The IJV runs vertically on the anterolateral side of the neck, lateral to the CCA. The IJV joins the SCV to form the brachiocephalic, or innominate, vein that drains into the superior vena cava ( Fig. 36.1 ). In the neck, CVCs are generally inserted into the IJV between the clavicular and sternal heads of the sternocleidomastoid muscle (SCM).

Normal Neck Vascular Anatomy.

High-frequency, linear-array transducers, often called vascular probes, are used for vascular access procedures. The high-frequency waves give a high-resolution image to a maximum depth of 6 to 10 cm, and the IJV and the axillary/SCV are typically only a few centimeters below the skin.

Images are generated from sound waves reflected from each tissue interface, which determines the tissue echogenicity, or “brightness,” displayed on the screen. Dense tissue, such as needles, bones, and pleura, appear bright or hyperechoic. Fluid-filled structures, including arteries and veins, transmit and do not reflect sound waves, and therefore appear black or anechoic.

The ability to distinguish arteries from veins is essential. Veins are oval or triangular shaped, thin-walled, fully compressible, and change size with breathing (respiratory variation) or Valsalva. Arteries are round, thick-walled, partially compressible, and pulsatile.

Preprocedural scanning of the left and right neck should be performed to determine the best CVC insertion site. A linear transducer is placed transversely on the anterolateral neck and the IJV is assessed from the angle of jaw to the inferior anastomosis with the SCV ( Fig. 36.2 and Video 36.1 ). Turn the patient’s head slightly, no more than 30 degrees, to the contralateral side with the neck extended. Evaluate the IJV’s size, shape, depth, compressibility, proximity to CCA, and distal anastomosis with SCV. Respirophasic variation of the size of the IJV can be noted ( Video 36.2 ). Center the IJV on the screen, then slide the ultrasound transducer slowly toward the clavicle. Once the transducer cannot be advanced distally, tilt the transducer aiming the ultrasound beam toward the feet to visualize the subclavian and brachiocephalic veins. It is important to assess for complete compressibility of the IJV ( Video 36.3 ). Asymptomatic thrombosis in the IJV is not uncommon in hospitalized and critically ill patients, and lack of compressibility is diagnostic for deep venous thrombosis. Both complete and partially occluding thrombi manifest with lack of compression ( Fig. 36.3 and Videos 36.4 – 36.6 ). Color and spectral Doppler can supplement the compression ultrasound exam when evaluating for deep venous thrombosis ( Video 36.7 ) (see Chapter 35 ). Avoid serial compressions after diagnosing IJV thrombosis given the potential risk of dislodging the thrombus. Patients who have had multiple prior IJV cannulations, especially large-caliber temporary hemodialysis catheters, may have a stenotic IJV ( Fig. 36.4 and Video 36.8 ).

Cross-Sectional Anatomy of the Neck.

(A) The transducer is placed on the anterolateral neck in a transverse orientation. (B) The internal jugular vein is anterior and lateral to the common carotid artery (CCA) . The thyroid gland and trachea are medial to both vessels. RIJV , Right internal jugular vein; SCM , sternocleidomastoid muscle.

Thrombus in the Internal Jugular Vein.

A large, echogenic thrombus is visualized in the lumen of the internal jugular vein. CCA , Common carotid artery; IJV , internal jugular vein. It should be noted that even without thrombus present, this would not be a safe needle trajectory given the CCA lying immediately deep to the IJV.

Stenotic Internal Jugular Vein.

CCA , common carotid artery; IJV , Internal jugular vein.

Select the safest needle insertion site based on the following characteristics: 1) absence of thrombus, 2) widest diameter, 3) shallowest depth, and 4) relationship to the CCA (preferably not overlying the CCA). If the IJV directly overlies the CCA, the transducer should be rocked to assess whether the needle trajectory would avoid the CCA if the posterior wall were punctured.

After the best insertion site has been determined, the ultrasound machine should be prepared. Position the ultrasound machine in the operator’s direct line of sight to avoid head turning to view the screen. Cover the transducer with a sterile sheath prior to placing it on the sterile field. Hold the transducer in the nondominant hand while holding the needle in the dominant hand. Orient the transducer in the nondominant hand such that the left side of the transducer corresponds with the left side of the screen. Two approaches to real-time needle guidance are described: transverse (short-axis) and longitudinal (long-axis) (see Chapter 4 , Figs. 4.8 ).

In a transverse or short-axis approach, the introducer needle crosses the plane of the ultrasound beam, and only a portion of the needle shaft is visualized, rather than the actual tip of the needle, unless care is taken to first identify the needle tip. First, center the IJV in a transverse view on the screen and assess the depth to the vessel ( Fig. 36.5 ). Tilt the transducer pointing the ultrasound beam toward the operator. Insert the needle at a 45- to 60-degree angle relative to skin in the center of the transducer ( Fig. 36.6 ). Identify the needle tip on the screen by very subtly tilting the transducer to and from the needle insertion site. The first appearance of the hyperechoic needle with shadow is assumed to be the tip of the needle. It is imperative to identify and track the needle tip. Advance the needle only 1 to 2 mm at a time while continuously tracking the needle tip by tilting the transducer back and forth. Redirect the needle as needed if its trajectory is off target. As the skin is traversed as described above, the needle tip will be visualized denting the IJV ( Video 36.9 ), followed by puncturing and entering the vessel ( Fig. 36.7 and Video 36.10 ). The needle tip should be confirmed to be in the IJV ( Video 36.11 ).

Depth of Internal Jugular Vein.

Measure the distance from skin surface to center of the vessel lumen. In this example, this distance is 1.5 cm. CCA , Common carotid artery; IJV , internal jugular vein; SCM , sternocleidomastoid muscle. Note also that an orientation of the IJV and CCA is achieved whereby the CCA is not immediately deep to the IJV.

Transverse Approach (Short-Axis Technique).

The transducer is held tilted toward the needle. The needle insertion angle is 45 to 60 degrees to the skin surface and approximately 90 degrees relative to the ultrasound beam to maximize visualization of the needle tip.

Needle Tip in the Internal Jugular Vein.

The needle tip is seen in the center of the venous lumen before inserting the guidewire. CCA , Common carotid artery; IJV , internal jugular vein.

After the needle enters the IJV, a guidewire is inserted to maintain the track. After placing the guidewire, the operator should confirm proper placement of the guidewire in the IJV and not the CCA ( Fig. 36.8 and Video 36.12 ). Emerging literature supports visualization of the guidewire in the brachiocephalic vein to confirm proper placement prior to dilation of the vein. Compression and Doppler ultrasound (color flow, power, pulsed-wave) may also be used to confirm placement of the guidewire in the vein. If any doubt exists about placement of the guidewire in the IJV versus the CCA, the guidewire should be removed promptly with minimal risk of harm to the patient; however, if the IJV is dilated and a CVC is inadvertently inserted in the CCA, major complications can occur, including stroke. After the guidewire has been confirmed in the IJV, proceed using standard technique: make a skin nick, dilate, and insert the catheter over the guidewire.

Guidewire in the Internal Jugular Vein.

Visualization of the guidewire within the internal jugular vein to confirm proper placement without traversing the posterior wall of the vessel is a critical step.

In a longitudinal or long-axis approach, the plane of the ultrasound beam is parallel to the course of the target vessel. Insertion of CVCs in the IJV using a longitudinal approach is an advanced skill that should be attempted by providers experienced in performing real-time ultrasound-guided procedures. First, the IJV should be centered in a transverse view on the screen and then the transducer is rotated 90 degrees with the transducer orientation marker pointed toward the operator. Once the transducer is centered over the IJV in a longitudinal plane, the operator must focus on ensuring the transducer remains in the same plane without sliding medially or laterally. Care must be taken to prevent the transducer from sliding medially over the arterial lumen, and mistaking the CCA for the IJV. The pulsatility and thick walls distinguish the CCA from IJV in a longitudinal view. Insert the needle at a 45- to 60-degree angle relative to skin in the center of the short side of the transducer ( Fig. 36.9 ). The needle insertion angle and distance from the transducer should be appropriate for the depth of the target vessel. Shallow needle insertion angles are used for superficial vessels, whereas steep angles are used for deep vessels ( Fig. 36.10 ) . The needle tip and shaft have to remain in the plane of the ultrasound beam to ensure visualization throughout needle advancement. Adjust the needle trajectory to aim the tip toward the target vessel at its widest diameter in a longitudinal view. Track the needle tip in real time as it traverses the soft tissues and enters the IJV.

Longitudinal Approach (Long-Axis Tech­nique).

The transducer is positioned longitudinally over the course of the internal jugular vein. The needle insertion angle is steep (45–60 degrees) relative to the skin surface.

Needle Insertion Angle and Vessel Depth.

The needle insertion angle is normally 30–60° and should be adjusted for the depth of the target vessel.