Indications
Suspected upper limb deep vein thrombosis (sudden swelling, pain, visible collateral veins), surveillance of central venous catheters and implanted ports, suspected Paget-Schroetter syndrome in athletes or after repetitive effort, assessment before device implantation, and superficial venous mapping before creation of an arteriovenous fistula or vein harvest for bypass.
Equipment and patient position
- Linear array transducer 7–12 MHz for the whole superficial course; for the retroclavicular subclavian and brachiocephalic segment, which is poorly compressible because of the bony shadow, colour Doppler becomes central, since the compression manoeuvre cannot be applied there.
- Patient supine, the arm abducted to 90° and slightly externally rotated, to expose the axillary and brachial course.
- For the internal jugular vein: the head rotated to the opposite side and, where possible, mild reverse Trendelenburg, to reduce the physiological venous collapse of the upright position.
Compression technique
The main diagnostic criterion for DVT is failure of the vessel to compress completely: progressive pressure is applied with the transducer, in the transverse plane, every 1–2 cm along the whole course, until the venous walls appose completely under normal conditions. A lumen that does not collapse, even partially, indicates intraluminal thrombus.
Where direct compression is not possible (the deep retroclavicular subclavian and brachiocephalic segment), colour and pulsed-wave Doppler are relied upon: loss of the normal respiratory phasicity, absence of spontaneous flow, or a monotonous continuous signal are indirect signs of proximal thrombosis.
Systematic scanning
Recommended sequence, always bilateral where the clinical picture requires it:
- Internal jugular vein: from the neck to its confluence with the subclavian vein.
- Subclavian vein: the distal (infraclavicular) segment can be compressed directly; the proximal segment is assessed with colour and pulsed-wave Doppler.
- Axillary and brachial veins (often duplicated, accompanying the artery of the same name): serial compression technique, as for the deep system of the lower limbs.
- Basilic and cephalic veins (superficial system): running medially and laterally respectively, relevant to peripheral venous access and to planning an arteriovenous fistula.
Suspected Paget-Schroetter syndrome
Effort-related subclavian and axillary vein thrombosis, typical of young and athletic patients (weightlifting, swimming, repetitive throwing), caused by dynamic compression of the vein in the costoclavicular space. The subclavian and axillary segment is assessed with the arm at rest and then during abduction and retraction of the shoulder (the elevated or hyperabducted position), looking for the appearance or worsening of dynamic venous compression, to be correlated with the clinical picture and, in doubtful cases, with venography.
Catheter-related thrombosis
In patients with a central venous catheter or PICC, the whole course of the device is examined, documenting the relationship between catheter and venous wall, any echogenic material around the catheter (fibrin sheath or mural thrombus) and, where present, the extent of thrombus proximal and distal to the insertion site.
What to document
- Complete or partial compressibility, segment by segment.
- Presence, site and extent of thrombus (occlusive or non-occlusive).
- Respiratory phasicity of flow in the segments that cannot be compressed.
- The result of the dynamic manoeuvres, where performed for suspected Paget-Schroetter syndrome.
- The relationship between the central venous catheter and the vessel wall, where relevant.
- Calibre and quality of the superficial veins, where the examination is requested for mapping before fistula creation or bypass.