Does Povidone-Iodine Irrigation of the Breast Implant Pocket Really Help to Prevent Biofilm Formation and Capsular Contracture? Where Is the Evidence?
Capsular contracture (CC) has been associated to breast implant colonization by Staphylococcus epidermidis (SE), "Betadine" breast pocket irrigation has gained universal acceptance and continues being recommended to reduce implant contamination.
10% Povidone-iodine (PVP-I) contains 1% available iodine, which must be converted to free iodine to exert its bactericidal activity. In vitro, the free iodine concentration is 1ppm; in vivo, may be insufficient to kill bacteria because it's neutralized by organic substances mainly blood, being converted to iodide. Furthermore PVP-I has no residual activity; it's toxic for granulocytes and monocytes; and inhibits leukocyte chemotaxis. The few papers reviewing its microbiologic spectrum in vitro, don't mention SE on their list.
As the microbicidal activity of free-iodine increases in more dilute solutions, 10% PVP-I solutions reach a maximum of efficacy in vitro with dilutions of 1:100. Nevertheless, the dilutions reported for breast pocket irrigation in literature are suboptimal, ranging from 1:1 to 1:10.
Taking into consideration the abovementioned facts we then wonder whether povidone-iodine irrigation of breast implant pocket helps to prevent biofilm formation and CC.
Methods
A 38-year-old female, underwent retromuscular augmentation through periareolar approach with texturized cohesive silicone gel implants 4 years ago. The surgeon claims he used cephazolin as prophylaxis and irrigated the pocket with "Betadine". Three years later, the patient wanted to improve her implant mal-position. Implants in a high position, nipples pointed downward, animation deformity, skin laxity, and mild asymmetric contour of the breast pockets without palpable thickening of the capsule or hardening of the breasts were observed. A preoperative ultrasound showed a bilateral small amount of peri-implant fluid without signs of rupture. We used Ciprofloxacin as prophylaxis and 4% chlorhexidine for skin antisepsis. Periareolar donut-type skin deepithelialization, and dissection to reach the capsule through a lower hemi-areolar incision were performed.
On each side, once the capsule was opened, 3 samples of 1,5 cc of periprosthetic fluid were obtained with 3 different syringes. Two of them were sent to different labs for bacterial cultures and the other for cytopathology. Implant was removed, the capsule looked normal and insufficient muscle release was observed. A dual-plane pocket was created and irrigated with a ciprofloxacin dilution before texturized cohesive gel silicone implant replacement. Finally, layered closure and interlocking periareolar suture were done. Ciprofloxacine was prescribed for ten days.
Results
Both labs reported a few colonies of SE in the left breast susceptible to ciprofloxacin. H&E stains showed abundandt macrophages. With this result, rifampicine was ordered too. After one-year follow-up, the patient doesn't have clinical findings of CC
Breast implants are expose to endogenous breast flora, when a periareolar approach is used. Unfortunately, there isn't an antiseptic able to eliminate all resident flora, therefore, SE may persist at the site of incision following skin antisepsis.
Due to the capability to colonise and establish highly structured biofilms on polymer surfaces, as well to the multidrug-resistant pattern, SE device-related infections remain a challenge. Has been demonstrated that planktonic bacteria are sensitive to antimicrobial therapy while biofilm bacteria are resistant to both disinfectants and antibiotics, making device-associated infections hard to eradicate. Therefore, prevention should be a priority in order to avoid implant removal.
Studies have shown low effectivity of PVP-I in eliminating Coagulase-negative staphylococci after antisepsis and a few reported PVP-I wasn't better than normal saline. Some researchers believe that CC decreased in breast pocket irrigated with PVP-I is due to the antibiotics used in the mixture for irrigation.
Comparative studies have shown advantages of using chlorhexidine: higher bacterial reduction; greater residual activity; it isn't inactivated by blood or serum proteins. The aforementioned benefits and the fact that SE has been reported as susceptible organism in vitro, have led us to choose chlorhexidine for surgical antisepsis in these surgeries.
There aren't established guidelines for treatment of SE prosthetic infections due to the absence of randomized trials. 80% of Coagulase-negative staphylococci had become resistant to methicillin but resistance to rifampin has remained at 10%. Rifampin is one of the most common constituent of antibiotic combinations active against SE biofilms. Fluoroquinolones have shown effectiveness too. Rifampin- ciprofloxacin combinaion has been demonstrated one of the most potent choices in vivo and was used in this case.
Seroma, defined as a periprosthetic fluid collection > 20 cc documented by ultrasound, doesn't apply in this case. Keeping in mind the previous periareolar augmentation, samples of peri-implant liquid were taken. SE in planktonic form was found on the left breast, maybe the old implants were covered by biofilm. There's a remote possibility that samples were contaminated.
Conclusion:
We recommend use chlorhexidine for antisepsis instead of PVP-I, as better
choice in surgery to reduce the potencial implant contamination; Implant replacement in revision surgery and intraoperative cultures of periprosthetic fluid in patients without clinical signs of CC, to plan the appropriate antibiotic treatment according to planktonik bacteria found, avoiding future biofilm formation on the new implants.