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

Participation of Arterial Ischemia in Positional-Related Symptoms among Patients Referred for Thoracic Outlet Syndrome

Objectives: The coexistence of arterial compression with neurogenic thoracic outlet syndrome (TOS) is associated with a better post-surgical outcome. Forearm transcutaneous oxygen pressure (TcpO2) using the minimal decrease from rest of oxygen pressure (DROPmin) can provide an objective estimation of forearm ischemia in TOS. We hypothesized that a linear relationship exists between the prevalence of symptoms (PREVs) and DROPmin during 90° abduction external rotation (AER) provocative maneuvers. Thereafter, we aimed to estimate the proportion of TOS for which arterial participation is present. Methods: Starting in 2019, we simultaneously recorded forearm TcpO2 recordings (PF6000 Perimed®) and the presence/absence of ipsilateral symptoms during two consecutive 30 s AER maneuvers for all patients with suspected TOS. We retrospectively analyzed the relationship between the prevalence of symptoms and DROPmin results. We estimated the number of cases where ischemia likely played a role in the symptoms, assuming that the relationship should start from zero in the absence of ischemia and increase linearly to a plateau of 100% for the most severe ischemia. Results: We obtained 2560 TcpO2 results in 646 subjects (69% females). The correlation between PREVs and DROPmin was 0.443 (p < 0.001). From these results, we estimated the arterial participation in TOS symptoms to be 22.2% of our 1669 symptomatic upper limbs. Conclusions: TcpO2 appears to be an interesting tool to argue for an arterial role in symptoms in TOS. Arterial participation is frequent in TOS. Whether DROPmin could predict treatment outcomes better than the sole presence of compression is an interesting direction for the future.

Nerve entrapment complicating neurogenic thoracic outlet syndrome surgery: A 10-year retrospective study

Neurogenic thoracic outlet syndrome results from compression of the brachial plexus. The symptoms are mainly pain, upper-limb weakness and paresthesia. Management always starts with a rehabilitation program, but failure of rehabilitation may necessitate surgery. In practice, we observed that several patients developed secondary distal nerve entrapment in the months following surgery, with no preoperative compression. We aimed to assess the occurrence of distal nerve entrapment after surgery for neurogenic thoracic outlet syndrome in a retrospective cohort study. Seventy-four patients were included; 82% females; mean age, 39.4 ± 9.4 years. There were 36.5% with high intensity and 63.5% with low to moderate intensity work. Eighteen (24.3%) developed secondary upper-limb entrapment at 10.6 ± 5.8 months after surgery. Sixteen had a single entrapment and 2 had two different entrapments. In 10 cases (50%) the ulnar nerve was involved at the elbow, in 7 (35.0%) the radial nerve at the radial tunnel, and in 3 (15.0%) the median nerve. No differences were found between patients with and without secondary nerve entrapment in gender (p = 0.51), mean age (p = 0.44), symptom duration (p = 0.92) or work intensity (p = 0.26). Further studies are needed to confirm these results and to shed light on the underlying mechanisms.

Possible role of the botulinum toxin in the management of neurogenic thoracic outlet syndrome: a systematic review

INTRODUCTION

Thoracic outlet syndrome (TOS) is related to the compression and/or the traction of the upper-limb neurovascular bundle, responsible for a chronic painful impairment. Neurogenic TOS (NTOS) is the most common manifestation. It remains a challenging diagnosis and its treatment is also difficult. Botulinum toxin (BTX) has been described to help both the diagnosis and the symptoms improvement.

EVIDENCE ACQUISITION

A systematic literature research was performed using PubMed, ScienceDirect, and Embase databases to collect studies reporting the use of BTX in NTOS management. We followed the PRISMA guidelines, and the included studies were evaluated using the GRADE approach.

EVIDENCE SYNTHESIS

We included 10 original articles representing 555 patients. Various outcomes were considered, and results varied from a study to another. Symptoms relief varied from an absence of BTX effectiveness to 84.1% of improvement; relief duration was also reported from none to 88 days. BTX injections were debatable predictors of surgical procedure successes due to low evidence. There was a huge gap between the studies concerning side-effects of the BTX procedures, from none to 100% of the patients.

CONCLUSIONS

There is no evidence for considering BTX injection as a validated tool for the management of NTOS. There might be a slight effect on symptoms, but outcomes are very variable, which prevents further interpretations. The use of BTX should be evaluated in larger prospective cohorts with more standardized outcomes.

Rapid Functional Recovery After Thoracic Outlet Decompression in a Series of Adolescent Athletes With Chronic Atraumatic Shoulder-Girdle Pain, Scapular Winging/Dyskinesis, and Normal Electrodiagnostic Studies

BACKGROUND

Spontaneous shoulder-girdle pain and scapular winging/dyskinesis can be caused by several neuromuscular disorders identifiable by electrodiagnostic studies (EDX). We describe a group of adolescent athletes with this clinical presentation but normal EDX, followed by later development of neurogenic thoracic outlet syndrome (NTOS).

METHODS

We identified patients referred for evaluation of NTOS that had a history of chronic atraumatic shoulder-girdle pain, scapular winging/dyskinesis, and normal EDX. Each was refractory to conservative management and underwent supraclavicular decompression and brachial plexus neurolysis for NTOS. Functional disability was quantified by Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) scores.

RESULTS

There were 5 female patients with a mean age at symptom onset of 14.2 ± 0.4 years, including spontaneous severe pain in the shoulder, scapula, and arm, along with prominent scapular winging/dyskinesis, and normal EDX. Symptoms had persisted for 18.9 ± 4.0 months prior to referral, with pronounced upper extremity disability (mean QuickDASH, 54.6 ± 6.9). By 3 months after surgical treatment for NTOS, all 5 patients experienced near-complete symptom resolution, including scapular winging/dyskinesis, with markedly improved function (mean QuickDASH, 2.2 ± 1.3) and a return to normal activity.

CONCLUSIONS

A subset of patients with chronic atraumatic shoulder-girdle pain, scapular winging/dyskinesis, and normal EDX may develop dynamic brachial plexus compression characteristic of NTOS, exhibiting an ischemic "Sunderland-zero" nerve conduction block for which surgical decompression can result in rapid and substantial clinical improvement. The presence of surgically treatable NTOS should be considered for selected patients with long-standing scapular winging/dyskinesis who fail conservative management.

General Overview and Diagnostic (Imaging) Techniques for Neurogenic Thoracic Outlet Syndrome

Thoracic outlet syndrome is an uncommon and controversial syndrome. Three different diagnoses can be made based on the compressed structure, arterial TOS, venous TOS, and neurogenic TOS, though combinations do exist as well. Diagnosing NTOS is difficult since no specific objective diagnostic modalities exist. This has resulted in a lot of controversy in recent decades. NTOS remains a clinical diagnosis and is mostly diagnosed based on the exclusion of an extensive list of differential diagnoses. To guide the diagnosis and treatment of TOS, a group of experts published the reporting standards for TOS in 2016. However, a consensus was not reached regarding a blueprint for a daily care pathway in this document. Therefore, we constructed a care pathway based on the reporting standards for both the diagnosis and treatment of NTOS patients. This care pathway includes a multidisciplinary approach in which different diagnostic tests and additional imaging techniques are combined to diagnose NTOS or guide patients in their treatment for differential diagnoses. The aim of the present work is to discuss and explain the diagnostic part of this care pathway.

Use of Electroneuromyography in the Diagnosis of Neurogenic Thoracic Outlet Syndrome: A Systematic Review and Meta-Analysis

Neurogenic thoracic outlet syndrome (NTOS) is a disabling condition. Its diagnosis remains challenging and is mainly guided by examination. Yet, electrophysiological evaluations are the gold standard for diagnosis of entrapment syndromes. We aimed to assess the interest of electrophysiological evaluation to diagnose NTOS. A systematic literature research was performed using PubMed, ScienceDirect, Embase, Cochrane and Google Scholar databases to collect studies reporting results of electrophysiological assessment of patients with NTOS. Then, a meta-analysis was conducted. Nine studies were eligible and concerned two hundred and thirteen patients. Results were heterogenous among studies and the quality of evidence was very low to moderate. Data could not evaluate sensitivity or specificity of electrophysiological evaluations for NTOS. The meta-analysis found significantly decreased amplitudes of medial antebrachial cutaneous nerve SNAP (sensory nerve action potential), ulnar SNAP, median CMAP (compound motor action potential) and ulnar CMAP. Needle examination found abnormalities for the abductor pollicis brevis, first dorsal interosseous and adductor digiti minimi. Unlike most upper-limb entrapment syndromes, nerve conduction assessment only provided clues in favour of NTOS. Decreased amplitude for ulnar SNAP, medial antebrachial cutaneous SNAP, median CMAP and ulnar CMAP should be assessed, as well as needle examination. Larger studies are needed to evaluate the sensitivity and specificity of electrophysiology in NTOS diagnosis.

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.