Percutaneous Central Lines

Traditional central lines are placed with use of the Seldinger technique, which is described in detail later in this chapter. The subclavian vein, internal jugular vein, or femoral vein is cannulated percutaneously, and the catheter is placed with use of guide-wire assistance. There is a very short distance between the skin and the catheter’s entry point into the vein. Theoretically, this proximity to skin flora increases the risk of subsequent central line infection.

These central lines are in common use throughout most hospitals for patients with cancer, critically ill patients, or any patients who require infusions that are poorly tolerated via peripheral intravenous access. Such central lines provide excellent short-term access to the central venous system. In general, percutaneous central lines are considered only for short-term use, and after the first 7 to 10 days, percutaneous central lines have a markedly higher incidence of infection despite optimal skin entrance site dressing techniques. Obviously, prolonged patient neutropenia and episodes of bacteremia could result in shorter life spans of such catheters.

Patients with cancer who require a relatively short course of an infusion or need a bridge to placement of a more long-term catheter could benefit from these traditional central venous catheters. Meticulous sterile dressing changes are an absolute necessity for outpatients who need short-term therapy via these lines. Patients without the resources or dexterity to care for percutaneous central lines are at a prohibitively increased risk of line infection, bacteremia, or a thrombotic event and should be provided with a long-term form of central access. Certain comorbid conditions (e.g., burns, open wounds near the line site, or a tracheostomy) preclude placement of this type of vascular access.

Surgically Tunneled Central Lines

Most patients with cancer need a long-term form of central venous access rather than a traditional short-term central line. Surgically tunneled central lines were developed to increase the distance between the skin entrance site and the puncture of the vein. The hypothesis was that by increasing this distance, the life span of the central access would be increased by decreasing the incidence of infection and thrombosis. Tunneled central lines are commonly referred to by the name of the first brand that was marketed—Hickman. Other examples include Broviac, Quinton, and Groshong (Fig. 26-1). These polymeric silicone rubber venous access catheters are placed via a subcutaneous tunnel that is described in detail later in this chapter. Clinical studies have supported the hypothesis that increasing the distance between the catheter exit site in the skin and the hole in the vein decreases the incidence of externally derived infection.^1,2 Studies suggest that the incidence of bloodstream infections associated with tunneled catheters is approximately 1 to 2 per 1000 catheter days.³ The frequency of bacteremia among nontunneled catheters has been reported at between 1.0 and 13.0 per 1000 catheter days.^6–6

A Dacron cuff located 3 to 4 cm from the exit site encourages scar formation to fix the catheter in place. This exaggerated scarring eliminates the need for long-term sutures to hold the catheter in place to the skin. Avoiding these fixation sutures can decrease the incidence of stitch reactivity and associated localized skin infections. One drawback of this type of central access device is the inconvenience of placing and removing the lines. In most instances, surgeons or interventional radiologists insert these lines under local anesthetic and intravenous sedation. Therefore these procedures require coordination of the patient, the surgeon or interventional radiologist, and possibly the anesthesia/operating room staff. Tunneled catheters are more uncomfortable to remove than are nontunneled lines because of the Dacron cuff scar reaction. Removal requires local anesthesia but can be accomplished outside of the operating room.

Surgically Implanted Infusion Ports

Implantable ports consist of a small injection reservoir with a self-sealing membrane placed entirely beneath the skin. There is no external catheter. An internal catheter runs from the reservoir into the subclavian or internal jugular vein to provide central access. The internal catheter is essentially identical to those used for tunneled central lines. A noncoring (Huber) needle can pass directly through the skin into the reservoir for infusion or aspiration. The self-sealing rubber cap on the reservoir prevents leakage from the reservoir after withdrawal of the Huber needle. The gauge of the noncoring needle—not the catheter—typically limits flow through the port system (Fig. 26-2). The ports can also be used for continuous drug infusion, as shown in Figure 26-3.

The theoretical concern that bacteria more easily traverse the short distance between the skin and the “neo-vein” or reservoir and cause increased rates of infection does not prove true.⁷ Sterile technique and site care lead to an infection risk comparable with that of tunneled catheters. With adequate care, the rate of infection could be fourfold to fivefold less than that for tunneled catheters.³ The low rate of infection and extravasation make infusion ports ideally suited for patients with cancer who need long-term single-lumen access and a low-maintenance catheter. However, experience has shown that patients with prolonged periods of neutropenia or significant risk of cutaneous eruptions might not be good candidates for port devices. The visible lump of the port could bother extremely thin patients; however, the port on the anterior chest wall is easily hidden from plain view for most people.

Long-Line Central Access

Also known as a peripherally inserted central catheter (PICC line), the long-line central access vascular access device is becoming increasingly popular. The catheter is inserted into a brachial, cephalic, or antecubital vein and advanced into the subclavian vein or higher. These lines can be placed simply and easily in the outpatient office setting and are well tolerated by patients, with minimal risk. However, many patients with cancer have poor-quality arm veins after undergoing multiple peripheral infusions and are therefore poor candidates for this technique. The 50% risk of catheter-related thrombosis is the greatest drawback to more widespread use of PICC lines in patients with cancer. This problem is a result of the presence of a long length of catheter within the vein and to the catheter tip in the relatively low-flow subclavian vein. Advancing the catheter tip into the SVC can reduce the incidence of thrombosis by more than half.⁸ Accurate placement of the catheter tip in the SVC can be complicated by the large displacement of the catheter tip (up to 8 cm) with normal arm range of motion.⁹

Choosing Insertion Location

Vascular access devices can be placed with use of a number of different access points, including the internal jugular, subclavian, external jugular, and femoral veins. The vast majority of catheters that are used for long-term vascular access in patients with cancer are placed in the internal jugular and subclavian veins. We will limit this discussion to these most common access sites.

The most frequent site for insertion of vascular access devices in the oncology population is the subclavian vein. Clavicular fracture or a previous median sternotomy can alter the anatomy of this location. For a patient with such a history, an alternative site should be considered. Even for patients with standard venous anatomy, the acute angle at the confluence of the subclavian and internal jugular veins at the brachiocephalic vein can complicate the passing of the guide wire into the SVC. A higher incidence of pneumothorax, hemothorax, and catheter malposition occurs among inexperienced operators, and a higher incidence of vein stenosis occurs with subclavian vein placement than with internal jugular placement.¹⁰ A subclavian artery puncture during line placement can be difficult to control because of the position of the artery posterior to the clavicle. A catheter placed on the anterior chest wall is more comfortable and easier to cover with clothing, however, than is a line in the neck.

In many ways, the internal jugular vein is the ideal location with regard to ease of placement of a central catheter. The path of the guide wire during placement is straight, thereby limiting many guide-wire complications and catheter malposition. In the event of carotid artery puncture, arterial bleeding can be controlled safely with the application of direct pressure. This advantage is especially important in the patients with thrombocytopenia. The incidence of central venous occlusion is decreased, which could be important for patients who are likely to need an arteriovenous fistula for hemodialysis in the future. Unfortunately, patients often report pain with neck and shoulder movements after placement of an internal jugular catheter.

Preparing to Place the Vascular Access Device

Adequate preparation for placing a central venous catheter in a patient with cancer includes several steps before the actual line insertion. The surgeon must make several decisions that can limit the incidence of both immediate and delayed complications and ensure optimal line function.

Studies suggest that providing a single dose of prophylactic antibiotic to cover common skin flora before inserting the vascular access device reduces central line infection. However, it is difficult to determine how this small benefit affects antibiotic resistance and subsequent infections. Use of central venous catheters impregnated with antibiotics could be more effective in dealing with infectious complications and will be discussed later in this chapter.¹¹

A sterile surgical field with mask, gown, cap, gloves, and a large sterile drape should be used to minimize the risk of line infection.¹² The skin of the entire anterior neck and chest should be prepared with chlorhexidine, which is superior to povidone-iodine or alcohol in limiting line infections.^13,14

The choice to use ultrasound guidance to identify the vein during cannulation should be addressed before beginning the procedure. Less-experienced operators will likely benefit from the use of ultrasound guidance as an adjunct to the anatomic landmarks technique.15,16 Ultrasound can decrease the incidence of arterial puncture and placement failure. Although a few reports exist in the literature regarding the advantage of these techniques, such superiority is often judged when compared with high rates of complications using the landmark approach as the control group.

The operator must also decide where to position the catheter tip within the central vein. Catheters positioned with the tip in the right atrium will function longer as a source for aspirating blood samples than will those with the tip positioned in the SVC.17,18 A case review of thrombosed catheters documents that the position of the tip of the catheter at the time of thrombosis seems to be the most important contributing factor.^19,20 The closer the catheter tip is to the right atrium, the lower is the frequency of thrombosis and infection. The risk of a catheter tip in the right atrial position is primarily that of cardiac arrhythmias when the tip is near the tricuspid valve. An additional risk of right atrial catheter placement is right atrial thrombus or right atrial erosion.²⁰ These risks have led the U.S. Food and Drug Administration to publicly warn operators to avoid placement of the catheter tip within the right atrium. Instead, the catheter tip should sit at the junction of the SVC and the right atrium.

Insertion Technique

After informed consent is obtained, a rolled towel is placed directly under the vertebral column at the shoulders to extend the clavicles. A peripheral line is established, and the patient is connected to an electrocardiogram monitor and a pulse oximeter. Intravenous sedation is typically established by using small doses of benzodiazepines. The fluoroscopy operating table and the patient are placed in the Trendelenburg position. The skin of the neck and the entire upper anterior thorax is prepared, and sterile drapes are positioned. The skin and deep tissues are anesthetized with 1% lidocaine using a 25-gauge needle for the skin followed by a 22-gauge needle for the anticipated insertion tract (Fig. 26-4, A).

For subclavian vein puncture, the site of skin puncture is usually 1 cm below the angle of the lateral third of the clavicle. The long insertion needle, as depicted in Figure 26-4, A, is slowly inserted below the clavicle, aiming for a point approximately one fingerbreadth above the sternal notch. During insertion, a small amount of negative pressure is maintained on the syringe. With experience, the physician develops a feel for the actual puncture of the vein, and when this occurs, the syringe fills easily with venous blood.

As the position of the needle is being carefully maintained, the syringe is removed, and the guide wire is inserted (Fig. 26-4, B). If the patient experiences discomfort in the neck, the guide wire is partially withdrawn. Turning the patient’s head away from the site of insertion and exerting a gentle downward pull on the ipsilateral arm may facilitate entrance of the catheter or guide wire into the SVC. Minimizing extreme or sudden neck and arm movements can limit the risk of injury to the punctured vein. Cardiac ectopy indicates that the guide wire has entered the right atrium, and the wire should be withdrawn slightly.

Fluoroscopy may be used to pass the wire when difficulty is experienced. The correct position of the catheter is confirmed by fluoroscopy or a chest radiograph before the catheter is secured with a 3-0 nylon suture at the skin exit site. The tip of the catheter is positioned 1 cm above the SVC–atrial junction when the patient is in the Trendelenburg position. A chest radiograph is obtained to document the absence of pneumothorax and accurate placement of the catheter within the SVC.

When it is necessary to use the veins in the neck, the right internal jugular vein provides more direct access to the SVC and right atrium. In this case, the patient’s head is turned to the opposite side. The insertion site is located just lateral to the carotid artery and approximately two fingerbreadths above the head of the clavicle. Another useful landmark for the insertion site is the angle formed by the sternal and clavicular heads of the sternocleidomastoid muscle (Fig. 26-5).

Placement of a permanent Silastic catheter, such as a Hickman catheter, is depicted in Figure 26-6. Placement of the introducing needle and guide wire is as described in previous figures except that a 1-cm incision is made before insertion of the introduction needle. A prophylactic antibiotic is administered before the procedure. It is often beneficial to provide the patient with intravenous sedation.

A second 1-cm incision is placed lower on the anterior chest, usually at the level of the fourth or fifth interspace. The skin and subcutaneous tissues are first anesthetized with 1% lidocaine. The projected course of the tunneled catheter is also infiltrated with lidocaine. A tunneler is passed from the lower incision to the upper incision, where the guide wire is exiting. A heavy suture is tied to the end of the tunneler and brought down through the tract. The suture is tied to the end of the catheter and used to pull the catheter up through the tract, securing the cuff 3 to 4 cm from the skin exit site. The catheter is trimmed to the correct length that will position it about 1 cm above the SVC-right atrium junction with the patient in Trendelenburg position. This location is approximately four fingerbreadths below the sternal notch.

Care is taken to cut the catheter squarely and smoothly. An introducer and a tear-away sheath are passed over the guide wire into the vein (Fig. 26-7). A slight rotary motion facilitates the introduction of the sheath and avoids crimping. To avoid developing a false passage, the guide wire should be withdrawn occasionally as the introducer is inserted. The guide wire is then removed, and a syringe is attached to the introducer to confirm that blood can be aspirated. The introducer is removed, and the thumb is used to control bleeding or air intake through the sheath. It is important to have the catheter tip poised to be inserted as the introducer is removed. The passage of the catheter could meet minimal resistance as it is passed between the clavicle and first rib.

Fluoroscopy or a chest radiograph is obtained to confirm correct positioning and the absence of pneumothorax. The catheter is aspirated and flushed to confirm function. Care should be taken to avoid any angulations of the catheter through the subcutaneous tract, especially at the bend toward the subclavian vein. The incision below the clavicle is closed with a subcutaneous absorbable suture. The catheter is secured at the exit site with a 3-0 nylon suture, which is maintained for approximately 3 weeks to allow the fibrous tissue ingrowth into the subcutaneous cuff. The exit site is covered with a sterile gauze dressing.

Similar techniques apply to the use of neck veins. The catheter is tunneled over the clavicle, with the exit site the same as for subclavian vein placement. When other sites are required (e.g., the femoral vein with the catheter tip in the inferior vena cava), direct cut-down exposure of the saphenous vein or another large femoral branch is preferred.

Figure 26-8 illustrates the placement of an implanted injection port. A 1-cm incision is placed below the clavicle at the site planned for subclavian venipuncture. A second, 3-cm incision is placed lower on the chest in a position that provides a relatively flat surface and stability for the port chamber. Local anesthesia is provided via 1% lidocaine with 1:200,000 epinephrine. A subcutaneous pocket just large enough to accommodate the port is dissected inferior to the incision. Ideally, the level of this pocket is over the underlying pectoral fascia. The skin coverage needs to be thick, but the port must be percutaneously accessible. A tunneler is passed subcutaneously from the pocket through the infraclavicular incision. A suture is tied to the tunneler and brought down through the tract. The suture is tied to the end of the port catheter and used to pull the catheter through the tract to the intraclavicular incision. Care should be taken to position with a gentle curve and to avoid catheter angulation. The port is secured in the pocket with three sutures of 0 Prolene. It is necessary to anchor the port adequately to prevent flipping or rotation of the device.

The guide wire is inserted as described, and the dilator and sheath are passed over it. The catheter is cut to the desired length. The dilator and guide wire are removed, and the catheter is inserted through the sheath as described. The incision for the port pocket is closed with interrupted 3-0 absorbable sutures placed in the subcutaneous layer. The skin is approximated with a running subarticular 4-0 absorbable suture. A transparent nonpermeable dressing is used at the port incision.

Open insertion methods are quite safe in a skilled surgeon’s hands. The major complication of the open technique is the possibility of air embolus during the actual catheter insertion. This complication is most likely to occur in patients who are hypovolemic, cachectic, or unable to tolerate positioning in the Trendelenburg position. An air embolus happens most frequently when the internal jugular vein is used; however, extreme care with use of the purse-string suture around the insertion site and venous occlusion with vascular clamps should limit the possibility of the introduction of air into the vascular system. With open direct surgical placement—although it takes considerably longer than the closed Seldinger technique—complications should be much lower than 5%.²¹ The open method results in a complication rate of less than 1%. Although the open method is a safer technique, it requires more training, more experienced operative personnel, and larger incisions. The open method should be used with any patient who has had repeated problems with closed insertions because the open method is the most controlled and safest format for that patient. Sometimes previous operations or radiation therapy in the region of the cardinal veins makes the open operative approach more difficult, but generally such problems are limited.

Published complication rates for pneumothorax after jugular vein central line placement are approximately 0.5%, and they are up to four times higher for subclavian vein procedures.9,23,24,28 The risk of this technical complication can be reduced dramatically among experienced operators or among physicians who have experienced supervisors.²²

Infectious complications are the most common complications of long-term vascular access devices in the oncology patient population. Two factors make the interpretation of this relatively well-studied topic challenging. First, many of the large randomized controlled trials that have studied central line infections have concentrated on patients in the ICU. The ICU population has different risk factors and susceptibilities from those of the outpatient population of people with cancer. Nevertheless, by carefully reviewing the available data, we can make some conclusions regarding the pathogenesis, prevention, and treatment of line-related infections among patients with cancer. In studies of patients in the ICU with central lines, factors that predispose to line infection have included malignancy, neutropenia, extended duration of indwelling time, and coincident parenteral nutrition. All of these factors can contribute to the incidence of infection among patients with vascular access for oncologic treatment.³⁰

Second, the confusing terminology regarding line-related infections can make the literature on this topic difficult to interpret. Local infection is a positive culture at the catheter insertion site. Catheter colonization or infection is the positive culture of a segment of removed catheter. Catheter-associated bacteremia is evidenced by a positive blood culture from a site other than the catheter and the positive culture of a segment of removed catheter with the same pathogen.

Understanding the pathophysiology of catheter-associated bacteremia can help limit the incidence of this complication. Up to 50% of catheter-associated bacteremia is caused by coagulase-negative staphylococcus. This common skin flora can colonize the catheter during insertion or later. A thrombus that forms at or along the catheter tip can become a nidus for bacterial proliferation, with resultant bacteremia. Thrombosis significantly increases the risks of colonization and infection.²³ Bacteria can also be introduced into the bloodstream by hub contamination, by hematogenous seeding from another focus of infection, and, rarely, by the infusate itself.

Factors increasing the risk of catheter infection include prolonged indwelling time, multiple-lumen catheters, femoral vein location, difficult catheter placement, and non–catheter-related bacteremia.30,31 As was mentioned previously, nontunneled catheters are at increased risk of catheter infection compared with tunneled catheters, and totally implantable devices are even less susceptible than are tunneled catheters.³²

Multiple-lumen catheters have demonstrated higher infection rates than single-lumen catheters. The addition of each lumen exponentially increases the incidence of infection.33,34 There are two possible explanations for this observation. First, the increased internal lumen diameter of the line is associated with a higher thrombosis rate and accumulation of loose thrombus at the catheter tip. Thrombosis causes more breaking of the line and more line manipulation when declotting is attempted, leading to subsequent infection. Second, the multiple ports invite multiple interruptions of the line for access and result in a greater likelihood of the introduction of bacteria. Despite their greater risk of iatrogenic infection, multiple-lumen catheters have great appeal for patients who need multiple simultaneous infusions of incompatible drugs. Very strict nursing guidelines must be followed in the management of multiple-lumen catheters to prevent iatrogenic infections and thrombosis.³⁵

Diagnosis and management of catheter-related infection differ between nontunneled and tunneled catheters. However, some diagnostic principles apply to both tunneled and nontunneled catheters. Routine surveillance blood cultures should not be performed. When a catheter-related infection is suspected because of fever, chills, or purulence around the catheter site, percutaneous and catheter blood samples should be submitted for culture.36,37 Qualitative culture with continuously monitored differential time to positivity compares the time to positivity for catheter blood cultures with percutaneous peripheral blood cultures. This technique has demonstrated excellent specificity and sensitivity for detecting catheter-related infection in tunneled catheters.³⁸

In most patients with nontunneled central venous catheters, the line should be removed if the patient demonstrates signs of site infection or sepsis or if blood culture results from the catheter and percutaneous blood samples are positive.³⁸ Seven to 10 days of narrow-spectrum antibiotic therapy is generally recommended. In selected cases of clinically stable patients with a single episode of coagulase-negative staphylococcus, a trial of antibiotic therapy might salvage the catheter.³⁴ For any patient with persistent bacteremia despite antibiotic therapy and removal of the infected catheter, a thorough investigation of possible septic sources, such as endocarditis or septic thrombus, is warranted.

Tunneled catheters or infusion ports should be removed in cases of sepsis, complicated infections, tunnel tract infections, or port abscesses.³⁹ A thorough evaluation confirming the surgically implanted catheter as the source of infection should precede the removal of any of these vascular access devices. In the absence of complicated infection, catheter salvage could be indicated. Antibiotic lock therapy is a reasonable approach for attempting to salvage lines with common coagulase-negative staphylococcus, Staphylococcus aureus, or gram-negative bacilli intraluminal infections. This therapy consists of instilling the catheter lumen with high concentrations of antibiotics and leaving them there for several days.⁴⁰ If salvage therapy fails, the infected catheter should be removed. A new tunneled catheter can be placed after treatment with an appropriate course of antimicrobial therapy until blood cultures are negative.