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. Unlike the cephalic vein 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.  Compelling evidence has implicated the infraclavicular musculotendinous complex in mechanical lead failure and occlusion of subclavian catheters. [2, 3]
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
Chronic or ongoing ipsilateral cellulitis
Known occlusion of the ipsilateral venous system
Relative contraindications include the following:
Ipsilateral arteriovenous fistula
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.  (See the image below.)
Techniques for accessing the axillary and subclavian system with the aid of ultrasonography have also been employed. Because fluoroscopy is an essential component of pacemaker and implantable cardioverter-defibrillator (ICD) insertion, ultrasonography is rarely, if ever, used for gaining access to the axillary system for these procedures. On the other hand, ultrasonographic 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. 
In 2003, Galloway and Bodenham published their experience in using ultrasonographic guidance to define the axillary system.  They sought to define the reliability of ultrasonography 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 ultrasonography, 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.
Their data 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 ultrasound visibility. 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 ultrasound-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 in ultrasound-guided cannulation of the axillary vein in 2004.  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.  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.