Study Highlights Lubricity Differences Among Urological Catheters: Implications for Clinical Practice "Presentation" - Bruce Gao
August 14, 2024
At the World Congress of Endourology and Uro-Technology, Bruce Gao presents a study characterizing the lubricity of various urological catheters using a tribometer and a novel urethral tissue holder. The research tests 12 14 French catheters against porcine urethral segments, measuring the coefficient of friction to determine lubricity. Dr. Gao highlights that the Cook Medical Flexor Ureteral Access Sheath demonstrates the highest lubricity among tested catheters.
Biographies:
Bruce Gao, MD, Urologist, Department of Urology, University of California, Irvine, CA
Biographies:
Bruce Gao, MD, Urologist, Department of Urology, University of California, Irvine, CA
Read the Full Video Transcript
Bruce Gao: Dear UroToday viewer, my name is Bruce Gao. I'm an Endourology Fellow at the University of California, Irvine. We sought to characterize the lubricity of commonly used urethral access sheaths, ureteral dilators, and urethral dilators using a tribometer and a novel urethral tissue holder.
Twelve 14 French urological catheters were immersed in normal saline and then tested against six porcine urethral segments. As you can see here, a custom-designed urethral holder for bivalve ureters was used for testing. After the catheter was placed on the saline-freshened mucosal surface of the ureter, a constant perpendicular normal force of 4 Newtons was applied while the catheter was advanced and retracted at a constant rate. The coefficient of friction was defined as the ratio between the frictional and normal force.
This figure indicates the overall relative lubricity of the best and worst catheters tested. On the left, the Cook Medical Flexor Urethral Access Sheath displayed the lowest coefficient of friction and therefore had the highest relative lubricity. On the right, the polyethylene urethral dilator demonstrated the highest coefficient of friction and thus had the lowest relative lubricity.
In addition to measuring lubricity, we also performed white light interferometry to assess the average surface roughness of the catheters tested. As you can see in the diagram on the right, although these three Cook Medical catheters all had the same proprietary AQ hydrophilic coating, the higher surface roughness of the AQ ureteral and AQ urethral dilators was associated with lower lubricity compared to the AQ Urethral Access Sheath. Overall, among the catheters tested, a higher surface roughness was associated with a higher coefficient of friction and thus, a lower lubricity.
In conclusion, the Cook Medical Flexor AQ-coated Urethral Access Sheath demonstrates the highest lubricity. Of note, despite similar surface coatings, all tested ureteral and urethral dilators had higher surface roughness and thus, poorer lubricity compared to urethral access sheaths. Thank you.
Bruce Gao: Dear UroToday viewer, my name is Bruce Gao. I'm an Endourology Fellow at the University of California, Irvine. We sought to characterize the lubricity of commonly used urethral access sheaths, ureteral dilators, and urethral dilators using a tribometer and a novel urethral tissue holder.
Twelve 14 French urological catheters were immersed in normal saline and then tested against six porcine urethral segments. As you can see here, a custom-designed urethral holder for bivalve ureters was used for testing. After the catheter was placed on the saline-freshened mucosal surface of the ureter, a constant perpendicular normal force of 4 Newtons was applied while the catheter was advanced and retracted at a constant rate. The coefficient of friction was defined as the ratio between the frictional and normal force.
This figure indicates the overall relative lubricity of the best and worst catheters tested. On the left, the Cook Medical Flexor Urethral Access Sheath displayed the lowest coefficient of friction and therefore had the highest relative lubricity. On the right, the polyethylene urethral dilator demonstrated the highest coefficient of friction and thus had the lowest relative lubricity.
In addition to measuring lubricity, we also performed white light interferometry to assess the average surface roughness of the catheters tested. As you can see in the diagram on the right, although these three Cook Medical catheters all had the same proprietary AQ hydrophilic coating, the higher surface roughness of the AQ ureteral and AQ urethral dilators was associated with lower lubricity compared to the AQ Urethral Access Sheath. Overall, among the catheters tested, a higher surface roughness was associated with a higher coefficient of friction and thus, a lower lubricity.
In conclusion, the Cook Medical Flexor AQ-coated Urethral Access Sheath demonstrates the highest lubricity. Of note, despite similar surface coatings, all tested ureteral and urethral dilators had higher surface roughness and thus, poorer lubricity compared to urethral access sheaths. Thank you.