The effect of extralumenal safety wires on ureteral injury and insertion force of ureteral access sheaths: Evaluation using an ex vivo porcine model

Objective: To evaluate the effect that a safety wire (SW) had on insertion force and direct ureteral trauma using ureteral access sheaths (UAS) in an ex vivo porcine model. Material and Methods: UASs were advance into 20 fresh ex vivo porcine kidney-ureters, either with or without SWs. The average and max force of insertion were recorded. Retrograde saline injection was used to identify the presence of lacerations. Results: For SW vs no SW, the mean insertion force (1.79 vs 0.67, P =.0003, respectively) and max insertion force (2.29 kg vs 1.00, P =.0007) was greater in the SW group. There were 9 lacerations, 6 of which were partial and 3 complete. Of the partial injuries, 2 were in the no SW group and 4 were in the SW group. Of the complete lacerations, 2 occurred in the no SW group and 1 in the SW group. However, there was no significant difference in the total number of lacerations (P = 1.00), the number of partial lacerations (P =.628), or the number of complete lacerations (P = 1.00) between the 2 groups. Conclusions: The use of an SW significantly increases the force required to insert a UAS; however, it does not appear to affect the force or the degree of ureteral injury.