GIANCARLO SCOPPETTUOLO and MAURO PITTIRUTI

Overview

The concept of achieving central venous access by cannulation of a peripheral arm vein is old, although only in the last decade has the peripherally inserted central catheter (PICC) emerged as a safe and cost-effective option. In the last century, PICCs were positioned by catheterization of visible or palpable superficial veins in the antecubital area (mostly the cephalic or the antecubital vein) or less often at the forearm or the upper part of the arm. Obviously, this “blind” cannulation could not provide any information about the actual diameter or trajectory of the vein. Hence, the rate of insertion failure, malpositioning, and catheter-related venous thrombosis was exceedingly high. Since the exit site of PICCs was usually located in the antecubital area, it was vulnerable to infections (because of extraluminal contamination) and local thrombophlebitis (because of catheter instability). Moreover, this exit site was rather uncomfortable for the patient and thus resulted in poor compliance with the device.

At the beginning of this century, the widespread use of ultrasound for guiding vascular access has dramatically changed the technique of insertion of PICCs.1–6 Currently, PICCs are inserted by ultrasound-guided puncture and cannulation of the deep upper arm veins (most often the basilic or brachial vein) via the modified Seldinger technique (venipuncture with a small-gauge needle, insertion of a thin guidewire through the needle, removal of the needle, insertion of a microintroducer-dilator over the guidewire, removal of the wire and dilator, insertion of the catheter through the introducer). This technique facilitates catheterization of large-bore veins of known diameter and trajectory while allowing positioning of the exit site in the upper part of the arm (halfway between the elbow and the axilla). As a final result, the rate of insertion failure is minimal, insertion-related complications are almost negligible, the exit site is handled easily by patients and nursing stuff (easy dressing and securement, good patient comfort), and the rate of late complications (infection, catheter-related venous thrombosis, dislocation) is low.

In other words, the 21st century ultrasound-guided PICC is a different venous access device than the 20th century PICC in terms of indications, insertion technique, expected rate of failure, and insertion-related complications, as well as the incidence of late complications.

Ultrasound anatomy of the arm veins

PICCs are usually inserted in the deep veins of the arm, which allows an exit site in the middle third of the upper part of the arm. Sometimes the only veins available for cannulation (in terms of diameter) are quite close to the axilla. In such cases the catheter can be tunneled downward to obtain a more favorable exit site. The deep veins of the forearm should not be considered for PICC insertion; however, these veins can be used for ultrasound-guided insertion of peripheral lines. The most frequently accessed vein is the basilic vein, which runs in the groove between the humerus and the biceps muscle. This vein usually has a large diameter (4 to 6 mm) and is located rather superficially (10 to 25 mm from the surface of the skin) and relatively distant from arteries and major nerves. The brachial veins are an alternative option. Their number may range between two and four, and they generally travel close to the brachial artery and the median nerve (which is typically located adjacent to the artery; see Chapter 51). The brachial veins are smaller (with diameters ranging from 1 to 4 mm) and usually travel medially and deeper than the basilic vein; however, anatomic variations are numerous. When visualized sonographically in a transverse plane, the artery and the two adjacent basilic veins appear to have a “Mickey Mouse”–like configuration. Because of their diameter and proximity to structures such as the brachial artery and the median nerve, the basilic veins are not a primary option for catheterization.

As the basilic vein travels upstream, it appears to be located progressively closer to the neurovascular brachial bundle, whereas close to the axilla it merges with the brachial veins to form the axillary vein. If the other deep arm veins are too small for cannulation (e.g., children, hypovolemic or malnourished adults), the axillary vein can be considered as an alternative option. However, catheterization of the axillary vein often implies tunneling the catheter to place the exit site far away from the puncture site. In obese (especially morbidly obese) patients, the basilic vein and the brachial veins may be located too deep (>30 mm from the skin surface). In such cases, PICCs can be inserted by cannulating the cephalic vein. The latter usually courses along the lateral side of the upper part of the arm quite superficially (above the muscular fascia) and displays a nonlinear trajectory, and it merges with the axillary vein in the infraclavicular area (10 to 20 mm before the transition of the axillary vein to the subclavian vein). Generally, this vein is not appropriate for PICC insertion, but in obese patients it is a relatively deep and “stable” vein that is easily accessible.

Sonographic visualization of all arm veins in a transverse plane is relatively easy and facilitates a “panoramic” view of all adjacent anatomic structures (e.g., nerves, arteries, muscles) in a region of interest (ROI). The importance of this “panoramic” view is analyzed elsewhere according to the holistic approach ultrasound concept (Chapters 1 and 51). When transducer compression is applied to an ROI, a vessel that pulsates is an artery, whereas a vessel that does not pulsate and is noncollapsible is most likely a thrombosed vein (Chapter 9).

Ultrasound-guided puncture is most commonly performed via an “out-of-plane” approach (the needle trajectory does not lie in the transducer plane). Even though transducers can be equipped with a needle holder to facilitate puncture, the “freehand” technique is usually favored by many experts because it is more versatile and effective. However, needle holders may be useful as a teaching tool.