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|Newsletters: The Challenges of Venous Access|
The Challenges of Venous Access
James Andrews, MD
This article is based on a presentation Dr. Andrews gave at Oley’s 2011 Annual Consumer/Clinician Conference. Dr. Andrews is an interventional radiologist at the Mayo Clinic, Rochester, Minnesota. The complete presentation is available on the conference DVDs, which you can borrow at no cost. Click here for details on borrowing Oley DVDs in the Online Store.
Venous access is a big part of my practice. If you go back to 1990, the interventional radiologist’s main role in venous access was evaluating malfunctioning devices and sorting out venous anatomy. Now, in 2011, we are one of the primary providers of venous access services. We place central venous access devices in a large fraction of patients in a large number of institutions.
You’ve been told it’s time to start home parenteral nutrition (HPN) and you need a central venous catheter, or a central venous access device.
A central venous access device is a catheter that enters the body from a variety of sources, with the tip generally placed at the junction of the superior vena cava and the heart. It can be placed from the jugular vein, a subclavian vein, an arm vein, or elsewhere. What types of devices are available? There are peripherally inserted central catheters (PICC lines); tunneled central venous catheters (Broviac® or Hickman®, for example); or implanted ports (Port-A-Cath® or many other brands).
PICC lines are placed from a vein in the arm. They are small catheters with one to three lumens. The best uses for PICC lines in my mind are either the short-term PN patient or as a bridge for someone who has an infection in a tunneled catheter and has to have the line out. We put in a PICC line, they get their antibiotics and their HPN, and when the infection is cleared up, we put a tunneled catheter back in.
I realize there are people who have had a PICC line for several years. These are deviations from the mean. If the PICC is working for them, there’s no need to change it. But the likelihood of a PICC line lasting very long is not great. For a new HPN consumer, I would not recommend a PICC.
One thing to remember about PICC lines is that they are not benign. We tend to think they’re safe little catheters and they don’t cause any problems. That’s unfortunately not true. I’ve seen several patients with PICC lines with asymptomatic subclavian vein occlusions. We only identify these occlusions when trying to place new catheters and we don’t know what the incidence of this is. I’m not telling you PICC lines are bad, but they aren’t without their complications.
Tunneled Cuffed Catheters
Probably the most common device for people getting long-term HPN is the tunneled cuffed catheter. These are catheters with one to three lumens, which have a Dacron cuff on the shaft. I use the jugular vein to place these catheters. They exit the body some distance from the venous puncture, at a site hopefully convenient for the patients.
The Dacron cuff is buried within the subcutaneous track. The body scars around the cuff, which keeps the catheter from inadvertently coming out and theoretically decreases the rate of infection along the track. I think for most people this is probably the best option.
The other option we have is an implanted port. In general, these devices are intended for long-term intermittent use. They were first developed for cancer patients. They consist of either a metal or plastic body with a rubber stopper in the top and a little chamber at the bottom that’s connected to the catheter. You access them with a special needle called a Huber needle. It goes through the skin, through that stopper, into the little reservoir under the stopper, and connects to the catheter. The catheter runs into the central venous system.
These are great because they are completely underneath the skin. They are better for body image, and better for people who want to swim or be more active. The down side is you have to stick them each time for use. Also, if an infection occurs with a port, it is a bigger problem to resolve than it is with a tunneled cuffed catheter.
Catheter Tip Position
Regardless of which device is used, the catheter tip should always end up at the junction of the superior vena cava and the right atrium. There is extensive evidence in the medical literature that this location results in the best long-term function, with the fewest complications. All central venous catheters belong there and nowhere else. That’s the number one basic principle: good tip position equals good long-term function.
The corollary is poor tip position equals poor long-term function and complications. One of the significant outcomes of this is often the loss of an access site. Preservation of access sites is my number one priority. You only have so many of them. Access sites are like gold, and I believe very strongly in preserving each and every one of them.
The Exit Site
Once you and your health care provider decide on the device, the most important question is, where’s the catheter going to come out? Here’s where you can be an advocate for yourself. You have to be involved in choosing the exit site for the tunneled catheter or where the port’s going to go.
This should be done before you go into the procedure room, preferably while you’re sitting up so you can see where things are going to lie when you’re in your upright position. You’ve got to live with this catheter. It is your lifeline. How it affects your self-image is important, so putting the catheter where you want it, within reason, is important.
A lot of surgeons and radiologists like to put catheters in with a short tunnel and no curves—it’s really easy. But the catheter comes out in the patient’s armpit. For most people, it is more reasonable if we put a big wide curve on it, and have it exit down on the chest somewhere.
Try and explain what you want. Hopefully they can give you what you want and help you with what you’re going through with your therapy. I once put a port down in a patient’s abdomen, over the lower ribs for support. I tunneled it underneath her breast, all the way up to the jugular vein puncture site. She was delighted. She was almost in tears because somebody would listen to make her feel better. Be an advocate for yourself.
What happens when you come to get your device placed? First you’ll go to the recovery room. Remember, the night before the procedure you can’t have anything to eat or drink after midnight (which I realize may not be an issue for some of you). This is because we like to give everyone some conscious sedation, which will make you sleepy, more comfortable.
In the recovery room, a nurse will start your IV, do a brief review of your history, and make sure you’re medically well enough to get your line. Hopefully, you’ll get your exit site marked here. If not, make sure one of us comes to talk to you.
Then you’ll come back to the procedure room. It isn’t an operating room (OR); it is an interventional radiology suite. We’ll do a good sterile prep, just like in the OR. The suite will have a fluoroscopy unit and ultrasound, and anesthesia available if you need it. The fluoroscopy allows us real-time imaging of where we’re putting the catheter, and all of our venous punctures are now under ultrasound guidance. The ultrasound makes it more effective and safer at the same time.
You’ll be monitored by a nurse and you’ll get conscious sedation if you need it. I’ve had patients who didn’t want any sedation. That’s fine, too. We use lots of local anesthetic; no amount of conscious sedation makes up for inadequate local. Without local anesthetic, you’ve got to put people to sleep, and that’s not necessary for this procedure.
When we’re done, we take a chest x-ray in the room so we know everything is ready to go. The line should be ready for use. Then you go back to the recovery room to recover from the sedation. Our nurses take care of discharge teaching—how to take care of the dressings and such. (If you’ve had conscious sedation, you need to have someone give you a ride home.)
What are the problems you can develop from a central line? I’m not going to talk about infection. There are people far more expert than I am to address this. But there are also other issues: venous thrombosis; venous occlusions; catheters can get broken or dislodged; catheters can become malpositioned. The most serious result from most of these complications (coming at it from my very narrow plumbing point of view) is the potential loss of that access site. What I mean by an access site is a vein that can be accessed with a needle to allow placement of the venous access device. I will do anything I can to try and maintain an access site. You only have so many of them.
What can we do as we’re running out of access sites? We can try to recannulize the occluded veins (using stents and techniques developed for arterial disease); we can use alternative access sites, such as translumbar access to the inferior vena cava, femoral lines, or transhepatic lines (going through the liver into the hepatic veins and the cava); or we can stick some of the collateral veins and put lines in through a very tortuous and alternative pathway.
A stent is like a cylindrical window screen that holds the vein open. In most people, venous occlusions are asymptomatic; there’s no arm swelling or head swelling, because they have good collateral veins that allow blood to drain around the occlusion. In that case, putting in a stent does no good. If someone comes in with blockage of the superior vena cava (SVC) and they have SVC syndrome—swelling of the head, neck, and arm—we’ll put in a stent to hold the vein open and reestablish blood flow. Then we can put a catheter through the stent. I reserve stents for patient with symptomatic occlusion.
In patients who have asymptomatic occlusions, we use an angioplasty balloon to open the vein enough to get the catheter through, and that’s all they need. I don’t think there’s any benefit to prophylactically putting in a stent because you get what’s called intimal hyperplasia, a scar, which grows on the inside of the stent.
Not everyone is a candidate for recannulizing an occluded segment, however. This is where we fall back on the translumbar catheter placement. We put the catheter directly into the inferior vena cava—the big vein running up the middle of the abdomen. We tunnel it to the right side, where the front of your abdomen meets your side. It sounds like a big deal when you’re sticking someone in the back, but these are really well tolerated under local anesthetic and conscious sedation.
It’s really critical to choose the exit site properly. It’s got to be above the belt line and it has to be far away from stomas. You don’t want your catheter hanging next to your stoma. It can lead to infection. Also, if the exit site is too far posterior, it will be hard to take care of. It’s really critical that the exit site is far enough to the front, but away from stomas.
We can put transfemoral lines in. You can also go transhepatic, through the liver into the hepatic veins. That’s sort of an act of desperation, but it gets you access.
I’ve even had to use collateral veins in the body wall as access sites when everything else is occluded. The path is long and tortuous, but it’s an option. Blood has to get back to the heart somehow, so one way or another, we can almost always get access if we’re creative enough.
Sometimes a catheter becomes malpositioned. We have a variety of techniques to fix this. Sometimes with PICC lines we can give a forceful injection of saline and it’ll flip down to the right position. Or we can manipulate PICC lines with guidewires.
For long-term devices, we actually need to go inside the vein and do something to pull the catheter into position. We can usually come in through the venous system, grab the catheter with a regular angiographic catheter, and pull it into place. This works great as long as the catheter was long enough in the first place that it’s going to be stable. I’ll only manipulate a catheter once. If it flips again, it’s probably because it’s too short. We see this is in kids. They have their devices put in, they grow, and the catheter’s not long enough anymore.
If your catheter breaks, can we do anything without giving up the access site? Yes. We can prep the site, slide the old catheter out over a wire (making sure the cuff is removed), slide a new one in, and suture it in place. This works best for old tracks that are nice and smooth. The key is it preserves the access site.
There have been some reports in the literature that even for infected catheters, it’s not guaranteed the patient will get a second infection if you go back in through the same track. It doesn’t feel good, I recognize, but in people with really limited access, it’s worth a try before you give up the access site.
Catheters break. You’ve probably all seen people with catheters that are fractured on the outside. Repair kits are available. For good long-term results you want a repair kit that’s intended for the catheter that you have in place. I’m going to keep saying the same thing: Don’t give up the access site. Try and fix it if you can.
The last thing that can go wrong is that the intravascular portion of the catheter can break. This is particularly true for subclavian catheters that are compressed underneath the clavicle, so called catheter pinch-off syndrome. This is one of the reasons we essentially never use the subclavian approach any longer.
If you do have a broken catheter, you should get it out as quickly as possible. We go in through the vein and grab it with a loop snare (like a cowboy’s lasso). As long as there’s a free end and we get to it quickly, we can usually get these out. If the catheter fragment is in the right side of the heart (the right atrium or the right ventricle), it can cause significant arrhythmias, so we want to get the catheter out as quickly as possible.
What I want you to take away from this is:
LifelineLetter, November/December 2011