Policy and Guidelines for Managing Chronic Cephalic Implants in Non-Human Primates

Policy:
Chronic cephalic implants in NHPs must be maintained to ensure that chambers are free of significant pathogens. Use aseptic techniques to maintenance NHP craniotomy sites. Exceptions to this Policy and the Guidelines as outlined below must be pre-approved by the IACUC.

Guidelines:

Purpose:
To provide guidelines for managing and monitoring the condition of chronic cephalic implants, i.e., those with/without associated craniotomy sites, in non-human primates (NHPs) The goal is to minimize pathogenic bacterial and fungal load and prevent the development of antimicrobial resistance. These guidelines refer to clinically healthy animals with intact dura. For other NHPs, a management plan will be developed by Veterinary Clinical Service (VCS) in consultation with NHP Investigator(s).

Overview: : Maintaining NHP cephalic implants is a multi-stage task involving 1)cleaning the implant at regular intervals; 2) keeping adequate records of the status of the implant; and, 3) culturing the implant twice yearly. Regarding cleaning the implant, a summary of recommended and required procedures for tending to the gross exterior (dental cement, visible hardware), the wound margin, and, any chamber covering a craniotomy site is provided below. A step-by-step generic" cleaning protocol" is provided in APPENDIX 1. Recommended treatments to be used in the context of cleaning are listed in APPENDIX 2. To assist in record-keeping, a 'treatment record" template is provided in APPENDIX 3. Finally, some discourse on implant pathology results is given in APPENDIX 4.

Throughout, the below-listed general principles of safety and cleanliness must be followed:

• Safety: Follow all required safety precautions/procedures for working with NHPs.
• General Cleanliness: Keep tools and the lab area used clean and in good working condition. Start cleaning with a glove-change and change gloves between different stages of cleaning (exterior, wound margin, cylinder interior) and after contaminated regions/surfaces are touched.
• Specific Cleanliness: Use aseptic technique and sterile supplies for cleaning the interior of chambers/cylinders.

1. Methods for cleaning chronic cephalic implants:
   The three components of the implant are cleaned in separate stages with glove changes between. Recommended solutions/treatments are listed in Appendix 2.
   • Implant exterior: Use non-irritating antiseptic/cleansing solutions and clean supplies and instruments. Consider a brush or betadine scrub pad.
   • Wound margin: Use non-irritating antiseptic/cleansing solutions and avoid excessive bleeding/irritation. Trimming hairs abutting the margin is useful. After cleaning, antibiotic treatment may remain on the tissue.
   • Interior of chambers/cylinders: Use only sterile supplies/instruments. Thoroughly irrigate the interior, i.e., use the equivalent of 3 flushes with each being at least 2-times the volume of the cylinder. Use suction when available. Antibiotic/other recommended treatments may remain in the cylinder. Only a sterile or disinfected cylinder cap (e.g., scrub and 20 min soak in Clidox) must be replaced. Apply a coating of antibiotic ointment to the underside of the cap to provide a firm seal. Implants must be cleaned prior to recording sessions with intervals between cleaning no greater than seven days when NHPs are off-testing. However, unhealthy implants generally need to be cleaned and have their local antibiotics replaced more often.
2. Record keeping.
   Record the status of the implant (both the methods used as well as its gross appearance) at regular intervals. See the sample form in Appendix 3. Particularly important is to note changes in the status quo of any component of the implant. These records should be kept available for review by VCS, IACUC, USDA, etc.
3. Taking cultures and pathogen monitoring:
   For normative microbiological monitoring of craniotomy sites, NHP Investigators must biennially (every 6 months) submit culture swabs of cylinder implants (obtained prior to cleaning) to Microbiology Lab staff (LSOG 121), preferably by 2:30 pm Monday through Thursday. This information will inform all treatment plans as devised by NHP Investigators and VCS. Two types of swabs may be used: a regular culture swab (must be submitted within 15 minutes of collection to ensure detection of anaerobic bacteria) or Amies Clear swabs, cat #723005 (Remel, Lenexa, KS ? can be submitted within 1 hour). If there are logistical issues with submitting swabs, VCS will assist with the culture with prior scheduling.