WCE 2018: Measuring Deployment Forces During Passage of an Ureteral Access Sheath in the Porcine Ureter: “If it don’t go easy, it don’t go at all”

Paris, France (UroToday.com) As an introduction to his talk Dr. Kamaljot Kaler stated that the widespread use of ureteral access sheaths during ureteroscopy has been limited due to concerns regarding ureteral injury. For his study, the team at UC Irvine developed a ureteral access sheath deployment force sensor to determine a measurable amount of force that causes significant ureteral injury within a juvenile porcine model.

This force device was used to measure UAS deployment forces in six juvenile female Yorkshire pigs. Under fluoroscopic guidance, ureteral dilators, sheaths and corresponding obturators, were sequentially advanced into one of the ureters in each pig. In the contralateral ureter, after 10F dilation, a 14F UAS was deployed without sequential dilation. Force was measured continuously for all deployments. After each dilation, a post ureteroscopic lesion score (PULS) (0-5) was recorded.

After analysis, they found that in 5 of the 6 pigs, ureters selected for 14F UAS deployment without prior sequential dilation were injured with a PULS score greater than or equal to 3, with a threshold force of 4.84N. Sequential dilation had a higher threshold for PULS scores of 3 and above with 5.56N.

Dr. Kaler concluded that the UAS force sensor device demonstrates that significant ureteral injury to a juvenile porcine ureter can be avoided provided that the force applied does not exceed 4.5N. Lastly, he stated that sequential dilation may be beneficial as it extends the force threshold for injury to 5.5N.

Presented by: Kamaljot S. Kaler, Clinical Assistant Professor, University of California, Irvine; University of Calgary, Orange, California
Co-Authors: Assistant Clinical Professor Roshan M. Patel, Clinical Researcher Mitchell O’Leary, Clinical Researcher Vinay Cooper, Renai Yoon, Zhamshid Okhunov, Michael Klopfer, Professor and Chair Jaime Landman, Professor Ralph V. Clayman
Author Affiliation: University of California, Irvine, Department of Urology, Orange, California

Written by: Renai Yoon, medical writer for UroToday.com at the 36th World Congress of Endourology (WCE) and SWL - September 20-23, 2018 Paris, France