Evaluation and treatment of thoracic outlet syndrome during the global pandemic due to SARS-CoV-2 and COVID-19.

The global SARS-CoV-2/COVID-19 pandemic has required a reduction in nonemergency treatment for a variety of disorders. This report summarizes conclusions of an international multidisciplinary consensus group assembled to address evaluation and treatment of patients with thoracic outlet syndrome (TOS), a group of conditions characterized by extrinsic compression of the neurovascular structures serving the upper extremity. The following recommendations were developed in relation to the three defined types of TOS (neurogenic, venous, and arterial) and three phases of pandemic response (preparatory, urgent with limited resources, and emergency with complete diversion of resources). • In-person evaluation and treatment for neurogenic TOS (interventional or surgical) are generally postponed during all pandemic phases, with telephone/telemedicine visits and at-home physical therapy exercises recommended when feasible. • Venous TOS presenting with acute upper extremity deep venous thrombosis (Paget-Schroetter syndrome) is managed primarily with anticoagulation, with percutaneous interventions for venous TOS (thrombolysis) considered in early phases (I and II) and surgical treatment delayed until pandemic conditions resolve. Catheter-based interventions may also be considered for selected patients with central subclavian vein obstruction and threatened hemodialysis access in all pandemic phases, with definitive surgical treatment postponed. • Evaluation and surgical treatment for arterial TOS should be reserved for limb-threatening situations, such as acute upper extremity ischemia or acute digital embolization, in all phases of pandemic response. In late pandemic phases, surgery should be restricted to thrombolysis or brachial artery thromboembolectomy, with more definitive treatment delayed until pandemic conditions resolve.

Technique of supraclavicular decompression for neurogenic thoracic outlet syndrome.

The supraclavicular approach to scalenectomy and first rib resection has been modified since the original description in 1985. The incision is 1 to 2 cm above the clavicle, 1 cm lateral to the midline, and 5 to 7 cm long. Subplatysmal skin flaps are created. The sternocleidomastoid muscle is mobilized on its lateral edge and retracted but not divided. The scalene fat pad is split vertically, the omohyoid muscle excised, and the C5 nerve root dissected free. The accessory phrenic nerve is identified, if present, arising medially from C5, and preserved. The rest of the plexus is dissected free, muscular and connective tissue removed from all nerve roots and trunks, and the subclavian artery identified. The phrenic nerve is identified on the medial edge of the anterior scalene muscle (ASM). The ASM is divided on the first rib. The ASM is elevated, freed, and divided as high as possible and free of C5. The middle scalene muscle is dissected. C5 and C6 branches of the long thoracic nerve are identified and protected as the portion of middle scalene muscle adjacent to the nerves of the plexus is excised. The decision on whether the first rib is to be removed is determined by whether the lower trunk of the plexus is touching the first rib. If the rib is removed, its posterior end is freed, divided, and 1 cm excised. The rest of the rib is freed from the intercostal muscles with a periosteal elevator or harmonic scalpel, the pleura is separated from the inner surface of the rib, and the anterior end divided with an infraclavicular rib cutter. The operation has been made safer by identifying and dissecting the C5 nerve root before looking for the phrenic nerve.

Amnion membrane improves results in treating neurogenic thoracic outlet syndrome.

A patient with neurogenic thoracic outlet syndrome was initially treated with scalenectomy, first rib resection, and wrapping of the brachial plexus (BP) with amnion membrane (AM) to prevent postoperative adhesions. Twelve months later, at reoperation for recurrent symptoms, the AM was observed to be intact. The BP had no scar tissue around it. Recurrence was due to scarring around the nerve roots superior to the portion of the plexus that had been wrapped with AM. It was concluded that the AM had successfully protected the portion of the BP that had been wrapped. Longer term studies are in progress.

Pectoralis Minor Syndrome: Subclavicular Brachial Plexus Compression.

The diagnosis of brachial plexus compression-either neurogenic thoracic outlet syndrome (NTOS) or neurogenic pectoralis minor syndrome (NPMS)-is based on old fashioned history and physical examination. Tests, such as scalene muscle and pectoralis minor muscle blocks are employed to confirm a diagnosis suspected on clinical findings. Electrodiagnostic studies can confirm a diagnosis of nerve compression, but cannot establish it. This is not a diagnosis of exclusion; the differential and associated diagnoses of upper extremity pain are always considered. Also discussed is conservative and surgical treatment options.

Thoracic outlet and pectoralis minor syndromes.

Compression of the neurovascular bundle to the upper extremity can occur above or below the clavicle; thoracic outlet syndrome (TOS) is above the clavicle and pectoralis minor syndrome is below. More than 90% of cases involve the brachial plexus, 5% involve venous obstruction, and 1% are associate with arterial obstruction. The clinical presentation, including symptoms, physical examination, pathology, etiology, and treatment differences among neurogenic, venous, and arterial TOS syndromes. This review details the diagnostic testing required to differentiate among the associated conditions and recommends appropriate medical or surgical treatment for each compression syndrome. The long-term outcomes of patients with TOS and pectoralis minor syndrome also vary and depend on duration of symptoms before initiation of physical therapy and surgical intervention. Overall, it can be expected that >80% of patients with these compression syndromes can experience functional improvement of their upper extremity; higher for arterial and venous TOS than for neurogenic compression.

Neurogenic thoracic outlet and pectoralis minor syndromes in children.

Brachial plexus compression (BPC) occurs above the clavicle as neurogenic thoracic outlet syndrome (NTOS) and below as neurogenic pectoralis minor syndrome (NPMS). It was recently noted that 75% of the adults seen for NTOS also had NPMS and in some this was the only diagnosis. This is also true in children but has not yet been reported. Because surgical treatment of NPMS is a minimum risk operation for pectoralis minor tenotomy (PMT), recognition of NPMS and distinguishing it from NTOS becomes important. In this study, 40 operations, 20 PMT and 20 NTOS procedures, were performed. Success rate for PMT was 85% and for thoracic outlet decompression was 70%. It was concluded that in children, as in adults, BPC is more often due to combined NTOS and NPMS. Surgical PMT should be considered first as the treatment of choice for children with NPMS. Thoracic outlet decompression is available if PMT is unsuccessful.