Content and Face Validation of a Curriculum for Ultrasonic Propulsion of Calculi in a Human Renal Model

Abstract

Purpose: Ultrasonic propulsion to reposition urinary tract calculi requires knowledge about ultrasound image capture, device manipulation, and interpretation. The purpose of this study was to validate a cognitive and technical skills curriculum to teach urologists ultrasonic propulsion to reposition kidney stones in tissue phantoms. Materials and Methods: Ten board-certified urologists recruited from a single institution underwent a didactic session on renal ultrasound imaging. Subjects completed technical skills modules in tissue phantoms, including kidney imaging, pushing a stone through a translucent maze, and repositioning a lower pole calyceal stone. Objective cognitive and technical performance metrics were recorded. Subjects completed a questionnaire to ascertain face and content validity on a five-point Likert scale. Results: Eight urologists (80%) had never attended a previous ultrasound course, and nine (90%) performed renal ultrasounds less frequently than every 6 months. Mean cognitive skills scores improved from 55% to 91% ( p < 0.0001) on pre-and post-didactic tests. In the kidney phantom, 10 subjects (100%) repositioned the lower pole calyceal stone to at least the lower pole infundibulum, while 9 (90%) successfully repositioned the stone to the renal pelvis. A mean -SD (15.7 -13.3) pushes were required to complete the task over an average of 4.6 -2.2 minutes. Urologists rated the curriculum's effectiveness and realism as a training tool at a mean score of 4.6/5.0 and 4.1/5.0, respectively. Conclusions: The curriculum for ultrasonic propulsion is effective and useful for training urologists with limited ultrasound proficiency in stone repositioning technique. Further studies in animate and human models will be required to assess predictive validity.

Preclinical Safety and Effectiveness Studies of Ultrasonic Propulsion of Kidney Stones

“…Lastly, an experienced ultrasonographer held the ultrasound probe on four of the animals; however, a urologist performed the ultrasonic propulsion on animal #5 and was comparably successful. The findings from our training study of ten urologists is reassuring that this technique can be successfully learned with training 15 .…”

“…Thus, the potential exists for further improvement with training and practice on the system. A training curriculum was developed and tested on board certified urologists, who at the completion of training, moved a stone in a human torso phantom from the lower pole to the UPJ in 4.6 ± 2.2 minutes 15 . This reinforces the critical importance of the alignment of the acoustic force with the desired trajectory of the stone toward the renal pelvis and UPJ.…”

Ultrasonic propulsion of kidney stones

“…Hsi et al [23] piloted a training curriculum on the fundamentals of renal ultrasound and ultrasonic propulsion and enrolled 10 board-certified urologists. Total 90% of participants did not perform renal ultrasounds before the study.…”

Characterizing the Acoustic Output of an Ultrasonic Propulsion Device for Urinary Stones

“…A novel non-invasive system has been developed for the ultrasonic propulsion of kidney stones to facilitate stone passage [1-7]. The device incorporates conventional brightness mode (B-mode) and Doppler mode for imaging the kidney and kidney stones, plus a Push mode, which uniquely applies focused ultrasound to reposition the stone.…”