Paget-Schretter syndrome is a primary thrombosis of the subclavian vein associated with intense and repetitive load on the upper extremities. The disease is quite rare, but characteristic of physically active young people and associated with the risk of complications. It is manifested by edema, a change in skin color, a feeling of bursting, pain, expansion of the subcutaneous venous network. Verification of the diagnosis is carried out by instrumental methods – using ultrasound, phlebography, MR and CT angiography of the subclavian zone. Treatment is based on a combination of conservative and operative techniques (anticoagulants, selective thrombolysis, decompression techniques).
Paget-Schretter syndrome (thrombosis of effort or overstrain) is named after the English surgeon D. Paget, who first described in detail the case of edema and cyanosis of the upper limb (1875), and the Austrian otolaryngologist L. Schretter, who in 1884 suggested the connection of disorders with damage to a vein on the background of muscle tension. The disease accounts for 30-40% of spontaneous thrombosis of the subclavian-axillary segment and 10-20% of all phlebothrombosis of the upper extremities. For the general population, pathology is quite rare – it occurs in 1-2 people per 100 thousand people per year. Usually young people aged 20 to 30 years get sick (men 2-4 times more often), although cases of pathology have been recorded even in the elderly and children.
Overstrain thrombosis usually occurs during sports involving constant and vigorous movements in the shoulder girdle (with retroversion, hyperabduction, arm extension) – wrestling and other martial arts, gymnastics, swimming. Basketball players, hockey players, billiards players are subject to it. A similar situation is typical for people engaged in physical labor (painters, car mechanics, movers, workers of steel workshops). From 60% to 80% of patients report a history of vigorous exercise or intense muscle work.
Although the disease has a primary character, there are certain prerequisites for its development. The role of some anatomical features contributing to damage (cervical rib, congenital adhesions, hypertrophy of the tendons of the stair muscles, abnormal attachment of the costoclavicular ligament) has been proven. They limit the mobility of the subclavian vein, making it more susceptible to mechanical injury and compression from physical effort involving the shoulder girdle.
Unlike phlebothrombosis of other localization (lower extremities, visceral), the role of hereditary and acquired thrombophilia in the development and progression of Paget-Schretter syndrome remains unclear. Some authors describe a higher frequency of mutations of factor V Leiden and prothrombin, revealing them in 2/3 of patients with primary subclavian segment lesion. Other researchers refute such a connection, showing that the occurrence of coagulopathies is comparable to that in the population.
The narrowing of the venous lumen is mediated by external compression of the hypertrophied musculature of the shoulder girdle (anterior stair, subclavian, scapular, large pectoral muscles) with the involvement of bone-tendon formations that limit the gap between the vessel and the I rib. This creates an excessive load, leading to microtrauma of the endothelium with activation of the coagulation cascade.
The morphological basis of the syndrome is disorders in the terminal part of the vein. Chronic traumatization and hypoxia trigger intimal hyperplasia and synthesis of connective tissue fibers. Under the influence of fibrous changes, the vascular wall becomes rigid, aseptic phlebitis with parietal thrombosis develops in it.
Constant compression triggers a pathological process in the paravasal tissue. The loose connective tissue surrounding the vessel is replaced by scar tissue. As a result, the vein becomes less mobile, which only increases the risk of further injury to the endothelium. The wall is stretched and damaged whenever the diameter of the costoclavicular space changes.
The passage of cycles of alteration, local inflammation, thrombosis and recanalization gradually increases intravascular defects, limiting blood flow and leading to stasis. The negative impact is initially reduced due to the collaterals formed, but later parietal thrombi spread to adjacent segments (axillary, shoulder).
Thrombosis of effort in clinical phlebology is attributed to the venous variant of thoracic compression syndrome. There is a classification according to the clinical course, according to which the process goes through acute, subacute, chronic stages. The first has several degrees of severity, objectively distinguished by the level of venous hypertension in the distal segments (in mm of water):
- Mild (up to 300 mm H2O). Intravascular disorders are of a limited nature. Due to the developed collaterals, the symptoms increase slowly and are poorly expressed. The function of the hand does not suffer.
- Medium (from 400 to 800 mm H2O). There is a common phlebothrombosis. Signs of venous insufficiency are combined with arterial spasm. The function of the upper limb is impaired.
- Heavy (up to 1200-1300 mm H2O). There is a transition of the thrombotic process to the axillary and shoulder zones. The symptoms are pronounced.
The pressure in the veins in the chronic course of pathology increases moderately. Before the acute stage, there is sometimes a prodromal period due to gradually progressive vascular lumen stenosis. The shorter it is, the more intense the symptoms of phlebothrombosis.
The disease develops acutely, for 24 hours after heavy physical exertion or movements with shoulder retraction and rotation outward. Less often, symptoms occur without connection with any provoking factors. Usually the right (dominant) limb is involved. The most typical sign is swelling on the side of the lesion with a tendency to rapid progression, often spreading to the upper chest. After pressing, the fossa does not remain, which indicates venous and lymphatic stagnation with the accumulation of fluid in the subcutaneous tissue.
The asymmetry of the limb in volume and muscle mass is complemented by weakness, a feeling of heaviness and tension, cyanosis (rarely pallor), an increase in the local temperature of the skin. Patients are concerned about aching pains of varying intensity, radiating to the axillary region. First, in the ulnar fossa, and then on the shoulder, the anterior portion of the chest wall, at the base of the neck, enlarged collaterals are noticeable (Urschel’s sign). A dense painful weight can be palpated in the axillary-brachial zone.
Despite pronounced local manifestations, the general condition is not disturbed. Acute symptoms persist for 1-3 weeks, after which the process turns into a chronic stage. Patients note a feeling of fatigue and swelling in the arm. Subcutaneous collaterals become less noticeable, moderate tissue density remains.
Among the complications of Paget-Schretter syndrome, recurrent thrombosis, pulmonary embolism, postthrombotic disease are noted. Although some studies show a lower frequency of pulmonary embolization compared to phlebothrombosis of the lower half of the body and catheter-associated lesions, but the probability of a dangerous condition still seems real and quite significant. The prevalence of post–thrombotic disease in the primary process is higher – up to 46% of cases. Extremely rarely, venous gangrene may occur in the acute period.
The clinical signs of Paget-Schretter syndrome have a relatively low specificity. Only half of patients with obvious symptoms are diagnosed with phlebothrombosis. In such conditions, additional methods are given exceptional importance:
- Ultrasound duplex scanning of veins. USDS is recognized as the best way of initial visualization of thrombotic masses in the subclavian segment. Having a high sensitivity (78-100%) and specificity (82-100%), it allows differentiating a fresh thrombus from a chronic one, determining the parameters of blood flow at the site of narrowing, evaluating the recanalization process, identifying collaterals. Difficulties may arise with the intimate location of the vessel under the clavicle, the presence of fibrous-altered areas.
- MRI and CT with vascular contrast. Magnetic resonance angiography shows high informativeness in occlusive thrombi, but poorly visualizes parietal and “short” clots. CT venography, in addition to the internal lumen of the vessel, gives an idea of the surrounding tissues, bone formations, the width of the costal-subclavian gap. As second-line methods, they are indicated with a high clinical probability of the disease and negative results of USDS.
- Traditional phlebography of the upper extremities. It is used in cases when noninvasive diagnostics is not informative enough. It allows you to visualize the subclavian-axillary region well, identifying compression zones and areas of stenosis. The accuracy of contrast phlebography is increased by performing a test with external rotation and shoulder retraction. After verification of the lesion, the diagnostic procedure can immediately turn into a therapeutic one, as part of a multimodal strategy aimed at performing catheter-controlled thrombolysis.
The violation of venous outflow can be indirectly judged by the results of phlebotonometry, lymphography, skin thermometry. Some anatomical features of bone structures are visible on the chest X-ray. The coagulogram shows an increase in blood clotting ability.
Diagnosis of Paget-Schretter syndrome is carried out by a vascular surgeon (phlebologist). Pathology should be differentiated with secondary thrombosis, superficial thrombophlebitis, arterial form of thoracic outlet syndrome, lymphedema. Pathology has to be distinguished from tumor occlusion, common shoulder phlegmon, osteomyelitis.
There is no unambiguous opinion regarding the standards of treatment of phlebothrombosis associated with physical effort. The relative rarity of pathology, lack of awareness, lack of large randomized trials do not contribute to clarifying the situation. Most often they focus on an integrated approach involving the use of several correction methods:
- Conservative. In the acute period, the affected arm is provided with rest, given a somewhat elevated position (on a kerchief bandage), local blockades are carried out. In order to prevent the progression of thrombotic changes, anticoagulants are prescribed – low molecular weight heparins, oral agents. But a conservative strategy alone is not able to ensure the full elimination of symptoms and prevent complications.
- Surgery. A combination of selective thrombolysis and decompression techniques is used as the method of choice in the surgical treatment of Paget-Schretter syndrome. Catheter-controlled dissolution of the clot is performed in the first 7 days after the manifestation of pathology by local administration of alteplase, tenecteplase, streptokinase. Decompression is performed by resection of the first rib, collarbone, tendon of the anterior stair muscle.
There is evidence of the effectiveness of venolysis (removal of scarring from the outer wall of the vessel), perivascular sympathectomy. If necessary, decompression manipulations are supplemented by direct thrombectomy with plastic surgery of the anterior wall of the vessel. The role of bypass surgery requires further research.
In the early postoperative period, passive movements and massage are prescribed to prevent shoulder stiffness. After 4 weeks, strength exercises aimed at strengthening the muscles are added. Patients return to full activity after 3-4 months.
Prognosis and prevention
Although complete recovery is rare, the prognosis for life with Paget-Schretter syndrome is relatively favorable. Affecting mainly young active people, progressive thrombosis often leads to disability. Due to inadequate therapy, up to 15% of cases are complicated by pulmonary embolism. However, timely and correct treatment tactics can achieve restoration of blood flow with a low risk of relapses. No primary prevention measures have been developed, long-term anticoagulant therapy is recommended to prevent repeated episodes in people with a high risk of thrombotic conditions.
- Paget-Schroetter Syndrome: Review of Pathogenesis and Treatment of Effort Thrombosis/ Venkata M. A., Nagendra N., Manu K. et al. West J Emerg Med. – 2010 Sep; 11(4).
- Paget-Schroetter Syndrome: A Review of Effort Thrombosis of the Upper Extremity From a Sports Medicine Perspective/ Nathan A. M., Geoffrey S.T., Wendell M. H. et al. Sports Health. – 2013 Jul; 5(4).