Veins of the arm drain via the brachial or cephalic system. The brachial vein flows into the axillary vein, which is then joined by the cephalic vein to form the subclavian vein. The axillary vein is contiguous to the brachial vein traveling in the tunnel formed by the clavicle and subclavius muscle, anterior on the scalene muscle laterally, the first rib posterior-inferiorly, and the costo-clavicular ligament medially. In the subscapular region, the axillary vein receives both the subscapular and suprascapular veins. There are many anastomotic collateral pathways that can potentially bypass the axillary subclavian venous system. They may be divided into the shoulder to chest wall, the shoulder to ipsilateral anterior neck, the shoulder to ipsilateral posterior neck, and the shoulder to contralateral neck. In the event of axillary vein thrombosis, collaterals will usually develop from the shoulder to the chest wall. If the thrombosis extends to the subclavian vein, the collaterals generally develop to the posterior ipsilateral neck or from the shoulder to the contralateral neck [18] (see Fig. 39.1).

Thoracic outlet syndrome (TOS) refers to compression of the neurovascular bundle including the brachial plexus, subclavian artery, and subclavian vein as it exits the thoracic inlet delimited by the scalene muscles, the clavicle, and the first rib. Cervical ribs, musculofascial bands, and clavicular first rib anomalies have also been described as other causes. Symptoms include a combination of vascular and neurologic findings [19].

The upper extremity examination begins with a detailed assessment of signs, symptoms, past medical history, and risk factor analysis. The patient is then placed in a supine position and the radial vein is visualized from the wrist to the brachial vein. Next, the ulnar vein is followed from the wrist to the antecubital fossa; where the ulnar and radial veins form the brachial vein; the brachial vein is followed into the upper arm. At the junction of the basilic and brachial veins, the axillary vein is formed. The axillary vein is followed under the shoulder in the direction of the clavicle. The junction of the cephalic and axillary veins forms the subclavian vein. The junction of the subclavian and jugular veins originating at the innominate vein is not visualized routinely because of its depth; however, Doppler signals analyzed in this area provide indirect information about the patency of the central veins and newer color scanners have increased the ability to image them. Doppler signals of the subclavian vein are assessed. Normally, the flow is spontaneous and phasic with augmentation, and no reflux is identified. The internal jugular vein is examined from the clavicle cephalad until it dives under the mandible. Doppler signals of the internal jugular vein also are obtained to assess spontaneous and phasic flow. Finally, the superficial veins are assessed by following the basilic vein along the ulna until it joins the brachial vein. The largest-diameter antecubital vein connects the basilic and cephalic systems at the antecubital fossa. The antecubital perforator also is seen connecting the cephalic and brachial veins. The cephalic vein is traced along the radius and up the arm, where it joins with the axillary vein. The antecubital, cephalic, and basilic veins are the superficial veins of the upper extremity.

For reporting convenience and ease of communication, the upper extremity is divided into zones (see Fig. 39.2). In each examination, the position of the probe and localizing abnormal findings are reported. Each zone covers approximately 10 cm in length. Zone 1 is located at the suprasternal notch, Zone 3 at the acromial clavicular process, Zone 5 at the anticubital fossa, and Zone 8 at the wrist. Zones are used to report thrombus location allowing accurate comparison between studies and technologists.

When a visible intraluminal thrombus is identified, several of its characteristics are assessed to determine its relative age. These characteristics include clot occlusiveness, clot retraction, clot distention, vein compressions, echogenicity and homogeneity, the development of collateral venous channels, and recanalization. The clot may be partially or totally occluding. A totally occluding clot indicates an acute process. Free-floating thrombi actually are tethered distally but extend cephalad in the vein without a more proximal attachment to the vessel wall. These free-floating thrombus tails exhibit a side-to-side waving in the venous lumen that can be induced by gently bouncing the probe on the skin or with respiration. Free-floating tails usually become attached to the venous wall within 1–2 weeks. Characteristics of thrombi help age the thrombus (see Table 39.4).

Because of the limited ability to compress the deep venous system, especially in the area where the subclavian passes beneath the clavicle, technical modifications such as the use of adjunctive procedures and color flow duplex analysis are critical for correct assessment. In the areas where the vein may not be accessible to compression color Doppler, it is important to pay close attention to color flow gain settings to avoid oversaturation, which may obscure small intraluminal clots or areas of incomplete thrombosis [20].

It is important to document the full extent of the disease including the contralateral neck and proximal arm. Radio­nuclide venography may be of further benefit to diagnose Port-A-Cath thrombosis in clinical practice [21]. Duplex ultrasonography is the method of choice for the initial diagnosis of patients suspected with thrombosis of the upper extremities. However, in patients with isolated flow abnormalities, contrast venography should be performed [22]. Imaging pitfalls to avoid include the cephalic vein being diagnosed as the axillary vein. Probable occlusion of the internal jugular vein may also occur and mirror image artifact may result in the appearance of two subclavian veins in the supraclavicular region [23].

The use of duplex imaging of the upper extremity has increased dramatically. In the instance of dialysis access, upper extremity evaluations increasingly are being requested before placement. Preoperative evaluation of dysfunctional dialysis grafts allows operative planning [24]. Vein mapping improves graft durability in patients with disadvantaged outflow and vein size, and continuity can be established. The protocol implemented in the author’s vascular laboratory evaluates both veins and arteries (see Fig. 39.3). Blood flow in the superficial palmar arch is assessed at baseline with radial and ulnar comparison. In addition, calcifications and aberrant arterial anatomy are identified. Veins are evaluated using tourniquet distention if less than 3 mm at rest.

Thrombosis of the upper extremity has distinct characteristics when compared to the venous thromboembolism of the lower extremity. The American DVT Registry Database enrolled over 5,000 consecutive adult patients with acute DVT between October 2001 and October 2010, which reported approximately 11% of patients with UEDVT. The database included catheter-related venous thromboembolic disease of the upper extremity (6% of total cases), noncatheter-related venous UEDVT (5% of total cases), and lower extremity DVT (89% of total cases) [40].

When compared with lower extremity DVT, UEDVT patients were younger, less often white, leaner, had a lower body mass index, and most frequently presented with edema and less commonly with extremity discomfort, dyspnea, or chest pain [41]. Patients with UEDVT also had symptomatic PE less frequently (3% vs. 16%, P  <  0.001) [40]. The differences reported in comparison of lower extremity DVT in the upper extremity includes patients less frequently had a family history of venous thromboembolism (18% vs. 31%, P  =  0.06) or concomitant PE (8% vs. 31%, P  =  0.001). Additionally, they were less frequently carriers of Factor V Leiden (12% vs. 30%, P  =  0.009) and had lower thrombin generation marker levels [41].