Innovating Incrementally: Development of the Modern Inflatable Penile Prosthesis

History of penile implants: from implants made of bone to modern inflatable penile implants

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 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. The understanding of the historical process behind the evolution of inflatable penile prostheses will drive further innovation to increase efficiency and the rate of patients satisfaction.

Safety and Efficacy of Inflatable Penile Prostheses for the Treatment of Erectile Dysfunction: Evidence to Date

Erectile dysfunction (ED) is a common problem, and prevalence rates are expected to rise as life expectancy increases worldwide. In more severe cases of ED, penile prosthesis implantation has been an excellent option for patients. Over the past few decades, significant design improvements have been made to the penile prosthesis and modifications to surgical technique to improve clinical outcomes. The purpose of this review is to summarize the safety and efficacy of FDA-approved penile implants in the US market. Design modifications have greatly improved the safety and reliability of the implant. Development of improved surgical techniques has decreased intraoperative injuries and reservoir-related complications. With its high overall satisfaction rates and low risk of complications, the inflatable penile prosthesis remains an excellent option for patients with erectile dysfunction.

Penile prosthesis and complications: Results from 577 implants

OBJECTIVE

Penile Prosthetic Surgery is already well characterized but the problems connected with possible complications still need to be evaluated and discussed.

MATERIAL AND METHODS

The Authors revaluated their experience in Penile Prosthetic Surgery involving 577 patients (18 - 86 years, mean age 51.3 years) operated by the same surgeon since 1984. We implanted 199 silicone-semi-rigid (Small Carrion, Implantal, Eurogest, Subrini, SSDA GS), 200 malleable (Jonas, Omniphase, Duraphase, AMS600, MentorColoplast Genesis, Vedise) and 178 inflatable (Mentor: Mark II, Alpha I, Titan OTR; AMS: mono-component Hydroflex, Dynaflex; bi-component Ambicor; multicomponent: 700 Ultrex, 700 CX, 700 LGX) prostheses. Operative, postoperative, infectious and malfunctioning complications have been recorded. A total of 156 patients drop out at follow-up and we may not exclude possible late complications treated at different hospitals.

RESULTS

The recorded complications and the therapeutic modalities utilized to treat them are examined. Operative complications were recorded in 2 malleable prostheses (MPP) and in one inflatable prosthesis (IPP). Postoperative complications have been recorded in three cases of MPP (1.5%) and in 9 IPP (5.0%) and were strictly connected to general medical co-morbidities as diabetes mellitus (DM), coronary artery dysfunction (CAD), and Peyronie's disease (PD). In three cases of IPP implantation, hematomas were related to the blunt surgical maneuvers utilized to insert the reservoir or the scrotal pumps. Infectious complications were mostly observed in patients with DM: 4 patients with MPP (1.0%) and 15 patients with IPP (8.4%). Malfunction rate of the prostheses in our series was really disappointing considering that 13/17 cases (77%) of mono-component IPP broke while in patients with multicomponent IPP the percentage of malfunction has been of 13/161 (8%) and malfunction was observed in only one case of MPP. We were forced to explant the prostheses in 2 patients with MPP (0.5%) and 40 with IPP (22%). However, after excluding 17 mono-component IPPs, the percentage of explants of multicomponent IPP (23 patients, 4.2%) is in line with other significative experiences.

CONCLUSION

The number of complications of PPS are similar to those reported by well qualified urological institutions. In our experience a scrupulous antibiotic therapeutic schedule, avoiding direct contact between the prostheses and the patient's skin, reduced time of surgery with surgeon's experience positively influenced the results.In a limited number of patients medical treatment or minimal surgical acts allowed to solve the complications preserving the prostheses and avoiding the prosthetic explant.

A prospective study analyzing both inflation and deflation preference for commonly available inflatable penile prostheses

Despite popularity, satisfaction rates of inflatable penile prosthesis (IPP) use can be improved by evaluating the ability to operate devices in the preoperative setting. The purpose of this study was to prospectively analyze the preference of three commonly available IPPs. In total, 125 IPP-naïve men 60 years of age or older were prospectively recruited from an outpatient Urology clinic from June 2019 to January 2020. A questionnaire standardized to all encounters was utilized to collect demographics, selected medical information, and key pinch strength. Participants were then asked to rank three models in terms of preference (from 1 to 3, 1 representing most preferred) for each inflation and deflation in a double-blinded manner. Statistical analysis was performed using ANOVA, a Chi-square test and multivariable logistical regression analysis. The results demonstrated preference for Coloplast Titan (44%) for inflation, and preference for AMS 700 (40%) for deflation. Men who preferred the Coloplast Titan inflation had a lower chance of preferring the AMS 700 MS deflation (OR = 0.29; p = 0.010) and Coloplast Titan Touch deflation (OR = 0.27; p = 0.012). Preference for Coloplast Titan was weakly associated with participant history of coronary artery disease (OR = 5.96, p = 0.006) and osteoarthritis (OR = 3.04, p = 0.044). Neither key pinch strength nor age was associated with preference for a particular model. IPP-naïve men over 60 years favor Coloplast Titan for inflation and AMS 700 for deflation, and men who preferred the Coloplast Titan for inflation were less likely to choose the AMS 700 MS or Coloplast Titan Touch for deflation. Further studies should aim to confirm these findings.