Neurogenic thoracic outlet syndrome: Bringing order to chaos

Surgical Management of Neurogenic Thoracic Outlet Syndrome: Exploring the Efficacy of the Posterior Intermuscular Approach in Cases Involving Bone Anomalies

BACKGROUND AND OBJECTIVES

This article presents a cohort study focusing on neurogenic thoracic outlet syndrome (NTOS) caused by bone anomalies in the cervicothoracic region, specifically the extraforaminal area and the scalene triangle. Our aim was to contribute to understanding NTOS diagnosis and management, particularly in patients with bone anomalies, and to highlight the potential benefits of the posterior intermuscular approach as a surgical option in this particular patient group.

METHODS

We retrospectively evaluated the patients who underwent surgery for NTOS with accessory ribs or an elongated cervical vertebrae 7 (C7) transverse process (n = 9). Patients' clinical data, preoperative neurophysiological tests, cervical computed tomography (CT) scans, CT angiography, and postoperative cervical CT scans were reviewed. A single experienced surgeon used the posterior intermuscular approach on all patients. The accessory rib and/or elongated C7 transverse process and fibrous bands were removed; C7, C8, and T1 branches of the plexus were decompressed; and neurolysis was performed. Quality of life, a functional outcome, was measured by using Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, and pain was measured using visual analog scale scores.

RESULTS

The mean follow-up time after surgery was 7 months (range: 4-10 months). Before surgery, the mean DASH score was 55.8 ± 5.6. At the 3- and 6-month postoperative evaluations, the mean DASH scores decreased to 15.7 ± 5.8 and 15.4 ± 5.7, respectively. The mean visual analog scale score was 8.2/10 before surgery and decreased to 2.4/10 and 2.1/10 at the 3- and 6-month postoperative evaluations, respectively. All patients experienced good or excellent recovery at the 3- and 6-month postoperative evaluations.

CONCLUSION

Cervicothoracic extraforaminal area may be the primary site of nerve compression in NTOS, and posterior decompression using the posterior intermuscular approach can provide efficient access to extraforaminal nerve roots.

Upper arm versus forearm transcutaneous oximetry during upper limb abduction in patients with suspected thoracic outlet syndrome

Context: Thoracic outlet syndrome (TOS) is common among athletes and should be considered as being of arterial origin only if patients have “clinical symptoms due to documented symptomatic ischemia.” We previously reported that upper limb ischemia can be documented with DROPm (minimal value of limb changes minus chest changes) from transcutaneous oximetry (TcpO2) in TOS.

Purpose: We aimed to test the hypothesised that forearm (F-) DROPm would better detect symptoms associated with arterial compression during abduction than upper arm (U-) DROPm, and that the thresholds would differ.

Methods: We studied 175 patients (retrospective analysis of a cross-sectional acquired database) with simultaneous F-TcpO2 and U-TcpO2 recordings on both upper limbs, and considered tests to be positive (CS+) when upper limb symptoms were associated with ipsilateral arterial compression on either ultrasound or angiography. We determined the threshold and diagnostic performance with a receiver operating characteristic (ROC) curve analysis and calculation of the area under the ROC curve (AUROC) for absolute resting TcpO2 and DROPm values to detect CS+. For all tests, a two-tailed p < 0.05 was considered indicative of statistical significance.

Results: In the 350 upper-limbs, while resting U-TcpO2 and resting F-TcpO2 were not predictive of CS + results, the AUROCs were 0.68 ± 0.03 vs. 0.69 ± 0.03 (both p < 0.01), with the thresholds being −7.5 vs. −14.5 mmHg for the detection of CS + results for U-DROPm vs. F-DROPm respectively.

Conclusion: In patients with suspected TOS, TcpO2 can be used for detecting upper limb arterial compression and/or symptoms during arm abduction, provided that different thresholds are used for U-DROPm and F-DROPm.

Clinical Trial Registration:ClinicalTrials.gov, identifier NCT04376177.

Quantitative analysis of venous outflow with photo-plethysmography in patients with suspected thoracic outlet syndrome

Background

Venous compression is the second most frequent form of thoracic outlet syndrome (TOS). Although venous photo-plethysmography (PPG) has been largely used to estimate the consequences of chronic thromboses (Paget Schroetter syndrome), systematic direct quantitative recording of hemodynamic consequences of positional venous outflow impairment in patients with suspected TOS has never been reported.

Objective

We hypothesized that moving the arms forward (prayer: “Pra” position) while keeping the hands elevated after a surrender/candlestick position (Ca) would allow quantification of 100% upper limb venous emptying (PPGmax) and quantitative evaluation of the emptying observed at the end of the preceding abduction period (End-Ca-PPG), expressed in %PPGmax.

Materials and methods

We measured V-PPG in 424 patients referred for suspected TOS (age 40.9 years old, 68.3% females) and retrieved the results of ultrasound investigation at the venous level. We used receiver operating characteristics curves (ROC) to determine the optimal V-PPG values to be used to predict the presence of a venous compression on ultrasound imaging. Results are reported as a median (25/75 centiles). Statistical significance was based on a two-tailed p < 0.05.

Results

An End-Ca-PPG value of 87% PPGmax at the end of the “Ca” period is the optimal point to detect an ultrasound-confirmed positional venous compression (area under ROC: 0.589 ± 0.024; p < 0.001). This threshold results in 60.9% sensitivity, 47.6% specificity, 27.3% positive predictive value, 79.0% negative predictive value, and 50.8% overall accuracy.

Conclusion

V-PPG is not aimed at detecting the presence of a venous compression due to collateral veins potentially normalizing outflow despite subclavicular vein compression during abduction, but we believe that it could be used to strengthen the responsibility of venous compression in upper limb symptoms in TOS-suspected patients, with the possibility of non-invasive, bilateral, recordable measurements of forearm volume that become quantitative with the Ca-Pra maneuver.

Clinical trial registration

[ClinicalTrials.gov], identifier [NCT04376177].

Redo surgery for neurogenic thoracic outlet syndrome is useful

INTRODUCTION

Surgery for Neurogenic Thoracic Outlet Syndrome (NTOS) has shown good outcome in numerous case series. However, 5-30% of patients will have persistent or recurrent symptoms, caused by incomplete first rib resection, reattachment of residual scalene muscle, fibrous scarring around the brachial plexus or a wrong NTOS diagnosis. In patients with a sound diagnosis of recurrent or persisting NTOS, not responding to conservative measures, a secondary procedure can be considered. We report the results of redo thoracic outlet decompression surgery through the supraclavicular approach (SC-REDO-TOD) for persistent or recurrent NTOS.

METHODS

A retrospective review of a prospective database was performed. Every patient referred from September 2016 until January 2020 was eligible for inclusion. In a SC-REDO-TOD we perform complete (cartilage-cartilage) resection of the first rib, any bony and fibrous anomalies, complete anterior and middle scalenectomy and complete neurolysis of the brachial plexus (= complete anatomical decompression of the brachial plexus). Clinical outcomes were assessed by questionnaires including the DASH (Disability of Arm, Shoulder and Hand), CBSQ (Cervico-Brachial Symptoms Questionnaire) and TOS disability scale.

RESULTS

In total, 45 patients had a SC-REDO-TOD. The median duration of hospital admission after SC-REDO-TOD was 1.41 days (IQR 1.00). In total 30/45 (66.66%) patients had recurrent NTOS and 15/45 (33.33%) patients had persisting NTOS. Postoperative complications were seen in 8 (18.18%) patients. 1 Patient had postoperative complications with permanent impairment (Horner syndrome). 7 Patients had postoperative complications with full recovery (3 patients had a chylous leakage which was treated with a median-chain triglycerides diet for 6 weeks, 3 patients had transient phrenic nerve palsy with full recovery < 6 weeks, 1 patient had a discrete Horner syndrome which resolved in 6 weeks). The median time of follow-up was 19.50 months (interquartile range (IQR) 14.00) and the response rate to the questionnaires was 91.11% at 6 months and 64.44% at 12 months. We found a positive and statistically significant difference for DASH score, CBSQ score and TOS Disability Scale score comparing scores for all patients. (DASH score: p<0.001; CBSQ score: p<0.001; TOS Disability Scale: p<0.001). Patients with first rib remnants showed a significant better response (lower DASH, CBSQ and TOS Disability Scale scores) compared to patients without first rib remnants (DASH score: p=0.004; CBSQ score: p<=0.014; TOS Disability Scale: p=0.009).

CONCLUSION

SC-REDO-TOD after a previous NTOS surgery shows good results with a low risk of permanent impairment. NTOS patients with first rib remnants after primary surgery seem to benefit the most from REDO surgery.

Relationship Between Inflow Impairment and Skin Oxygen Availability to the Upper Limb During Standardized Arm Abduction in Patients With Suspected Thoracic Outlet Syndrome

Objective

Thoracic outlet syndrome (TOS) should be considered of arterial origin only if patients have clinical symptoms that are the result of documented symptomatic ischemia. Simultaneous recording of inflow impairment and forearm ischemia in patients with suspected TOS has never been reported to date. We hypothesized that ischemia would occur in cases of severely impaired inflow, resulting in a non-linear relationship between changes in pulse amplitude (PA) and the estimation of ischemia during provocative attitudinal upper limb positioning.

Design

Prospective single center interventional study.

Material

Fifty-five patients with suspected thoracic outlet syndrome.

Methods

We measured the minimal decrease from rest of transcutaneous oximetry pressure (DROPm) as an estimation of oxygen deficit and arterial pulse photo-plethysmography to measure pulse amplitude changes from rest (PA-change) on both arms during the candlestick phase of a “Ca + Pra” maneuver. “Ca + Pra” is a modified Roos test allowing the estimation of maximal PA-change during the “Pra” phase. We compared the DROPm values between deciles of PA-changes with ANOVA. We then analyzed the relationship between mean PA-change and mean DROPm of each decile with linear and second-degree polynomial (non-linear) models. Results are reported as median [25/75 centiles]. Statistical significance was p < 0.05.

Results

DROPm values ranged −11.5 [−22.9/−7.2] and − 12.3 [−23.3/−7.4] mmHg and PA-change ranged 36.4 [4.6/63.8]% and 38.4 [−2.0/62.1]% in the right and left forearms, respectively. The coefficient of determination between median DROPm and median PA-change was r² = 0.922 with a second-degree polynomial fitting, but only r² = 0.847 with a linear approach.

Conclusion

Oxygen availability was decreased in cases of severe but not moderate attitudinal inflow impairments. Undertaking simultaneous A-PPG and forearm oximetry during the “Ca + Pra” maneuver is an interesting approach for providing objective proof of ischemia in patients with symptoms of TOS suspected of arterial origin.

Duplex Ultrasound Studies Are Neither Necessary or Sufficient for the Diagnosis of Neurogenic Thoracic Outlet Syndrome

BACKGROUND

Duplex ultrasound (DU) is used in the diagnosis of neurogenic thoracic outlet syndrome (NTOS) to measure compression of the subclavian artery (SCA) which is thought to strengthen the NTOS diagnosis. However, the value of DU in NTOS remains unclear.

METHODS

A retrospective review of a prospectively acquired database from the TOS center of the Catharina Hospital Eindhoven was performed of patients referred between January 2017 and December 2019. Only "proven NTOS" patients, defined as a successful response to thoracic outlet decompression (TOD) surgery based on patient-reported outcomes (NRS pain scale, CBSQ and DASH score) were included to exclude wrongfully diagnosed NTOS patient. The presence of vascular symptoms (defined as discoloration, edema or temperature changes of the hand or fingers), results of provocative maneuvers, and outcome of DU was used for analysis. To assess the link between vascular symptoms and compression on DU, a chi-squared test was performed. Further, we looked for a correlation between vascular symptoms, compression on DU and clinical outcome using a repeated measures analysis of variance (ANOVA).

RESULTS

Vascular symptoms were seen in 49 of 133 patients (36.8%). In total, 51 of 133 patients (38.3%) had at least 50% variation in SCA peak systolic velocity (PSV) during DU at the level of SCA stenosis. SCA occlusion was seen in 11 patients (8.3%) during provocative maneuvers. The presence of clinical "arterial symptoms" was not significantly correlated with vascular laboratory findings, neither for alterations in PSV during DU (P = 0.245) nor for positional SCA occlusion (P = 0.540). No statistically significant correlations between the degree of SCA stenosis and postoperative outcomes, as measured with the DASH, CBSQ, or NRS scale for pain were found (P = 0.787).

CONCLUSIONS

The role of DU in the work-up of NTOS in patients with vascular complaints is questionable. Changes in flow velocities are seen in NTOS patients and do not correlate with "vascular symptoms" or clinical outcome.

Evaluation and Management of Neurogenic Thoracic Outlet Syndrome with an Overview of Surgical Approaches: A Comprehensive Review

Neurogenic thoracic outlet syndrome (NTOS) represents a disorder believed to involve compression of one or more neurovascular elements as they exit the thoracic outlet. This comprehensive literature review will focus on the occurrence, classification, etiology, clinical presentation, diagnostic measures, and both nonoperative and operative therapies for NTOS. NTOS represents the most common subtype of thoracic outlet syndrome and can significantly impair quality of life. Botulinum toxin injection into the anterior scalene muscle, or even the middle scalene or pectoralis minor muscles, can reduce the symptoms of this syndrome. The best available evidence for botulinum toxin therapy to the cervicothoracic muscles supports the value of this treatment for reducing pain in the affected extremity, and for an approximate duration of 2 months or more. Surgical approaches and newer minimally invasive surgical approaches offer high rates of improvement in select centers.

Arterial Digital Pulse Photoplethysmography in Patients with Suspected Thoracic Outlet Syndrome: A Study of the "Ca+Pra" Maneuver

The level of pulse amplitude (PA) change in arterial digital pulse plethysmography (A-PPG) that should be used to diagnose thoracic outlet syndrome (TOS) is debated. We hypothesized that a modification of the Roos test (by moving the arms forward, mimicking a prayer position (“Pra”)) releasing an eventual compression that occurs in the surrender/candlestick position (“Ca”) would facilitate interpretation of A-PPG results. In 52 subjects, we determined the optimal PA change from rest to predict compression at imaging (ultrasonography +/− angiography) with receiver operating characteristics (ROC). “Pra”-PA was set as 100%, and PA was expressed in normalized amplitude (NA) units. Imaging found arterial compression in 23 upper limbs. The area under ROC was 0.765 ± 0.065 (p < 0.0001), resulting in a 91.4% sensitivity and a 60.9% specificity for an increase of fewer than 3 NA from rest during “Ca”, while results were 17.4% and 98.8%, respectively, for the 75% PA decrease previously proposed in the literature. A-PPG during a “Ca+Pra” test provides demonstrable proof of inflow impairment and increases the sensitivity of A-PPG for the detection of arterial compression as determined by imaging. The absence of an increase in PA during the “Ca” phase of the “Ca+Pra” maneuver should be considered indicative of arterial inflow impairment.

Long-term outcome over a decade after first rib resection for neurogenic thoracic outlet syndrome

OBJECTIVES

The aim was to determine long-term outcomes over a decade after first rib resection (FRR) in patients with neurogenic thoracic outlet syndrome (NTOS). A secondary aim was to investigate correlation of residual rib stump with long-term symptoms.

METHODS

This ambispective cohort included patients who underwent transaxillary FRRs for NTOS between 1998 and 2007. Short-term outcomes at 3-month clinical follow-up were retrospectively collected from medical records. Patients who agreed to participate in the study were invited to a long-term clinical follow-up in 2019. Disabilities of Arm, Shoulder, and Hand Score and Cervical Brachial Symptom Questionnaire were used. A chest X-ray limited to a clavicular projection was taken, and the length of the residual first rib was measured.

RESULTS

Twenty patients {mean age 41.8 [standard deviation (SD): 10.3 years]} who underwent 27 FRRs participated in the study. The mean follow-up time was 14.9 (SD: 3.6) years. Excellent or good recovery was noted after 16 (59.3% of operated arms) operations in the short-term follow-up and 22 (81.5%) operations in the long-term follow-up. No reoperations were necessary for residual symptoms. The mean Cervical Brachial Symptom Questionnaire score was 26.7 (SD: 28.2) (maximum 120), and the Disabilities of Arm, Shoulder, and Hand Score was 21.1 (SD: 18.4) (maximum 100) points. Twenty-six patients (96.3%) had a noticeable residual first rib stump. The mean length of the residual first rib was 28.9 (SD: 9.5) mm. More than 30-mm rib stump did not indicate a worse long-term outcome.

CONCLUSIONS

This study showed good long-term outcome without symptom recurrence after FRR for NTOS. In most patients, after surgery, quality of life and ability to work improved. Residual rib stump length was not associated with the treatment outcome.

Normal Costoclavicular Distance as a Standard in the Radiological Evaluation of Thoracic Outlet Syndrome in the Costoclavicular Space

BACKGROUND

The costoclavicular space is a common site of thoracic outlet syndrome. When there is no anatomical alteration, the diagnosis of thoracic outlet syndrome is difficult. Several authors relate costoclavicular distance to symptoms of thoracic outlet syndrome; however, there is no standardized site for measurement of the costoclavicular distance. This study aimed to determine the standard costoclavicular distance at neurovascular bundle crossing points (near the subclavian vein [Measure V] and the subclavian artery/brachial plexus branches [Measure NA]) using high-resolution chest computed tomography (CT) scans and evaluate its variations with respect to age, sex, height, and body mass index.

METHODS

This prospective cross-sectional observational study analyzed 150 of 156 CT scans from consecutive adult patients (72 females and 78 males). Costoclavicular distance was measured at the subclavian vein and brachial plexus/subclavian artery sites, where narrowing of the costoclavicular distance could lead to symptoms of thoracic outlet syndrome. Costoclavicular distance was analyzed with respect to sex, laterality, age group (<50 and ≥50 years) and body mass index group (body mass index <25 and ≥25 kg/m²).

RESULTS

Measures of V and NA were normally distributed. The measured costoclavicular distances were 1.23 cm (±0.40) and 1.24 cm (±0.47), respectively. Age (≥50 years) and body mass index (≥25 kg/m²) increased the costoclavicular distance. Measurements V and NA below the fifth percentile indicated a narrowed costoclavicular distance and a greater chance of developing thoracic outlet syndrome. For young (<50 years) and eutrophic patients (body mass index <25 kg/m²), these measurements were 0.46 and 0.44 cm, respectively; for young people and body mass index ≥25 kg/m², they were 0.54 and 0.24 cm, respectively; for the elderly (≥50 years) and eutrophic, they were 0.57 and 0.48 cm, respectively; and for the elderly and body mass index ≥ 25 kg/m², they were 0.83 and 0.73 cm, respectively. There was no significant difference between measurements V and NA regarding patient laterality, gender, and height.

CONCLUSIONS

Standardization of costoclavicular distance measurements at neurovascular bundle crossing points (subclavian vein and brachial plexus/subclavian artery) is possible. It may aid the diagnosis and help direct the therapeutic indications for symptomatic patients with thoracic outlet syndrome.

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

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.