Axillary Vein Catheterization

Several anatomic access points and methods to gain central venous access have been described. Because the upper-body approaches are generally deemed to be cleaner than femoral approaches (ie, upper-body sites are less likely to be contaminated), cardiologists, surgeons, and anesthesiologists alike have long favored them. The axillary, cephalic, and subclavian veins, as well the internal and external jugular veins, have all been used to gain central access for placement of pacemaker or defibrillator leads or central venous lines.

This article reviews the techniques for gaining access to the axillary venous system for the purposes of lead placement as well as adapting those techniques for central venous line placement. To learn about other techniques for central venous line placement, see Central Venous Access via Subclavian Approach to Subclavian Vein and Central Venous Access via Supraclavicular Approach to Subclavian Vein.

The axillary vein has become the favored conduit for the placement of pacing and defibrillation leads for several reasons.[1] Unlike the cephalic and external jugular veins, the axillary vein is almost always large enough to accommodate multiple pacing leads. In comparison with the subclavian vein, the properly accessed axillary vein affords a less acute course. This potentially decreases mechanical stress on the implanted leads or catheters and, hence, results in a lower incidence of mechanical lead failure or catheter occlusion.[2] Compelling evidence has implicated the infraclavicular musculotendinous complex in mechanical lead failure and occlusion of subclavian catheters.[3, 4]

Additionally, subclavian access comes with the risk of inadvertently accessing the noncompressible subclavian artery and the potential for increased mechanical stress on the lead or indwelling catheter from crossing the subclavius muscle and the clavipectoral fascia. Finally, use of the axillary system, unlike use of the jugular system, does not require tunneling of the leads over or under the clavicle.

Indications for axillary vein catheterization include the following:

• Placement of pacing or defibrillation leads
• Central venous access for delivery of medications or fluids
• Placement of dialysis catheters
• Placement of temporary pacing wire or pulmonary artery catheters

Absolute contraindications for axillary vein catheterization include the following:

• Ipsilateral radical lymph node resection
• Ipsilateral lymphedema
• Chronic or ongoing ipsilateral cellulitis
• Known occlusion of the ipsilateral venous system

Relative contraindications include the following:

• Ipsilateral arteriovenous fistula
• Ipsilateral mastectomy

Anatomy

A thorough understanding of the regional anatomy is essential to successful cannulation of the axillary system. The axillary vein begins at the lower margin of the teres major as a continuation of the brachial vein. It continues its course proximally until it terminates at the lateral margin of the first rib to become the subclavian vein. Along its course, it receives tributaries from the cephalic and basilic veins. The vein is accompanied, along its course, by the axillary artery, which lies slightly superior and posterior to the vein. Overlying the vein are the pectoralis minor and the clavipectoral fascia, followed more superficially by the pectoralis major.

By remaining cognizant of these anatomic relations, a clinician can accurately and reliably cannulate the target vessel while minimizing the chance of injury to adjacent structures.[5] (See the image below.)

Techniques for accessing the axillary and subclavian system with the aid of ultrasonography (US) have also been employed. Because fluoroscopy is an essential component of pacemaker and implantable cardioverter-defibrillator (ICD) insertion, US is rarely, if ever, used for gaining access to the axillary system for these procedures. On the other hand, US guidance is a well-recognized aid for gaining access to the axillary system for the purpose of central venous line insertion and brachial plexus blockade.[6]

In 2003, Galloway and Bodenham published their experience in using US guidance to define the axillary system.[7] They sought to define the reliability of US as a modality for imaging the axillary vein as well as to define the caliber of the vessel and its relation to the axillary artery. They examined 50 patients with US, taking images in the transverse plane at the midclavicular line and at 2 cm and 4 cm lateral to the midclavicular line. These images were repeated with the arm at 0º, 45º, and 90º of abduction in the supine position.

The data from this study showed that the Trendelenburg position only afforded a 1 mm (1.2-1.3 cm) increase in the diameter of the axillary vein and that arm position did not cause significant differences in vessel size or visibility on US.[7] They observed that as the axillary vein coursed laterally, its diameter decreased (from 12.2 mm to 8.5 mm), its depth increased (from 19.5 mm to 32.2 mm), and its proximity to the axillary artery decreased (from 3.4 mm to 8.9 mm). On the basis of these data, the authors proposed US-guided axillary access as a viable alternative to subclavian access based on surface anatomy.

Having shown the axillary vein to be a suitable target, Bodenham, Mallik, and Sharma went on to publish their experience with US-guided cannulation of the axillary vein in 2004.[8] The authors included 200 consecutive patients in their study, all of whom were to receive Hickman vascular catheters. They placed their patients in 15º of Trendelenburg and used a 7.5-MHz ultrasound probe to image the axillary vein and artery in cross-section. The needle was then visualized in real time as attempts were made to cannulate the axillary vein.

With this method, they were able to successfully cannulate the vessel in 194 patients, 76% of whom required only a single needle pass.[8] Of the remaining six patients, four were deemed unsuitable for axillary access because of the small caliber of the axillary vein, bilateral venous thrombosis, or a very deeply located axillary venous system. The remaining two patients were not successfully cannulated after three attempts and were then cannulated successfully via the internal jugular vein.

Equipment used for axillary vein catheterization includes the following:

• Surgical blade (No. 10 or 15)
• Weitlaner retractors
• Forceps
• Bovie electrocautery pen
• Army-Navy retractors
• Needle (18 gauge) and slip-tip syringe
• Soft J-tip guide wire
• Hemostatic sheath and dilator system
• Fluoroscope
• Ultrasound machine
• Intravenous (IV) radiocontrast agent

Anesthesia

Local anesthesia with 1% lidocaine is sufficient for accessing the axillary system with the aim of placing a central venous line. For more information, see Local Anesthetic Agents, Infiltrative Administration.

When the patient is particularly anxious, or when the vein is accessed for the purpose of placing a pacemaker or defibrillator, some degree of procedural sedation is customary and adds to patient comfort. Typically, sedation is achieved with titrated doses of IV benzodiazepines and narcotics; when the services of an anesthesiologist are available, propofol may be used. For more information, see Procedural Sedation.

General anesthesia is rarely required.

Positioning

Place the patient in the supine position. Prepare and drape the area in the customary sterile manner. Trendelenburg positioning is helpful because it leads to engorgement of the upper-extremity venous system. When Trendelenburg positioning is used, an appropriate compensation with cranial angulation of the fluoroscopic camera should be employed to maintain the standard view.

When a patient has difficulty lying flat and a wedge-shaped pillow or reverse Trendelenburg positioning is used, the image intensifier should be rotated to a degree of caudal angulation matching the degree to which the patient is elevated.

In addition, some practitioners use a folded towel or roll between the scapulae, which moves the lateral aspect of the clavicles posteriorly. This potentially facilitates access, especially in patients of greater habitus in whom the vein may be relatively deep.

With the patient appropriately positioned (see Periprocedural Care, Patient Preparation), an assessment of the surface anatomy is helpful, not only for locating the vein but also for planning the location of the incision if the goal is to implant a pacemaker or implantable cardioverter-defibrillator (ICD).

Locate the inferior clavicular margin, the coracoid process, and the deltopectoral groove. In addition, palpate for the pulse of the axillary artery; in thin patients, this can be readily appreciated in the infraclavicular fossa.

Whereas the surface anatomy is undoubtedly important, these landmarks can be misleading, especially in larger patients. In some patients, especially elderly patients and those with chronic obstructive pulmonary disease (COPD), the clavicle is often displaced superiorly and cannot necessarily be used as a landmark. It is essential to remember that the constant relation of the axillary vein is to the first rib, not to the clavicle or the surface anatomy.[9]  Keeping this point in mind can help avoid inadvertent arterial puncture as a result of using the clavicle as a landmark.

The authors' preference is first to identify the surface anatomy and then to lay the needle and syringe on the skin surface over the intended course of the puncture and perform a fluoroscopic study (see the image below). This technique can avoid creating a subcutaneous pocket that is too distant from the intended access site.

Once the surface and fluoroscopic anatomy have been identified, make the incision and carry it to the level of the prepectoral fascia. At this level, create a pocket large enough to accommodate the device to be implanted. Ensure hemostasis before directing attention to accessing the vein.

To access the vein, advance the needle under fluoroscopic guidance toward the greatest curvature of the first rib while maintaining negative traction on the plunger of the syringe. By maintaining a relatively steep angle (45-70°), the possibility of passing beyond the rib and entering the pleural space is minimized. As a precaution against pneumothorax, do not advance the needle beyond the medial border of the first rib. If the vein is not entered upon the initial attempt, withdraw the needle, redirect it, and advance it again in a similar manner.

Remember that once the needle passes below the clavicle, if the subclavian artery is entered, it is noncompressible. Because the axillary and subclavian arteries lie in a superior or cephalad relation to the respective veins, redirecting the needle in a more cephalad direction should be done in a gradual stepwise fashion.

Once the vein is entered, remove the syringe from the needle, and pass a guide wire into the vessel. At this point, quickly pan the fluoroscopic image to the level of the diaphragm to confirm that the guide wire passes to the inferior vena cava (IVC) below the diaphragm (within the shadow of the liver); this confirms that the access is venous rather than arterial and helps ensure that a sheath is not inadvertently placed into the axillary artery. (See the video below.) Observing the course of the guide wire can also alert the operator to the presence of venous anomalies such as a persistent left superior vena cava (SVC).

Patients who require central venous cannulation are often quite ill and may have significant disorders of oxygenation as well as cardiac valvular pathology. Consequently, the color of the flash of blood cannot always be relied upon to distinguish venous from arterial blood. In addition, patients with marked tricuspid regurgitation may exhibit pulsatile flow in the axillary vein.

Once venous access is confirmed, remove the needle and place a sheath and dilator over the guide wire.

If gaining entry into the vein is difficult, several steps can be taken to facilitate the process. If the difficulty is likely to be due to an awkward access angle because the pocket is too lateral with respect to the access point, the needle may be redirected to access the vein as it overlies the second rib rather than the first. This is the preferred initial approach of many operators. To access the vein as it courses over the second rib, advance the needle exactly as is described above, but direct it to the area where the second and third ribs overlie each other on the fluoroscopic image.

If the difficulty is not due to the access angle, intravenous (IV) contrast may be employed to aid in gaining access. To do this, inject a small amount of radiocontrast material (typically 10 mL) into the ipsilateral arm. Follow immediately with a vigorous flush. Access may be gained in real time while the contrast is still visible via fluoroscopy within the lumen; alternatively, a fluoroscopic image of the contrast-filled vein may be stored as a roadmap.

Occasionally, injection in this fashion selectively enhances the cephalic vein rather than the axillary vein. This can usually be avoided by placing the IV line in the ulnar aspect of the forearm rather than the radial aspect. When the cephalic vein is selectively enhanced, the application of a tourniquet or blood pressure cuff at low pressure preferentially redirects flow toward the axillary vein.[10]

If the patient has undergone an invasive electrophysiologic study before the venous access procedure, a “poor man’s venogram” can be performed. Advance one of the electrophysiology catheters from the femoral vein to the axillary vein under fluoroscopic guidance. A fluoroscopic snapshot of the catheter positioned in the axillary system (see the image below) may then be saved as a roadmap for future access.[11]

Techniques for accessing the axillary and subclavian system with the aid of ultrasonography (US) are well-recognized aids for gaining access to the axillary system for the purposes of central venous line insertion and brachial plexus blockade, as well as dialysis catheter implantation.[6, 12, 13, 14, 15] Long-axis/in-plane (LA-IP), short-axis/out-of-plane (SA-OOP), and oblique-axis/in-plane (OA-IP) approaches have been described.[16, 17, 18, 19]

Both proximal and distal approaches to accessing the axillary vein under US guideance have been described; at present, there are no specific recommendations favoring one over the other. In a study comparing the success rate and safety of the two approaches in cardiac surgery patients susceptible to bleeding, Su et al found that both methods were feasible and safe but that the proximal approach was superior to the distal approach with respect to first puncture success rate and cannulation time.[20]  A study by Wang et al comparing the same two approaches in elderly patients also found the proximal approach to be superior.[21]

To access the vein under US guidance, place the patient in the supine position, preferably with 10-15º of Trendelenburg, and prepare the patient in the usual sterile manner. Cover the ultrasound probe with a sterile wand cover, and obtain an image in which both the axillary vein and the artery are seen. Abducting the arm 90º may facilitate visualization of the axillary vein in some cases.[22, 23]

Next, position the needle and syringe to be used for access at the point where the center of the probe meets the skin surface. This positioning ensures that the needle remains in the US field of view as it is advanced. Advance the needle while maintaining negative pressure on the plunger and observing the US image.

Once the axillary vein is seen to compress, puncture the anterior wall of the vein with a brief staccato motion of the needle. Once the needle is seen to enter the vein and blood flashes into the syringe, remove the syringe and place a guide wire into the lumen. From this point, a sheath and dilator may be placed in the usual fashion.

If both walls of the vein are punctured, maintain negative pressure on the syringe and withdraw until the flash of blood is seen, then thread the guide wire as described above. Double-wall puncture of the vein is fairly common and typically does not result in any significant adverse outcome.

If the axillary artery is inadvertently entered, remove the needle and apply firm pressure over the vessel for 3-5 minutes. This is typically sufficient to prevent ongoing bleeding and hematoma formation. Hemostasis can be confirmed with the US image as well.

Blind access techniques have been described,[24, 7]  but they are not routinely applied in clinical practice. These techniques, which are based on surface anatomy and palpable landmarks, are hampered by the fact that the position of the axillary vein depends on the position of the ipsilateral arm and the close relation of the axillary vein to the axillary artery. The greatest concern with the use of a truly blind technique is the risk of pneumothorax as a consequence of the inability to visualize the needle tip as it advances.

In order to perform a blind stick, identify the coracoid process and deltopectoral groove, paying attention to the angle of the groove. Make an incision at the level of the coracoid process, and carry it to the level of the prepectoral fascia. At this point, the pectoralis muscle and the deltopectoral groove can be directly visualized.

Advance a needle through the pectoralis muscle at a point 1-2 cm medial to the deltopectoral groove, pointed in a superior and medial direction, while maintaining an orientation parallel to that of the deltopectoral groove. By maintaining a shallow angle of roughly 45º to the chest wall, the risk of pneumothorax is diminished.

In Belott’s description of the above technique, fluoroscopy was used and the technique carried out as described previously when blind access was not successful after a few passes.[24] Because the incision is long enough to visualize the deltopectoral groove, a cephalic cutdown remains a viable bailout option if the blind access method fails. If the blind access technique is unsuccessful, the other techniques described above can also be used.

Accessing the axillary venous system is quite safe in experienced hands. Potential complications include the following:

• Pneumothorax
• Hemothorax
• Arterial access
• Arteriovenous fistulae
• Hematoma
• Bleeding
• Infection
• Venous thrombosis
• Entry into innominate or other vessels

When recognized promptly, these complications rarely result in significant morbidity.