Ask the Clinical Instructor

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“I have heard that there are specific ways to prepare balloons and stents for use. All of the doctors seem to have a different way to do so. What is the standard?” 
— From an RCIS Review online student

Well, there is a simple answer. “Always refer to the manufacturer’s instructions/directions for use.” You can often see this as “IFU” or “DFU.” This is the specific step-by-step detail on how to use the product according to the manufacturer’s recommendations. These recommendations are generally based upon their testings of their products and what processes should be used to properly deploy balloons and balloons with stents mounted on them. For the purposes of this article, we will only talk about coronary devices, not peripheral devices.

Following the manufacturer’s steps can be important for a few reasons. First, it can help assure proper delivery of the item. Second, it can reduce complications or adverse events related to its use. Finally, should something go wrong and there is an adverse outcome related to the product usage, the manufacturer will want assurance that their product was used according to their specific instructions and recommendations.

That is the short answer to your question.

While I have worked with cardiologists who prep EXACTLY according to manufacturer’s instructions/directions for use, I have also worked with cardiologists who do NO prep whatsoever. And then I have worked with cardiologists who do their own thing somewhere in-between, at each end of the spectrum. Following the manufacturer’s instructions/directions for usage is certainly the most appropriate way to utilize the product. Physicians are ultimately responsible for the usage of interventional equipment, and have every right to adjust the usage of equipment in a way that they feel most appropriate. 

We asked CLD’s clinical editor, Dr. Morton Kern, for a physician perspective on this point. He commented:

“Interesting question. From my personal experience and teaching, the preparation steps of the balloon and stent have nearly been the same for the past 20 years. I haven’t read an IFU, although it might prove enlightening. My preference, and it may not be that of others, is simple. For balloons alone, flush the monorail lumen. Hook up to indeflator, draw negative, point syringe down to let 50/50 contrast saline mix fill vacated space on release of vacuum. Then pull negative once more and it’s ready to insert. The only difference for stents is I don’t pull negative the second time and leave the indeflator neutral during insertion. Also, we try not to touch the drug-eluting stent with our fingers if possible. I am sure there is widespread variation on this approach and look forward to hearing about it.”

        — M. Kern

It would be outside of the limitation of space for this article to list the specific IFU/DFU for each and every coronary balloon (with or without stent) on the market. I will summarize the basic steps of balloon preparation by combining most of the IFUs/DFUs. Since many of the products no longer have the IFU/DFU ‘in the box’ as they used to, at the end of this article, I will provide links to a sample of the major vendors’ IFUs/DFUs for a product that they may manufacture.  It is up to you to perform the research to obtain these for any product that you may use. (In other words, I am providing a disclaimer that the information listed below is a general presentation of product preparation, and that the product you use may use slightly different processes.)

1. Carefully inspect the package to assure that the integrity of the sterile packaging. Do not use the product if there are any signs of damage.
2. Do not use after the “Use By” or “Expiration” date. Sometimes this date is identified by the hourglass sign. Don’t confuse this icon with the “manufactured date” icon (Figures 1-2).
3. If you have a “pouch in a pouch” product, the outside of the inner pouch is not sterile. It is packaged this way in order for the drug-eluting stent to maintain the medication.
4. Carefully remove the delivery system from the protective tubing. If a monorail (Rx), do not bend or kink the hypotube during removal (Figure 3).
5. Remove the product mandrel and/or protective sheath that may be present on the product (Figure 4).
6. a.    For over-the-wire (OTW) products, flush the guide wire lumen with a heparin/normal saline mixture until fluid exits the distal end of the delivery system (Figure 5). 

    b.    For monorail (Rx) products, flush the guide wire lumen with a heparin/normal saline mixture using the flushing tool provided with the product. Insert the flushing tool into the tip of the catheter and flush until fluid exits the guide wire exit notch (Figures 6-8).

7. Prepare an inflation device/syringe with diluted contrast medium. Note: Most manufacturers will not specifically state the concentration. My experience has shown most facilities will use a 50/50 mixture (Figures 9-10).
8. Attach an inflation device/syringe to the stopcock; attach it to the inflation port of the product. Do not bend the product hypotube when connecting to the inflation device/syringe (Figures 11-12). 
9. With the tip down, orient the delivery system vertically (Figure 13).
10. Open the stopcock to the delivery system; pull negative for 15-30 seconds; slowly release to neutral for contrast fill of the delivery system tube (Figures 14-15).
11. Close the stopcock to the delivery system; purge the inflation device/syringe of all air.
12. Repeat steps 9-11 until all air is expelled. If bubbles exist, do not use the product.
13. If a stopcock was used, attach a prepared inflation device to the stopcock. Utilize a “meniscus to meniscus” connection whether connecting to a stopcock or directly to the delivery system (Figures 16-17).  
14. Open the stopcock to the delivery system.
15. Leave on “neutral.”
16. STENTS: While introducing the delivery system to the vessel, do not induce negative pressure on the delivery system. This may cause dislodgement of the stent from the balloon.
17. If air is seen in the shaft of the delivery system, repeat instructions above to prevent uneven balloon/stent expansion.
18. Backload the delivery system onto the proximal portion of the guide wire while maintaining guide wire positioning across the target lesion.
19. Carefully advance the product to the target lesion.

Note: Most manufacturers have specific IFU/DFU for the inflation and deployment process. The scope of this article is for the preparation of the balloon. Refer to the IFU/DFU for further directions on deployment procedures.

Hopefully, the list above will help you navigate the proper preparation of balloons (with and without stents).  Understanding the manufacturer’s IFU/DFU can be confusing, but realize that they are mostly the same.

We need your questions! No question too big or small. Please do not hesitate to send a question to Cath Lab Digest via cathlabdigest@aol.com or to me directly, at tginapp@rcisreview.com.

Sample Vendor List for IFUs/DFUs (with shortened website addresses)

Medtronic Driver (https://bit.ly/GBmqxF)
https://manuals.medtronic.com/wcm/groups/mdtcom_sg/@emanuals/@era/@cardio/documents/documents/m707281b001_cont_20071018.pdf

Medtronic Resolute Integrity  (https://bit.ly/GBulwc)
https://manuals.medtronic.com/wcm/groups/mdtcom_sg/@emanuals/@era/@cardio/documents/documents/contrib_109182.pdf

Cordis Firestar/Durastar  (https://bit.ly/GDkKGX )
https://www.cordis.com/products/dura-star-ptca-dilatation-catheters/epi

Boston Scientific Promus Element  (https://bit.ly/GAXNnx)
https://www.bostonscientific.com/Device.bsci?page=ResourceDetail&navRelId=1000.1003&method=DevDetailHCP&id=10154661&resource_type_category_id=1&resource_type_id=82&pageDisclaimer=Disclaimer.ProductPage

Boston Scientific Apex  (https://bit.ly/GBmUnn)
https://www.bostonscientific-international.com/Device.bsci?page=ResourceDetail&navRelId=1000.1003&method=DevDetailHCP&id=10132711&resource_type_category_id=1&resource_type_id=91&pageDisclaimer=Disclaimer.ReservedForMedProfs

Abbott Xience Prime  (https://bit.ly/GBqAb4)
https://www.abbottvascular.com/static/cms_workspace/pdf/ifu/coronary_intervention/XIENCE_PRIME_Everolimus_Eluting_Coronary_Stent_System.pdf

Abbott Voyager  (https://bit.ly/GDl0FM)
https://www.abbottvascular.com/static/cms_workspace/pdf/ifu/coronary_intervention/PPL2052911_Rev_E_Voyager_NC.pdf