PITTSBURGH, Jan. 3, 2015 – Few published studies have examined the mechanical properties of the animal ureter and none have determined the tensile strength of the human ureter, which may help prevent iatrogenic injuries. Researchers at the University of Pittsburgh conducted a trial to determine the tensile strength in the human ureter, and the preliminary results were published in a recent issue of the Journal of Endourology.  

Yaniv Shilo, MD, assistant professor of urology at the University of Pittsburgh and lead author of the study, and colleagues harvested 11 human proximal ureters from patients undergoing nephrectomy, and uniaxially tested tissue strips circumferentially and longitudinally. Corresponding force and displacement were recorded, and stress at failure was noted as the tensile strength of the sample.

The tensile strength of the ureter in circumferential and longitudinal orientations was found to be 457.52±33.74 Ncm(-2) and 902.43±122.08 Ncm(-2), respectively (P<0.001). The circumferential strength in the proximal portion of the ureter was 409.89±35.13 Ncm(-2) in comparison with 502.89±55.85 Ncm(-2) in the distal portion (P=0.08).

The authors found that the “circumferential tensile strength of the ureter was significantly lower than the longitudinal strength” and “circumferential tensile strength was also lower with more proximal parts of the ureter.” The results may be important for the design of “intelligent” devices and simulators to prevent ureteral injuries.

Additional authors included Joseph Pichamuthu, Timothy Averch, MD, and David A. Vorp, PhD, all of the University of Pittsburgh.

To view the full abstract, please visit PubMed.gov.