Microvascular Response to the Roos Test Has Excellent Feasibility and Good Reliability in Patients With Suspected Thoracic Outlet Syndrome

Abstract

Background: Exercise oximetry allows operator-independent recordings of microvascular blood flow impairments during exercise and can be used during upper arm provocative maneuvers. Objective: To study the test-retest reliability of upper-limb oximetry during the Roos test in patients with suspected thoracic outlet syndrome (TOS). Materials and Methods: Forty-two patients (28 men, 14 women; mean age: 40.8 years) were examined via transcutaneous oxygen pressure (TcpO2) recordings during two consecutive Roos tests in the standing position. The minimal decrease from rest of oxygen pressure (DROPmin) value was recorded after each maneuver was performed on both arms. The area under the receiver operating characteristic (ROC) curve defined the DROPmin diagnostic performance in the presence of symptoms during the tests. The Mann-Whitney U-test was used to compare the DROPmin in the symptomatic vs. asymptomatic arms. The test-retest reliability was analyzed with Bland-Altman representations. The results are presented as means ± standard deviations (SD) or medians [25-75 percentiles]. Results: The symptoms by history were different from the symptoms expressed during the Roos maneuvers in one-third of the patients. The DROPmin measurements were -19 [-36; -7] mmHg and -8 [-16; -5] mmHg in the symptomatic (n = 108) and asymptomatic (n = 60) arms, respectively. When TOS observed on ultrasound imaging was the endpoint, the area under the ROC curve (AUC) was 0.725 ± 0.058, with an optimal cutoff point of -15 mmHg. This value provided 67% sensitivity and 78% specificity for the presence TOS via ultrasound. When symptoms occurring during the test represented the endpoint, the AUC was 0.698 ± 0.04, with a cutoff point of -10 mmHg. This provided 62% sensitivity and 66% specificity for the presence of pain in the ipsilateral arm during the test. The test-retest reliability of DROPmin proved to be good but not perfect, partly because of unreliability of the provocation maneuvers. Conclusion: To the best of our knowledge, this study is the first to investigate microvascular responses during the Roos maneuver in patients with suspected TOS. The presence of symptoms was significantly associated with ischemia. TcpO2 facilitated the recording of both macrovascular and microvascular responses to the Roos test. The Roos maneuver should probably be performed at least twice in patients with suspected TOS.

Keywords: exercise; ischemia; microcirculation; oximetry; peripheral artery disease; provocative maneuvers.

FIGURE 1

Example of the Roos maneuver with TcpO2 recordings. The DROP calculation at time (t) is based on subtraction of the chest measurement from the arm measurements. Chest and arm changes are accounted for in the mean values measured over the 30 first seconds of recording “0.” TcpO2, transcutaneous oxygen pressure; DROP, decrease from the rest of oxygen pressure.

FIGURE 2

Transcutaneous oxygen pressure recordings are expressed as DROP values (mmHg) during two consecutive Roos maneuvers (gray squares). The x-axis represents the time in minutes. As shown, a dramatic decrease in the DROP values occurs during the Roos maneuvers on both sides, below –15 mmHg (dotted line). The corresponding arteriography shows the right (left panel) and left (right panel) sides, confirming occlusion of the subclavian artery during abduction of the arms (white arrows). This arteriography is from a 31-year-old woman who suffered for more than 4 years from upper limb pain, mostly on the right (dominant) side. She previously worked as a hairdresser, but had to stop this activity because of the pain. The pain originated at the shoulder and extended to the hands, with some paresthesias in the fourth and fifth digits. During the clinical examination, the Wright and Adson positions quickly led to a loss of the radial pulses. The Tinel test was negative. Bilateral TOS was suspected. A routine chest X-ray showed no abnormality of the cervico-thoracic junction. A duplex-scan demonstrated dynamic arterial and venous obstructions. Objective signs of lower plexus nerve lesions on electromyogram favored a neurogenic-type outlet syndrome. We also performed a dynamic bilateral angiography via a 4-Fr femoral puncture. This confirmed arterial outlet syndrome with an occlusive costoclavicular grip and a significant dynamic stenosis in the pectoralis minor muscle tunnel. She was prescribed an extended period of kinesiotherapy. DROP, decrease from the rest of oxygen pressure; TOS, thoracic outlet syndrome.

FIGURE 3

Bland-Altman representation of test-retest reliability on logarithmic scales. “LA” are 95% limits of agreement.

FIGURE 4

Transcutaneous oxygen pressure recordings expressed as DROP values (mmHg) during two consecutive Roos maneuvers (gray squares). The x-axis represents time in minutes before and after surgery. The –15 mmHg limit is shown as a dotted line. These recordings were performed on the same patient described in Figure 2 above. While she previously underwent an extended period of kinesiotherapy for several months without additional benefit, we proposed surgical treatment for her outlet syndrome. As shown, during the new pre-surgical visit (upper panel), the tests are positive on both sides. The surgery included complete resection of the right first rib (image 2) and pectoralis minor muscle resection through a Roos axillary approach. The patient rapidly recovered from surgery and expressed rapid pain relief. After surgery (lower panel), a moderate decrease in DROP is observed with test 2 on the left side, while test 1 was normal on both sides. The patient had no complaints of pain on the right side, but expressed moderate discomfort on the left side with test 2. DROP, decrease from the rest of oxygen pressure.