Comparative Analysis of Lubricity in Ureteral Access Sheaths, Ureteral Dilators, and Urethral Dilators Using an Ex Vivo Porcine Ureteral Model "Presentation" - Brandon Camp
April 28, 2025
Brandon Camp discusses a tribometer with a urethral holder to objectively measure the lubricity of various ureteroscopy devices. This analysis confirms that both surface coating and surface roughness are critical factors in device lubricity, with white light interferometry revealing the smoother surface of the Cook access sheath as the key differentiator in reducing friction against the urothelial surface during insertion and retraction.
Biography:
Brandon Camp, Department of Urology, University of California, Irvine, Orange, CA
Brandon Camp, Department of Urology, University of California, Irvine, Orange, CA
Read the Full Video Transcript
Brandon Camp: Dear viewers, we examine the surface lubricity of various sheaths and dilators deployed during ureteroscopy. The friction of insertion and retraction of 8, 14 French urethral access sheaths, as well as 14 French urethral and urethral dilators, was measured using a tribometer and a novel urethral holder.
A constant force of 4.0 Newtons was applied perpendicular to the ureter as the device encountered the urothelial surface. This allowed us to calculate the coefficient of friction, abbreviated COF, a standard metric for lubricity. White light interferometry was used to measure surface roughness.
Sheaths and dilators were assigned point values based on their COF percentiles in each ureter, and cumulative lubricity scores were obtained by summing these values across all six ureters. The results were visually represented using radar plots, with larger areas indicating greater lubricity. The 14 French Cook Flexor access sheath displayed the lowest COF and therefore the greatest lubricity. Despite sharing a similar AQ hydrophilic coating, the smoother surface of the Cook access sheath provided greater lubricity compared to the Cook urethral and urethral dilators, as revealed by White light interferometry.
In conclusion, both surface coating as well as surface roughness directly affect the lubricity of urethral access sheaths as well as urethral and urethral dilators. Thank you.
Brandon Camp: Dear viewers, we examine the surface lubricity of various sheaths and dilators deployed during ureteroscopy. The friction of insertion and retraction of 8, 14 French urethral access sheaths, as well as 14 French urethral and urethral dilators, was measured using a tribometer and a novel urethral holder.
A constant force of 4.0 Newtons was applied perpendicular to the ureter as the device encountered the urothelial surface. This allowed us to calculate the coefficient of friction, abbreviated COF, a standard metric for lubricity. White light interferometry was used to measure surface roughness.
Sheaths and dilators were assigned point values based on their COF percentiles in each ureter, and cumulative lubricity scores were obtained by summing these values across all six ureters. The results were visually represented using radar plots, with larger areas indicating greater lubricity. The 14 French Cook Flexor access sheath displayed the lowest COF and therefore the greatest lubricity. Despite sharing a similar AQ hydrophilic coating, the smoother surface of the Cook access sheath provided greater lubricity compared to the Cook urethral and urethral dilators, as revealed by White light interferometry.
In conclusion, both surface coating as well as surface roughness directly affect the lubricity of urethral access sheaths as well as urethral and urethral dilators. Thank you.