BRIEF RESEARCH COMMUNICATIONS • Development of a New Technique for Ultrasound Imaging of the Innominate Vein and the Venous Angle

WhiteSwell is a new treatment for acute decompensated heart failure involving placing a device at the left venous angle to create a low-pressure zone to facilitate thoracic duct lymph flow.

In order to facilitate this, the authors developed a new technique using two acoustic windows with a microconvex probe that has a medium-range (4-10 MHz) frequency to enable deeper visualization of the left innominate vein (INV).

While ultrasound is a valuable tool to guide central venous access, it can be challenging to visualize the INV.

The authors conducted a prospective, single-center, noninvasive feasibility study to assess the technique in 65 subjects.

To confirm the ability to visualize the venous angle at the convergence of the left internal jugular vein and the left subclavian vein, three populations were enrolled:

1. Patients with acute decompensated heart failure
2. Subjects with cardiovascular implantable electronic devices
3. Healthy individuals

A microconvex probe (8C-RS, 4-10 MHz) was used for bifurcation and INV views. A linear probe (8L-RS, 4-12 MHz) was used for standard left internal jugular vein visualization. Visualization quality was rated on the basis of radiologist impression as follows: 1 = poor, 2 = good, and 3 = excellent.

The examination included identifying the left-sided vessels at the mid-neck using the linear probe in the short axis view.

Then, in the supraclavicular position a microconvex probe was used to fit into the narrow window at the supraclavicular notch and to cover a wider view of the venous angle. A sliding movement from the lower neck to the supraclavicular fossa following the skin contour was used until the probe was 45  to the vertical plane and 30 to the horizontal plane of the subject.

In this position, the venous angle with three vessels can be visualized:

1. Left internal jugular vein
2. Left subclavian vein
3. Innominate vein

For the suprasternal technique, the head was placed in a centered position with neck extension, allowing the use of a microconvex probe to have contact with the skin and a wider angle. A deeper scale preset was used, as the INV in this area is a deeper structure. The tail of the probe was directed cephalad, and fanning movements were used to optimize INV visualization.

The INV was visualized in 97% of subjects (63 of 65) using a suprasternal view and in 100% of subjects (65 of 65) using a supraclavicular view. The suprasternal window provides a horizontal view of the INV as it courses across the sector, thus enabling visualization of a longer portion.

INV visualization was good in both views in 44 of 65 patients, was good in at least one view in 17 of 65 and was challenging in both the supraclavicular and suprasternal views in four of 65 subjects.

The authors concluded that using both the suprasternal and supraclavicular windows with a microconvex ultrasound probe provided visualization of the venous angle and the INV.

They suggest that this new technique may support the placement of novel therapeutic devices in the innominate vein.