All Products
Also known as
Antibiotic-coated, antibiotic-eluting, antibiotic-loaded, local antibiotic delivery, antibiotic beads, antimicrobial impregnation.
Definition
Antibiotic impregnation is the incorporation of antibiotics into the surface of an implanted device so that they elute from the device components and reduce the incidence of device infection.1 In penile prosthesis surgery, two infection-retardant approaches are used: a combination of minocycline and rifampin coated onto the device during manufacturing, and a hydrophilic coating that absorbs antibiotics when the device is submerged in an antibiotic solution before implantation.2 Minocycline and rifampin were combined because the pairing is highly effective against Staphylococcus, the most prevalent cause of device infection.3 Infection-retardant coatings kill contaminant bacteria and prevent the formation of biofilms on implanted devices,2 and after implantation the antibacterial coating continues to elute from the device for around two weeks.3 According to the EAU Guidelines, careful surgical technique with appropriate prophylaxis reduces infection to 2-3% after primary implantation in low-risk patients at high-volume centres, and the rate may be further reduced to 1-2% by implanting an antibiotic-impregnated or hydrophilic-coated prosthesis.4
Clinical Context
A meta-analysis of 14 studies including 9,910 first-time implants found infection rates of 2.32% with non-coated and 0.89% with coated inflatable prostheses, including 0.63% with the minocycline/rifampin coating, and concluded that coatings that allow antibiotics to elute from the device decrease infection by approximately 50%.1 In a voluntary manufacturer registry, initial revision due to infection was reported in 1.1% of 35,737 men with impregnated implants and 2.5% of 3,268 men with non-impregnated implants at up to 7.7 years of follow-up.5 In vitro, minocycline-rifampin-impregnated surfaces kept their antimicrobial activity after irrigation with 0.05% chlorhexidine gluconate or vancomycin/gentamicin solution, although clinical efficacy of that combination remains to be evaluated.6
With the hydrophilic alternative the surgeon selects the antibiotic dip; rifampin/gentamicin is the most studied combination, but the ideal mixture has not been identified and controlled studies are still needed.7
Impregnation reduces, but does not eliminate, infection. The EAU Guidelines pair coated prostheses with strict protocols that avoid prolonged wound exposure and minimise skin contact (no-touch technique), and an infected prosthesis still requires removal and antibiotic treatment or immediate salvage using a wash-out protocol.4 In revision surgery, antibiotic-coated implants did not reduce infection unless an antiseptic washout was also used: infection occurred in 10% of revisions without washout and 3% with washout.8 Coatings may also change the microbiology of infection. Infecting organisms have shifted from Gram-positive bacteria toward Gram-negative bacteria and fungi,7 and coated implants have been associated with more atypical bacteria and fewer staphylococcal infections, suggesting a shift toward more virulent pathogens.2 In one study, 83% of fungal penile implant infections occurred in diabetic or obese men.9