Guidelines for the assessment of the circulation of the upper limbs and of the thoracic outlet syndrome

— Continuous Wave Doppler (CWD) — Duplex scanning (DS) — Color-coded duplex scanning (CDS) — Standard radiography (Xray) — Angiography by computed tomography (AngioCT) — Angiography by magnetic resonance (AngioMR) — Digital subtraction angiography (DSA) — Light reflection rheography (LRR) — Digital plethysmography — Capillary microscopy (CM) Procedure Vascular diseases of the upper limbs are less frequent than that of the lower limbs and of different nature. The most common in young patients is the thoracic out- let syndrome (TOS), due to compression of the subclavian artery and/or of the subclavianvein and/or of the roots of the brachial plexus or a combination of them. “Arterial TOS accounts for approximately 1% of the cases, “venous TOS” for 5% and the great majority is “neurogenic TOS”. When the vein becomes occluded by thrombosis such con- dition is called “Paget-Schroetter Syndrome”. The extrinsic compression of artery, vein or nervous roots is frequently secondary to anatomic anomalies as the presence of a cer- vical ribor an elongated C7 transverse process or anoma- lous fibrous or muscular bundles. On the arterial side a sec- ondary post-stenotic aneurysm may be observed and be the source of embolism. Primitive aneurysms are rare. Amongst atherosclerotic lesions, stenoses of the subcla- vian artery, usually pre-vertebral, or of the innominate ar- tery are the most frequent. On the venous side axillary-subclavian thromboses caused by central venous catheters or pacemakers are becoming more frequent. Lymph node compressions and neoplastic infiltrations are to be taken into consideration- frequent. After clinical assessment, the first investigations are by ultrasound. CWD and CDS are complementary in assess- ing both the extrinsic compression and the lesions of the arterial wall. An Xray of the cervical spine is indicated to detect a cer- vical rib and other osteo-articular anomalies. AngioMR and /or AngioCT complete the ultrasound studies in defining the site and nature of the compression and in assessing the lesions of the wall. DSA is indicated only for patients wno are candidates for open surgery or endovascular treatment when the non- invasive studies are insufficient. The assessment of the digital arteries and of the palmar arch can be performed both with CWD and with CDS or with plethysmography under basal conditions and with Al- len test. The circulation of the fingers can be completed with physical tests (hot and cold stimulation) or with phar- macological tests using plethysmography (photo plethys- mography). Microcirculation studies can also be undertak- en with nailfold capillary microscopy.Assessment of a thoracic outlet syndrome by US investigations The techniques are those described for arterial and ve- nous studies applied as follows: — Study of the patient seated and then laying down on his back — Assessment of the axillary-subclavian artery and vein with limb adducted along the body — Assessment of the axillary-subclavian artery and vein with the limb abducted (Wright manoeuvre 0-180°)