Antimicrobial activity of antibiotic-soaked, Resist-coated Bioflex

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.

Experience With Prophylactic Gentamicin During Penile Prosthesis Surgery: A Retrospective Comparison of Two Different Doses

BACKGROUND

Gentamicin has been determined to be active against a wide range of bacterial infections and has been commonly used as a preoperative antibiotic for inflatable penile prosthesis (IPP) implantation. However, the best dosing regimen to produce the safest optimal prophylactic effect remains to be determined.

AIM

To compare low- and high-dose gentamicin as prophylaxis during IPP implantation.

METHODS

We retrospectively analyzed two groups of patients who underwent IPP placement from April 14, 2012 through April 13, 2016. Group 1 was composed of 490 patients who underwent IPP placement from April 14, 2012 through April 13, 2014 and received a low dose of preoperative gentamicin at 80 mg every 8 hours for 1 day. Group 2 was composed of 407 patients who underwent IPP placement from April 14, 2014 through April 13, 2016 and received a single high dose of preoperative gentamicin at 5 mg/kg. We compared the infection rates of IPP and any gentamicin-related toxicities. The same surgeon performed all procedures. All patients received additional vancomycin 1 g before incision and at 12 hours postoperatively.

OUTCOME

Demographic data and IPP infection rate were compared and potential toxicities from the higher dose of gentamicin were closely monitored.

RESULTS

There were no significant differences in mean age, mean body mass index, and mean interval for IPP placement and IPP infection between the two groups. No toxicity was seen with the higher gentamicin dose. Six cases in group 1 (five de novo cases and one redo case, infection rate = 1.22%) and three cases in group 2 (two de novo cases and one redo case, infection rate = 0.74%) were found to have IPP infection. The infection rate in group 2 appeared to be lower than that in group 1, although a significant statistical difference was not achieved (P = .057).

CLINICAL IMPLICATIONS

These findings would help guide urologists in choosing an optimal preoperative gentamicin dose for IPP surgery.

STRENGTHS AND LIMITATIONS

This is the first study to report on the usage of high-dose preoperative gentamicin for IPP surgery but with limitations as a retrospective study.

CONCLUSIONS

Although not achieving a statistical difference, there was a trend for patients receiving a higher dose of preoperative gentamicin to have a lower IPP infection rate. No toxicity was encountered from the 5-mg/kg gentamicin dose. We recommend following prophylactic high-dose gentamicin guidelines. Xie D, Gheiler V, Lopez I, et al. Experience With Prophylactic Gentamicin During Penile Prosthesis Surgery: A Retrospective Comparison of Two Different Doses. J Sex Med 2017;14:1160-1164.

Minimising the risk of device infection in penile prosthetic surgery: a UK perspective

We have reviewed articles published on penile prosthetic infection in Medline and EMBASE databases from 2000 to 2012 with the intention of signposting ‘best evidence’ for the UK prosthetic implanter. Using the Oxford Centre for Evidence-based Medicine Levels of Evidence (LE), no paper exceeded an LE of 2b and the majority were LE 4 (case series) and LE 5 (expert opinion). This is not surprising from a UK perspective since HES data for 2009 to 2010 reported 263 penile prosthetic surgeries performed in 35 hospitals, with only five hospitals performing 15 or more. Our literature review suggests that the use of antibiotic-coated IPPs and measures aimed at reducing inoculating bacteria into the surgical wound with alcohol skin preparation, a no-touch technique and peri-operative antibiotic use are most important in minimising the risk of device infection. The use of post-operative antibiotics is contentious (LE 5). It remains unproven whether diabetics have a higher rate of prosthetic infection compared to nondiabetics. In cases of re-implantation for mechanical failure, it remains debatable whether a washout technique should be used and indeed uncertainty remains regarding the pathological role of biofilm in the causation of device infection in this scenario. A washout technique during salvage penile prosthetic surgery for device infection is advocated. Further research on biofilm may offer the best chance of reducing the incidence of device infections overall.

Morphological parameters for implantation of the screwless spring loop dynamic posterior spinous process stabilizing system

PURPOSE

This study aimed to quantify morphological characteristics of the posterior lumbar spinous process, which may affect stable implantation of screwless wire spring loops.

METHODS

Virtual implantations of a screwless wire spring loop onto pairs of lumbar spinous processes were performed for computed tomography (CT)-derived three-dimensional vertebral models of 40 Korean subjects. Morphological parameters of lumbar vertebrae 1 through 5 (L1-L5) were measured with regard to bone-implant interference.

RESULTS

In males, the transspinous process fixation lengths decreased from 57.8±3.0mm to 48.8±3.2mm as the lumbar joints descend from L1-L2 to L4-L5, with those in females about 4.1±0.4mm shorter (p<0.05) than in males through all lumbar joints. The fixation angle on the sagittal plane varied from 105.0° to 101.3° relative to the transverse plane as the vertebrae descend. The clenched thickness in females was the least (6.7±1.2mm) for the L2 lower spinous process and the greatest (8.1±2.2mm) for the L4 upper spinous process; this was 1.0±10.3mm less than that for males at corresponding levels (p>0.05). The ratio of the spinous process clenched thickness to the transspinous fixation length increased from 0.133±0.016 to 0.196±0.076 for the upper spinous processes as the lumbar joints descend.

CONCLUSIONS

The ratio of the spinous process clenched thickness to the transspinous fixation length varies, depending on gender and whether the clenched level is the upper or lower spinous process. These parameters related to the clenching fixation stability should be considered in development and implantations of the screwless wire spring loop.

Infection rates of rifampin/gentamicin-coated Titan Coloplast penile implants. Comparison with Inhibizone-impregnated AMS penile implants

INTRODUCTION

It is a common practice to soak Titan(®) Coloplast penile implants in antibiotic solution prior to implantation. Experience with Inhibizone impregnation suggests that rifampin coating significantly reduces infection rates of penile implant surgery. In this article we describe the results of coating Titan Coloplast penile implants with rifampin/gentamicin solution.

AIM

To compare infection rates of Titan(®) Coloplast penile implants coated with vancomycin/gentamycin, rifampin/gentamicin, and Inhibizone-impregnated American Medical Systems (AMS) penile implants.

METHODS

Chart review was done for all Mentor/Coloplast and AMS implant surgeries performed at our center between the dates January 1, 2002 and February 8, 2010. Infection rates for Titan(®) Coloplast penile implants coated with vancomycin/gentamycin, rifampin/gentamicin, and Inhibizone-impregnated (AMS) penile implants were compared.

MAIN OUTCOME MEASURES

Infection rates for penile implants coated with different antibiotics.

RESULTS

Infection rates for Titan(®) Coloplast penile implants coated with vancomycin/gentamycin and Inhibizone-impregnated (AMS) penile implants was 4.4% and 1.3%, respectively (P = 0.05). None of the rifampin/gentamicin-coated Titan(®) Coloplast penile implants have developed infection. Rifampin is the common antibiotic both in rifampin/gentamicin-coated Coloplast implants and Inhibizone(®) . The infection rate in this combined rifampin/gentamicin-coated Titan Coloplast implants and Inhibizone-coated AMS implants group was 0.63% (P = 0.03).

CONCLUSION

Both rifampin/gentamicin-coated Titan(®) Coloplast penile implants and Inhibizone-impregnated (AMS) penile implants appear to have lower infection rates compared with vancomycin/gentamycin-coated Titan(®) Coloplast penile implants The present study does not suggest superiority of rifampin/gentamicin-coated Titan(®) Coloplast penile implants or Inhibizone-impregnated (AMS) penile implants but we strongly suggest that all Titan(®) Coloplast penile implants should be coated with rifampin/gentamicin solution.

Protheses péniennes: évaluation multicentrique des pratiques : résultats d’une série de 282 implantations

OBJECTIVES

Multicentre practice evaluation in the field of penile prostheses based on the Club des Implanteurs de Prosthèses Péniennes (CIPP) database.

METHOD

282 penile prostheses, including 276 inflatable prostheses (97.8%), were implanted in 254 patients between 1996 and 2005 in three centres (1 public and 2 private). Preoperative data (patient's age, aetiology and duration of erectile dysfunction, preliminary treatments) and intraoperative data (type of implant used, surgical approach) were recorded. Postoperative complications were studied and postoperative erectile function was evaluated by a self-administered questionnaire (IIEF). The mean follow-up was 27.7 months.

RESULTS

Penile prostheses were implanted after an average of 39.2 months of erectile dysfunction in patients with a mean age of 58.6 years. The main aetiologies were arterial disease (35.3%), diabetes (22.8%) and radical prostatectomy (16.5%). The postoperative sepsis rate was 2.2% and the mechanical dysfunction rate was 7.5% at the beginning of the operators' experience. The rate of other complications requiring repeat surgery (erosion, migration, self-inflation) was 1.8% at the beginning of the operators' experience. The septic risk was increased (7.6%) in the presence of diabetes (p = 0.01). The postoperative overall satisfaction was 86.7% and the IIEF score increased from 20.5 +/- 11.8 preoperatively to 68.9 +/- 5.4 postoperatively.

CONCLUSION

Penile prostheses achieve a high postoperative satisfaction score with a low complication rate. However, they are only indicated after failure of less invasive treatments and must be implanted by experienced operators. These results are comparable to those of large international single-centre series.

Outcomes and satisfaction rates for the redesigned 2-piece penile prosthesis

PURPOSE

We evaluated long-term viability, quality of life and satisfaction with the redesigned 2 piece Ambicor inflatable penile prosthesis. This device underwent revision of the rear tip extender and reinforcement of the pump tubing connection to decrease fluid leak failure in 1998.

MATERIALS AND METHODS

In this retrospective analysis we evaluated 146 men with erectile dysfunction at 2 centers who underwent device implantation between June 1999 and October 2004 with the redesigned prosthesis. Patient information forms were completed, including patient history, surgical information and revision data. Patients were mailed a modified Erectile Dysfunction Inventory of Treatment Satisfaction questionnaire, a modified Erectile Dysfunction Inventory of Treatment Satisfaction Partner survey and a questionnaire regarding pertinent inflatable penile prosthesis questions.

RESULTS

A total of 146 men with a mean age of 58.7 years (range 25 to 78) were evaluated after inflatable penile prosthesis placement. Time from implant to followup was 3 to 73 months (mean 38). Only 1 device (0.7%) was removed due to infection. One implant (0.7%) was replaced due to fluid loss and 1 (0.7%) was revised due to improper sizing. Kaplan-Meier life table analysis indicated that the percent of patients free from reoperation was 99.2% at 12 months, 99.2% at 36 months and 91% at 48 months or greater. Of the 101 subjects completing the survey the average patient used the prosthesis 5 times monthly and 88.9% reported continued use. Of the patients 91% said that it was easy to use and 95% had little to no trouble learning to use it, while 84% stated that the inflatable penile prosthesis provided good to excellent rigidity for coitus. Overall patient and partner satisfaction was 85% and 76%, respectively. Of the patients 86% said that they would recommend the prosthesis to friends or if need be undergo the procedure again.

CONCLUSIONS

The redesigned Ambicor 2-piece penile prosthesis appears to be safe and effective. It is associated with a low rate of revision as well as high patient and partner satisfaction.

Risk of Infection With an Antibiotic Coated Penile Prosthesis at Device Replacement for Mechanical Failure

PURPOSE

The inflatable penile prosthesis is well established as an effective treatment for select patients with organic erectile dysfunction. The risk of prosthetic infection at primary implantation is approximately 2%. However, for revision or replacement procedures the risk of infection has been reported to be as high as 13.3%. To minimize the overall risk of prosthetic infection an antibiotic coated inflatable penile prosthesis (InhibiZone) has been developed. To assess the impact on infection rates we reviewed our experience with the use of this device at prosthesis replacement for mechanical failure.

MATERIALS AND METHODS

We retrospectively reviewed the records of all patients undergoing inflatable penile prosthesis replacement for mechanical failure with an antibiotic coated prosthesis between May 2001 and November 2004. Salvage procedures for clinically infected prostheses were excluded from analysis. Chart review was performed with examination of operative notes, all postoperative contacts and microbiological data.

RESULTS

A total of 55 patients underwent replacement of an inflatable penile prosthesis for mechanical failure using a device coated with rifampin and minocycline HCL (InhibiZone). In all patients before reimplantation component spaces were irrigated in standard fashion. With a median followup of 32 months (range 12 to 54) postoperative device infection requiring explantation developed in 1 patient (1.8%). Intraoperative cultures from the pump site grew coagulase negative staphylococcus.

CONCLUSIONS

Our data suggest that an antibiotic coated inflatable penile prosthesis may lead to decreased infection rates in patients undergoing penile prosthesis replacement for mechanical failure.

Penile prosthetic surgery and its role in the treatment of end-stage erectile dysfunction - an update

The treatment of erectile dysfunction has been revolutionised with the introduction of orally active phosphodiesterase inhibitors which are successful in 70-80% of men. However, there remain a group of men in whom conservative treatment fails and surgical insertion of a penile prosthesis is required. This type of surgery has in the past been associated with technical difficulties and a high complication rate. This has spurred numerous developments in prosthesis design and surgical technique with the field changing at a rapid pace. Perhaps the most significant is the use of antimicrobial coatings on prostheses that have been shown to reduce the infection rate significantly. This review highlights those developments reported in the last 5 years.

The hydrophilic-coated inflatable penile prosthesis: 1-year experience

INTRODUCTION

Penile prosthesis infections are a devastating complication for both patient and surgeon. Efforts to reduce the risk of infection from these elective procedures are a major focus of research and development by the major prosthesis companies. The Titan inflatable penile prosthesis (Mentor Corporation, Santa Barbara, CA) is coated with polyvinylpyrrolidone (PVP), a hydrophilic substance that reduces bacterial adherence and absorbs and elutes the antibiotics the device is immersed in intraoperatively. The Titan device was introduced to the American market in September 2002. This study reports the 1-year experience in the U.S. with the Titan and compares infection rates with the noncoated Alpha-1 IPP made by Mentor.

MATERIALS AND METHODS

Two thousand three hundred and fifty-seven Titan prostheses were implanted in the U.S. from September 2002 to August 2003, compared with the 482 noncoated Alpha-1 IPPs implanted over the same time period. Infection rates were compared, along with bacterial culture data. All data were collected from Mentor's internal database, as generated from the FDA's mandatory reporting of explanted medical devices, and available on the internet.

RESULTS

The infection rate for the coated Titan IPP was 1.06% (25/2,357). During the same time period, the infection rate for the Alpha-1 noncoated prosthesis was 2.07% (10/482). Staphylococcus species predominated in both groups (9/25 Titan, 6/10 Alpha-1).

CONCLUSIONS

At 1 year of follow-up, the data demonstrate that the hydrophilic coating on the Titan IPP confers a significant advantage in reducing the rate of infection over the noncoated device. Long-term follow-up on this first year database is needed before this innovation is accepted as the standard of care for prosthetic surgery. Nevertheless, the theoretical reduction in bacterial adhesion conferred by the hydrophilic PVP surface and the ability to choose which antibiotic the device is immersed in intraoperatively gives the implanting surgeon distinct advantages with this new product.

Penile prosthesis implantation: surgical implants in the era of oral medication

In patients who are not satisfied with the results of oral agents (phosphodiesterase-5 inhibitors) or in whom oral agents or other medical treatment fails to produce an adequate response, penile prosthesis implantation is an excellent treatment modality for restoring erectile function. Patient/partner acceptance, use, and satisfaction rates of penile pros-theses are better than for many other alternatives including pharmacologic injections. In-flatable penile prostheses are most frequently used and have the highest satisfaction rates. Complications of these multipiece prostheses continue to decline, and patient satisfaction rates, tolerability, and longevity continue to increase.

Clinical experience with the Mentor Alpha-1 inflatable penile prosthesis: report on 65 patients

OBJECTIVE

To evaluate the complications and prosthesis survival associated with implantation of the Mentor Alpha-1 inflatable penile prosthesis (IPP) for the treatment of erectile dysfunction (ED).

MATERIAL AND METHODS

Between August 1995 and March 2003, 65 patients underwent implantation of a Mentor Alpha-1 IPP at the Urological Departments of Skejby or Aalborg University Hospitals. Patient data were obtained retrospectively from medical files.

RESULTS

The follow-up period ranged from 1 to 96 months (median 48.5 months). Twenty-one patients (32%) experienced complications that required revision. The majority of complications consisted of mechanical problems, but infection was also a large contributor to the complication rate. Seven patients (11%) had the prosthesis permanently removed due to infection. Kaplan-Meier estimates of the 5-year prosthesis survival rates with and without successful revisions due to complications were 88% and 63%, respectively.

CONCLUSIONS

The Mentor Alpha-1 IPP is an efficient treatment for ED in situations where less invasive therapy has failed. The risk of infection or mechanical failure must not be ignored. Patients should be informed of this risk before agreeing to implantation surgery.

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.

Current role of penile implants for erectile dysfunction

PURPOSE OF REVIEW

The purpose of this review is to appraise new developments and publications in the field of penile prosthetic surgery. Urologists dealing with erectile dysfunction need to recognize the value of penile prosthetic surgery as a very efficacious treatment for this common condition. This type of surgery is needed in a considerable proportion of patients with erectile dysfunction so this review is timely and relevant.

RECENT FINDINGS

The main themes in the literature covered include risk factors for infection of penile prostheses, its prevention with the use of hydrophilic and antibiotic-coated prostheses, particularly in re-operations, and its management with the new rescue procedures. Surgical tips for prosthetic surgery are also reviewed as well as clinical outcomes and factors influencing them.

SUMMARY

Of all the invasive treatments currently available, placement of a penile prosthesis is one of the most successful, giving high levels of satisfaction. With the aid of new technical advances, the risk of infection--the most feared complication--can be minimized so prosthetic surgery may play a major role in the treatment of erectile dysfunction.

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.