A 20-year-old male collegiate swimmer presented to the emergency department (ED) with right arm pain and swelling several days after a weight training session following swim team practice. The initial diagnosis was muscle strain, and he was discharged. The next day, the patient presented to his collegiate sports medicine physician, who ordered right upper extremity duplex ultrasonographic imaging. The results noted no flow in the right subclavian and axillary veins with thrombosis. He was sent back to the ED and was admitted to the hospital, where it was noted that he had swelling of the right arm along with pain throughout the extremity. His vital signs were unremarkable, and osteopathic structural examination findings were normal besides the right upper extremity swelling. His chest radiograph and blood test results were normal, and a hypercoagulable workup was started. A differential diagnosis was formed to include idiopathic thrombosis, cancer, exogenous hormone use, and vascular thoracic outlet syndrome among others. The vascular surgery department was consulted, and the patient's condition was diagnosed as vascular thoracic outlet syndrome (Paget-Schroetter syndrome). He was given anticoagulation therapy, which included a heparin bolus and infusion. 

The following day (hospital day 2), he underwent right upper extremity venography, which showed large clot burden in the right axillary and subclavian veins. He subsequently had a mechanical thrombectomy, and catheter-directed thrombolysis was initiated with placement of a lytic catheter for continuous infusion of tissue type plasminogen activator. On hospital day 3, he underwent repeated venography and evaluation of venolysis, which demonstrated marginal improvement. Repeated angioplasty was also performed, and a new lytic catheter was placed with continuous infusion of tissue type plasminogen activator. On hospital day 4, he underwent repeated venography and termination of thrombolysis. At that time, the subclavian and axillary veins were significantly improved in appearance with good flow, and the patient was transitioned to warfarin and discharged from the hospital on hospital day 5. He continued systemic anticoagulation for 3 months and was restricted from sports for 3 months, with permission to return to sport at the conclusion of that period. He was offered thoracic outlet decompression surgery, but he declined to pursue it. Within a few weeks, results of a full hypercoagulable workup were negative. 

Paget-Schroetter syndrome was coined in 1949 by E.S.R. Hughes, MD, MS, who compiled multiple cases of upper extremity thrombosis. He created the eponym in honor of Sir James Paget and Leopold von Schroetter, who described symptoms of upper extremity thrombosis and the relationship of thromboses and physical strain, respectively.^3,7 

This condition is more commonly found in people involved in sports such as rowing, wrestling, weight lifting, and swimming, as these sports require repetitive motions of the upper extremity.⁴ It is a rare occurrence and is more commonly found in men and in the dominant arm.³ 

The criterion standard of diagnosis had previously been contrast venography; however, ultrasonographic imaging of the upper extremity with color flow Doppler has become more commonly used because of cost, availability, and lack of radiation exposure. Timely treatment of this condition is paramount, as there can be significant disability if the diagnosis is delayed, missed, or not managed appropriately.⁴ Management of this condition involves both anticoagulation and catheter-directed thrombolysis. Additionally, surgical thoracic outlet decompression may be required, which can involve resection of the first rib, as well as the scalene muscles and costoclavicular ligament.² In some instances, the syndrome can present with pulmonary embolism.² Historically, treatment was anticoagulation and elevation of the affected extremity, but morbidity has decreased with the availability of thrombolytics and surgical decompression of the thoracic outlet.⁵ According to Molina et al,⁶ patients had significant improvement in outcomes with thrombolysis and thoracic outlet decompression. This study was carried out over 20 years and found excellent long-term results. However, if the condition is not diagnosed promptly, with aggressive and timely therapy, the veins will have irreversible fibrotic damage.⁶ 

In the current patient, a thrombus likely developed secondary to the repetitive nature of arm movements in swimming. The condition was initially misdiagnosed by the ED because of the rarity of the disease, which is commonly missed on initial early presentation. The patient was treated at the time of diagnosis with both anticoagulation and thrombolysis and was offered thoracic outlet decompression. Patients who have chronic thrombosis will have significant collateral vessels and may present with engorgement of those vessels; however, this patient did not have those signs on presentation. 

While timely treatment is critical, knowledge of this syndrome is necessary for accurate diagnosis and subsequent treatment. Additionally, treatment cannot be presumed to be consistent with lower extremity deep vein thrombosis. Ultrasonographic imaging is a reasonable option for diagnostic imaging of upper extremity thrombosis; however, further invasive studies will be required if ultrasonography findings are positive for Paget-Schroetter syndrome. Consultation with a vascular or thoracic surgeon is recommended on an emergent basis if the diagnosis is made. Although Paget-Schroetter syndrome is rare, knowledge of this syndrome is important in the fields of sports medicine, emergency medicine, and family medicine.