(179) SIMULATION OF ERECTILE TISSUE SHOCKWAVE ENERGY ABSORPTION DURING LOW LISWT FOR ERECTILE DYSFUNCTION

Low intensity shockwave therapy (LiSWT) treats ED by inducing mechanotransduction regenerative mechanisms; the greater the shockwave energy absorbed in cavernosal erectile tissue, the greater the opportunity for mechanotransduction. Energy absorption may be improved by erect vs flaccid penile treatment. Compared to flaccid, erect intracavernosal penile pressure is 16-fold higher and erect blood volume >2 times greater, both properties determinants of tissue energy wave velocity. Additionally, energy absorption may be improved using a symmetry-matched secondary reflector. This may reflect shockwave energy back to the erectile tissue that had previously passed through the penis. We performed a simulation of energy absorption during LiSWT in flaccid/erect penis with/without a reflector.

This energy model used the UroGold100 MTS/Softwave TRT electrohydraulic shockwave device. Sound propagation in tissue can be illustrated via computer simulation by mathematically calculating damping and deflection of the sound wave by different tissue structures. Finite Element Method (FEM) simulation models are suitable for the mathematical description of complex processes of shockwave propagation. Based on results, a “prediction” of propagation of LiSWT in tissue is possible. This patient-specific procedure is based on consideration of individual anatomical structures: corporal lacunar spaces and physical-acoustic laws. For FEM modeling of LiSWT propagation, program systems ANSYS, MATLAB and PZFLEX/ONSCALE were used.

Using the FEM calculation model of the simulation analyses, the shockwave pulse was applied at the bottom edge of the model. This pulse propagated through the erect/flaccid states; there was most energy absorption in the erect state with a reflector. In addition, the simulation model showed that increasing penile pressure during erection with a constant volume increased energy absorption.

More energy is absorbed in cavernosal erectile tissue to achieve mechanotransduction during erection than flaccidity, and with a symmetric reflector. Such strategies should be considered when performing shockwave therapy for ED.

Erich Theuer is a consultant to MTS.

Nikolaus Hopfenzitz is an employee of MTS.

John Warlick is owner of Softwave/TRT.