Paget–Schroetter syndrome is the sudden thrombosis of the subclavian vein in the setting of physical exertion of the arm. This syndrome is also known as effort thrombosis. It is the most extreme presentation of the venous form of thoracic outlet syndrome. It is a rare disease of active young people engaged in physical exertion of the arm (e.g., mechanics, rock climbers, swimmers, and weight lifters). Specifically, it is the forceful movement of pulling the extended arm from over the head down toward the torso that leads to the underlying basis of the disease; hypertrophy of the subclavius and anterior scalene muscles.
The subclavius is a triangular muscle that originates from the groove on the undersurface of the clavicle and inserts by thick tendon into the cartilaginous portion of the first rib. The subclavius muscle depresses the shoulder by drawing the clavicle downward and forward. The anterior scalene muscle arises from the transverse processes of the third to sixth cervical vertebrae and inserts into the scalene tubercle on top of the first rib, separating the subclavian artery and vein. When an arm extended over the head is pulled down vigorously toward the torso, the anterior scalene fixes the first rib into position, anchoring it against the transverse processes of the neck. The subclavius muscle, in turn, anchors on the fixed first rib and pulls the shoulder down by displacing the clavicle.1
The sudden and forceful pulling down of the arm toward the torso is accompanied by the powerful contraction of the anterior scalene and subclavius muscles. The hypertrophied subclavius muscle in particular appears to be the cause of the pathologic injury. The sudden and powerful compression of the subclavian vein between these two muscles is sufficient to tear the intima of the vein, and thrombosis occurs (Fig. 145-1). The clot then propagates distally toward the shoulder. Thrombolysis or anticoagulation alone is insufficient to correct the clinical manifestations or to prevent recurrence. First rib resection with division of the two muscles prevents recurrence. The exposure given by an axillary approach to divide these muscles is inadequate and therefore not recommended.2 A subclavicular approach not only allows division of these muscles but also permits patch angioplasty of the vein.
Figure 145-1
A. In the relaxed normal position, the subclavian vein runs between the subclavius muscle tendon and the anterior scalene muscle. The floor of the tunnel through which the vein runs is formed by the first rib. B. Under tension, the vein is pinched severely between the subclavius tendon and the anterior scalene muscle. The intimal injury evolves into acute thrombosis of the vessel.
Paget–Schroetter syndrome is a clinical diagnosis confirmed by duplex ultrasound and venogram. The ipsilateral arm frequently is swollen with distended veins up to the shoulder. Range of motion of the arm is impaired as a result of pain. If not treated immediately, the patient may be left with a chronic debilitating condition that limits use of the arm. Lysis of the clot alone or anticoagulation alone is inadequate therapy. The surgeon must be prepared to divide the compressive muscles and to perform a patch angioplasty of the vein to restore its normal caliber. We describe the operative approaches to affect this type of repair.
Paget–Schroetter syndrome is rare, and the average surgeon may see only a few cases across a career. J. Ernesto Molina is a cardiothoracic surgeon at the University of Minnesota who developed an interest in treatment protocols for this disease. He has educated a generation of surgeons from the University of Minnesota program, and this chapter is indebted to his work.3–6
The diagnosis of Paget–Schroetter syndrome is based on history, physical examination, and Doppler assessment of the ipsilateral axillary and subclavian veins. The history is one of recent efforts of the ipsilateral arm and sudden pain. The physical examination generally reveals a swollen and functionally impaired forearm and hand. Although distention of arm veins is seen commonly, development of venous collaterals around the shoulder is a late finding and suggestive of a chronic condition. Doppler ultrasound shows venous occlusion with thrombosis of various extent.
At the University of Minnesota since the early 1990s, this diagnosis has been followed by the placement of a venous catheter, which is advanced into the clot. The catheter provides access for a venogram to assess the length of the clot, as well as for local delivery of fibrinolytics. Although urokinase was initially used as our preferred thrombolytic agent in the 1980s, this now has been supplanted by recombinant tissue plasminogen activator (Activase, Alteplase, TNK-TPA). The catheter-directed infusion of thrombolytics at recommended doses is a very safe procedure with no systemic bleeding complications. The clot always dissolves within 24 hours of infusion, and as soon as that stage is reached, thrombolysis is discontinued and the patient is prepared for surgery, which should follow within a few hours.
