Objective
To compare a novel nickel-titanium (Ni-Ti) shape memory alloy (SMA) penile prosthesis
of our own design with commercially available prostheses using a format similar to
mechanical testing done at major penile prosthesis manufacturers. We evaluated the
mechanical parameters of commercially available penile prostheses and used this information
to guide the development of the Ni-Ti-based physiological penile prosthesis that expands
and becomes erect with a small amount of heat applied.
Methods
A penile prosthesis consisting of an exoskeleton of temperature-tuned Nitinol was
designed and prototyped. Mechanical testing was performed in a model of penile buckling,
penile lateral deviation, and original penile shape recovery commonly used by penile
prosthesis manufacturers for testing.
Results
Our SMA penile prosthesis demonstrated useful mechanical characteristics, including
rigidity to buckling when activated similar to an inflatable penile prosthesis (2.62 kgf
SMA vs 1.42 kgf inflatable penile prosthesis vs 6.45 kgf for a malleable prosthesis).
The Ni-Ti also became more pliable when deactivated within acceptable mechanical ranges
of existing devices. It could be repeatedly cycled and generate a restorative force
to become erect.
Conclusion
An SMA-based penile prosthesis represents a promising new technology in the treatment
of erectile dysfunction. We demonstrated that an Ni-Ti-based prosthesis can produce
the mechanical forces necessary for producing a simulated erection without the need
for a pump or reservoir, comparable with existing prostheses.
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References
- Management of erectile impotence. Use of implantable inflatable prosthesis.Urology. 1973; 2: 80-82
- Review of penile prosthetic reservoir: complications and presentation of a modified reservoir placement technique.J Sex Med. 2012; 9: 2759-2769
- High submuscular placement of urologic prosthetic balloons and reservoirs via transscrotal approach.J Sex Med. 2013; 10: 603-610
- Outcomes and satisfaction rates for the redesigned 2-piece penile prosthesis.J Urol. 2007; 177: 262-266
- Historical advances in penile prostheses.Int J Impot Res. 2000; 12: S101-S107
- Penile prosthesis surgery: a review of prosthetic devices and associated complications.J Sex Med. 2007; 4: 296-309
- Penile prosthesis infection: approaches to prevention and treatment.Urol Clin North Am. 2011; 38: 227-235
- Small-Carrion penile prosthesis. New implant for management of impotence.Urology. 1975; 5: 479-486
- Experience with Tube (Promedon) malleable penile implant.Urol Int. 2007; 79: 244-247
- Penile prostheses in urology.in: White R.W. Palmer J.M. New Techniques in Urology. 1987 (Mount Kisco, NY)
- Evaluation of a Ni-Ti shape memory alloy for use in a novel penile prosthesis.J Urol. 2013; 189 (Conference: Annual Meeting of the American-Urological-Association (AUA), San Diego, CA): e502
- Penile prosthesis, useful to treat erectile dysfunction, comprises a shape memory alloy having dimension that enlarges radially in response to increase in temperature, and a cylindrical outer contour along its longitudinal axis. USPN US2013131443-A1.Northwestern University, Evanston, IL2013
- Finite element simulation modeling to study the behavior of a novel shape-memory based penile prosthesis.J Sex Med. 2014; 11: 161
- Biomechanics of male erectile function.J R Soc Interface. 2007; 4: 1031-1047
- Biomechanical analysis of penile erections: penile buckling behaviour under axial loading and radial compression.BJU Int. 2008; 102: 76-84
- Measurement of pressure necessary for vaginal penetration.Sleep Res. 1985; 14: 269
- The evolution of the inflatable penile prosthetic device and surgical innovations with anatomical considerations.Curr Urol Rep. 2014; 15: 410
- Modern utilization of penile prosthesis surgery: a national claim registry analysis.Int J Impot Res. 2014; 26: 167-171
- Heat transfer to deep tissue: the effect of body fat and heating modality.J Med Eng Technol. 2009; 33: 337-348
Article info
Publication history
Published online: September 14, 2016
Accepted:
September 3,
2016
Received:
June 27,
2016
Footnotes
Financial Disclosure: Brian Le and Alberto Colombo received grant from Boston Scientific (formerly American Medical Systems). Kevin McVary received grant from Boston Scientific Research and Educational Grant. The remaining author declares that he has no relevant financial interests.
Funding Support: The work was funded in part by Boston Scientific (formerly American Medical Systems).
Brian Le and Alberto Colombo contributed equally to this work.
Identification
Copyright
© 2016 Elsevier Inc. All rights reserved.
