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Photodynamic therapy improves skin antisepsis as a prevention strategy in arthroplasty procedures: A pilot study
Isabelle Waldmann1, Tobias Schmid2, Julia Prinz1
1Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
Background:
Current standard skin antisepsis to prevent surgical site infections are ineffective to eradicate all skin-colonizing bacteria. Photodynamic therapy (PDT) has shown bactericidal effects in vitro, but no clinical study with improvements in skin antisepsis has been documented.
Methods:
We investigated the effect of methyl aminolevulinate (MAL)-PDT versus no PDT for skin antisepsis treatment (povidone-iodine/alcohol) in the groin of 10 healthy participants. Skin swabs were taken at baseline, immediately after PDT, and after skin antisepsis treatment to cultivate bacteria. At day 7 and 21, bacterial cultures were repeated before and after antisepsis treatment without PDT. Skin biopsies were performed to examine the grade of inflammation.
Results:
Skin-colonizing bacteria were found in all 20 participants at baseline sampling. Immediately after MAL-PDT, skin was sterile in 7 (70%) participants before and in all 10 (100%) participants after skin antisepsis treatment. In contrast, we found skin-colonizing bacteria in 5 (50%) participants of the control group receiving only skin antisepsis. After 7 and 21 days, skin sterility was similar to the baseline. We observed slight perivascular inflammation with lymphocytes and eosinophils without changes in the histomorphology of eccrine or sebaceous glands in skin biopsies. PDT was generally well tolerated except for localized redness.
Conclusion:
MAL-PDT with skin antisepsis treatment sterilized skin immediately after its use but did not maintain sterility 7-21 days post-treatment. Due to local side effects, further clinical studies with less intensive PDT conditions or other photosensitizers are needed before PDT is integrated into clinical practice.
Insights
Methyl aminolevulinate-photodynamic therapy (MAL-PDT) combined with standard antisepsis effectively sterilized skin immediately after treatment. However, this enhanced skin antisepsis did not maintain bacterial sterility long-term, indicating a need for further research.
Area of Science:
- Dermatology
- Infectious Disease Prevention
- Photodynamic Therapy
Background:
- Standard skin antisepsis methods are insufficient for eradicating all bacteria contributing to surgical site infections.
- Photodynamic therapy (PDT) demonstrates in vitro bactericidal properties, but clinical evidence for improved skin antisepsis is lacking.
Purpose of the Study:
- To evaluate the efficacy of methyl aminolevulinate-photodynamic therapy (MAL-PDT) as an adjunct to standard skin antisepsis.
- To assess the immediate and short-term effects of MAL-PDT on skin bacterial colonization in healthy participants.
Main Methods:
- A study involving 10 healthy participants investigated MAL-PDT followed by povidone-iodine/alcohol antisepsis versus antisepsis alone.
- Skin swabs were collected at various time points (baseline, immediately post-PDT, post-antisepsis, days 7 and 21) for bacterial culture.
- Skin biopsies were analyzed to assess inflammation and histomorphological changes.
Main Results:
- Immediately after MAL-PDT and antisepsis, 100% of participants achieved skin sterility, compared to 50% with antisepsis alone.
- Skin-colonizing bacteria returned by day 7 and 21, with bacterial levels similar to baseline.
- Histological examination revealed mild inflammation, and PDT was generally well-tolerated with localized redness as the primary side effect.
Conclusions:
- MAL-PDT combined with standard skin antisepsis provides immediate skin sterilization but lacks sustained efficacy.
- Further clinical investigations exploring modified PDT protocols or alternative photosensitizers are necessary for potential integration into clinical practice.
