Uzer Khan and Hannah W. Hazard
Once the diagnosis of cancer has been made, the oncology patient will go through rigorous staging that results in the development of a plan of care for the newly diagnosed. Typically, blood tests are drawn to help facilitate the staging and treatment of the patient’s disease. Additionally, tests are done to document the patient’s clinical well-being and monitor the progress of their treatment. Added to this is the potential for a rigorous venous sampling schedule and the use of contrast agents during radiologic imaging studies done for staging purposes. Most of these studies can be instituted without establishment of a long-term venous access device. However, it is prudent to assess the need for central venous access early in treatment. Chemotherapy administration for the cancer patient may be delivered on a more prolonged schedule with the placement of a long-term, central venous access device (CVAD). Moreover, these devices have facilitated the implementation of increasingly complex treatment regimens at home.
The rationale for placing CVADs is derived from the caustic properties of chemotherapeutic agents and the consequences of repeated venipuncture on the peripheral veins. The innermost layer of a vein is known as the tunica intima. It is this layer that becomes damaged with the repeated trauma associated with peripheral venipuncture. This damaged endothelium results in exposure of the underlying thrombogenic layer and results in platelet aggregation and subsequent thrombosis. Implanted venous access devices are either tunneled through the periphery or bypass the periphery altogether and are directly implanted in the central venous system. In both circumstances, trauma to the peripheral veins is reduced. The instillation of potentially damaging substances is more tolerable in the central veins, which have a much larger volume of blood flow and thicker vein walls. Once the decision has been made that a patient will benefit from a CVAD, various issues are brought into consideration. Factors to consider include specific patient characteristics and preferences, the patient’s history and associated comorbidities, and the specific infusion needs. The various options for venous access can then be considered in a cooperative fashion.
The initial interaction with the patient should be used to evaluate the level of care they will be capable of providing for whichever vascular device is ultimately selected. Moreover, lifestyle and habits should be taken into account during the selection process. Patients may prefer to have devices placed on their nondominant side to facilitate care. Devices implanted in the chest may be positioned low to assist in hiding them under garments and to provide for easy visualization without the need of a mirror. Consideration should be given in females to the position of bra straps and modifying placement accordingly. Occupational and recreational activities should be assessed and device selection and positioning modified accordingly.
A history of previous venous device placement must be assessed as this could modify the preferred site of device insertion. Moreover, any surgical interventions or currently placed devices such as AICDs and pacemakers should be noted. The presence of inferior vena cava (IVC) filter devices should also be noted as this may require the use of an alternate type of access wire (i.e., straight wires instead of J-curved wires). Patient allergies need to be documented as well and the device and surgical equipment modified accordingly. The physical examination is also a key part of the preoperative patient assessment. The skin at the insertion and final placement sites should be assessed for adequacy. Moreover, evidence of dilated superficial veins may herald an undisclosed central venous stenosis that may complicate catheter placement.
The ultimate type of infusion needed will dictate the type of access device used. Patients in need of chronic and continuous infusion may best benefit from tunneled devices, whereas subcutaneous ports are ideal devices in situations where they are only accessed intermittently.2 The type of infusates used and their relative compatibilities may also be a consideration in deciding the number of lumens that may be needed in a particular device.
INDICATIONS
Indications for venous access placement in the oncology patient are guided by complex factors that evolve during the transition from diagnosis to treatment and finally into remission. Consideration is given to the composition of the infusates being administered, the frequency of treatment (monthly, weekly, and daily), the size or number of lumens required, the patient’s ability to provide self-care of the device, the patient’s preference (which may be influenced by vanity, an appropriate consideration in the decision-making process), and the cost of the catheter. Additional factors to take into consideration are the potential for daily maintenance needs such as flushes and dressing changes that may not be covered by insurance. A bone marrow transplant patient, for example, may require a large-bore multichannel catheter for stem cell collection initially, but will also need a long-term catheter for the remainder of the transplant process.
CONTRAINDICATIONS
The placement of various CVADs has been associated with very few contraindications. Patients with uncontrolled coagulopathy are at risk for developing hematomas at sites of dissection and around catheter insertion sites. These patients’ coagulopathy should first be corrected before CVADs requiring more dissection are placed, such as subcutaneous ports. A bloodstream infection, as demonstrated by positive blood cultures, is also a contraindication for chronic CVADs due to the high chance that these catheters will become colonized and require subsequent removal. The CVAD may be placed once the infection has been adequately treated and negative blood cultures are documented.
Certain CVADs that require the positioning of a subcutaneous device over the chest may not be appropriate options in situations of trauma, burns, or certain types of tumor. Moreover, certain patients, such as those with cystic fibrosis, may require constant chest percussive therapy making a secondary site of placement a more viable option. These sites include the upper arm or a part of the abdomen.
INFUSION DEVICES
Venous access devices can be categorized into five groups based on the mechanism of insertion and catheter dwell. These categories include peripheral angiocatheters, peripherally inserted central catheters (PICCs), percutaneous, nontunneled central catheters, tunneled central catheters, and implanted ports. Each category is then further defined by device-specific characteristics such as flow rates, lumen size, catheter tip location, and dwell time. In utilizing this process, it is easier to identify which catheter meets the specific needs of the patient (Table 41.1).
Peripheral Angiocatheter
The simplest access utilized in patients is the standard peripheral intravenous angiocatheter (PIV). The angiocatheters are relatively easy to insert and remove. Specialized training or certification is not required for standard insertions and most practitioners are qualified to place a PIV. These catheters come in a variety of gauges and lengths to accommodate patients with small vasculature as well as large-bore peripheral catheters preferred for rapid infusion of large volumes such as venous contrast or blood products. Intermittent nonvesicant chemotherapy can be administered via peripheral access. However, reliability of obtaining access during each treatment session may be unpredictable and if unsuccessful, may delay treatment. Therapeutic agents with extremes of pH (normal pH = 7.35 to 7.45) or osmolarity (normal 280 to 295 mOsm/L) should not be administered through peripheral access as the concentration of material infused can lead to patient discomfort, infiltration, clotting, and infection.3 One exception is parenteral nutrition in which dextrose contents are under 10% and the osmolarities >500 mOsm/L (INS). In this case, it is considered safe to administer this therapy peripherally. Limitations of PIV catheters include short dwell time (1 to 3 days), high thrombophlebitis rates, thrombosis and shear of the vessel, infiltration into the surrounding tissue, cellulitis, and pain with infusions. As a result of these limitations, PIVs are reserved primarily for hospital/clinic use and management by health-care professionals.
Midline Catheters
One subclass of peripheral angiocatheters is the midline catheter. Midline catheters are PICCs. They are usually inserted into the antecubital fossa or into the brachial veins with the guidance of a handheld ultrasound device. The catheter is then advanced 8″ to 10″, just proximal to the axillary line. In this position, the catheter is not considered central and should be treated as a peripheral angiocatheter with regard to infusates. However, since the catheter tip is in a larger vessel with increased blood flow, the risk of phlebitis and infiltration is decreased as compared to peripheral angiocatheters. Typical dwell time for midline catheters is 1 to 2 weeks with careful monitoring for complications.3 In addition to extended dwell time, the midline catheter, unlike the PICC, does not need radiographic verification for tip placement, since it is not advanced centrally. This benefit yields less costly insertion fees and simplification of insertion-related malpositioning. Phlebitis and thrombosis are also less likely to occur when compared to central venous lines. Midlines are particularly beneficial in patients who would otherwise require serial placements and replacements of short PIVs and do not need the long-term access or central venous dwell of a PICC line. Midline catheters can also be used in the setting of a relative contraindication to PICC access such as in patients with end-stage renal disease where the central veins should be accessed as minimally as possible.
Midline catheters do have limitations. First, their tips do not reside centrally so infusates are limited to those that are safe for PIVs. Since the axillary vein lies deep in the axillary region, it may be difficult to identify early phlebitis, infiltration, or infection. Frequently, a blood return is not achieved for confirmation of vascular patency or specimen collection. The short intravenous catheter length compared to the external component yields increased risk of dislodgement. Midline catheters require daily flushing to maintain patency and dressing changes at least weekly, which may require home health services. Moreover, catheter-related bloodstream infection rates are similar to those of PICCs.
Peripherally Inserted Central Catheter
The peripherally inserted central venous catheter (CVC) was first described in 1975 by Hoshal in a case series in which he described using a 61 cm silicone catheter that was threaded to the superior vena cava (SVC) through the basilic or cephalic veins. The series demonstrated successful application of the concept in the implementation of total parenteral nutrition with 30 of 36 catheters lasting the entire duration of treatment (up to 56 days).
A PICC is a long, flexible catheter that is inserted into a peripheral vein and advanced into the central circulation. It is typically placed in a vein of the upper arm, although it can also be introduced in the internal or external jugular veins, the long or short saphenous veins, the temporal vein, or the posterior auricular veins. The saphenous vein, temporal vein, and posterior auricular veins are usually reserved for pediatric patients. Once the vein is cannulated, the catheter is digitally advanced until its distal tip resides in the SVC or the IVC. There is minimal risk to chest organs as compared to catheters placed directly in the central venous system. The tip location of the PICC is desired in the lower third of the SVC, preferably at the junction of the right atrium with either the SVC. The external component is secured to skin, preferably with a removable locking device or sutures.
PICCs come in single, double, or triple lumens in a variety of sizes. The catheters have a small outer diameter allowing for initial insertion into smaller vessels prior to advancement centrally and are radio-opaque for visualization of catheter tip placement on chest radiograph. These devices can be modified in length, specific to each patient. Some PICCs are approved for use with power injectors that can rapidly administer a radiologic contrast bolus. Insertion can be done during inpatient hospitalization, outpatient settings, and in the home by certified nurses.
PICCs are used for patients with poor venous access that need infusions of solutions with extreme pH or osmolarity, extended intravenous medications use (1 week to several months in duration), intermittent blood sampling, and as a respite from long-term catheters. For these purposes, PICCs are associated with greater ease and safety with insertion when compared with conventional CVCs. Moreover, PICCs also help minimize the pain associated with repeated venipuncture whether for replacement IVs or lab draws. Power-injectable PICCs may be utilized in patients where frequent contrasted imaging studies are likely.
The relatively small lumen and long length result in decreased flow rates, especially with infusions of viscous solutions such as blood products or intravenous nutrition therapy and often cannot be used for gravity-driven infusions when pumps are unavailable such as in home settings. Due to their small caliber, these lines are not considered adequate intravenous access for resuscitation in the setting of hemodynamic compromise. Frequent flushing of the catheter with normal saline and/or heparin lock, and dressing changes weekly or more frequently may be challenging for some patients. In addition, careful attention is required to protect the exposed catheter exit site from contamination or damage. The patient’s modesty may be compromised due to visibility of the external component. There are activity limitations including no straining maneuvers such as heavy lifting or straining that could alter the intrathoracic pressure that could lead to catheter malposition. Malpositioning can even occur with physiologic pressure changes during cough or forceful emesis. Submersion of the extremity in water when bathing in pools or hot tubs during catheter dwell is forbidden secondary to infection risks. Patients may not be candidates for PICCs if they have had surgical alteration of anatomy, lymphedema, ipsilateral radiation to the chest or arm, or loss of skin integrity at the anticipated insertion site, or anticipate future dialysis access needs.
However minimal, PICC-related complications should be recognized. These include infection, phlebitis, vein thrombosis, catheter occlusion, catheter breakage/leaking, and inadvertent removal prior to completion of therapy (Table 41.2). Oncology patients are at increased risk for venous thrombus formation secondary to their malignancy, treatment regimen, and the trauma of catheter insertion.8 Improper final tip positioning and subclavian access as opposed internal jugular access may also contribute to thrombosis.9,10 In cancer patients, PICCs have been shown to have less incidence of deep venous thrombosis than tunneled catheters used for the same purpose.
Percutaneous Central Venous Catheters
Aubaniac was the first to describe cannulation of a central vein (the subclavian) for venous access.11 These CVCs, either the thin flexible or the larger rigid variety, are inserted directly into the central circulation via the subclavian vein, the external jugular vein, the internal jugular vein, or the femoral vein. Catheters included in this category include the standard CVCs or temporary rigid hemodialysis/apheresis catheters. The CVC is utilized in the hospital setting for acute central venous access with a dwell time of up to 14 days. CVCs are typically used for rapid infusion, multiple infusates needed simultaneously, or hemodynamic monitoring (central venous pressure measurement). Thus, CVCs are for use in acute care settings, thus reserving them for hospitalized patients only.
Frequent assessment of the catheter for integrity, dislodgment, and site evaluation is required. Flushing of each catheter lumen is performed frequently for patency. Complications related to these devices include infection, bleeding, inadvertent arterial access, air embolism, pneumothorax, hemothorax, cardiac perforation and tamponade, and cardiac dysrhythmia. The cancer patient with cachexia is at increased risk for insertion complications as are patients with large body habitus or coagulopathies. Utilization of image-guided placement with ultrasound technology for venipuncture and modified Seldinger approach helps to minimize these risks. During catheter dwell, infections, thrombosis of the accessed vein, loss of catheter lumen patency, and dislodgment can occur and consideration should be made for removal of the device if this occurs.
The rigid, nontunneled, central catheters are typically used for acute hemodialysis, hemodialysis access after removal of an infected tunneled dialysis catheter, stem cell collection for autologous transplant or healthy donor collection, or therapeutic apheresis. These catheters can be placed by certified nurse practitioners, physician assistants, or physicians in a surgical suite, or in interventional radiology. Image guidance is essential. Catheter exchange at the same venous site can indefinitely maintain a single access site, which may be limited in hemodialysis patients or oncology patients due to prior access and thrombosis of other central access points. This practice should be reserved for the patient with truly limited central venous access.
The catheter exit site must be kept dry with an intact occlusive dressing changed biweekly to minimize infection risks. The lumens are given a high-dose heparin lock to maintain patency. Accidental dislodgment of the rigid catheter can occur even though sutures are placed. Due to the large caliber of these devices, unrecognized dislodgement can lead to life-threatening hemorrhage. Usage of these catheters and dressing changes are typically reserved for certified dialysis technicians to provide optimal consistent management. Dressing changes and flushing for patients undergoing stem cell collection are managed by nursing services.
Tunneled Catheters
A tunneled catheter is a larger-bore catheter inserted into the central circulation followed by tunneling through the subcutaneous tissue to an exit site remote from the access site. The tip of the catheter should terminate in the SVC/right atrial junction or IVC/right atrial junction. A retention cuff, which causes inflammation and ingrowth into the cuff, is integrated on the catheter. The cuff is positioned approximately 1 to 2 cm within the skin insertion point. The cuff serves as a barrier to bacterial migration along the tract into the central circulation. After tunneling, the catheter is threaded into the central circulation via the jugular veins, subclavian vein, femoral vein, or lumbar vein access (only in vein-compromised patients).
Tunneled catheters can be further divided into three types: traditional tunneled catheters, dialysis catheters, and hybrid tunneled catheters. The traditional tunneled catheters are best known as the Hickman or Broviac catheter. These are intended for patients requiring long-term central venous access use such as total parenteral nutrition, chemotherapy, chronic medication administration, and blood infusion or sampling. The second are the dialysis catheters. These are typically used for hemodialysis but more recently they have been utilized for stem cell collection and posttransplant venous access. The final catheter type, the hybrid tunneled catheter, is most often used for stem cell collection, transplant access, or photophoresis treatments in graft-versus-host disease in transplant patients. All three of these catheters are available in single, double, or triple lumens, with a variety of lumen sizes and catheter lengths. These catheters are known for lower infection rate as compared to nontunneled catheters.
Management of tunneled catheters requires flushing protocols, weekly dressing changes, and protection from inadvertent dislodgment. In addition, the patient is restricted from submersion of the catheter during bathing or swimming. Tunneled catheters with high-dose heparin lock solution require removal of the lock prior to catheter use to prevent inadvertent systemic heparinization. Catheters containing valve devices may only require saline flushes, thus simplifying this regime.
Complications of tunneled catheters include those associated with the insertion procedure (i.e., bleeding, air embolus, pneumothorax, hemothorax, and cardiac dysrhythmia) as well as long-term issues (i.e., infection, migration, thrombosis, and catheter shear). Most medical centers will stock catheter repair kits that allow for the salvage of cracked or leaking catheter. Extrusion of the cuff from the subcutaneous position is an indication for replacement or removal of the tunneled catheter.
Implanted Ports
Implanted ports are CVCs attached to a reservoir with a self-sealing septum. The reservoir is surgically implanted into a pocket in the subcutaneous tissue and the attached catheter is tunneled subcutaneously before advancement into the central venous circulation.
The implanted port is ideal for patients undergoing intermittent or cyclic therapy when daily access is not required. Ports are suited to chemotherapy administration or venous access for lab draws in vein-compromised patients requiring chronic venous access. It should be noted that the need for a port in a cancer patient should be anticipated such that healing and recovery after the procedure has been completed prior to the neutropenia and weakness of chemotherapy sets in. Newer models of implanted ports allow power injections of contrast material for radiologic imaging. Medical device companies also promote ports with differing flow patterns or characteristics within the reservoir chamber (i.e., “the port”) that claim to improve infusion, blood draws, and lower thrombosis rates. Compared to tunneled catheters, studies have also demonstrated up to a 10-fold advantage in long-term infection rates due to the completely implanted nature of the catheter. Nevertheless, continuous access of the port will certainly defeat this advantage. Ports provide patients with privacy as it is not visible, especially if the port pocket is located in a discrete location. In addition, active patients may find more freedom during deaccessed periods. These catheters have an extended dwell time of several years or longer depending on the number of punctures into the septum and the needs of the patient. Consideration should be given to retaining the port for a period of time after completion of therapy for use in surveillance blood testing purposes.
Patients with uncontrolled coagulopathy or sepsis should have those conditions addressed prior to the placement of a new indwelling device, as with other CVADs. Some individuals with severe malnutrition or cachexia may have an extremely poor healing capacity and may be at undue risk for port erosion through the skin. These patients should undergo therapy with a PICC or other an alternative until such a time when a port may be better tolerated.
The locations of the subcutaneous port most commonly used include a location on the anterior chest wall, the arm, or thigh placement with the catheter advanced into the corresponding vein. Use of the port requires sterile preparation of the site and access with a noncoring, Huber needle, to prevent damage to the reservoir. As the entire system is subcutaneous, the patient may feel a needle stick as the port is being accessed, but the discomfort may be minimized by applying topical anesthetics, to the skin over the port prior to the needle stick. While the port is accessed, it requires daily flushing. It must be flushed after each use as well. When the port is not actively being used, monthly flushes are required to maintain patency. Complications associated with ports are rare and are divided into early and late events. Early complications in oncology patients include hematomas, malposition, and iatrogenic pneumothoraxes. Late complications are dominated by catheter thrombosis and infection; however, catheter facture and embolization can also occur.
Power Injection Catheters
Catheters, such as PICCs and infusaports, have been studied in the past for safety in power injection with mixed results in efficacy. This is dependent on the gauge, length, and material of the catheter. Incidence of inadequate flow rates and catheter rupture due to limited pounds per square inch (PSI) restrictions as outlined by the manufacturers have limited the use of most catheters for power injection, until recently. Optimal contrast imaging requires uniform contrast delivery, which is best achieved by power injection at 2 mL per second. In fact, these limitations have led to current trends in catheter manufacturing in which some catheters can tolerate 300 PSI (Bard Access). Candidates for power injection catheters include those anticipated to have recurring contrast medium injection studies. Herts et al. studied a variety of CVCs including standard CVC, tunneled catheters, and implanted ports and found that power injections are possible without harm to the patients or the catheters.15 Their findings suggest usage of central lines as a possible alternative to peripheral angiocatheters. Institutional policies are needed to address this as there may be additional training required of the staff prior to utilizing such devices to minimize complications. Special equipment may be required for accessing power injection ports so as to prevent rupture or extravasation. In addition, the more rigid catheter required for power injection may lead to increased complications such as phlebitis or thrombosis.
Valve Technology
Ongoing clinical presentation of heparin allergies, specifically heparin-induced thrombocytopenia, has led to marketing of catheters with valve technology. The valve remains closed unless acted upon by negative (aspiration) or positive (infusion) pressure. It is this technology that opposes central venous pressure and prevents the reflux of blood into the catheter tip during the cardiac cycle or changes in intrathoracic pressure that naturally occurs in everyday life such as with straining of vomiting. Additionally, removal of a syringe after flushing or deaccessing the port can facilitate negative pressure drawing blood into the catheter. Without blood in the catheter tip, the risk of catheter occlusion related to internal clotting is thought to be eliminated as well as decreased infection rate. Lamont et al. found the PASV (Boston Scientific Corporation, Natick, MA) valved implanted port had a lower incidence of difficulty in obtaining a blood return than the Groshong (Bard Access System, Salt Lake City, UT), which resulted in less nursing time troubleshooting malfunctioning or poorly functioning catheters. Valve technology has been incorporated into some catheters at the distal tip or in the proximal end piece. This technology is also available as an “add-on” device for catheters. A saline-only flush is recommended; however, heparin flushes are not a contraindication.
REVIEW QUESTIONS
1.A 54-year-old male has been admitted to the hospital for neutropenic fever after his most recent dose of chemotherapy. He is currently getting neoadjuvant therapy for advance rectal cancer via a double-lumen PICC. You are called to the bedside by the nurse for mental status changes, hypotension, and tachycardia. The nurse also reports a large volume bloody bowel movement. The next most appropriate step is
A.Move the patient to the appropriate level of acuity, send labs for coagulation studies and an H/H, establish two large-bore peripheral IVs, and type and screen.
B.Move the patient to the appropriate level of acuity, send labs for coagulation studies and an H/H, establish two large-bore peripheral IVs, and type and cross for 4U PRBCs.
C.Move the patient to the appropriate level of acuity, send labs for coagulation studies and an H/H, and type and cross for 4U PRBCs.
D.Move the patient to the appropriate level of acuity, and send labs for coagulation studies and an H/H bolus 1 L of crystalloid.
E.Bolus 1 L crystalloid, send labs, and call GI.
2.Which component of the vein, when injured with repeated venopuncture, is responsible for generating platelet aggregation and eventual thrombosis?
A.The valve
B.The adventitia
C.The tunica media
D.The tunica intima
E.The lamina
3.A 34-year-old woman has recently been diagnosed with stage III (T3, N1) invasive ductal cancer. Her tumor is Her-2/neu positive and she will be having a year of Herceptin in addition to her systemic chemotherapy. The most appropriate venous access is
A.Peripheral IV
B.Midline catheter
C.Nontunneled catheter
D.Infusaport
E.Tunneled catheter such as a Hickman
Suggested Readings
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3.Herts B, O’Malley C, Wirht S, Lieber M, Pohlman B. Power injection of contrast media using central venous catheters. Am J Roentgenol. 2001;176:447-453.
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11.Sansivero G. Features and selection of vascular access devices. Semin Oncol Nursing. 2010;26(2):88-101.
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13.Scott E, Hudson K, Trerotola S, Smith H, Porter D, Sood S. Risk factors for venous thromboembolism in hospitalized cancer patients with central catheters. ASH Annu Meet Abstracts. 2010;116:810-855.
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18.Williamson E, McKinnley J. Assessing the adequacy of peripherally inserted central catheters for power injection of intravenous contrast agents for CT. J Comput Assist Tomogr. 2001;25(6):932-937.