Evolution Toward Minimally Invasive Brachial Plexus Surgery
The management of the infraclavicular brachial plexus has traditionally been one of the most challenging domains in peripheral nerve surgery. Situated deep within the axilla and shoulder girdle, this region is anatomically complex, housing vital vascular structures and the convergence of nerve cords that govern upper limb function. Historically, surgical intervention for nerve injuries or compression syndromes in this area required extensive open dissections, often involving significant morbidity, prolonged recovery, and the risk of scarring that could further entrap neural elements. However, the emergence of endoscopic and arthroscopic techniques is shifting the paradigm toward minimally invasive decompression and neurolysis. Two landmark studies have recently highlighted the efficacy of these approaches in treating both traumatic nerve injuries and neurogenic thoracic outlet syndrome (nTOS), offering clinicians a more refined toolkit for patient care.
The Burden of Infraclavicular Nerve Pathologies
Pathologies of the infraclavicular brachial plexus typically fall into two categories: traumatic injury and chronic compression. Glenohumeral joint (GHJ) dislocation is a frequent cause of the former. While many nerve palsies secondary to dislocation are transient neurapraxias, a subset of patients suffers from persistent deficits due to axonotmesis or even neurotmesis. For these patients, the decision of when and how to intervene is critical to prevent permanent atrophy.
On the other hand, neurogenic thoracic outlet syndrome represents a chronic compression challenge. Often driven by the pectoralis minor space or the costoclavicular interval, nTOS leads to debilitating pain, paresthesia, and weakness. Traditional treatments, such as first rib resection (FRR) or scalenectomy, are invasive and carry risks of thoracic and major vascular complications. The need for a safer, equally effective alternative has led to the development of arthroscopic pectoralis minor release and infraclavicular decompression.
Highlights of Clinical Advancement
1. Endoscopic neurolysis offers a safe and reliable method to shorten recovery times in patients with brachial plexus palsy following shoulder dislocation, with minimal additional morbidity.
2. In cases of traumatic injury, endoscopic visualization allows for the early identification of nerve ruptures that require secondary reconstruction, preventing unnecessary waiting periods.
3. Arthroscopic pectoralis minor release (PMR) for nTOS achieves clinical outcomes and patient satisfaction scores equivalent to open first rib resection but with a superior safety profile.
4. Minimally invasive decompression significantly reduces visual analog scale (VAS) pain scores and improves functional shoulder scores in chronic nTOS populations.
Endoscopic Neurolysis for Post-Dislocation Nerve Palsy: Study Analysis
Le Hanneur et al. (2020) investigated the role of endoscopic brachial plexus neurolysis in patients suffering from infraclavicular nerve injuries due to GHJ dislocation. The study included 11 patients who exhibited persistent motor or sensory deficits six weeks after their initial trauma. The methodology focused on a standardized timeline: if no significant improvement was noted by the six-week mark, endoscopic neurolysis was performed.
Clinical Outcomes and Diagnostic Clarity
The results were compelling. In patients with cord lesions or isolated axillary nerve palsy without rupture, recovery was rapid. All muscles reached at least Grade 3 strength (BMRC scale) within six weeks of the procedure. By the three-month follow-up, strength improved to Grade 4, and nearly all patients achieved full recovery by six months.
Crucially, the endoscopic approach served a diagnostic purpose. In three patients with isolated axillary nerve palsy, the magnification provided by the endoscope identified complete nerve ruptures or severe structural damage that was not apparent on initial examination. This allowed for early nerve transfer procedures, ensuring that these patients received definitive treatment within a year rather than languishing in a state of ‘wait and see.’ No intraoperative or postoperative complications were reported, emphasizing the safety of the endoscopic corridor.
Arthroscopic Decompression for Neurogenic Thoracic Outlet Syndrome
The study by Wagner et al. (2025) addressed the ‘old problem’ of nTOS using a novel arthroscopic approach. This study focused on nTOS of infraclavicular etiology, specifically cases driven by pectoralis minor tightness and scapular dyskinesia. The surgical intervention included endoscopic pectoralis minor release, subclavius release, and neurolysis of the infraclavicular plexus.
Key Results and Comparative Efficacy
The cohort of 55 patients (58 shoulders) showed dramatic improvements. The average Visual Analog Scale (VAS) pain score dropped from a preoperative 7.0 to 2.1 at a mean follow-up of 25.8 months. Functional improvement was equally stark, with Single Alpha-numeric Evaluation (SANE) scores rising from 37% to 84%.
When compared to historical data for open first rib resection and scalenectomy, the arthroscopic approach held its own. Approximately 90% of patients achieved ‘good’ or ‘excellent’ outcomes under the Derkash classification. Significantly, the rate of major complications—such as pneumothorax or major vessel injury—was zero in the arthroscopic group, compared to the known risks associated with open thoracic outlet surgery. The study did note, however, that patients with prior cervical surgeries (like ACDF) or prior open FRR had slightly lower postoperative functional scores, suggesting that primary intervention with minimally invasive techniques may yield the best results.
Expert Commentary: Shifting the Treatment Paradigm
The findings from these two studies suggest a significant shift in how we approach the infraclavicular space. The use of endoscopic magnification provides several advantages: better visualization of the nerve architecture, reduced blood loss, and the ability to perform precise neurolysis without the extensive muscle-cutting required in open approaches.
From a clinical decision-making perspective, the Le Hanneur study validates an earlier intervention window (6 weeks) for traumatic injuries. By utilizing the endoscope as both a therapeutic and diagnostic tool, surgeons can avoid the ‘diagnostic delay’ that often plagues peripheral nerve recovery. In the realm of nTOS, the Wagner study challenges the necessity of first rib resection for all patients. If the compression is primarily infraclavicular and pectoralis minor-driven, an arthroscopic release offers a much lower-risk profile with equivalent functional gains.
However, it is important to note that these techniques require a steep learning curve. The proximity of the axillary artery and vein requires the surgeon to be highly proficient in arthroscopic anatomy. Furthermore, while the outcomes are promising, these studies are primarily Level IV case series. Future prospective, randomized controlled trials comparing open vs. endoscopic approaches would provide the definitive evidence needed to establish a new gold standard.
Conclusion: A New Standard of Care?
The integration of endoscopic and arthroscopic techniques into the management of the infraclavicular brachial plexus represents a major step forward in surgical medicine. Whether addressing the acute aftermath of a shoulder dislocation or the chronic misery of neurogenic thoracic outlet syndrome, these procedures offer a path to recovery that is less traumatic for the patient and highly precise for the surgeon. As these techniques become more widely adopted, they have the potential to significantly reduce the burden of disability associated with infraclavicular nerve pathologies.
References
1. Le Hanneur M, Colas M, Serane-Fresnel J, Lafosse L, Grandjean A, Silvera J, Lafosse T. Endoscopic brachial plexus neurolysis in the management of infraclavicular nerve injuries due to glenohumeral dislocation. Injury. 2020 Nov;51(11):2592-2600. doi: 10.1016/j.injury.2020.08.005.
2. Wagner ER, McQuillan TJ, Omole O, Khawaja SR, Cuneo KR, Hussain ZB, Cooke HL, Chopra KN, Gottschalk MB, Bowers RL. Arthroscopic Pectoralis Minor Release and Infraclavicular Brachial Plexus Decompression for Neurogenic Thoracic Outlet Syndrome: A Novel Treatment for an Old Problem. JBJS Open Access. 2025 Mar 14;10(1):e24.00203. doi: 10.2106/JBJS.OA.24.00203.
