(060) Evaluation of the Mechanical Properties of the Human Tunica Albuginea

Abstract

Abstract Introduction The penis is in its essence a biomechanical implement and the Tunica Albuginea is the main load-bearing tissue during erection and its biomechanical properties are critical to understanding the penile physiology and the expansion of corpora cavernosa. There is surprisingly a paucity of data surrounding the biomechanical properties of the (TA) in literature. Objective We previously quantified the Young’s modulus and ultimate tensile strength (UTS) of TA in primates and we now compare these values with human TA tissue. Methods Strips of TA were dissected from patients undergoing penectomy in both longitudinal and circumferential orientations. We measured the thickness, the width and the length of every sample in three different locations for statistical purposes and we generated stress-strain curves via mechanical extensometry using an Instron machine. From this curve the Young’s modulus (a measure of stiffness) and ultimate tensile strength were calculated. Comparisons between human and baboon values were performed with a t-test. Results Six samples from 3 penes produced a mean Young’s modulus of 8.1 MPa (SD 1.7) longitudinally (n=3) and 10.3 MPa (SD 3.1) circumferentially (n=4). The mean ultimate tensile strength was 1.8 MPa (SD 0.6) longitudinally and 1.7 MPa (SD 0.1 MPa) circumferentially. These values show that human tunica albuginea has a stiffness between cartilage and cancellous bone. In comparison with baboons (Papio anubis), human samples had a lower Young’s modulus longitudinally (8.1 vs 34.0, p <0.01) but not circumferentially (10.3 vs 11.7, p=0.32). Additionally, the human samples had a lower maximum stress longitudinally (1.8 vs 4.3, p=0.01) but not circumferentially (1.7 vs 2.0, p=0.29). These data show that baboon TA is stiffer and stronger longitudinally than human TA. Conclusions These measures of fresh human TA show some variation between human and primate models and support the need for fresh human tissue measurements to characterize the mechanical properties of the penis. These data will be critical in developing in silico models that can be used to investigate mechanical disease states of the penis and predict tissue/prosthesis interactions. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Uronext.