Dr. Mendez-Probst presented data that showed it becomes cost-effective to use an ARD at or above a 6.3% retropulsion rate. In addition to the Escape, Ntrap and Stone Cone there are alternatives including water-based jelly and coiling an angle tip guidewire such that it forms a loop on itself proximal to the stone. The Accordion utilizes braided nitinol mesh and is 12mm in diameter. Data from Dr. Mendez-Probst showed that its use reduced intraoperative stone migration length (27mm versus 46mm); however, there was no difference in stone free rate (CT at 1 month).
Dr. Mendez-Probst had several take-home messages. First, consider using an ARD when a flexible ureteroscope is not readily available. ARDs are less efficient when the proximal ureteral diameter is greater than 10mm. It is important to know the specifications of each ARD as each has its own tricks and pitfalls. Laser damage can occur to the ARD with Accordion > Stone Cone > Ntrap. In conclusion, when choosing an ARD, choose wisely as the cost may be significant.
Presented by: Carlos E. Mendez-Probst, MD, Department of Urology, National Institute of Medical Science and Nutrition, Mexico
Written by: Roshan M. Patel, MD, Department of Urology, University of California, Irvine, California at the 37th World Congress of Endourology (WCE) – October 29th-November 2nd, Abu Dhabi, United Arab Emirates