WCE 2017: A Critical Evaluation of Intra-renal Pressures Based on Ureteral Access Sheath Size and Irrigation Flow Rate for Safe and Effective Robotic Assisted Retrograde Intra-renal Surgery

Vancouver, Canada (UroToday.com) Dr. Kemal Sarica, professor of urology at the Health Sciences University of the Kartal Lutfi Kirdar Training and Research Hospital, presented data that evaluated the effects of varying UAS sizes (10/12F – 12/14F) and changing irrigation flow rates modulated by a custom designed pump system on intra-renal pressure levels during Robotic assisted retrograde intrarenal surgery RIRS (RA-RIRS). Dr. Sarica began by presenting the advantages of using ureteral access sheaths, such as easy access to the kidneys, stable pressure within the kidneys, and protection of the ureteral wall. 

For this evaluation, a Minnesota University kidney model was used to measure flow rates and intra-renal pressure values. A customized pump system (ELMED, Turkey) was used and adjusted for stepwise flow rate increases between 5-60 ml/min to evaluate the changing irrigation flow rate effects on intra-renal pressure values during RA-RIRS utilizing 5 different types of access sheaths. In addition to measuring baseline flow rates, the study was repeated using a custom pump system. 

Following analysis of the difference in intra-renal pressures based on varying UAS sizes, the data demonstrated that using smaller UAS sizes without a pump system causes increased intra-renal pressure and limited irrigant efflux. Larger UAS sizes (11/13 F and 12/14F) allowed for lower intra-renal pressure values (<30cmH2O), even with increasing irrigation flow rates up to 60 ml/min. 

Dr. Sarica concluded that using the correct UAS size based on intra-renal pressure values is of the utmost importance while performing R-RIRS. Utilizing a precisely controlled custom designed pump system can be crucial for a safe and effective procedure, particularly for large or complex stones. After the presentation, a fellow physician asked Dr. Sarica what size UAS he typically works with for large or complex stones in his clinical practice, to which Dr. Sarica answered that he often uses a 10/12F, and only uses larger sizes with a small percentage of highly complex stones. 

Presented by: Kemal Sarica 

Authors: Nida Zafer Tokatli, Kemal Sarica, A. Sinan Kabakci, Remzi Saglam, Anup Patel
Affiliation: Medicana International Ankara Hospital Ankara, Turkey, Health Sciences University Kartal Lutfi Kirdar Training and Research Hospital Istanbul, Turkey, Dept. of Bioengineering Hacettepe Unviersity Ankara, Turkey, Spire Roding London, England, United Kingdom

Written by: Taylor Capretz, Department of Urology, University of California- Irvine at 35th World Congress of Endourology– September 12-16, 2017, Vancouver, Canada.