A Surgeon's Guide to the Various Antibiotic Dips Available During Penile Prosthesis Implantation

Antibiotic dip and irrigation solutions confer increased antimicrobial efficacy of inflatable penile prosthesis hydrophilic surfaces compared with 0.05% chlorhexidine gluconate

BACKGROUND

Chlorhexidine gluconate (CHG) (0.05%) has recently been suggested as both a dip for the hydrophilic surface and an irrigation solution in the setting of penile prosthesis (PP) surgery.

AIM

The study sought to compare the antimicrobial efficacy of 0.05% CHG with vancomycin and gentamicin (VG) antibiotics as dip and/or irrigation solutions in the setting of a hydrophilic PP surface in vitro.

METHODS

Sterile PPs with a hydrophilic coating were obtained. A series of experiments were performed to evaluate the efficacy of normal saline (NS), 0.05% CHG, or VG as dip and/or irrigation solutions to reduce methicillin-sensitive Staphylococcus aureus adhesion to PP surfaces. The 8-mm discs from PPs were incubated in 105 colony-forming units/mL of methicillin-sensitive S aureus for 48 hours, plated, and counted. Disc-diffusion tests were conducted by suspending 6-mm discs for 2 minutes in NS, 0.05% CHG, or VG, then placing them coated side down onto plates streaked with the following organisms: methicillin-sensitive S aureus, S epidermidis, Enterococcus, and Escherichia coli. After 24 hours of growth, zones of inhibition were measured.

OUTCOMES

We found average bacterial counts (colony-forming units/mL) and zones of inhibition (mm) following a series of treatment protocols of PP discs.

RESULTS

PP discs dipped in VG reduced bacterial adhesion to the implant surface >0.05% CHG (~5.5 log vs ~1.5 log; P < .01). Discs irrigated with either 0.05% CHG or NS removed all dip solution adsorbed to the hydrophilic surface, allowing bacterial growth. VG irrigation adsorbed to the hydrophilic surface even after 0.05% CHG or NS dips, reducing bacterial adherence (~3 log). Dipping and irrigating discs with VG was most effective in reducing adherent bacteria (~5.5 log) and was the only irrigation that showed antimicrobial activity.

CLINICAL TRANSLATION

VG, when used both as a prophylactic dip and as an intraoperative irrigation solution for hydrophilic penile implant surfaces, has improved efficacy to 0.05% CHG and NS.

STRENGTHS AND LIMITATIONS

This is the first study to compare the use of VG, 0.05% CHG, and NS as prophylactic dips and intraoperative irrigations for hydrophilic penile implant surfaces. Limitations include the use of in vitro studies, which serve as a proxy for in vivo practices and may not be entirely accurate nor translatable clinically.

CONCLUSION

We demonstrated the superior efficacy of VG as a combined dip and irrigation solution for hydrophilic penile implant surfaces compared with 0.05% CHG.

Maximizing outcomes in penile prosthetic surgery: exploring strategies to prevent and manage infectious and non-infectious complications

Inflatable Penile Prostheses (IPP) implantation is a surgical treatment for patients desiring definitive treatment for erectile dysfunction. While this procedure has proven to be effective, it also carries its own set of unique risks that need to be carefully considered. The article reviews the current understanding of complications associated with penile prosthetic surgery and provides strategies to mitigate these adverse events. This article covers various aspects of IPP implantation, including the risks of infection, bleeding, injury to nearby structures, glans ischemia, and device malfunction. It also discusses the importance of careful preoperative screening to identify risk factors and the implementation of infection reduction strategies such as antimicrobial prophylaxis, skin prep, and operative techniques. In addition, it emphasizes the need for postoperative vigilance and prompt management of any complications that may arise. Overall, the article provides a comprehensive overview of the risks and strategies for mitigating complications associated with IPP implantation. Our recommendations are given based on the current consensus in the field and highlight the importance of careful planning, attention to detail, and effective communication between healthcare providers and patients. Despite the potential risks, this review underscores the fact that complications following penile prosthesis implantation are relatively rare.

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.

Stem-Cell, Shockwave, and Platelet Rich Plasma Therapy for the Treatment of Erectile Dysfunction and Peyronie's Disease: A Survey of Clinics Across the USA

OBJECTIVE

To identify clinics offering off-label therapies for erectile dysfunction (ED) and Peyronie's disease (Pyd) including stem cell, platelet-rich plasma (PRP), and shockwave therapy and to determine the transparency they provided to patients inquiring about these treatment modalities.

METHODS

Clinics were identified in different regions in the US using a systematic search on online website directories and were approached by asking a series of standardized questions regarding the cost of treatment, duration of therapy, the medical staff involved, and patient outcome data. A total of 26 clinics were surveyed for stem cell therapy, 26 for PRP treatment, and 27 for shockwave therapy.

RESULTS

Of the 79 clinics contacted, 93.7% provided some answers to the questions we asked, with a majority offering treatments for both ED and Pyd. The cost of treatment varied widely between clinics. The average cost per stem cell therapy injection was $5291, PRP per injection was $1336, and shockwave therapy per session was $413. A physician was involved in 67% of treatments, and only 6 of 79 clinics reported that a urologist was involved. Over 75% of the clinics reported patient satisfaction following treatment. Durability of benefits to patients ranged from months to years according to the clinics' reports.

CONCLUSION

Our data not only demonstrate the widespread use of off-label therapies for ED and PyD across the United States but also the lack of scientific data to support the claims made to patients. This study highlights the need for more oversight and standardization in novel regenerative therapies for ED and PyD.

Effect of 0.05% chlorhexidine gluconate in water on the hydrophilic inflatable penile prosthesis: biocompatibility, adherence, and dip time

BACKGROUND

Rates of infection after inflatable penile prosthesis range from 1% to 3%; however, a new surgical irrigation solution is Food and Drug Administration cleared as antimicrobial wound lavage and appears to be safe for patients and noncaustic during hydrophilic inflatable penile prosthesis (hIPP) dipping and irrigation.

AIM

To evaluate if 0.05% chlorhexidine (CHG) lavage is caustic to the hIPP coating and if dip adherence is dependent on time.

METHODS

Preconnected hIPP devices were tested at a Coloplast research and development laboratory. The devices were soaked in the 0.05% CHG lavage solution or normal saline for 1, 15, 30, and 60 minutes. Subsequently, all parts were dried for 15 minutes in a 35 °C oven. A Congo red dye test was performed following a Coloplast-validated and Food and Drug Administration-cleared test method to ensure product reliability. Implants were then visually inspected for deleterious effects as well as dip coverage. In addition, we evaluated 0.05% CHG lavage solution vs previously published hIPP dipping solutions.

OUTCOMES

0.05% CHG lavage does not appear to damage the hIPP coating, and adherence of this solution is not dependent on dip time.

RESULTS

All components of the preconnected hydrophilic IPPs were tested for coating adherence and defects. All tested IPPs achieved a "satisfactory" coating, meaning a uniform coat without flaking or clumping. Furthermore, there were no noticeable caustic effects or differences in coating adherence between the normal saline-soaked control and 0.05% CHG-coated arms with increasing dip time. A review of the literature for 0.05% CHG lavage solutions vs previously published hIPP dipping solutions revealed that it may have some advantages over previously reported antibiotic solutions.

CLINICAL IMPLICATIONS

This study serves as a foundation to introduce 0.05% CHG lavage to the urologic literature as a potentially new "magic bullet" irrigation.

STRENGTHS AND LIMITATIONS

Major strengths of the study are that it is the first study of its kind to address the question of what dip duration should be used and whether it is scientifically reproducible. A limitation is the in vitro model, thus needing validation in a clinical setting.

CONCLUSION

0.05% CHG does not appear to negatively affect the hIPP coating or differ in adherence with increasing dip time; however, long-term device performance has not been verified.

Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis

BACKGROUND

Delayed infection, thought to be due to gradual biofilm formation, remains a feared complication after inflatable penile prosthesis (IPP) insertion. Understanding and preventing biofilm formation is necessary to prevent infections.

AIM

To develop an in vitro model and compare growth of biofilm by different bacteria on IPPs and evaluate the anti-infective efficacy of the Coloplast Titan and AMS 700 InhibiZone.

METHODS

Sterile IPPs (Coloplast) were cut into rings and incubated with S. epidermidis, S. aureus, P. aeruginosa, A. baumannii, or K. pneumoniae cultures in tryptic soy broth (TSB) (4 hour) to ensure adequate bacteria attachment, and then in only TSB (120 hours) to allow for biofilm formation. Rings were fixed with ethanol and biofilm measured by spectrophotometer (OD570) after crystal violet staining. This methodology was repeated for S. epidermidis and P. aeruginosa with Coloplast rings dipped in 10 ml of a 10 mg/ml Rifampin, 1 mg/ml Gentamicin, and deionized water solution and undipped AMS InhibiZone rings. Crystal violet assay (OD570) was repeated after incubation within bacteria (2 hour), and then only TSB (120 hours).

OUTCOMES

The primary outcome of the study was OD570 readings, indirectly measuring biofilm mass on implant rings.

RESULTS

S. epidermidis, S. aureus, A. baumannii, P. aeruginosa, and K. pneumoniae all formed significant biofilm. P. aeruginosa showed the strongest predilection to grow biofilm on IPPs. P. aeruginosa also formed significant biofilm on antibiotic-treated Coloplast and AMS rings, while S. epidermidis was inhibited. No significant difference was found in biofilm inhibition between the implants.

CLINICAL TRANSLATION

Our findings suggest gram-negative bacteria may form biofilm more proficiently and quickly on IPPs than gram-positive organisms. Commonly used antibiotic treatments on IPPs may be effective against S. epidermidis but not against P. aeruginosa biofilm formation.

STRENGTHS & LIMITATIONS

This is the first study comparing biofilm formation by different bacteria organisms on IPPs and the inhibitive ability of Coloplast and AMS implants against biofilm formation. Clinical data on organisms responsible for infected IPPs is needed to determine the clinical relevance of our findings.

CONCLUSION

Our novel in vitro model of biofilm formation of IPPs evaluated the effect of a gentamicin/rifampin antibiotic dip on Coloplast Titan implants and the anti-infective capacity of the minocycline/rifampin precoated AMS 700 InhibiZone against S. epidermidis and P. aeruginosa. P. aeruginosa was able to grow on both antibiotic-treated implants, with no significant difference, and should continue to be a specific target of investigation to reduce delayed post-operative IPP infections. Narasimman M, Ory J, Bartra SS, et al. Evaluation of Bacteria in a Novel In Vitro Biofilm Model of Penile Prosthesis. J Sex Med 2022;19:1024-1031.

Prevention of Penile Prosthesis Infection

INTRODUCTION

Management protocols for treatment of severe erectile dysfunction have changed little in the last 20 years. Most algorithms consider penile prostheses as the last option of treatment in patients who have failed medical management. Despite multiple advances in current devices, prosthetic infection remains the most feared complication by implanting surgeons and patients. This report tries to make a compilation of the factors that can be impacted to prevent penile implant infections, and to make penile implantation a safer and more reliable way to solve an erection deficit.

PURPOSE OF REVIEW

List events related to the surgical act (pre-operative, intra-operative, and post-operative) that are related to the risk of infection to contextualize possible actions/measures used to avoid prosthetic infection.

RECENT FINDINGS

The impact of coated implants on reduction of infection rates. The recommendation to use chlorhexidine-based solutions over iodine solution for preoperative skin preps. Appears to be no difference in infection rates according to the approach chosen by the surgeon (infrapubic vs penoscrotal). The change in the microbial colonies that are colonizing implants in recent years are dramatic. Lack of evidence of which solutions to use for salvage or revision washout surgery: Chemical eradication or mechanical lavage cleansing?. Despite the importance of metabolic control in the literature, there is a disparity in exact glycemic values ​prior to the intervention in our literature. Factors such as preparation of the operative site, presence of comorbidities or previous surgeries, surgical time, or additional maneuvers during surgery can negatively impact the final result of penile prosthetic surgery.

Is There a Role for Antifungal Prophylaxis in Patients Undergoing Penile Prosthesis Surgery? A Systematic Review

OBJECTIVE

The aim of this study is to review the literature on the use of antifungal prophylaxis in penile prosthesis (PP) surgery and provide a summary on its efficacy as an adjunct to current prophylactic regimes in patients undergoing PP surgery.

MATERIALS AND METHODS

PubMed, Medline, and EMBASE databases were systematically searched up to May 2020. All included studies were analysed and the information extracted included author, title of study, year of publication, type of study, journal of publication, and main findings regarding post PP implantation fungal infections.

RESULTS

Nine relevant studies were included in this review, comprising retrospective single-centre studies and retrospective multicentre studies ranging from 2017 to 2020. Fungal infections were found responsible for 11.1% of all PP infections, with a greater risk in patients with diabetes, obesity, and from warmer climates. Current American Urological Association (AUA) and European Association of Urology (EAU) prophylaxis guidelines do not incorporate the use of antifungals. Trials of antifungal prophylaxis regimes combined with antibiotic prophylaxis have demonstrated a reduction in PP fungal infections.

CONCLUSIONS

Fungal infections represent a significant proportion of implant infections and therefore antifungal prophylaxis is warranted. Future studies comparing the efficacy of traditional antibiotic prophylaxis as set out by AUA/EAU with novel prophylaxis regimes including the addition of an antifungal may provide more definitive guidance on this issue. Until then antifungal prophylaxis in all patients undergoing PP procedures may provide a significant cost-effect benefit.

Penile prosthesis salvage: a historical look at the Mulcahy technique and a review of the latest literature

Historically, management of inflatable penile prosthesis infection was explantation of the device with delayed reimplantation at a later date. In 1991, this paradigm was challenged when early attempts at washout and immediate salvage proved successful. The clinical experiences and data generated over the past 30 years have allowed implanters to refine their salvage procedures to improve patient outcomes. In this article, we review the original Mulcahy technique for salvage and discuss updates to this protocol based on recent data.

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.

[Penile prosthesis]

The insertion of a penile prosthesis (PP) is a definitive treatment option for erectile dysfunction (ED), induratio penis plastica, after phalloplasty or priapism. The aim is a "normal" erection with the possibility of a satisfactory sexual life. The costs of the operation are covered by the health insurance. In addition, manual dexterity, concomitant diseases and possible contraindications should be considered preoperatively. While semirigid PPs are simply aligned in the desired position when used, inflatable PPs must be activated and deactivated via a pump. In addition to injury to local structures and postoperative infections, long-term complications such as mechanical implant failure or an undesirable cosmetic result may also occur. Careful patient selection and a detailed counselling and information session are therefore of decisive importance. Implantation is performed in the supine or lithotomy position via an infrapubic or penoscrotal approach. PPs should not be implanted if cutaneous, systemic or urinary tract infections are present. Inflatable PPs are preferred by most patients as they come closest to a "natural" erection. A PP offers one of the highest satisfaction rates among treatment options, regardless of indication, and is highly rated by patients and their partners across models due to product reliability. Differences between the models of the various manufacturers could not be demonstrated. The choice of prosthesis should therefore be adapted to the patient's individual requirements and health conditions.

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.

Updates in penile prosthesis infections

Inflatable penile prostheses are an important tool in the treatment of medically refractory erectile dysfunction. One of the major complications associated with these prostheses is infections, which ultimately require device explanation and placement of a new device. Over the past several decades, significant work has been done to reduce infection rates and optimize treatment strategies to reduce patient morbidity. This article reviews the current state of knowledge surrounding penile prosthesis infections, with attention to the evidence for methods to prevent infection and best practices for device reimplantation.

Perioperative management of patients undergoing penile prosthesis surgery in the UK: A survey of current practice

Objectives:

This study aimed to define contemporary perioperative management of patients undergoing penile implant surgery in the UK.

Methods:

All consultant urological surgeons responsible for the insertion of penile prostheses in the UK were invited to complete an online survey comprising of 25 questions relating to surgeon demographics, patient selection, preoperative work-up, intraoperative management and postoperative care. Anonymised responses underwent descriptive statistical analysis, with particular focus on measures employed to reduce the risk of perioperative infection.

Results:

Of the 34 invited surgeons, 26 (76.5%) responded to the survey. The majority reported undertaking between 10 and 30 cases in 2018 ( n=17; 65.4%). A total of 23 (88.5%) respondents reported employing a threshold for diabetic control, although the exact limit varied between surgeons. Most respondents ( n=22; 84.6%) reported routinely sampling urine for microscopy, culture and sensitivity. All but one ( n=25; 96.2%) reported routinely performing cavernosal washouts, with the most common solution being a mixture of gentamicin and vancomycin (42.3%). All reported routinely giving intravenous antibiotics on induction of anaesthesia, and although there was no clear consensus, most surgeons preferentially used an aminoglycoside in combination with one other agent (including penicillins or teicoplanin).

Conclusion:

The variation in current perioperative management demonstrates a potential need for the development and introduction of evidence-based guidelines to standardise practice nationwide. Level of evidence: 5

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.

Antibiotics and Inflatable Penile Prosthesis Insertion: A Literature Review

INTRODUCTION

Antibiotic stewardship is now a priority for the urologic community. Perioperative antibiotic use at the time of inflatable penile prosthesis (IPP) insertion has become a topic of interest.

OBJECTIVES

To review the literature available to inform the practice of antibiotic administration before, during, and after IPP insertion.

METHODS

We performed a literature review based on a search for the terms "Antibiotics" and "Penile Prosthesis" in the PubMed database. Manuscripts were individually reviewed for relevance to the administration of antibiotics in conjunction with IPP insertion. Best practice statements and guidelines from stakeholder organizations were also reviewed.

RESULTS

The benefits of preoperative antibiotic prophylaxis have been well studied in the orthopedic and general surgery literature, but a dearth of studies are available in the specific context of IPP insertion. High-quality retrospective studies have demonstrated reduced infection rates with the use of antibiotic-impregnated or antibiotic-coated IPPs. Limited research on the use of postoperative antibiotics after IPP insertion has actually not demonstrated a benefit from this very common practice. Indeed, the broader surgical literature suggests a net harm from continued postoperative antibiosis. A 2017 guideline recommendation from the Center for Disease Control and Prevention states that additional prophylactic antibiotics should not be administered after procedures deemed clean or clean-contaminated.

CONCLUSION

The benefits of single-dose preoperative antibiotics and the use of antibiotic-impregnated or antibiotic-coated IPPs are well established. Postoperatively, the available IPP and broader surgical literature does not reflect a benefit from the administration of additional antibiotics and demonstrates higher rates of antibiotic-associated adverse events and the emergence of drug resistance. In average-risk patients undergoing IPP insertion, contemporary data suggest that it is safe for postoperative antibiotics to be withheld. Dropkin BM, Kaufman MR. Antibiotics and Inflatable Penile Prosthesis Insertion: A Literature Review. Sex Med 2021;9:174-180.

The Effect of Bupivacaine on the Efficacy of Antibiotic Coating on Penile Implants in Preventing Infection

Background

In an effort to reduce dependence on opioids following inflatable penile prosthesis placement, intra-operative soaking of the implant in Bupivacaine (BUP) has been proposed as part of a multimodal approach to pain control. However, no study has shown if the addition of BUP affects the antimicrobial properties of InhibiZone on AMS700 (Boston Scientific, Marlborough, MA) and/or of antibiotic soaked Titan Coloplast (Coloplast Corporation, Minneapolis, MN).

Aim

To determine if BUP alters the zone of inhibition (ZOI) against Staphylococcus epidermidis (S epidermidis) and Escherichia coli (E coli), common gram-positive and gram-negative bacterial causes of infection, respectively, created by InhibiZone coated AMS and/or by antibiotic-soaked Coloplast implant.

Methods

S epidermidis and E coli were spread on agar plates. After a 30-minute incubation, four AMS with InhibiZone strips treated with sterile saline or BUP (1.25 mg/mL) were placed on a plate. 4 Coloplast strips were dipped in varying routinely used concentrations of Rifampin (0–10 mg/mL) plus Gentamicin (0–1 mg/mL; rifampin and gentamicin (R+G)) solution with or without BUP. The ZOI for AMS with InhibiZone and Coloplast dipped in antibiotic solution was measured using ImageJ software. Normalized ZOI was calculated as (ZOI area/plate area) × 100. Unpaired t-test compared the mean ± SD ZOI between BUP and no BUP groups (n = 4/group).

Outcomes

The primary outcome of the study was the ZOI against E coli and S epidermidis at 24 and 48 hours.

Results

Growth of both S epidermidis and E coli at 24 and 48 hours of incubation was inhibited in both implants and the addition of BUP did not alter the ZOI. Coloplast strips dipped in R+G produced a ZOI in a dose-dependent manner. Interestingly, the ZOI against S epidermidis compared to that of E coli was much wider for both implants.

Clinical Implications

This suggests that the use of BUP does not affect the protective effects of antibiotic dips and can potentially be used during penile prosthesis surgery pending clinical trials.

Strengths and Limitations

This is the first study to evaluate the effect of BUP on anti-bacterial dips. As with all in vitro analysis, further research must be done to see if these findings hold true in the clinical setting.

Conclusions

The addition of BUP does not impede the in vitro antibacterial activity of InhibiZone-coated AMS or R+G-soaked Coloplast. Whether these in vitro findings translate to surgical outcomes needs to be evaluated in future preclinical trials.

Lokeshwar SD, Horodyski L, Lahorewala SS, et al. The Effect of Bupivacaine on the Efficacy of Antibiotic Coating on Penile Implants in Preventing Infection. J Sex Med 2019;7:337−344.