Tunneled Central Venous Catheters

Indications

One of the keys to successful, safe, long-term central venous access is placement of the most appropriate device at the initiation of therapy. The ordering physician and the proceduralist should maintain an open dialogue regarding the goals and duration of therapy so the device can be individualized for the patient. A recent expert opinion consensus paper published in the Annals of Internal Medicine attempts to set guidelines for the appropriate use of CVCs. An international expert panel utilized the RAND/UCLA Appropriateness Method to develop criteria for the appropriate use of PICCs. In doing so, all common forms of venous access were included. The recommendations were based on literature review and expert opinion, and centered around rating clinical scenarios as appropriate, neutral, or contraindicated for placement of a PICC versus other central venous access devices. In addition, the criteria took into consideration real-world clinical situations such as patients with end-stage renal disease, critical illness, cancer, and general hospitalization. Collectively, they were called the “Michigan Appropriateness Guide for Intravenous Catheters (MAGIC).” The panel deemed use of cuffed tunneled catheters appropriate when infusion was needed for more than 30 days, unless the infusate could not be placed through a peripheral intravenous or midline catheter. In that case, there was no preference between a PICC or a cuffed tunneled line for more than 15 days. There is considerable overlap between use of PICCs, tunneled catheters, and ports, and there are considerations to be made when deciding on which device to place.

Generally, cuffed tunneled catheters are suited for intermediate-term (<6 months) to long-term (>6 months) use in patients who are not overly debilitated. Their design is ideal for patients who need frequent-to-continuous access and two to three lumens. The ability of the patient (or appropriate caregiver) to care for this device is extremely important and crucial for its long-term success. Cuffed tunneled catheters are ideal for patients receiving continuous therapy, including epoprostenol sodium, dobutamine, and magnesium. The ease of placement and exchange also allows site preservation in these patients, who will need access for many years. These catheters can remain in place long-term because of the nature of the tunnel. Tunneling under the skin allows the body’s natural defenses to ward off infection and prevents pathogen access to the venous entry site. The addition of a Dacron cuff or one made of other fiber promotes the ingrowth of fibroblasts and scar tissue, which secures the catheter. Some catheters are designed with an “antimicrobial” cuff (VitaCuff [Integra LifeSciences Corporation/Bard Access Systems, Salt Lake City, UT]) that is used in tandem (closer to the skin exit site) and intended as a temporary barrier until the Dacron cuff is secure.

Ultimately, the interventionalist should adopt a role of vascular “consultant” to help guide referring clinicians on the most appropriate device to use for each unique clinical scenario. Interventionalists should be familiar with the aforementioned MAGIC criteria, the Kidney Dialysis Outcome Quality Initiative (KDOQI), and guidelines published by the Infusion Nursing Society and Society of Interventional Radiology to help guide decision-making and to help educate our colleagues.

Contraindications

Although there are no absolute contraindications to placement of a tunneled CVC, most proceduralists avoid placement in patients with active infection or proven bacteremia. If central venous access is needed in these patients, a nontunneled temporary line can be placed. Generally, patients must be culture negative for 48 hours before considering placement of a tunneled line. Coagulopathy is a relative contraindication. A tunneled line is an elective procedure in most patients, so acute correction of coagulopathy is rarely needed. If necessary, replacement of platelets or administration of fresh frozen plasma can be performed. According to the Consensus Guidelines for Periprocedural Management of Coagulation Status and Hemostasis Risk in Percutaneous Image-Guided Interventions, placement of a cuffed tunneled central venous catheter is categorized as a procedure with a “Moderate Risk of Bleeding” and is therefore subject to the following recommended parameters: a total platelet count of greater than 50,000/mm ³ and an international normalized ratio of less than 1.5. If the patient is on a regimen of chronic anticoagulation, conversion to either standard or low-molecular-weight heparin is carried out before the procedure. The heparin is discontinued for the appropriate amount of time for each type (1–2 hours for standard heparin and 24 hours for low-molecular-weight heparin). Patients taking clopidogrel bisulfate should stop taking it 5 days before the procedure and can resume immediately afterward. It is not recommended to withhold aspirin before the procedure. Other relative contraindications are lack of a suitable vein for access and severe skin conditions that will not accommodate a tunnel (scleroderma, graft-versus-host disease, or Stevens-Johnson syndrome). Careful evaluation of the venous access needs must be weighed against the risk for infection or bleeding in such patients. Finally, allergy to the material the catheter is made of is rare but can result in replacement with a catheter made of different material.

Equipment

The history of CVCs dates back to 1733, when an English clergyman, Stephen Hales, inserted a glass tube into the jugular vein of a horse to measure pressure. The first prolonged use of catheters for central venous infusion was reported by B.J. Duffy in 1949, reporting on 72 catheters. The catheter we use most often today was created at the University of Washington by a team including Belding Scribner, John Broviac, and Robert Hickman in 1973. The basic design of the catheter has not changed, although new technologies have allowed different brands to distinguish themselves. Over the past years, valve technology was developed to reduce thrombosis and infection and eliminate the need for heparin packing. Recently, with the advent of faster computed tomography (CT) scanning, power injectability has been introduced.

Valves have been used on catheters dating back to the Groshong catheter (Bard Access Systems, Salt Lake City, Utah). The Groshong has slits in the sides of the catheter near the tip. The tip is closed with an atraumatic rounded end. The slits are closed except during infusion or aspiration. The company claims this results in lower infection and occlusion rates. Groshong catheters are flushed with heparin solution.

CT has become an irreplaceable technology for diagnosing all types of diseases. Newer protocols rely on rapid introduction of a bolus of contrast material for CT angiography and evaluation of tissue perfusion. Many patients with chronic disease undergo regularly scheduled CT scans to evaluate the effectiveness of treatment, and these same patients have some form of central venous access for that treatment. Rather than start a peripheral intravenous line each time the patient needs a CT scan, it would be desirable to use the patient’s existing access. This has been accomplished with newer power-injectable cuffed tunneled catheters. The use of polyurethane for the construction of the catheter has allowed larger inner lumens and faster flow rates. The POWERHICKMAN (Bard Access Systems [ Fig 84.1 ]) was the first such catheter. It is capable of injection rates up to 5 mL/s, which is clearly marked on the catheter’s hub. In addition, the catheter has a distinct purple color that has become a universal signal of power injectability, present on PICC lines and ports from Bard as well as other manufacturers. Although there are many studies that have safely shown the use of regular catheters for power injection, these were done off-label, and the readily available power injection–safe catheters today render this practice obsolete.

Technique