Mechanism of DVT in Pickleball-Related Upper Extremity Thrombosis
This patient most likely developed effort-related thrombosis (Paget-Schroetter syndrome), where repetitive overhead swinging motions caused extrinsic compression of the subclavian vein at the thoracic outlet, leading to repetitive endothelial injury, venous stasis, and subsequent thrombus formation 1.
Primary Mechanism: Venous Thoracic Outlet Syndrome
The pathophysiology follows a specific sequence:
Anatomical compression: Repetitive overhead arm motions during pickleball swinging compress the subclavian vein between the first rib, clavicle, and hypertrophied anterior scalene or subclavius muscles at the thoracic outlet 2, 3
Endothelial injury: This repeated mechanical compression causes direct trauma to the vein wall, resulting in endothelial damage 3, 4
Venous stenosis and stasis: The compression creates a functional stenosis that impairs venous outflow, leading to blood stasis in the subclavian and axillary veins 3
Thrombosis formation: The combination of endothelial injury and stasis triggers the coagulation cascade, resulting in thrombus formation—classically involving the subclavian, axillary, and sometimes brachial veins 5, 2
Clinical Context
This represents primary UEDVT, which accounts for approximately one-third of all upper extremity DVT cases 1. The condition characteristically affects:
- Young, otherwise healthy individuals engaged in vigorous upper extremity activity 5, 3, 6
- Athletes performing repetitive overhead motions (baseball pitchers, weightlifters, swimmers—and now pickleball players) 5, 2, 6
- Predominantly males, though females are also affected, particularly when additional risk factors are present 5, 3
Important Distinguishing Features
This is NOT secondary UEDVT, which would be caused by:
- Indwelling venous catheters, pacemakers, or defibrillators (the most common cause of UEDVT overall) 1
- Malignancy
- Hypercoagulable states
- Extrinsic compression from tumors
Critical Diagnostic Pitfall
Initial duplex ultrasonography may be falsely negative in early Paget-Schroetter syndrome 5. In the case series, a 16-year-old cheerleader with effort-related UEDVT had an unremarkable initial ultrasound, only to have occlusive thrombus confirmed on repeat imaging nine days later 5. Therefore, if clinical suspicion remains high despite negative initial imaging, repeat ultrasonography or advanced imaging (CT venography) should be pursued when symptoms persist 5.
Additional Risk Factors to Consider
While the primary mechanism is mechanical compression from repetitive motion, look for potential contributing factors that may have lowered the thrombotic threshold:
- Recent initiation of estrogen-containing contraceptives (as seen in the cheerleader case) 5
- Underlying hypercoagulable states 1
- Dehydration during athletic activity
- Anatomical variants predisposing to thoracic outlet compression 3
The repetitive overhead swinging motion in pickleball creates the same biomechanical stress pattern seen in other overhead athletes, making this a classic presentation of effort-related primary UEDVT.