Purpose

Ureteral access sheaths (UAS) pose the risk of severe ureteral injury. Our prior studies revealed forces ≤6 Newtons (N) prevent ureteral injury. Accordingly, we sought to define the force urologists and residents-in-training typically use when placing a UAS.

Materials & methods

Among urologists and urology residents attending two annual urological conferences in 2022, 121 individuals were recruited for the study. Participants inserted 12Fr, 14Fr, and 16Fr ureteral access sheaths into a male genitourinary model containing a concealed force sensor; they also provided demographic information. Analysis was completed using t-tests and Chi-square tests to identify group differences when passing a 16Fr sheath UAS. Participant traits associated with surpassing or remaining below a minimal force threshold were also explored via polychotomous logistic regression.

Results

Participant force distributions were: ≤4N (29%), >6N (45%), and >8N (32%). More years of practice were significantly associated with exerting >6N relative to forces between 4-6N; results for >8N relative to 4N-8N were similar. Compared to high-volume ureteroscopists (those performing >20 ureteroscopies/month), physicians performing ≤20 ureteroscopies/month were significantly less likely to exert forces ≤4N (p=0.017 and p=0.041). Of those surpassing 6N and 8N, 15% and 18% respectively were high-volume ureteroscopists.

Conclusions

Despite years of practice or volume of monthly ureteroscopic cases performed, most urologists failed to pass 16Fr access sheaths within the ideal range of 4N-6N (74% of participants) or within a predefined safe range of 4N-8N (61% of participants).