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A 21-year-old woman presented to the hospital for right lower neck pain. The patient reported that the pain started after she attempted to stretch backward. In addition, she complained of pain and swelling over her right upper arm which started a day after the neck pain started. On admission, vitals were within normal limits. Physical examination was positive for erythema, swelling and tenderness in the upper right arm and right subclavicular region. CT angiography of the neck and CT of the cervical spine were unremarkable. Complete blood count and a complete metabolic panel were within normal range. Ultrasound venous of the right upper extremity showed a large echogenic thrombus of the right subclavian vein (figure 1). Given the above findings, further detailed history was obtained. The patient denied a family history of coagulation disorder. However, she admitted to being on oral contraceptive pills. Coagulation studies showed a normal protein S activity along with a negative factor V Leiden, anticardiolipin and prothrombin G20210A mutation. Antithrombin III level was slightly lower. The patient was subsequently placed on a heparin infusion and was scheduled to undergo thrombolysis. Venography performed before procedure via the right basilic vein which showed complete occlusion as the axillary vein and scant collateral vessels (figure 2). The patient underwent intravenous catheter thrombolysis with 10 mg alteplase bolus continued with 1 mg/hour intravenous infusion for 24 hours without any complications. An interval venography which was performed after a day of the procedure demonstrated a reduction in the size of the subclavian thrombus but persistent large obstructing thrombus at the first rib. There was a residual 80% obstruction that correlated with the triangle formed by the scalene anterior muscle posterior to the subclavian vein, the first rib beneath the vein and the clavicle above the vein (figure 3). The obstruction appeared to be complex indicative of possible residual fibrotic material or thrombus. An additional 2 mg alteplase intracatheter bolus was given and intravenous infusion of 1 mg/hour was restarted for another 24 hours. A 12 mm (length)×40 mm (diameter) balloon angioplasty with pressure of 10 atm was later performed. Interval venography showed persistent 80% obstruction in the subclavian vein with good flow into a central venous system with no progression compared with the previous image findings (figure 4). No embolism following balloon angioplasty has been observed. The patient was discharged on rivaroxaban and was scheduled to undergo thoracic first rib resection in 3–4 weeks.
We considered hereditary hypercoagulability, thrombosis related to trauma or catheter placement, and thoracic outlet anatomic abnormalities (Paget-Schroetter syndrome) in our working differential diagnosis. The diagnosis of Paget-Schroetter syndrome was established given the nature of the presentation and negative hypercoagulability work-up. Paget-Schroetter syndrome is characterised by primary spontaneous upper extremity deep vein thrombosis (DVT) usually due to anatomical abnormalities of the thoracic outlet with subsequent compression of the axillosubclavian vein.1 Various structural anomalies known to cause thoracic outlet obstruction are hypertrophied muscles, cervical ribs, long transverse processes of the cervical spine, musculofascial bands and clavicular anomalies of the first rib.2 The syndrome is predominantly witnessed among young healthy individuals and it usually manifests with sudden upper extremity pain and swelling following repetitive or strenuous exercise.1 Repetitive movements of the upper extremity result in perivenous subclavian fibrosis, thus increasing the risk of thrombosis.3 There are only a few reported cases of thrombosis in the absence of the above risk factors.4 5 Regardless, the initial work-up should include an ultrasound to rule out the presence of a venous thrombus. A serial ultrasound or CT venography or MRI venography should be considered in cases with high suspicion for venous thrombosis even though the initial US does not show any evidence of thrombosis.6 Management goals are aimed at prevention of complications of venous thrombosis such as pulmonary embolism, recurrences and post-thrombotic symptoms. A minimum of 3 months of anticoagulation is recommended for all patients identified for upper-extremity DVT.7 For patients with moderate or severe symptoms, thrombolysis is recommended with the anticoagulation. Following thrombolysis, surgical decompression of thoracic outlet has been shown to lower rates of recurrent thrombosis and reduce long-term morbidity; however, the recommendations are very weak.1
The presentation of severe pain in the extremities among patients with known anatomic abnormalities should raise a high index of suspicion for Paget-Schroetter syndrome and should be worked up appropriately.
This upper extremity thrombotic event is usually preceded by strenuous exercise or repetitive movements of the upper extremity. However, there are a few case reports which mild activities could also trigger the event.
Thrombolysis is reserved for patients presenting with moderate to severe symptoms. Even though surgical decompression is known to lower rates of recurrent thrombosis and reduce long-term morbidity, the recommendation is weak since it is based on observational studies.
Contributors AF and MM wrote the primary manuscript and was revised by MPR and AA.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent Obtained.
Provenance and peer review Not commissioned; externally peer reviewed.
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