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Acta Biomaterialia Apr 2024Erectile dysfunction (ED) predominantly affects men in their 40-70s and can lead to poor quality of life. One option for ED treatment is surgical implantation of an...
Erectile dysfunction (ED) predominantly affects men in their 40-70s and can lead to poor quality of life. One option for ED treatment is surgical implantation of an inflatable penile prosthesis (IPP). However, they can be associated with negative outcomes including infection, migration or fibrosis. To improve outcomes, the interaction between the IPP device and surrounding tissues needs further investigation and this could be achieved using pre-clinical testbeds, but they need to be informed by extensive tissue testing. In this study, an experimental approach is adopted to characterise the mechanics of horse penile tissue and establish a testing protocol for penile tissue. The whole penis segments were tested in plate compression tests to obtain whole penis behaviour which is necessary for validation of a pre-clinical testbed, whilst tensile and compression tests were performed on individual penile tissues, namely corpus cavernosa and tunica albuginea. The second part of the paper deals with the development of a computational model employing an inverse finite element approach to estimate the material parameters of each tissue layer. These material parameters are in good agreement with the experimental results obtained from the individual tissue layers and whole organ tissue tests. This paper presents the first study proposing realistic nonlinear elastic material parameters for penile tissues and offers a validated testbed for IPPs. STATEMENT OF SIGNIFICANCE: Erectile Dysfunction (ED) affects over half the male population aged 40-70 potentially leading to poor quality of life. Patients not responding to conventional treatments of ED, are advised to use penile prostheses which can create an erection using implanted inflatable cylinders. A significant drawback of such prostheses, however, is the substantial tissue damage they can induce during their usage. Preclinical testbeds, including computational and bench-top models, could offer an efficient means of improving device designs to mitigate this damage but such testbeds require extensive knowledge of penile tissue properties. In this study, the authors determine penile tissue mechanics and apply an inverse FE approach to characterise the penile material properties required to validate preclinical models of the penis.
Topics: Male; Penis; Finite Element Analysis; Animals; Horses; Tensile Strength; Penile Prosthesis; Erectile Dysfunction; Biomechanical Phenomena
PubMed: 38494081
DOI: 10.1016/j.actbio.2024.03.013 -
Translational Andrology and Urology Feb 2024Erectile dysfunction (ED) is a common condition in men, and many patients refractory to conservative treatment may undergo penile prostheses (PPs) placement. The primary... (Review)
Review
BACKGROUND AND OBJECTIVE
Erectile dysfunction (ED) is a common condition in men, and many patients refractory to conservative treatment may undergo penile prostheses (PPs) placement. The primary concern following PP implantation is device infection. Although antibiotic and hydrophilic coatings have reduced the incidence of inflatable PP (IPP) infections, there remains room for improvement. Optimization of PP outcomes requires a practical model to better understand mechanisms of infection and to test new infection control strategies. We aimed to describe a new rabbit model which contains a functional IPP and review previously reported animal PP models.
METHODS
An IPP was placed into rabbit flanks and cycled for functionality testing. Rabbits were evaluated for signs of pain and distress over 14 days. Separately, narrative review methodology was utilized to search the PubMed and Scopus databases for all publications through March 21, 2023, which studied PP within an setting. Three independent reviewers ultimately selected 12 papers from 1992-2021 for inclusion.
KEY CONTENT AND FINDINGS
Several animal studies highlighted the initial functionality or feasibility of devices for ED before their introduction in the clinical setting. There are several subsequent studies aimed at optimizing the type of antibiotic use or coating material using segments of PP material in an setting. However, the literature lacks a contemporary animal model containing a functional IPP. Our novel rabbit model offers a safe, practical way to implant a functioning IPP and investigate new perioperative infection prevention and treatment strategies before trials in the clinical setting.
CONCLUSIONS
Animal models have played a key role in testing medical devices, including PPs, prior to their clinical introduction. Our review uncovered no modern animal studies involving placement of a functional PP. A new animal model can facilitate study of evolving microorganism profiles, novel methods to enhance antibiotic delivery, and proposed treatment options.
PubMed: 38481874
DOI: 10.21037/tau-23-353 -
Translational Andrology and Urology Feb 2024This article provides a comprehensive discussion of 3-piece inflatable penile implant surgery when performed through an infrapubic approach in patients presenting with...
This article provides a comprehensive discussion of 3-piece inflatable penile implant surgery when performed through an infrapubic approach in patients presenting with challenging anatomy or corporal fibrosis. The infrapubic approach is one of the primary approaches for inflatable device placement with excellent long-term functional outcomes. While the literature is rich in descriptions of infrapubic placement in the primary, uncomplicated setting, its role in the management of complex patients presenting to centers of excellence is less elucidated. In uncomplicated cases, the infrapubic approach offers several theoretical advantages including shorter operative time and quicker return to sexual function. In addition to describing specific details of our infrapubic technique and perioperative management, I discuss scenarios in which an infrapubic approach may allow for better exposure for correction of dorsal deformity, facilitate secondary surgical maneuvers such as suprapubic lipectomy, or protect existing incontinence prosthetics already in place. Specific technique and surgical pearls from our prosthetic center of excellence are reviewed for each of these challenging scenarios. Ultimately, prosthetic surgeons should be adept at placing, revising, and removing devices through both approaches so that various forms of anatomical deformity and device failures can be addressed proficiently. In addition to my own clinical reflections, a critical review was performed using the Medline database to support our statements.
PubMed: 38481867
DOI: 10.21037/tau-23-182 -
Translational Andrology and Urology Feb 2024Male stress urinary incontinence (SUI) and erectile dysfunction (ED) are well established diagnoses within Men's Health, often more specifically within the prostate... (Review)
Review
BACKGROUND AND OBJECTIVE
Male stress urinary incontinence (SUI) and erectile dysfunction (ED) are well established diagnoses within Men's Health, often more specifically within the prostate cancer survivorship cohort. Taken individually, well defined treatment algorithms exist with which many surgeons are comfortable; however, treatment of both in a single setting or staged fashion introduces complexity. Emerging treatment options also exist, and there is immature or minimal data when these are combined with inflatable penile prosthesis (IPP) insertion, radiation history, and/or variable degrees of incontinence. Our objective was to describe and summarize the currently available treatment options for SUI particularly at the time of IPP insertion.
METHODS
A literature review was performed to summarize contemporary treatment of SUI at time of IPP placement. Anecdotal experience was added from high volume, subspecialty trained Men's Health and Reconstructive Urologists.
KEY CONTENT AND FINDINGS
Non-invasive approaches such as pelvic floor muscle training (PFMT), behavioral modification, and external compression devices play some limited role in treatment and/or management of SUI, particularly in the early post operative period, or for those unwilling or unable to undergo more definitive intervention. More invasive options such as artificial urinary sphincter (AUS) implantation, male sling, or other implantable devices are more appropriate for good surgical candidates with higher bother and/or more severe incontinence. These options can be concomitant or staged relative to IPP placement. Climacturia, particularly with mild or no bothersome SUI, can successfully be addressed at the time of penile prosthesis placement with the utilization of the Mini-Jupette suburethral sling.
CONCLUSIONS
A variety of treatment options exist for concomitant treatment of SUI at time of IPP, and both safety and efficacy have been demonstrated for many in the same operative setting. As with treatment of ED or SUI in isolation, patient selection, careful counseling, and management of expectations can lead to high patient satisfaction.
PubMed: 38481860
DOI: 10.21037/tau-23-137 -
Arab Journal of Urology 2024As available data on implantation-related infections is contradictory, the aim was to identify the predictors of penile prosthesis infection. (Review)
Review
BACKGROUND
As available data on implantation-related infections is contradictory, the aim was to identify the predictors of penile prosthesis infection.
METHODS
We performed an umbrella review and meta-analysis including systematic reviews with extractable data. Literature search was done in two databases: PubMed and Google Scholar. The participants were males with erectile dysfunction regardless of etiology who underwent penile implant surgery. Using a standardized form, three trained researchers reviewed each reference (systematic review) by title and abstract. The meta-analysis was performed using Review Manager 5.4.1 (RevMan® 5.4.1).
RESULTS
A total of 78 systematic reviews were identified with the search strategies. Of these, 35 duplicates were removed. Thirty-seven full-text reviews were then excluded after revision. Six systematic reviews with a total of 271,226 patients (156,553 patients in the study group and 114,673 patients in the control group) were included in the meta-analysis. The analysis identified various predictors of adverse outcomes (infection). Among them were glycated hemoglobin (HbA1c) and different characteristics of penile implants.
CONCLUSIONS
The systematic review and meta-analysis revealed significant risk factors/predictors of penile prosthesis infection: glycated hemoglobin levels; reoperation, and two predictors associated with the type of penile prosthesis. The weighted mean HbA1c levels of patients with and without infections were 8.37% and 7.17% respectively. The OR was as follows: first surgery/revision OR 0.36 (95% CI 0.29-0.45); antibiotic-coated/non-coated prosthesis OR 0.47 (95% CI 0.31-0.72); malleable/inflatable prosthesis OR 3.51 (95% CI 1.41-8.74).
PubMed: 38481412
DOI: 10.1080/2090598X.2023.2242204 -
Canadian Urological Association Journal... Mar 2024Our goal was to compare the perceived readiness of graduating urologic residents and fellows to program directors (PDs) in U.S.-based postgraduate training programs....
INTRODUCTION
Our goal was to compare the perceived readiness of graduating urologic residents and fellows to program directors (PDs) in U.S.-based postgraduate training programs. Additionally, we set out to assess the impact of COVID-19 on postgraduation plans to pursue fellowship training.
METHODS
Graduating residents, fellows, and PDs of accredited residency/fellowship programs in the U.S. were surveyed. The ranked preparedness of trainees to perform common urologic procedures was measured using a Likert scale from 1 (not comfortable) to 5 (fully proficient). The impact of COVID-19 was measured using a three-point Likert scale. Chi-squared and Kruskal-Wallis analyses were used to compare the groups.
RESULTS
From 93 responders, 21 were residents, 19 were fellows, 24 were residency PDs, and 29 were fellowship PDs. The median levels of comfort for transurethral resection of the prostate, hydrocelectomy, vasectomy, and urethral sling were at or above (≥3) moderate for both PDs and trainees. PDs were more likely to report underperformance for hypospadias repair (60% vs. 39%), penile prosthesis implantation (39% vs. 26%), and orthotopic neobladder formation (57% vs. 18%) than the trainees. Fifty-three (57.0%) of the surveyors felt that COVID-19 did not impact the trainees' comfort in performing general urologic procedures. COVID-19 influenced trainees' decision to pursue a fellowship or opt to practice as general urologists (p=0.002).
CONCLUSIONS
Our study suggests there may be a self-reported discrepancy between graduating trainees and their PDs regarding trainees' comfort levels performing general urologic procedures.
PubMed: 38466868
DOI: 10.5489/cuaj.8639 -
Urology Case Reports Mar 2024Refractory ischemic priapism is a difficult to treat clinical entity for which there are a host of shunt procedures identified, but no singular agreed upon technique for...
Refractory ischemic priapism is a difficult to treat clinical entity for which there are a host of shunt procedures identified, but no singular agreed upon technique for surgical therapy. Recent literature describes success using a penoscrotal decompression technique that uses a similar dissection of a penoscrotal penile prosthesis placement. We demonstrate that this technique is easily applicable in the private practice setting as it uses a familiar setup to most general urologists in our case report.
PubMed: 38420333
DOI: 10.1016/j.eucr.2024.102681 -
Translational Andrology and Urology Jan 2024Peyronie's disease (PD) is a fibrotic disorder of the tunica albuginea that results in penile deformity and/or curvature. Patients usually present complaining of penile... (Review)
Review
Peyronie's disease (PD) is a fibrotic disorder of the tunica albuginea that results in penile deformity and/or curvature. Patients usually present complaining of penile pain, shortening and deformity resulting in dissatisfaction with intercourse. Many patients with PD will present with concomitant erectile dysfunction (ED). This disease is a significant concern for patients as it impacts both sexual function and overall quality of life. While there are several interventions available for PD treatment, inflatable penile prosthesis (IPP) implantation is considered the gold standard approach for those with moderate to severe concomitant ED, refractory to medical therapy. The goal of treatment is to give a man a functionally straight erection. Placement of an IPP alone may achieve this. However, when curvature still exists, several adjunct procedures may be performed to include manual modeling, plication, plaque incision or excision and grafting. Additionally, advanced lengthening procedures may also be used. In this paper we will present a comprehensive review of the adjuvant straightening techniques that can be used during IPP placement in men with PD and refractory ED when curvature still exists. Patient selection is a key predictor of implant success, as is preoperative and postoperative management to optimize overall patient care and satisfaction. These topics along with the different surgical approaches to IPP insertion for PD will also be discussed, including the benefits and shortcomings of each. A flowchart to aid surgeons in their intraoperative decision making based on curvature characteristics and specific patient concerns is presented.
PubMed: 38404553
DOI: 10.21037/tau-23-180 -
Translational Andrology and Urology Jan 2024In contemporary Urology, the gold standard for treatment of erectile dysfunction refractory to medical therapy has been implantation with a penile prosthesis. The past... (Review)
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.
PubMed: 38404551
DOI: 10.21037/tau-22-741 -
Translational Andrology and Urology Jan 2024Implantation of penile prosthesis (PP) into scarred and fibrotic corpora can be a difficult challenge. In this review article, we provide a review of penile fibrosis,... (Review)
Review
BACKGROUND AND OBJECTIVE
Implantation of penile prosthesis (PP) into scarred and fibrotic corpora can be a difficult challenge. In this review article, we provide a review of penile fibrosis, discuss current medical and surgical management and summarize preventative strategies.
METHODS
In this study, we searched PubMed between the years 2000-2023 for publications with search strategy: "penile fibrosis" OR "scarred corpora" OR "fibrosed corpora".
KEY CONTENT AND FINDINGS
This search returned a total of 137 articles. We examine the evidence for preoperative patient evaluation and penile ultrasound (US), oral phosphodiesterase-5 inhibitors, pentoxifylline, and L-arginine, vacuum device therapy and the use of surgical approaches and tools in the context of complex penile fibrosis cases. Severe penile fibrosis is most associated with priapism and infection. Estimating the degree of fibrosis via preoperative US may help set realistic patient expectations. Phosphodiesterase inhibitors and L-arginine reduce fibrosis in animal models however their impact in humans remains unclear despite theoretical advantage for their use. Vacuum device therapy may preserve penile length following priapism and infected PP cases. The use of Coloplast Narrow-Based or AMS-700 CXR implants are used primarily for severe fibrosis. Various surgical excisional/incisional techniques, the Carrion-Rossello, Mooreville Uramix cavernotomes and reverse cutting scissors are all options, and their use varies from case to case. Finally, prevention of penile fibrosis in patients with history of penile implant infection and the safety of early implantation of a penile implant in patients with refractory priapism is encouraged.
CONCLUSIONS
The management of penile fibrosis remains a challenge but there are multiple options to assist clinicians. Complex cases should be managed and studied at high volume centers.
PubMed: 38404545
DOI: 10.21037/tau-23-206