Post-traumatic thoracic outlet syndrome

Neurogenic Thoracic Outlet Syndrome: A Primer for Hand and Peripheral Nerve Surgeons

Neurogenic thoracic outlet syndrome is a complex condition and is commonly misunderstood. Historically, much of this confusion has been because of its grouping with other diagnoses that have little in common other than anatomic location. Modern understanding emphasizes the role of small unmyelinated C type pain and sympathetic fibers. Diagnosis is primarily clinical, after ruling out other common conditions. Hand therapy is usually the first-line treatment with variable success. Local anesthetic, botulinum toxins, or steroid injections can aid in diagnosis and offer short-term relief. Although surgery can yield reliable results, it is technically challenging, and the preferred surgical approach is a matter of debate. Despite limitations in diagnosis and treatment, recognition and successful treatment of this condition can be highly impactful for the patient.

Congenital, Acquired, and Trauma-Related Risk Factors for Thoracic Outlet Syndrome-Review of the Literature

Thoracic outlet syndrome is a group of disorders that affect the upper extremity and neck, resulting in compression of the neurovascular bundle that exits the thoracic outlet. Depending on the type of compressed structure, the arterial, venous, and neurogenic forms of TOS are distinguished. In some populations, e.g., in certain groups of athletes, some sources report incidence rates as high as about 80 cases per 1000 people, while in the general population, it is equal to 2-4 per 1000. Although the pathogenesis of this condition appears relatively simple, there are a very large number of overlapping risk factors that drive such a high incidence in certain risk groups. Undoubtedly, a thorough knowledge of them and their etiology is essential to estimate the risk of TOS or make a quick and accurate diagnosis.

Considerations for Surgical Treatment of Neurogenic Thoracic Outlet Syndrome: A Meta-Analysis of Patient-Reported Outcomes

PURPOSE

It remains unclear whether the first rib resection, performed via a supraclavicular (SCFRR) or transaxillary (TAFRR) approach, is necessary for patients with neurogenic thoracic outlet syndrome (nTOS). In a systematic review and meta-analysis, we performed a direct comparison of patient-reported functional outcomes following different surgical approaches for nTOS.

METHODS

The authors searched PubMed, Embase, Web of Science, Cochrane Library, PROSPERO, Google Scholar, and the gray literature. Data were extracted based on the procedure type. Well-validated patient-reported outcome measures were analyzed in separate time intervals. Random-effects meta-analysis and descriptive statistics were used where appropriate.

RESULTS

Twenty-two articles were included, with 11 discussing SCFRR (812 patients), 6 discussing TAFRR (478 patients), and 5 discussing rib-sparing scalenectomy (RSS; 720 patients). The mean difference between preoperative and postoperative Disabilities of the Arm, Shoulder and Hand score was significantly different comparing RSS (43.0), TAFRR (26.8), and SCFRR (21.8). The mean difference between preoperative and postoperative visual analog scale scores was significantly higher for TAFRR (5.3) compared to SCFRR (3.0). Derkash scores were significantly worse for TAFRR compared to RSS or SCFRR. RSS had a success rate of 97.4% based on Derkash score, followed by SCFRR and TAFRR at 93.2% and 87.9%, respectively. RSS had a lower complication rate compared to SCFRR and TAFRR. There was a difference in complication rates: 8.7%, 14.5%, and 3.6% for SCFRR, TAFRR, and RSS, respectively.

CONCLUSIONS

Mean differences in Disabilities of the Arm, Shoulder and Hand scores and Derkash scores were significantly better for RSS. Higher complication rates were reported after the first rib resection. Our findings suggest that RSS is an effective option for the treatment of nTOS.

TYPE OF STUDY/ LEVEL OF EVIDENCE

Therapeutic IV.

Elective brachial plexus decompression in neurogenic thoracic outlet syndrome

We aimed to evaluate functional outcome following elective brachial plexus decompression by compressive fibrous band resection and limited on-demand bone abnormality resection in patients with neurogenic thoracic outlet syndrome (N-TOS). A retrospective continuous observational study was conducted in 17 patients (15 women and 2 men), with a mean age of 42 years, operated on between 2013 and 2021. Twenty brachial plexus decompressions were performed, for 13 objective and 7 subjective N-TOSs, including 3 recurrent N-TOSs. At last follow-up, outcomes were evaluated in terms of residual pain, paresthesia and hand motor deficit, plus patient-reported assessment and Quick-DASH functional scoring. No postoperative complications occurred. At a median follow-up of 12 months (range 6-48 months), complete pain relief and paresthesia resolution were found in 11/15 and 9/14 cases, respectively. All patients reported that their symptoms had improved. In contrast, hand muscle atrophy persisted in all cases (n = 11). Sensorimotor recovery seemed to be poorer and mean Quick-DASH score better in objective than subjective N-TOS patients. Elective brachial plexus decompression seemed to be a safe procedure, providing constant improvement in subjective symptoms related to lower trunk irritation. However, nerve release did not provide hand muscle recovery in patients with objective N-TOS. LEVEL OF EVIDENCE: IV.

Outcomes of 53 thoracic outlet syndrome cases with confirmed neurological deficit

INTRODUCTION

Neurogenic thoracic outlet syndromes (TOS) are dominated by the nonspecific forms. This study focuses only on the rarer true forms related to proximal nerve compression in the thoracic outlet, with the presence of motor (atrophy of the hand's intrinsic muscles) and/or sensory (hypoesthesia in the territory of the medial antebrachial cutaneous nerve) deficits. The objectives of this study were to define the clinical characteristics, anatomical causes and surgical results of this condition.

PATIENTS AND METHODS

Single-center retrospective study of 53 consecutive cases in 50 patients with an objective clinical deficit confirmed by nerve conduction studies. The population consisted of 47 adults and 3 children, 9 males and 41 females, with a mean age of 39 years (9-80 years), diagnosed between July 1994 and December 2019. An objective motor deficit was present in 50 cases, with the remaining 3 having a sensory deficit only. Forty cases underwent surgery, most often via the supraclavicular approach, while 13 cases did not undergo surgery because their deficit was longstanding and non-progressive.

RESULTS

One operated patient was lost in follow-up. An analysis of the medical records of 18 cases, including 15 operated cases found complete recovery in 4 cases, significant improvement in 9 cases and small improvement in 2 cases at a mean follow-up of 53 months (1-162 months). Thirty-four cases were reviewed in person, including 24 operated cases and evaluated with a mean follow-up of 135 months (36-284 months): the pain had disappeared in 21 cases, thenar atrophy persisted in 17 cases, which was associated with a claw-hand deformity in 3 cases, while 2 cases had an isolated claw-hand deformity. The patients were very satisfied with the procedure in 15 cases and satisfied in 9 cases. They evaluated the benefit of surgery at 87% and their upper limb function increased from 38% (10-60%) preoperatively to 77% (60-100%) at the review.

CONCLUSION

Few studies in the literature have focused on true neurogenic TOS cases. The treatment is surgical in progressive cases; an anatomical anomaly is always present. Surgical treatment eliminates the pain and helps to stabilize or even partially resolve the deficit. Despite a moderate objective gain, the patients' feeling of functional improvement is important with a high satisfaction rate.

LEVEL OF EVIDENCE

IV, retrospective.

Outcomes of Surgical Management of Neurogenic Thoracic Outlet Syndrome: A Systematic Review and Bayesian Perspective

PURPOSE

To provide a summary of the relevant evidence on outcomes of transaxillary first rib excision (TAFRE), supraclavicular first rib excision with scalenectomy (SCFRE), and supraclavicular release leaving the first rib intact (SCR) for patients with neurogenic thoracic outlet syndrome (TOS), and interpret the treatment effects from a Bayesian perspective.

METHODS

A systematic literature search and review were performed. Random-effects meta-analyses were conducted to estimate success rate and complete relief rate of each procedure. The probabilities of specified success rates and complete relief rates were calculated using a Bayesian method. Sensitivity analyses for TOS type, neck trauma, and cervical rib were performed. Complications of each procedure were also reviewed.

RESULTS

Data were extracted from 17 studies of TAFRE, 9 of SCFRE, and 14 of SCR to conduct the meta-analyses. The pooled success rate and complete relief rate were 0.76 (95% confidence interval [95% CI)], 0.65-0.85) and 0.53 (95% CI, 0.38-0.68) for TAFRE, 0.77 (95% CI, 0.68-0.85) and 0.57 (95% CI, 0.41-0.72) for SCFRE, and 0.85 (95% CI, 0.76-0.92) and 0.61 (95% CI, 0.35-0.84) for SCR, respectively. The probabilities of success rate greater than 70% were 90%, 87%, and 99% for TAFRE, SCFRE, and SCR, respectively. If the success rate of 80% or greater was considered, the probabilities were 34%, 31%, and 91%, respectively. The probabilities of complete relief rate of 50% or greater were 67%, 71%, and 69% for TAFRE, SCFRE, and SCR, respectively. Sensitivity analyses showed similar results. The complication rates for TAFRE, SCFRE, and SCR were, respectively, 22.5%, 25.9%, and 12.6%.

CONCLUSIONS

The SCR has a high probability of success rate greater than 80%; both TAFRE and SCFRE have high probabilities of a success rate greater than 70% but only low probabilities of success rate greater than 80%. The TAFRE and SCFRE have more complications than SCR.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Thoracic outlet syndrome as a consequence of isolated atraumatic first rib fracture

Neurogenic thoracic outlet syndrome (nTOS) resulting from an isolated first rib fracture is extremely infrequent. We report a case of performance limiting nTOS in a college athlete who was initially evaluated and treated for upper extremity ligamentous injury with only transient improvement. Subsequent noninvasive studies were consistent with TOS physiology and MRA showed a large hypertrophic callus on the first rib adjacent to the brachial plexus. With continued athletic limitations and radiographic findings consistent with TOS, surgical decompression was performed resulting in resolution of symptoms. Although apparent atraumatic isolated first rib fractures are infrequently reported etiologies for TOS in athletes, they are a reasonable consideration in this population with corresponding presentations.

Neurologic thoracic outlet syndrome: summarizing a complex history and evolution

Thoracic outlet syndrome (TOS) is a blanket term encapsulating many different clinical entities. Neurologic or neurogenic TOS (NTOS) is its main contributor, but it remains a complicated and sometimes controversial entity. NTOS incorporates numerous types, etiologies, clinical presentations, diagnostic findings, and therapeutic modalities. This article reviews the spectrum of disease within the thoracic outlet that affects the brachial plexus, with a special emphasis on the commonly afflicted sports medicine patient.