A Novel Method to Measure the Mechanical Pushing and Pulling Forces During Ureteroscopy in a Normal Clinical Setting

Abstract Background and Purpose: The forces needed to move the ureteroscope up and down the urinary tract may injure the ureter, but a method to measure these forces in patients is lacking. The purpose of the study was to develop and test a novel method for measuring the pushing and pulling forces exerted on a semirigid ureteroscope during ureteroscopy (URS) in a clinical setting. Materials and Methods: During 2010 to 2011, 20 patients planned for retrograde flexible URS or percutaneous lithotripsy for renal pelvic stones were recruited to a study measuring the forces exerted on a semirigid ureteroscope during retrograde URS. A coupling device was constructed to connect a digital force meter to a standard semirigid ureteroscope. The pushing and pulling forces, given in Newton (N), were measured at four defined locations in the ureter. The experiment was repeated twice to evaluate the reproducibility of the results. Paired-samples t test and Intraclass Correlation Coefficient (ICC) addressed the reproducib...