Recent technological development of penile prosthesis: a literature review.

Background and Objective: In contemporary Urology, the gold standard for treatment of erectile dysfunction refractory to medical therapy has been implantation with a penile prosthesis. The past 40 years has witnessed evolutions in technology and surgical techniques, which have led to increased patient satisfaction rates and decreased complication and infection rates. This review is an update to a prior review article that evaluates these advancements in the context of patient satisfaction and different rates of complications following surgeries. In addition, the review compares malleable and inflatable prostheses with regard to infection rate, mechanical failure rate, and erosion rate. Methods: A literature search was conducted using Medline and Google Scholar to examine papers from 1973 to the present day. Keywords, such as, "penile prosthesis surgery", "malleable penile prosthesis", "inflatable penile prosthesis", "two-piece Inflatable Penile Prosthesis (IPP)", and "three-piece IPP" were utilized during the search. A total of 76 papers were included, and all were in English. Key Content and Findings: Studies on the latest models of each of the three prostheses (malleable, two-piece IPP, three-piece IPP) revealed patient satisfaction ratings at or above 75%. Both types of IPPs were associated with greater satisfaction and lower erosion rates while malleable prostheses were associated with lower mechanical failure rates. Although no significant differences in infection rates were noted between the prosthesis types, a history of diabetes, obesity, and smoking were predictive of infection events. Conclusions: The three-piece IPP, if indicated for a suitable patient, is generally accepted as the best type of prosthesis given its biological mimicry to an erect human penis.

Molecular mechanisms of penile traction for penile rehabilitation in a bilateral cavernous nerve crush injury rat model.

Background: Prostate cancer is the most common solid-organ malignancy in adult men. Early detection and treatment of prostate cancer with radical prostatectomy (RP) has improved cancer-specific survival but is associated with penile shortening and erectile dysfunction. Penile traction therapy (PTT) has been demonstrated to increase stretched penile length (SPL) prior to penile prosthesis placement and may improve erectile function (EF) in patients with Peyronie's disease. We aimed to evaluate the efficacy of PTT in preserving penile length and EF after bilateral cavernous nerve crush injury (BCNI) in a rat model. Methods: Twenty-four male Sprague-Dawley rats aged 11-13 weeks were randomly assigned to three groups (n=8, each): sham operation with no PTT (Sham), BCNI without PTT (Crush), and BCNI with PTT (Traction). PTT was started on postoperative day 3. A traction force of 1 Newton was applied to the penis for 30 minutes each day for 28 days. After 28 days of traction, the cavernous nerve was stimulated while recording the intracavernosal pressure (ICP) and the mean arterial pressure (MAP) simultaneously. Cavernosal tissue was excised, and western blot analysis for endothelial nitric oxide synthase (eNOS) was performed. Significance was determined by using ANOVA with Tukey-Kruger post-hoc testing. Results: At 4 weeks after nerve injury, the Traction group had significantly greater SPL compared to the Sham and Crush groups (30 vs. 28 and 27 mm, respectively). The Sham group had significantly greater EF (ΔICP/MAP) compared to the Crush group at 2.5, 5, and 7.5 V. The EF of the Traction group was between that of the Sham and Crush groups and was not significantly different from the Sham group at any voltages. Further downstream analysis revealed that the Traction group had significantly greater eNOS expression in cavernosal tissue compared to the Crush group, which was confirmed on western blot analysis and immunohistochemistry (IHC) staining. Conclusions: Findings from this animal study suggest that PTT has the potential to mitigate penile retraction after RP. While more studies are needed to determine the effect of PTT on preservation of EF, the increased eNOS expression observed in the Traction group offers a potential protective mechanism of action.

Do Minimally Invasive Benign Prostatic Hyperplasia Treatments Preserve Sexual Function? A Contemporary Review of the Literature.

PURPOSE OF REVIEW: The aim of this study is to compare the sexual function outcomes related to minimally invasive surgical therapies (MISTs) (UroLift®, Rezum™, Aquablation®, prostate artery embolization, and iTind®) for the treatment of benign prostatic hyperplasia (BPH). RECENT FINDINGS: Clinical trials and retrospective data evaluating MISTs for BPH have demonstrated improved or stable sexual function outcomes when compared to sham control or transurethral resection of the prostate. Outcomes were assessed at baseline and following treatments using patient-reported outcome measures. Rezum and Aquablation demonstrated preservation of overall ejaculatory function and erectile function at 36-month follow-up. Similar outcomes occurred with UroLift after a 60-month follow-up. Erectile function was preserved following prostate artery embolization and iTIND up to 12 months. MIST for the management of BPH has been demonstrated to be effective in improving urinary function and appears to minimize potential collateral damage on sexual function following treatment.

Narrative review of penile prosthetic implant technology and surgical results, including transgender patients.

Over the past 40 years, the technological and surgical advancements in penile prostheses have led to increased patient satisfaction rates and decreased complication and infection rates. In cis males with erectile dysfunction (ED), these technological improvements tremendously improve quality of life. In female to male transgender patients, prostheses provide the ability to engage in penetrative intercourse and to urinate standing. This review evaluates technological and surgical advancements in penile prosthetics in the context of documented patient satisfaction and complication rates from prosthesis surgeries. Retrospective studies of penile implant usage in female to male gender-affirming surgeries report that infection and complication rates are higher than those seen in cis males. There are newer prostheses developed specifically for female to male reassignment surgeries, but outcome data is limited. Continued research and development are needed to develop more efficacious penile implantation options for gender affirmation surgery.

A Systematic Review of Penile Prosthesis Surgery in Organ Transplant Recipients.

INTRODUCTION: There is an increased prevalence of erectile dysfunction in patients with solid organ transplant (SOT) compared with the general population. Many of these patients may become refractory to medical treatment of erectile dysfunction and penile prosthesis (PP) is often recommended. Concerns regarding the safety of PP in patients with SOT are due to their immunosuppressed state. OBJECTIVE: We aim to review all current literature on the outcomes of patients with SOT who have received PP. METHODS: A PubMed search was performed to identify articles pertaining to the outcomes of PP in patients with SOT. RESULTS: We identified and included 14 studies that report on outcomes of PP placement in 143 patients with SOT and 191 non-SOT controls from interval period from 1979 to 2019. Studies included retrospective cohort studies, case series, and case reports. Compared with non-SOT controls who had PP, aggregate analysis demonstrated that patients with SOT who had PP did not develop significantly increased overall complications. However, they were significantly more likely to experience future surgical complications. CONCLUSION: Our aggregate analysis demonstrated that patients with SOT are not at a significantly increased risk of overall complications when receiving a PP. Nevertheless, there is an increased risk of experiencing PP injury during subsequent surgeries, which may be mitigated by the earlier involvement of a urologist. Given the lack of recent data, large studies are prerequisite to further evaluate the safety and overall outcome of PP surgery in patients with SOT. Dick B, Greenberg JW, Polchert M, et al. A Systematic Review of Penile Prosthesis Surgery in Organ Transplant Recipients. Sex Med Rev 2021;9:636-640.