Thoracic Outlet Syndrome
Michael N. Tameo, M.D.
Ronald L. Nath, M.D. , F.A.C.S.
to Dr. Begos
who was selected again as one of of Boston’s top doctors by Boston Magazine in 2015
CSA Vein Center
receives accreditation by the IAC:
CSA is the first vein practice in Northeast Massachusetts to be fully accredited as a Certified Vein Center by the IAC (Intersocietal Accreditation Commission).
Thoracic Outlet Syndrome, or TOS, refers to compression of the subclavian artery, subclavian vein, or nerves as they travel through an area called the thoracic outlet on their way to the arms. The thoracic outlet is located in the upper chest just below the clavicle (‘collar bone’). Compression occurs because this space is often too small in some patients or they contain an extra rib called a cervical rib in that location. The artery, vein, or nerves can be pinched against the clavicle by the first rib, scalene muscles, or cervical rib causing symptoms.
symptoms that occur depend on which of the 3 structures (artery, vein, or
nerves) is being compressed. ‘Arterial’ TOS can cause painful ischemia and
coldness of the affected arm or hand from lack of blood flow due to the
pinched artery itself or from embolization of thrombus (blood clot) from
within an aneurysm that can typically form just after the compressed area.
Embolization is when the thrombus breaks-off, travels down the artery, and lodges itself into a smaller part of the artery further downstream. This can stop blood from flowing down the remainder of the artery. ‘Venous’ TOS, also known as effort thrombosis or Paget-Schroetter syndrome, can cause arm swelling and associated pain from thrombosis (blood clot formation) of the pinched subclavian vein which occludes it and prevents blood return from the arm. ‘Neurogenic’ TOS can cause various forms of pain, numbness, and/or weakness in the affected arm due to compression of the nerves.
Diagnosis of TOS and its complications requires a thorough history and physical exam by a vascular surgeon. An ultrasound and/or computed tomography (CT) scan is usually required. Occasionally, an arteriogram or venogram is required, which involves injection of contrast dye into the artery or vein for imaging.
Treatment of arterial TOS requires removal of the first rib to stop the
compression and then repair of the compressed and likely damaged artery and
any associated aneurysm that may exist using open surgical grafting.
Treatment of venous TOS requires a combination of medical, endovascular and
open surgery. Medical therapy involves blood-thinning medication to prevent
additional clotting. A procedure to remove the blood clot is then required
using minimally invasive (endovascular) treatment with thrombolysis (removal
of thrombus with medicine through a catheter), thrombectomy (mechanical
disruption and removal of thrombus through a catheter), and possibly also
balloon angioplasty to repair the narrowed vein. Finally, open surgery is
required to remove the first rib to stop the compression. If the vein is
still narrowed due to scarring from years of compression then a stent may be
needed to hold it open. Neurogenic TOS is mostly treated with physical
therapy. Surgery is rarely needed as it can often worsen the problem.