Radiologists continue to expand their role in the initiation and maintenanceof central venous access.1 At the University of Chicago, we began insertingcentral venous catheters (CVC) in 1995, and have placed over 1000 devices inthe past two years. With the benefit of image guidance, radiologists are wellsuited to place CVCs. Ultrasound-guided veni- puncture is associated with lowrates of puncture-related complications such as pneumothorax,2,3 and cathetersare rarely malpositioned because they are inserted with the aid of fluoroscopicvisualization. With strict adherence to sterile technique, infection rates forCVC insertion are similar to those reported in surgical series..2-4

A tunneled CVC courses through the subcutaneous tissues on the chest wallprior to entry in the subclavian, external jugular, or internal jugular vein(figure l). The catheter may be used for hemodialysis, plasmapheresis, orlong-term central venous access. A cuff attached to the outer surface of thecatheter is positioned within the subcutaneous tunnel and helps to hold thecatheter in place after tissue healing. This article reviews the techniques ofcatheter insertion in the interventional radiology suite and describes commonpitfalls.

Pre-catheterization preparation

The procedure and possible complications are discussed with the patient, andinformed consent is obtained. Risks include, but are not limited to,hemorrhage, pneumothorax, and infection. Infection is the most commoncomplication. Sterility is essential during catheter placement. To minimize therisks of infection, radiologists are fully masked and gowned for the entireprocedure and should observe standard surgical scrub protocol.

The patient's platelet count should be 50,000/mm3 or greater and theprothrombin time international normalization ratio should be=1.3. Although nodata exists to support pre-procedural antibiotics, it is the standard ofpractice at many institutions including our own. We administer l gm ofintravenous ceftizoxime approximately one hour before the procedure, unless thepatient is already taking antibiotics. Patients in other institutions commonlyreceive a first generation cephalosporin such as 1 gm of cephazolin sodium,administered intravenously. Although we occasionally administer a small amountof intravenous contrast, we do not routinely check serum creatinine levels. Atour institution, most tunneled catheters are placed for hemodialysis andpatients undergo dialysis immediately after the procedure. Conscious sedationwith fentanyl citrate and midazolam hydrochloride may be provided perradiologist preference.

The patient is placed in the supine position and instructed to turn his orher head away from the physician (i.e., if the right internal jugular vein isused as access, the patient should look to the left). Patients may wear a capand mask per radiologist's preference. For obese patients, it is helpful to usea pillow to slightly extend the neck. The area from the angle of the mandibleto the nipple line on the side of the puncture is scrubbed with a standardsurgical skin preparation kit that contains iodophor detergent soap andpovidone-iodine. The skin is first scrubbed with detergent for several minutesthen cleansed with povidone-iodine three times consecutively. Liberal use ofcleansing solution is suggested. After the application of betadine, towels aredraped around the puncture site and chest. It is best to partially cover thepatient's face as it avoids increased anxiety during the procedure and improvespatient monitoring. The patient should be covered from head-to-feet, and allequipment near the patient, including the image intensifier, should be properlycovered with sterile drapes.

Pitfalls

Inadequate draping-It is very important to cover as much of the patient andsurrounding area as possible because the wires and catheters commonly come incontact with anything near the field.

Patient with history of previous CVCs-Since indwelling catheters may incitethrombosis or occlusion of the central veins, a cursory ultrasound examinationof the neck is performed to ensure vein patency before prepping and draping thepatient.

Women with a abundant subcutaneous tissue or large breasts-It is helpful totape the subcutaneous tissue and breast as caudal as possible. This minimizesretraction of the central venous line when the patient assumes an uprightposition.

Venous puncture techniques

If possible, all central venous lines for hemodialysis should be placed viathe right or left internal jugular vein (IJV). The subclavian veins should beavoided in patients requiring hemodialysis because catheter placement in asubclavian vein may cause stenosis, which will render the ipsilateral extremityunsuitable for a synthetic graft or arteriovenous fistula.5 In addition,subclavian vein catheters have a higher incidence of symptomatic central venousthrombosis than internal jugular vein catheters.6

The right IJV is the best access site because it is nearly always orientedin a straight cephalocaudal course toward the heart. We perform all punctureswith a Micropuncture Introducer Set (Cook, Bloomington, IN) using ultrasoundguidance. The set contains a 21-gauge needle, .018=guidewire, and co-axial 3Fr. and 5 Fr. dilators.

IJV puncture: Freehand real-time needle insertion-The IJV is easilylocalized adjacent to the carotid artery and thyroid gland. Although puncturethrough the muscle usually can be performed without complications, it is bestto puncture the vein between the medial and lateral heads of thesternocleidomastoid muscle approximately 1 cm above the clavicle. Puncturingtoo low in the neck increases the risk of pneumothorax, while puncturing toohigh may cause the catheter to kink at the vein entry site (figure 2).

A 5 or 7 MHz probe is covered with a sterile drape containing a small amountof acoustic gel, and betadine is applied to the neck as a coupling agent. For aright internal jugular vein puncture, the radiologist should stand at the headof the bed with the probe held in transverse orientation (figure 3). The probeis positioned so that the IJV is in the center of the image. After subcutaneousadministration of 1% lidocaine, the puncture needle is attached to a 10-ccsyringe and the bevel of the needle is placed on the skin directly beneath thecenter of the probe (figure 4). The needle should be oriented slightly mediallyand caudally, and advanced toward the vein under ultrasound guidance withsimultaneous gentle aspiration.

The walls of the IJV tend to coapt with constant pressure so that the needlefrequently passes through both the front and back walls of the veinsimultaneously. If the bevel is passed deep to the vein, the needle is slowlywithdrawn with gentle suction on the syringe until venous blood is aspirated.The .018=guidewire is then advanced through the needle into the superior venacava (SVC). The needle is removed, and the 3 Fr. and 5 Fr. dilator combinationis advanced over the wire. This combination may be left in place while thesubcutaneous tunnel is formed. Alternatively, a .035=J-tipped guidewire may bepassed through the 5 Fr. dilator and the dilator exchanged for an end-holecatheter. The wire-catheter combination can then be advanced into the inferiorvena cava (IVC).

Subclavian vein puncture-For subclavian punctures, an injection of iohexolis performed through an intravenous catheter in the wrist or hand to opacifythe subclavian vein. Using fluoroscopic guidance, the vein is punctured usingthe micropuncture set at the lateral aspect of the first rib.7 As the needle isadvanced, the vein will "tent," and the needle will then"pop" into the vein. It is helpful to direct the needle mediallytoward the lateral aspect of the first rib so that if the needle passes throughthe vein, it will stop at the rib instead of transgressing the pleural spaceand possibly causing a pneumothorax. It is important not to puncture medial tothe first rib because this can cause catheter compression by the subclaviusmuscle or costoclavicular ligament-subclavius tendon complex, causing"pinch-off" syndrome.8

Pitfalls

Not advancing the needle deep enough during IJV puncture-This is a verycommon and frustrating error resulting from inexperience. Occasionally, it maybe difficult to visualize the needle tip. Although the IJV usually is only 1 to2 cm below the skin surface, the needle frequently needs to be advanced deeperbecause the walls of the vein coapt with constant pressure. It is important tovisualize the needle tip at all times to prevent inadvertent vertebral arteryor carotid artery puncture or pneumothorax.

Withdrawing too forcefully after venipuncture-Only gentle suction isrequired to aspirate blood from the vein. If too much suction is used, softtissue may be drawn into the needle, subsequently occluding the needle's lumen.

Inability to pass wire-The needle may be against the back wall of the vein.After pulling the wire into the needle, withdraw the needle 1 to 2 mm and thenadvance the wire. If the wire enters the IJV or SVC but will not pass distallyinto the more central veins, exchange the needle for the 3 Fr. dilator includedin the micropuncture set and inject contrast to evaluate patency of the centralveins.

Uncertainty of which vessel the needle has entered-This may be a problemwhen the carotid is immediately posterior to the IJV. If either the subclavianartery or common carotid artery is inadvertently punctured, brisk back bleedingusually is evident through the micropuncture needle. The operator should removethe needle and compress the area for five minutes. If the operator is unsure ofwhich vessel the needle has entered, the wire should be advanced into thevessel and the needle exchanged for a 3 Fr. inner dilator. A small amount ofcontrast can then be injected using fluoroscopic guidance to identify thevessel. If an artery has been punctured, the dilator is removed, and the areais compressed for five minutes.

Technique of forming a subcutaneous tunnel

Lidocaine is infiltrated along the expected subcutaneous course of thetunnel. We prefer to use lidocaine without epinephrine, although lidocaine withepinephrine may decrease bleeding along the catheter tract. Lidocaine withepinephrine should be avoided in patients with sickle cell anemia because ofthe risk of skin necrosis. After lidocaine infiltration, a subcutaneous tractis fashioned with a blunt-tipped metal or plastic trocar. The tunnel should beat least 8 to 10 cm in length. We usually enter the skin on the anterior chestwall approximately 4 to 5 cm caudal to the lateral third of the clavicle. Ascalpel (#11 blade) is used to make a 5 mm incision at the desired entry siteon the chest. In women, the exit site should be placed in a position that doesnot affect bra straps. The trocar is advanced to the lateral aspect of thepuncture site, and a scalpel and hemostat are used to dissect to theblunt-tipped trocar. The tip of the trocar is then pulled through the skin(figure 5). The incision site at the neck should be 5 to 10 mm in length.

Pitfalls

Previous tunneled catheters--In patients with previous catheters, there maybe abundant scar tissue on the chest wall which makes tunneling difficult.Using a metal trocar may be especially helpful in this situation.

Difficulty passing a trocar--If the skin dimples with passage, the trocar istoo shallow. Redirect the tip more subdermally.

Inadequate neck incision site--The incision site in the neck should beapproximately 1 cm in length; if the site is too short, it will be difficult topass the trocar through the skin, and later it will be nearly impossible toadvance the dilator-peel-away sheath combination into the vein. This problem isexacerbated by patients who have scar tissue in the neck from previouscatheters. If the incision is not deep enough, a tag of skin will tend to kinkthe catheter when it runs from the tunnel into the vein (figure 6A). If it isnot wide enough, it will kink the peel-away sheath when the dilator is removed,precluding the catheter from advancing into the vein, or it may crimp thepeel-away sheath on the dilator, making it difficult to pass into the vein(figure 6B).

Inability to pass the trocar through a puncture site in the neck--In obesepatients and patients who have scar tissue in the neck, it may be difficult topass the trocar out of the skin. Frequently, the trocar is able to be advancedvery close to the IJV but not out through the tissue adjacent to the puncturesite. Plastic trocars are especially susceptible to this complication. Ratherthan push vigorously, it is best to carefully dissect to the tip of the trocarwith a scalpel and hemostat and then pull it through the skin with a hemostat.

Catheter placement

Catheters that are pre-cut to appropriate lengths are utilized forhemodialysis or plasmapheresis. In general, a 36-cm catheter is placed from theright and a 40-cm catheter is placed from the left. Note that differentmanufacturers measure catheters differently; some measure the length from thetip to the hub while others measure the length from the tip to the cuff. Theoperator should be familiar with the catheter used in his or her institutionand that particular manufacturer's terminology. After the tunnel is made, thecatheter is attached to the trocar and pulled through the tunnel. For pre-cutcatheters, it is best to pull the subcutaneous cuff 5 to 6 cm into the tunnelinitially. It is much easier to pull back a catheter that is placed too deep inthe right atrium than to advance a catheter that is not in deep enough.

For catheters which need to be cut, appropriate length determination can bedone in several ways. The .018=micropuncture set wire used for initial accessmay be positioned so that its tip is at the junction of the superior vena cavaand right atrium. It is then bent at the hub of the dilator, removed, and theportion from tip to kink is measured. Alternatively, the catheter can be placedon the chest on its projected course. The correct length is then determinedwith fluoroscopy. After trimming the catheter (if necessary), a .035=guidewireis advanced through the 5 Fr. dilator in the neck into the IVC. As the wire isadvanced from the SVC through the right atrium into the IVC, an ECG is used tomonitor for ectopy. The wire is then directed away from the right ventricle andtricuspid valve. If an IVC filter has been previously placed, the wire shouldbe positioned cephalad to the filter.

The .035=wire is exchanged for a .035=superstiff wire through an end-holecatheter (the stiffer guidewire allows better support when placing thesheath-dilator combination). Under fluoroscopic guidance, the catheter isexchanged for the dilator-peel-away sheath combination provided in the kit(figure 7). A slight twist at the skin with firm, constant pressure will helpthe dilator-sheath combination pass into the vein. The guidewire is thenremoved, and the opening of the dilator is covered with a finger. The patientis instructed to hold his breath (to prevent air embolism), the dilator is thenremoved, and the sheath is crimped between two fingers to prevent excess backbleeding. If the angiographic table tilts, the patient should be placed inslight reverse Trendelenburg's position. The tip of the catheter is advancedthrough the peel-away sheath as far as possible into the SVC, and the sheath ispeeled away while the catheter is held in position (figure 8). After the sheathis completely peeled apart, the catheter is pushed under the skin with a fingeror hemostat. The hub of the catheter is retracted slightly to clear any kinksfrom the catheter (figure 9).

The catheter tip should be slightly distal to the junction of the SVC andright atrium. It will migrate cephalad 1 to 2 cm when the patient stands. Theports of the catheter are flushed with 3 to 5 ml of 1000U/ml heparin. The skinedges at the puncture site are approximated with a single 3-0 Ethilon suture(Ethicon, Somerville, NJ) or a subcuticular resorbable suture. The catheter isthen secured to the skin on the chest with an 0 suture. Antibacterial ointmentis then placed at the skin incision sites, and the sutures are removed at 3weeks. Iodophor antibacterial ointment also can be applied, as it is at ourinstitution, though some epidemiologists and infectious disease consultants donot feel that the ointment provides additional benefit. A completion radiographis then obtained on the angiography table (figure 10). We do not routinelyperform post procedure chest radiographs unless venipuncture was difficult.

Pitfalls

The catheter won't advance through the sheath-This is not uncommon when aleft-sided approach is used or when abundant scar tissue in the neck crimps thepeel-away sheath. Place a stiff-shaft hydrophilic guidewire into the catheter.In most situations, the reinforced catheter should advance easily.

The catheter kinked at puncture site (figure 11)-This usually occurs if theincision site in the neck is too short, too superficial, or if the skinincision is not connected to the puncture site. To resolve this, take ahemostat and bluntly dissect the tag between the catheter and vein.

Persistent bleeding-Sit the patient upright and compress both the puncturesite and the tract. If bleeding persists after 30 minutes, obtain bloodcoagulation parameters. Persistent bleeding can be caused by venoushypertension or fluid overload. If too much heparin was inadvertently givenwhen the catheter was flushed, consider administering 10 mg of protaminesulfate intravenously. Avoid giving protamine to diabetics taking neutralprotamine hagedorn insulin, as protamine insulin use may immunologicallysensitize patients to protamine, leading to anaphylactoid reactions.9

Inability to pass the wire into the IVC-If this occurs, use a 5 Fr. catheterto direct the wire through the right atrium into the IVC.

Presence of a previously placed IVC filter-A guidewire passed into the IVCcan become entangled with an IVC filter. Use fluoroscopy to quickly scan theabdomen before placement of the central venous catheter. The tip of theguidewire should be positioned in the IVC above the filter.

Presence of a left-sided catheter- Due to the tortuous course of theleft-sided veins, the guidewire should be located in the lower IVC beforeattempting to pass the dilator-sheath combination. If the wire is left in theSVC or right heart, these structures could be punctured by thelaterally-directed force of the dilator. It is best not to advance thedilator-sheath combination distal to the junction of brachiocephalic veins.

Presence of the catheter tip high in the SVC-First, place a guidewire intothe catheter, and then advance the wire.

Conclusion

With the aid of image guidance, tunneled central venous catheters can beplaced by radiologists with excellent safety and success. In the interventionalradiology suite, ultrasound is used to guide internal jugular vein puncture,and fluoroscopy enables visualization of both the course and position of thecatheter as it is being deployed. Image guidance virtually eliminates the riskof several complications reported with unguided placement, such aspneumothorax, hematoma due to arterial puncture, and catheter malposition. Amajor impetus for radiologic placement of central venous catheters in ourhospital is ease of scheduling. In most cases, same day or next day placementis possible in the radiology department, whereas scheduling delays often areencountered for insertion in our busy operating rooms. In our opinion,conventional insertion techniques using anatomic landmarks offer no definiteadvantages when compared with image-guided insertion.

References

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2. Funaki B, Szymski GX, Hackworth CA, et al: Radiologic placement ofsubcutaneous implantable chest ports for long-term central venous access. AJR1997 169:1435-1437, 1997.

3. Trerotola SO, Johnson MS, Harris VJ, et al: Outcome of tunneledhemodialysis catheters placed via the right internal jugular vein byinterventional radiologists. Radiology 203:489-495, 1997.

4. Lund GB, Trerotola SO, Scheel PF Jr, et al: Outcome of tunneledhemodialysis catheters placed by radiologists. Radiology 198:467-472, 1996.

5. Cimochowski GE, Worley E, Rutherford WE, et al: Superiority of theinternal jugular over the subclavian access for temporary dialysis. Nephron54:154-161, 1990.

6. Henriques HF III, Karmy-Jones R, Knoll SM, Copes WS: Avoidingcomplications of long-term venous access. Am J Surg 59:555-558, 1993.

7. Jacques PF, Campbell WE, Dumbleton S, Mauro MA: The first rib as afluoroscopic marker for subclavian vein access. J Vasc Interv Rad 6:619-622,1995.

8. Krutchen AE, Bjarnason H, Stackhouse DJ, et al: The mechanisms ofpositional dysfunction of subclavian venous catheters. Radiology 200:159- 163,1996.

9. Vincent GM, Janovski M, Menlove R: Protamine allergy reactions duringcardiac catheterization and cardiac surgery: Risk in patients takingprotamine-insulin preparations. Cath and Cardiovasc Diag 23:164-168, 1991.