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Chap-10.qxd 29~8~04 14:48 Page 141
DUPLEX ASSESSMENT OF UPPER EXTREMITY ARTERIAL DISEASE
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Provocation maneuvers used for the assessment of TOS. A: Hyperabduction test. The arm is abducted (1) and the arm externally rotated (2). The arm can also be raised or lowered during this test (3 and 4) and the head rotated to either side (5 and 6). B: Costoclavicular maneuver. During deep inspiration (1) the chest is pushed forward (2) and the arms backward (3). The head is turned from side to side (4).
Figure 10.10
possible compression between the scalene muscles or the presence of a cervical rib.
Finally, the patient should also be asked to place the arm in any position that provokes symptoms, such as raising it above the head. Any change to, or loss of, the Doppler signal during these maneuvers suggests compression of the SA. The patient should also be asked to indicate any symptoms that occur during arm maneuvers, as a normal Doppler signal in the presence of symptoms may indicate a nonvascular cause for the complaint.
Duplex assessment of TOS
To perform a duplex scan for TOS, the patient should lie supine on the examination table with the arms resting by the sides. Sometimes it may be nec- essary to image the arteries with the patient in a
sitting position so that certain provocation tests can be performed. The SA is initially imaged from the supraclavicular and infraclavicular positions. The flow velocities are recorded and any abnormal- ities, such as tortuosity or aneurysmal dilations, noted. The SA can then be imaged using any of the provocation maneuvers that were found to reduce or obliterate the radial artery signal with pencil Doppler. One ver y useful maneuver involves scanning of the SA from the infraclavicular position while the arm is fully abducted (Fig. 10.11). The hand can be drawn toward the back of the patient’s head and eventually placed behind the head. Pressure is then gently applied to the arm to push it back- ward. Any changes in the flow pattern or areas of significant velocity increase along the SA during provocation tests should be recorded. Typically, most high-velocity jets are recorded in the region of the