In 1975, we started a research project for the development of microexplosion lith-otripsy. In this project, we investigated the mechanical properties of the urinary tract organs to clarify factors to prevent complications from the method. Tension and expansion tests were performed on the middle portion of the normal ureter taken from fresh cadavers in 1983.
A tension test was performed on eleven ureters in the longitudinal direction and seven in the transverse direction using a universal tensile tester. Tensile strength and maximum tensile stress in the transverse direction of the ureter were weaker than those in the longitudinal direction. Accordingly, it was presumed that ureteral injury first occurred in the transverse direction. The maximum tensile stress of the ureter was higher than that of the bladder, which was previously reported in another paper.
Expansive tests were performed on ten ureters. At the leakage point, the tensile strength and elongation ratio of the external diameter were approximately equal to the tensile strength and elongation ratio measured by tension test in the transverse direction.
It could be concluded from the results that microexplosion lithotripsy could be applicable even in the ureter under certain conditions.