Management of prosthesis infections in urologic surgery

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

PURPOSE OF REVIEW

Inflatable penile prosthesis (IPP) is a treatment for erectile dysfunction. IPPs have undergone improvements; however, post-surgical infections still occur. Furthermore, the type of pathogens infecting the implants has changed recently from Gram-positive to Gram-negative bacteria and fungi due to advances in antibiotic dips targeting the skin flora. To protect against infection, the AMS 700 is pre-coated with InhibiZone (mixture of Rifampin/Minocycline) and the Coloplast Titan, with several antibiotic dip options of differing efficacies. This review discusses strategies to decrease the infection rates in implant surgery, focusing on antibiotic dips.

RECENT FINDINGS

Current research endorses the use of rifampin/gentamicin as the most studied combination; however, some studies have utilized different dips for additional coverage including the InhibiZone on the AMS 700. With the increasing prevalence of diabetes and Gram-negative organisms, there is a need to develop strategies for increased coverage against infections. Controlled studies with different antibiotic combinations are needed to identify the ideal cocktail to decrease infection.

Purulent Inflatable Penile Prostheses Can Be Safely Immediately Salvaged in Insulin-Dependent Diabetics

INTRODUCTION

Historically, contra-indications for immediate salvage of an infected penile prosthesis have included purulence on the device, purulent infections in diabetic patients, and severe diabetes. These clinical principles are from the 1990s to early 2000s and based on limited retrospective series or expert opinion. Since the publication of these contra-indications there have been improvements in device design, surgical technique, corporal washout protocols, and perioperative antibiotic prophylaxis that allow us to re-evaluate whether we can broaden the criteria for immediate salvage of an infected penile prosthesis.

AIM

To report whether patients with severe diabetes can safely have a purulent inflatable penile prosthesis (IPP) immediately salvaged.

METHODS

We considered a "severe diabetic" as a patient whose disease has progressed past diet control and oral medications and, therefore, has insulin-dependent type 2 diabetes mellitus (IDDM II). We retrospectively reviewed 6 consecutive patients with IDDM II and a purulent IPP who had been immediately salvaged from July 2011 to November 2017. In addition to immediate exchange, each received catheter-directed anti-microbial intracorporal irrigation and device culture. All patients were discharged home the next day with oral antibiotics.

MAIN OUTCOME MEASURE

Outcomes included repeat penile prosthesis infection or any other complication following immediate salvage.

RESULTS

All 6 patients have healed well and remained infection free at their 6- to 8-week post-operative follow-up appointment. 15-39 months after salvage, no patients have had a repeat infection or any other complication. 5 patients received a malleable replacement device and 1 patient was electively converted to an IPP 7 months after his salvage procedure. 1 patient received an IPP during salvage per patient preference. All patients are currently pleased with either their malleable penile prosthesis or IPP.

CLINICAL IMPLICATIONS

Immediate salvage attenuates the morbidity associated with an infected penile prosthesis such as irreversible penile shortening and corporal fibrosis. Our findings suggest that more patients than originally thought may be a candidate for immediate salvage.

STRENGTH & LIMITATIONS

To our knowledge, this is the first study evaluating outcomes after immediate salvage of a purulent IPP in patients with advanced diabetes. Limitations of the study include the small sample size and retrospective nature.

CONCLUSION

Our results suggest that those with IDDM II who have a purulent penile prosthesis may be candidates for safe and effective immediate salvage. Peters CE, Carlos EC, Lentz AC. Purulent Inflatable Penile Prostheses Can Be Safely Immediately Salvaged in Insulin-Dependent Diabetics. J Sex Med 2018;15:1673-1677.

Chapitre B-3 A - Traitement chirurgical des dysfonctions neurologiques des sphincters urinaires

The treatment of neurogenic detrusor-sphincter dyssynergia is primarily medical (drugs and catheterization). Some patients may not be eligible for or fail to respond to these treatment options and endoscopic sphincterotomy or permanent prosthesis may be indicated. In this article, the authors review the indications, results and contraindications of these various treatments.

The role of biofilm infection in urology

In the process of endourological development a great variety of foreign bodies have been invented besides urinary catheters on which biofilm can be formed. Bacteria in the biofilm are less sensible to antibiotics. An additional problem of medical biomaterials in the urinary tract environment is the development of encrustation and consecutive obstruction. In this review, we tried to sum up the conditions where biofilm formation has a great impact on the development or maintenance of urological infections and on treatment success. Modification of the biomaterial surface seems to be the most promising prevention strategy for bacterial biofilms. Easier methods for diagnosing and quantifying biofilm infection, to develop more specific antimicrobial agents and ideal device surfaces would surely help the fight against biofilm formation.

Penile prosthesis coating and the reduction of postoperative infection

Despite the recent development of effective oral agents for the treatment of erectile dysfunction, penile prosthesis implantation remains an effective and acceptable treatment for the significant number of men who fail to respond to nonsurgical therapy. The most serious complication that can affect the use of most prosthetic devices is infection. In penile prostheses, this can be devastating and frequently results in removal of the device despite aggressive antibiotic therapy. In recent years, new strategies have been developed in an attempt to minimize this risk. This review focuses on one such method, namely the use of an antibiotic coating on the device. It reviews recent published data regarding the effectiveness of such devices at decreasing infection rates.

Antibiotic Soaked Hydrophilic Coated Bioflex: A New Strategy in the Prevention of Penile Prosthesis Infection

OBJECTIVES

To find conditions that reduce the susceptibility of penile prostheses to infection, we studied the effect of coating the surface of polyurethane (Bioflex) with a hydrophilic material with and without antibiotics in decreasing bacterial colony counts both in vitro and in experiments in rats.

MATERIALS AND METHODS

The in vitro experiment was performed using seven strips each of polyvinylpyrrolidone (PVP)-coated and uncoated polyurethane. These strips were dipped in saline for 5 minutes followed by incubation in a suspension of Staphylococcus epidermidis (SE) for a period of 10 minutes. Colony counts were determined after sonication of strips. For the in vitro experiments, 60 rats were used. Thirty animals each had uncoated or coated polyurethane implanted subcutaneously. In each group, strips were implanted after dipping them in either saline (N = 15) or an antibiotic solution (N = 15) consisting of 1 g/L vancomycin and 160 mg/L gentamicin. A bacterial suspension containing SE was then directly introduced into the subcutaneous pockets of all the animals prior to closure. After 7 days, strips were explanted along with 0.5 x 0.5 cm of surrounding tissue, and sonicated. Colony counts were performed on each sonicate. The data were analysed using Student's t-test. A P-value less than or equal to 0.05 was considered to be statistically significant.

RESULTS

The in vitro study demonstrated a statistically significant (41%) reduction in the colony count of SE within the coated polyurethane strips compared to the uncoated Bioflex strips (150 +/- 44.7 CFU vs. 253 +/- 45.0 CFU, respectively, P-value < 0.05). Animal studies showed that bacterial CFU was highest in the uncoated Bioflex strip (29 +/- 24.5 CFU), followed by uncoated Bioflex with antibiotic treatment (24 +/- 28.1 CFU), coated Bioflex (17 +/- 25.2 CFU) and coated Bioflex with antibiotic treatment (13 +/- 16.1 CFU). Antibiotic treatment of coated Bioflex caused a significant reduction in the bacterial CFU compared to uncoated Bioflex (13 +/- 16.1 vs. 29 +/- 24.5 CFU, respectively, P = 0.04). This represents a 55% reduction in the bacterial count. While the reduction in the bacterial count in the coated Bioflex strip was not statistically different from that in the uncoated strip, a trend towards significance was noted with a 41% reduction (P > 0.05) in bacterial count in the coated Bioflex group compared to uncoated Bioflex.

CONCLUSIONS

In conclusion, in vitro studies demonstrate a significant (41%) reduction in the colony count of SE in PVP-coated polyurethane compared to uncoated polyurethane. In vivo study in rats showed that antibiotic treatment of PVP-coated Bioflex resulted in a statistically significant reduction (55%) in colony count of SE compared to uncoated Bioflex.

Candida infections of medical devices

The number of indwelling medical devices is escalating, and an increasing proportion of device-related infections are being caused by Candida spp. Candida spp. produce biofilms on synthetic materials, which facilitates adhesion of the organisms to devices and renders them relatively refractory to medical therapy. Management of device-related Candida infections can be challenging. Removal of the infected device is generally needed to establish cure of Candida infections of medical devices. However, since the pathogenesis of Candida bloodstream infection is complicated, more studies are necessary to determine the role of catheter exchange in patients with both gastrointestinal tract mucositis and indwelling catheters. The medical and economic impact of these infections is enormous.

Controversies in antibiotic prophylaxis in urology

Antibiotic prophylaxis in urologic surgery remains controversial. However, progress has been made and some of the controversies have been answered. Firstly, it is important to underline that urologic diagnostic and therapeutic procedures can induce surgical site infections (SSIs), bacteriuria, pyelonephritis and septicaemia in a substantial number of patients, too great to be neglected. Secondly, as patients are different and have various risk factors, a careful assessment of the patient and its individual risk is crucial. Thirdly, the same procedure may be totally different from one individual to another and they can rarely be grouped as standard procedures. A floating level of invasiveness is followed by a variation of the risk of infection. Fourthly, the pathogens and their susceptibility pattern vary extensively in Europe so that no clear-cut recommendations as for the choice of antibiotics can be given. Basic principles of antibiotic prophylaxis in terms of timing, mode of administration and length of regiment apply for urologic interventions. Thus, clean operations will usually not require antimicrobial prophylaxis except for those including the implant of a prosthetic device, while clean-contaminated will benefit from preventive antimicrobials. It is the task of the urologists to carefully assess each individual patient and procedure to opt for an optimal prophylaxis.

Efficacy of antimicrobial-impregnated silicone sections from penile implants in preventing device colonization in an animal model

OBJECTIVES

To assess, in an animal study, the efficacy of minocycline/rifampin-impregnated silicone sections of pump bulbs from penile implants in preventing device colonization by Staphylococcus aureus. Infection constitutes a very serious complication of penile implants.

METHODS

Minocycline/rifampin-impregnated and control silicone pump bulb sections from penile implants were each inoculated with about 10(3) to 10(4) colony-forming units of S. aureus. After 8 hours of incubation with bacteria at room temperature, the test devices were allowed to dry for 30 minutes, and then subcutaneously implanted in the backs of rabbits. Eleven rabbits each received a total of six devices. The wounds were sutured, and the rabbits were monitored daily, then killed at 2 days after surgery. In vitro zones of inhibition against S. aureus by the minocycline/rifampin-impregnated and control devices were also determined.

RESULTS

All of the six tested antimicrobial-impregnated devices but none of the control devices produced zones of inhibition in vitro against S. aureus (mean zone of inhibition by antimicrobial-impregnated devices of 23 mm). The antimicrobial-impregnated devices retrieved from rabbits were sixfold less likely than were the control devices to be colonized with S. aureus (2 [6%] of 33 versus 11 [33%] of 33, respectively; P = 0.011).

CONCLUSIONS

The results of this animal study indicate that minocycline/rifampin-impregnated pump bulb sections from penile implants provide antimicrobial activity in vitro against S. aureus and protect against staphylococcal colonization of devices implanted for 2 days in animals.