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History of penile implants: from implants made of bone to modern inflatable penile implants (2023)
Alessandro Giordano, Francesco Smarrazzo, Simone Cilio, Gianluigi Califan, Claudia Collà Ruvolo and Paolo Verze
Penile prostheses are implantable devices used to definitively treat erectile dysfunction when previous forms of treatment have failed. The first example of a penile implant dates to 1935, when a rib was inserted in a neo-phallus reconstructed after a traumatic amputation. Since then, alternative artificial devices were adopted as penile prosthetic implants. The evolution of prosthetic devices had a dramatic thrust in 1973 when the first inflatable penile prosthesis was worldwide presented. Thanks to advances in device materials, design, surgical implant techniques, and perioperative management, nowadays inflatable penile prostheses are one of the most adopted definitive therapy for patients with drug-refractory erectile dysfunction or refusing alternative forms of treatments. Moreover, the clinical indications for inflatable penile prosthesis have also expanded, including female-to-male transmen or men who underwent penile reconstruction due to congenital aphallia or traumatic or surgical penile amputation. In order to summarise the process behind the development and evolution of penile prosthesis, we aimed at performing a historical review of the currently available literature to provide an easy and comprehensive overview of the topic. An understanding of the historical process behind the evolution of inflatable penile prostheses will drive further innovation to increase efficiency and the rate of patient satisfaction.
INTRODUCTION
Penile prostheses are implantable devices used to treat erectile dysfunction (ED), when patients are not suitable or refuse pharmacological and alternative treatments or prefer a definitive therapeutic solution [1]. Throughout history, many medical options to treat ED have been described. Indeed, in 1985, Zorgniotti & Lefleur first showed the efficacy of intracavernosal auto-injection of vasoactive drugs in reaching a full erection [2]. In 1998, the management of ED switched to oral phosphodiesterase 5 inhibitors (PDE5-i) [3, 4]. However, unresponsiveness to available pharmacological therapies leads urologists to indicate the implant of a penile prosthesis [1].
The first example of a penile prosthesis is ascribed to Nikolaj A. Bogoras who published in 1936 the example of the implant of a cartilage row into a rudimental neophallus created in a man who has suffered a traumatic penile amputation [5, 6]. Since then, medical research focused on finding an artificial solution capable of mimicking a natural erection. The year 1973 represents a tipping point in the evolution of penile prosthesis with the introduction of the first inflatable penile prosthesis (IPP) by doctors Bradley and Scott [7]. Furthermore, both the devices and the surgical implantation techniques have evolved in the last 50 years [8].
Thanks to scientific advancements, nowadays penile prostheses are also used as a treatment in cases of Peyronie’s disease with concomitant ED [9], and to create rigid neo-phallus after phalloplasty in gender reassignment surgery in female-to-male (FtoM) transmen or in men with congenital aphallia or underwent traumatic or surgical penile amputation [10–13].
Considering the growing interest and utilization of penile prostheses as a definitive treatment for a drug-refractory ED, or as a device enabling penetrative intercourses to men with a neophallus, the current manuscript aimed at providing a review of the historical process behind the development of the current available devices and components.
PENILE PROSTHESIS HISTORY: FROM THE BEGINNING TO THE ADVENT OF INFLATABLE PENILE PROSTHESIS IN 1973
PENILE PROSTHESIS HISTORY: FROM THE ADVENT OF INFLATABLE PENILE PROSTHESIS IN 1973 TO THE PRESENT
The development process of the IPP began in 1969 thanks to the cooperation among doctors Scott, Timm, and Bradley who were actively involved in bladder physiology and neurophysiology research [26]. Their work was first aimed at creating the artificial urinary sphincter, and they had the idea of applying the same hydraulic technology in the pressurization of expandable cylinders to inflate corpora cavernosa. The idea helped to develop the first prototype of IPP in July 1973 (Fig. 1) [27].
*American medical systems
*Mentor-Coloplast
THE EVOLUTION OF THE PUMP MECHANISM COMPONENTS: THE PUMP AND THE RESERVOIR
*Pump
*Reservoir
THE SURGICAL APPROACH OVER TIME AND POST-OPERATIVE MANAGEMENT OF INFLATABLE PENILE PROSTHESIS
PENILE PROSTHESIS OVER THE ERECTILE DYSFUNCTION: IMPLANTS AFTER PHALLOPLASTY
FUTURE EVOLUTION OF PENILE PROSTHESIS AND CONCEPT
Technological development in recent years has not only aimed at the “naturalness” of sexual intercourse but also to solve potential technical aspects as well as make the implantation procedure safer (Fig. 4). Open questions of the scientific community, engineers and researchers are related to find the perfect materials, to make possible to build a touchless penile prosthesis, or even to make IPPs capable of function without fluid and without risk of leak of the hydraulic components.
Among the various concepts developed in the last years, there is the touchless IPP based on the principle of the self-filling of the cylinders with the sexual stimulus. This mechanism is possible thanks to a sacral neurostimulation-like implantable battery that receives a central erectile stimulus and activates the filling of the pump [53].
Of particular importance in the development of new materials is the study of B. Le et al., published in 2016, in which a new penile prosthesis in nickel-titanium alloy (Ni-Ti) with shape memory (SMA) was presented. The thermoregulated Nitinol exoskeleton designed and prototyped with this IPP uses thermal variations induced by an external magnetic induction previously to any intercourse. This mechanism allows to modify the volume and prosthesis size demonstrating useful mechanical characteristics, including rigidity to buckling when activated, similar to a classic three-component IPP (2.62 kilograms-force (kgf) SMA vs 1.42 kgf inflatable penile prosthesis vs 6.45 kgf for a malleable prosthesis) [80, 81].
CONCLUSIONS
In a time interval of about 50 years there has been a constant improvement of penile implantable devices, to such an extent that nowadays IPPs are associated with extremely high patient and partner satisfaction, excellent long-term outcomes and are considered the best treatment option not only for patients presenting with drug-refractory ED, but also for FtoM transmen and men who underwent penile reconstruction. An understanding of the historical process behind the evolution of currently available IPPs, as well as a better understanding of the state of the art of modern devices, could drive further innovation to increase efficiency and satisfaction rates for patients.
Alessandro Giordano, Francesco Smarrazzo, Simone Cilio, Gianluigi Califan, Claudia Collà Ruvolo and Paolo Verze
Penile prostheses are implantable devices used to definitively treat erectile dysfunction when previous forms of treatment have failed. The first example of a penile implant dates to 1935, when a rib was inserted in a neo-phallus reconstructed after a traumatic amputation. Since then, alternative artificial devices were adopted as penile prosthetic implants. The evolution of prosthetic devices had a dramatic thrust in 1973 when the first inflatable penile prosthesis was worldwide presented. Thanks to advances in device materials, design, surgical implant techniques, and perioperative management, nowadays inflatable penile prostheses are one of the most adopted definitive therapy for patients with drug-refractory erectile dysfunction or refusing alternative forms of treatments. Moreover, the clinical indications for inflatable penile prosthesis have also expanded, including female-to-male transmen or men who underwent penile reconstruction due to congenital aphallia or traumatic or surgical penile amputation. In order to summarise the process behind the development and evolution of penile prosthesis, we aimed at performing a historical review of the currently available literature to provide an easy and comprehensive overview of the topic. An understanding of the historical process behind the evolution of inflatable penile prostheses will drive further innovation to increase efficiency and the rate of patient satisfaction.
INTRODUCTION
Penile prostheses are implantable devices used to treat erectile dysfunction (ED), when patients are not suitable or refuse pharmacological and alternative treatments or prefer a definitive therapeutic solution [1]. Throughout history, many medical options to treat ED have been described. Indeed, in 1985, Zorgniotti & Lefleur first showed the efficacy of intracavernosal auto-injection of vasoactive drugs in reaching a full erection [2]. In 1998, the management of ED switched to oral phosphodiesterase 5 inhibitors (PDE5-i) [3, 4]. However, unresponsiveness to available pharmacological therapies leads urologists to indicate the implant of a penile prosthesis [1].
The first example of a penile prosthesis is ascribed to Nikolaj A. Bogoras who published in 1936 the example of the implant of a cartilage row into a rudimental neophallus created in a man who has suffered a traumatic penile amputation [5, 6]. Since then, medical research focused on finding an artificial solution capable of mimicking a natural erection. The year 1973 represents a tipping point in the evolution of penile prosthesis with the introduction of the first inflatable penile prosthesis (IPP) by doctors Bradley and Scott [7]. Furthermore, both the devices and the surgical implantation techniques have evolved in the last 50 years [8].
Thanks to scientific advancements, nowadays penile prostheses are also used as a treatment in cases of Peyronie’s disease with concomitant ED [9], and to create rigid neo-phallus after phalloplasty in gender reassignment surgery in female-to-male (FtoM) transmen or in men with congenital aphallia or underwent traumatic or surgical penile amputation [10–13].
Considering the growing interest and utilization of penile prostheses as a definitive treatment for a drug-refractory ED, or as a device enabling penetrative intercourses to men with a neophallus, the current manuscript aimed at providing a review of the historical process behind the development of the current available devices and components.
PENILE PROSTHESIS HISTORY: FROM THE BEGINNING TO THE ADVENT OF INFLATABLE PENILE PROSTHESIS IN 1973
PENILE PROSTHESIS HISTORY: FROM THE ADVENT OF INFLATABLE PENILE PROSTHESIS IN 1973 TO THE PRESENT
The development process of the IPP began in 1969 thanks to the cooperation among doctors Scott, Timm, and Bradley who were actively involved in bladder physiology and neurophysiology research [26]. Their work was first aimed at creating the artificial urinary sphincter, and they had the idea of applying the same hydraulic technology in the pressurization of expandable cylinders to inflate corpora cavernosa. The idea helped to develop the first prototype of IPP in July 1973 (Fig. 1) [27].
*American medical systems
*Mentor-Coloplast
THE EVOLUTION OF THE PUMP MECHANISM COMPONENTS: THE PUMP AND THE RESERVOIR
*Pump
*Reservoir
THE SURGICAL APPROACH OVER TIME AND POST-OPERATIVE MANAGEMENT OF INFLATABLE PENILE PROSTHESIS
PENILE PROSTHESIS OVER THE ERECTILE DYSFUNCTION: IMPLANTS AFTER PHALLOPLASTY
FUTURE EVOLUTION OF PENILE PROSTHESIS AND CONCEPT
Technological development in recent years has not only aimed at the “naturalness” of sexual intercourse but also to solve potential technical aspects as well as make the implantation procedure safer (Fig. 4). Open questions of the scientific community, engineers and researchers are related to find the perfect materials, to make possible to build a touchless penile prosthesis, or even to make IPPs capable of function without fluid and without risk of leak of the hydraulic components.
Among the various concepts developed in the last years, there is the touchless IPP based on the principle of the self-filling of the cylinders with the sexual stimulus. This mechanism is possible thanks to a sacral neurostimulation-like implantable battery that receives a central erectile stimulus and activates the filling of the pump [53].
Of particular importance in the development of new materials is the study of B. Le et al., published in 2016, in which a new penile prosthesis in nickel-titanium alloy (Ni-Ti) with shape memory (SMA) was presented. The thermoregulated Nitinol exoskeleton designed and prototyped with this IPP uses thermal variations induced by an external magnetic induction previously to any intercourse. This mechanism allows to modify the volume and prosthesis size demonstrating useful mechanical characteristics, including rigidity to buckling when activated, similar to a classic three-component IPP (2.62 kilograms-force (kgf) SMA vs 1.42 kgf inflatable penile prosthesis vs 6.45 kgf for a malleable prosthesis) [80, 81].
CONCLUSIONS
In a time interval of about 50 years there has been a constant improvement of penile implantable devices, to such an extent that nowadays IPPs are associated with extremely high patient and partner satisfaction, excellent long-term outcomes and are considered the best treatment option not only for patients presenting with drug-refractory ED, but also for FtoM transmen and men who underwent penile reconstruction. An understanding of the historical process behind the evolution of currently available IPPs, as well as a better understanding of the state of the art of modern devices, could drive further innovation to increase efficiency and satisfaction rates for patients.
