TAIPEI, TAIWAN (UroToday.com) - Introduction and Objectives: To overcome a large impacted stone that impedes passage of the guide wire we sometimes use a ureteric catheter to support the flexible tip of the wire. We compared four guide wires with regard to their tip bending force when buttressed at various distances from the tip.
Methods: Using an Imada digital force gauge DS2 we measured the tip bending force of four guide wires at different distances from the tip (the Nitinol Biwire, the Fixed core polytetrafluoroethylene (PTFE), the Amplatz Extra stiff (Cook Medical Inc) and the Nitinol straight tip Sensor (Boston ScientificMicrovasive)).
Results: The PTFE and the Amplatz wires had a more rigid tip and required high forces to bend the tip when supported closer at 3 and 2 cm from the tip (1.51 – 0.6 vs 0.1 – 0.009 N, P < 0.001) and (6.86 – 5.5 vs 0.27 – 0.03 N, P = 0.001) respectively. The two Nitinol Hydrophilic tip wires required the least amount of force to bend the flexible tip at all distances measured, but this force increased dramatically to forces capable of perforating the ureter when supported at a distance less than 1 cm from the tip (2.85 – 0.34 vs 1.86 – 0.26 N, P < 0.001 @ 0.5 cm from the tip) for the Biwire and Sensor wire respectively.
Conclusions: It is safer to use Hydrophilic wires when using a ureteric catheter to buttress and support the wire, but the ureteric catheter should remain at least 1 cm proximal to the tip of the hydrophilic wire to minimize the risk of ureteric perforation when the wire exits the ureteric catheter.
Source of Funding: None
|Listen to an interview with Tarek Alzahrani, one of the authors of this study.|
Presented by Tarek Alzahrani,1, 2 Daniela Ghiculete,1, 2 Kenneth T. Pace,1, 2 and R.J. D’A Honey1, 2 at the 32nd World Congress of Endourology & SWL - September 3 - 7, 2014 - Taipei, Taiwan
1St. Michael’s Hospital, Canada
2University of Toronto, Canada