All new and exchanged transmitters shipped to an investigator are sterile and ready for implantation. In studies where transmitters are implanted for short periods, significant battery life may remain at the end of the study allowing reuse of the transmitter. DSI has developed procedures for cleaning and sterilizing transmitters on-site, and for re-gelling pressure catheters. These procedures will increase the number of times an investigator can use each transmitter before returning it to DSI via the Transmitter Exchange program, helping to reduce overall costs per study.  

DSI only recommend cold sterilization between uses and does not recommend ETO machines.  The implants will have changed compared to the unused product in that there would likely be more retained moisture and in particular disruption of gel (e.g water, blood, or air mixing in the gel).  This change in property may cause an increase risk in the pressure catheter to have the gel blow out of the catheter tip, when pressure catheters are present.  Secondly There are a lot of variables and differences between ETO machines to guarantee success (20+ parameters for the machines at DSI).  Even the machines at DSI was specifically tailored for DSI implants to meet our requirements and are proprietary information.  Lastly, even with our current process, there are some unused devices that do have gel or fill blowouts and must go back to be re-filled and gelled.  Note: If the customer would still like to sterilize with an ETO machine, it will be at the customer's risk and "off label".  In these cases, it should be at a low temperature and vacuum level.  

All products returned to DSI must be cleaned and decontaminated. Shipments that have not been cleaned and decontaminated will be charged a handling fee per item. These products are subject to transportation regulations as published by the US DOT or ICAO, or your carrier. If the products are fully decontaminated, they may be exempt from part or all of the requirements (including packaging, marking, labeling and documentation).

Supplies Needed

1. Enzymatic Detergent
   Available from most hospital supply companies, they are generally labeled for use on fabrics or surgical equipment/instruments. The purpose of the detergent is to remove blood, serum proteins, and tissue debris from the surface of the transmitter. DSI tested and approved products are:  Terg-A-Zyme® (Alconox, Inc.) and Haemo-Sol® N.S. (Haemo-Sol, Inc.).
   
   Terg-A-Zyme
   Terg-A-Zyme is an enzyme-active powdered detergent made by Alconox, Inc. To make a 1% solution, mix 10 grams of powder with 1 Liter of cold or warm water. Allow the device to soak for a minimum of 4 hours and a maximum of 72 hours in the solution. Rinse thoroughly, preferably with running water. Fisher Scientific is a vendor that supplies Terg-A-Zyme (catalog #50-821-785, www.fishersci.com) but please refer to the Alconox website for other domestic and international vendors (www.alconox.com).
   
   Haemo-Sol N.S.
   Haemo-Sol N.S. is a non-sudsing, proteolytic powdered detergent made by Haemo-Sol, Inc. To make 1 Liter of the solution, mix 5 grams of powder with 1 Liter of cold or warm water. Allow device to soak for a minimum of 4 hours and a maximum of 72 hours in the solution. Rinse thoroughly, preferably with running water. Fisher Scientific is a vendor that supplies Haemo-Sol N.S. (catalog #23-721050) but please refer to the Haemo-Sol website for other domestic and international vendors (www.haemo-sol.com). It is important to note that there are multiple types of Haemo-Sol available but DSI only recommends using the N.S. (non-sudsing) type.
2. Chemical Sterilant
   Available from most hospital supply companies, chemical sterilants are considered cold sterilants and should be used for the sterilization of heat sensitive medical equipment such as DSI transmitters. When used properly, chemical sterilants will destroy all viable forms of microbial life. DSI tested and approved products are:  Actril® (Medivators, Inc.).
   
   Actril
   Actril is a mixture of peracetic acid, hydrogen peroxide, and acetic acid chemical sterilant made by Medivators, Inc. Actril has a shelf life of 1 year from the date it is first opened. Actril is available directly from Medivators, Inc. (catalog #78337-000, http://www.medivators.com/products/renal-systems/cold-sterilants/actril). Actril is available in the U.S. and internationally. Please refer to Medivators, Inc. website for a list of domestic and international distributors (http://www.medivators.com/contact-us/distributor-map). 
   
   Spor-Klenz is another chemical sterilant composed of the same mixture of paracetic acid, hydrogen peroxide, and acetic acid as Actril, but produced by another company (Steris).  Please note that this solution has not been tested by DSI.  
   
   ***Note on Cidex***
   Cidex is a high level disinfectants, not a sterilant. DSI has assessed material compatibility but makes no expressed guarantee of sterilization post exposure to Cidex.
3. Sterile Saline*
   This can be used as a rinse for the sterilized transmitter in order to remove all traces of the chemical sterilant before implantation. Use it to temporarily store (< 48 hours) the transmitter aseptically until surgical implantation. See the technical note on transmitter storage if you need to store the transmitters longer.

Implant Procedures

Temperature Implants

Immediately following removal from the animal, rinse the transmitter in tap water to remove gross contamination from blood and tissue. Place the transmitter in the detergent and soak for at least 4 hours to allow breakdown of the surface contaminants. Remove and examine the transmitter. If traces of blood or tissue remain, additional soaking in the detergent may be required. Rinse the transmitter thoroughly in tap water.

To sterilize using Actril:  Use in a well-ventilated area. Pour an adequate amount (enough to cover and sterilize the transmitter) into a sterile container. Place the transmitter into the sterile container and tightly cap both the bottle with the remaining solution and the sterile container. Allow the device to soak in Actril for a minimum of 5.5 hours at approximately 25°C. Actril will remain a clear liquid. After sterilizing the transmitter in Actril, thoroughly rinse the transmitter three times with sterile saline and then soak the transmitter in sterile saline for a minimum of 5.5 hours. The transmitter can be left in the sterile saline until ready for implantation within 48 hours. Otherwise, air dry and store in a safe dry place. See the technical note on transmitter storage if you need to store the transmitters longer.

Biopotential Implants

Immediately following removal from the animal, ensure that the suture ties are intact around each biopotential lead tip to prevent moisture entry. Rinse the transmitter in tap water to remove gross contamination from blood and tissue. Take care to clean the suture rib/tab and remove any foreign material that may be present. Then place the transmitter in the detergent and soak for at least 4 hours to allow breakdown of the surface contaminants. Remove and examine the transmitter. If traces of blood or tissue remain, additional soaking in the detergent may be required. Rinse the transmitter thoroughly in tap water.

To sterilize using Actril:  Use in a well-ventilated area. Pour an adequate amount (enough to cover and sterilize the transmitter) into a sterile container. Place the transmitter into the sterile container and tightly cap both the bottle with the remaining solution and the sterile container. Allow the device to soak in Actril for a minimum of 5.5 hours at approximately 25°C. Actril will remain a clear liquid. After sterilizing the transmitter in Actril, thoroughly rinse the transmitter three times with sterile saline and then soak the transmitter in sterile saline for a minimum of 5.5 hours. The transmitter can be left in the sterile saline until ready for implantation within 48 hours. Otherwise, air dry and store in a safe dry place. See the technical note on transmitter storage if you need to store the transmitters longer.

*Sterile water should be used for rinsing and soaking 4ET transmitters.  Do not use sterile saline.  Please see the 4ET User Manual for additional information about re-sterilizing and reusing this device.

Pressure Implants

Immediately following removal from the animal, rinse the transmitter in tap water to remove gross contamination from blood and tissue. Carefully remove any residual tissue adhesive and suture material from the surface of the catheter. If there is blood in the tip of the catheter, remove as much as possible

by directing a stream of saline at the tip to flush it out. Take care to clean the suture rib/tab and remove any foreign material that may be present. Place the transmitter in the detergent and soak for at least 4 hours to allow breakdown of the surface contaminants. Remove and examine the transmitter. If traces of blood or tissue remain, additional soaking in the detergent may be required. Rinse the transmitter thoroughly in tap water.

To sterilize using Actril:  Use in a well-ventilated area. Pour an adequate amount (enough to cover and sterilize the transmitter) into a sterile container. Place the transmitter into the sterile container and tightly cap both the bottle with the remaining solution and the sterile container. Allow the device to soak in Actril for a minimum of 5.5 hours at approximately 25°C. Actril will remain a clear liquid. After sterilizing the transmitter in Actril, thoroughly rinse the transmitter three times with sterile saline and then soak the transmitter in sterile saline for a minimum of 5.5 hours. The transmitter can be left in the sterile saline until ready for implantation within 48 hours. Otherwise, air dry and store in a safe dry place. See the technical note on transmitter storage if you need to store the transmitters longer.

The PhysioTel Digital implant should be removed from Actril within 24 hours.  Discoloration of the titanium housing will occur after that time period; however; the housing will not be damaged.

The catheter may need to be re-gelled prior to sterilizing or immediately prior to the time of surgery. Use aseptic conditions if re-gelling prior to surgery to prevent contamination. For more information see the technical notes on re-gelling pressure transmitters.

Customers are liable for product repair if products other than the specified detergents and sterilants are used.

Some examples of chemicals that will cause damage to DSI transmitters include, but are not limited to: alcohols, phenols, iodophors, and hypochlorite.  Please check with DSI Technical Services before using any product other than the approved products listed.