Penile implant

The first modern prosthetic reconstruction of a penis is attributed to NA Borgus, a German physician who performed the first surgical attempts in 1936 on soldiers with traumatic amputations of the penis. He used rib cartilages as prosthetic material and reconstructed the genitals for both micturition and intercourse purposes. Willard E. Goodwin and William Wallace Scott were the first to describe the placement of synthetic penile implants using acrylic prosthesis in 1952. Silicone-based penile implants were developed by Harvey Lash and the first case series were published in 1964. The development of a high-grade silicone that is currently used in penile implants is credited to NASA. The prototypes of the contemporary inflatable and malleable penile implants were presented in 1973 during the annual meeting of the American Urological Association by two groups of physicians from Baylor University (Gerald Timm, William E. Bradley and F. Brantley Scott) and University of Miami (Michael P. Small and Hernan M. Carrion). Small and Carrion pioneered the popularization of semi-rigid penile implants with the introduction of Small-Carrion prosthesis (Mentor, USA) in 1975. Brantley Scott described the initial device as composed of two inflatable cylindrical bodies made up of silicone, a reservoir containing radiopaque fluid and two pumping units. Many device updates have been released by AMS since the first generation implants. In 1983, Mentor (currently Coloplast) joined the market. The latest additions to the market are Zephyr Surgical Implants and Rigicon Innovative Urological Solutions. Zephyr Surgical Implants, along with penile implants for biological males, introduced the first line of inflatable and malleable penile implants designed for sex reassignment for trans men. In recent years, Rigicon Innovative Urological Solutions, a US-based company, has made significant advancements in the field of penile implants. In 2017, they released the 'Rigi10,' a malleable implant that expanded the market's options. Following this, in 2019, they introduced both the 'Infla10' series, which includes the Infla10 AX, Infla10 X, and Infla10 models, and the 'Rigi10 Hydrophilic.' These inflatable and hydrophilic-coated malleable models respectively were important additions to the range of penile implant technologies available. These advancements have contributed to the diversity and progress in the development of penile implants, offering patients more varied and tailored treatment solutions. According to analysis of the 5% Medicare Public Use Files from 2001 to 2010 approximately 3% of patients diagnosed with erectile dysfunction opt for penile implantation. Each year nearly 25,000 inflatable penile prostheses are implanted in the USA. The list shows penile implants available in the market in 2020. ==Types==

Malleable penile implant The malleable (also known as non-inflatable or semi-rigid) penile prosthesis is a pair of rods implanted into the corpora of the penis. The rods are hard, but 'malleable' in the sense that they can be adjusted manually into the erect position. There are two types of malleable implants: one that is made of silicone and does not have a rod inside, also called soft implants, and another with a silver or steel spiral wire core inside coated with silicone. Some of the models have trimmable tails intended for length adjustment. Inflatable penile implant The inflatable penile implant (IPP), more recently developed, is a set of inflatable cylinders and a pump system. Based on the differences in structure, there are two types of inflatable penile implants: two-piece and three-piece IPPs. Both types of inflatable devices are filled with sterile saline solution which is pumped into cylinders when in process. The cylinders are implanted into the cavernous body of the penis. The pump system is attached to the cylinders and placed in the scrotum. ==Medical use==

Erectile dysfunction In spite of recent rapid and extensive development of non-surgical management options for erectile dysfunction, especially novel targeted medications and gene therapy, the penile implants remain the mainstay and the gold standard choice for the treatment of erectile dysfunction refractory to oral medications and injectable therapy. Penile deformity Penile implants can help recover the natural shape of the penis in various conditions that have led to penile deformity. These can be traumatic injuries, penile surgeries, disfiguring and fibrosing diseases of the penis, such as Peyronie's disease. Therefore, implantation of penile prosthesis in Peyronie's disease addresses several mechanisms involved in the pathophysiology of the disease. Female-to-male sex reassignment Although different models of penile prostheses have been reported to be implanted after phalloplasty procedures, with the first case described in 1978 by Pucket and Montie, the first penile implants designed and produced specifically for female-to-male gender reassignment surgery for trans men were introduced in 2015 by Zephyr Surgical Implants. Both malleable and inflatable models are available. These implants have more realistic shape with an ergonomic glans at the tip of the prosthesis. The inflatable model has an attached pump resembling a testicle. The prosthesis is implanted with a sturdy fixation on pubic bone. Another, thinner malleable implant is intended for metoidioplasty. ==Outcomes==

Satisfaction The overall satisfaction rate with penile implants reaches over 90%. The most frequent reasons for dissatisfaction are reduced penis length and girth, failed expectations and difficulties with device use. ==Complications==

The most common complication associated with penile implant placement appears to be infections with reported rates of 1–3%. Sliding techniques in which the penis is cut and elongated with penile implants have been performed in cases of severe penile shortening. However, these techniques had higher rates of complications and are currently avoided. Modern penile implant techniques are also widely practiced in the Middle East, including Jordan, where specialized urology centers offer both inflatable and malleable prostheses. ==References==