PNC were removed under sterile conditions after 72h or earlier in the case of signs of infection: Removal of the PNC was performed on the surgical ward by an anaesthesiologist according to a standardized procedure: Wearing a facemask and a cap, the adhesive skin dressing was removed. In the "WITH-group", the skin was now disinfected with an aerosolized alcoholic solution (propanol-biphenol). Procedure continued after three minutes, when the skin was dry with the anaesthesiologist wearing sterile gloves and using sterile tweezers.