Erectile dysfunction (ED) is a multifactorial disease that affects approximately 30 million American men and is continuing to increase along with the upsurge in diabetes, hypertension and cardiovascular disease. When first line and second line medications such as the phosphodiesterase 5 inhibitor class of medications or direct injections fail, surgical implantation of penile prostheses offers a permanent solution. Surgical implantation of prostheses is a known practical means of treating erectile dysfunction.
Two broad classes of penile prostheses are typically used, the inflatable prosthesis and the semi-rigid prosthesis. The inflatable penile prosthesis aims to closely parallel a natural erection by shifting fluid from one area of the device, usually a reservoir, to the cylinders within the corpora cavernosa under hydraulic pressure to mimic the erect state. It relies on a closed system of reservoirs, pumps, valves and hydraulic pressure to produce a simulated erection sufficient for coitus. Consequently, the surgical implantation of this device is more complex and is prone to mechanical failure. Indeed only 67 to 88% of such devices are fully functional after 10 years. The advantages of the inflatable prosthesis are that it appears more physiologic and does not exert constant pressure on surrounding tissues when in the flaccid state, thereby reducing the risk of erosion.
In contrast, the semi-rigid prosthesis strikes a balance between being rigid enough for penetration, but malleable enough to allow positioning of the prosthesis downwards when not in use. The advantages of a semi-rigid prosthesis are that the device is simple, reliable, involves a smaller dissection, has fewer parts, and requires minimal dexterity to use. The disadvantages are that the prosthesis appears constantly erect, exerts more force on the surrounding tissues, and has an increased risk for erosion.
A solution to these previous penile implants is a penile prosthesis that is implantable in the corpus cavernosum. The penile prosthesis has a cylindrical outer contour along its longitudinal axis, is comprised of a shape memory alloy, and has a dimension that enlarges in response to an increase in temperature around the penile prosthesis. A useful memory alloy would be a Nitinol-Titanium (or Ni—Ti or referred to as Nitinol) alloy that undergoes a transition from a more malleable martensitic state to a more rigid austenitic state with application of heat. Heat can be provided in different ways, however, in a romantic environment, few options are available that can ruin the mood of the moment. Such means of providing heat to the penile prosthesis can include getting a wash rag wet with warm water and applying it to the penis or heating a hot pad in a microwave and applying it to the penis. Other issues related to heat transfer may cause the skin and other tissue around the penile prosthesis to burn in trying to get the memory alloy in the penile prosthesis to respond. Furthermore, the application of these means of heating may cause parts of the penile prosthesis to respond to heat but other parts of the penile prosthesis not to respond because the heat is not appropriately distributed.
Thus there is a need for a tool that induces heat upon a penile prosthesis that uses a shape memory alloy that is discrete, efficient and responsive. The tool should be appropriately sized so that it can be portable and reusable. There should also be a means to distribute the heat to the penile prosthesis in a more evenly distributed manner so that the memory alloy is heated in an even manner.