SESSION TITLE: Thrombosis Jamboree: Rare and Unique CasesSESSION TYPE: Rapid Fire Case ReportsPRESENTED ON: 10/19/2022 12:45 pm - 1:45 pmINTRODUCTION: Paget Schroetter Syndrome is a primary spontaneous venous thrombosis of axillary-subclavian system that generally presents in the dominant arm of young individuals. It is a rare condition with an incidence of 1 to 2 per 100,000 individuals.1 Thrombosis is secondary to venous thoracic outlet compression through either anatomic predisposition or due to repetitive musculoskeletal motion.CASE PRESENTATION: 44-year-old female presented with 3 days of right upper extremity pain, swelling and limitation in ROM. She endorsed increased activity involvingabducting arm while performing her tasks as a cook during the holiday season. She denied any respiratory symptoms, recent trauma, instrumentation, or immobilization of her right arm. She was up to date with cancer screening, had no prior thrombotic episodes and denied use of oral contraceptives. She was tachycardic with exam findings of a swollen, warm, tender right arm without skin changes. Doppler US showed occlusive acute thrombosis of right axillary and subclavian veins with non-occlusive extension into right innominate vein. CT PE revealed bilateral segmental pulmonary emboli without evidence of right heart strain. Her hypercoagulable lab work-up was unremarkable. Thrombolysis and follow up surgery were discussed with patient, however, she opted for conservative therapy with anticoagulation. A follow up CT venogram to assess for thoracic outlet obstruction was found to be negative. She was discharged with thoracic surgery follow up for elective first rib removal.DISCUSSION: In PSS vigorous physical activity can cause microtrauma to the blood vessels and subsequent thrombus formation. Prompt diagnosis and definitive treatment are necessary to prevent both acute and post-thrombotic neurovascular complications. Clinically apparent pulmonary embolism can concomitantly occur in 5-8% of patients with upper extremity DVT2. Immediate management of proximal upper extremity DVT involves systemic anticoagulation for 3-6 months. In patients with limb-threatening acute thrombosis, catheter-directed thrombolysis may be beneficial3. However, there is a lack of high-quality trials on the management of PSS without formed guidelines. Definitive surgical intervention is aimed at decompressing the thoracic outlet with first rib resection, but the timing of decompression is debatable without a prospective randomized comparison. In absence of definitive measures, these individuals are at high risk for post-thrombotic complications as well as recurrent thrombosis of proximal vasculature of the arm. If inadequately treated, Paget Schroetter syndrome could contribute to significant morbidity and disability as it affects the dominant arm of the high-functioning population.CONCLUSIONS: Paget Schroetter syndrome is thrombosis of proximal vessels of the arm in a young population for which further research is required to establish a standard of care treatment algorithm.Reference #1: Lindbald B, Tengborn L, Bergqvist D. Deep vein thrombosis of the axillary-subclavian veins: epidemiologic data, effects of different types of treatment and late sequelae. Eur J Vasc Surg 1988;2:161–5Reference #2: Munoz FJ, Mismetti P, Poggio R, et al. Clinical outcome of patients with upper-extremity deep vein thrombosis: results from the RIETE Registry. Chest 2008;133:143-8Reference #3: Stevens SM, Woller SC, Kreuziger LB, Bounameaux H, Doerschug K, Geersing GJ, Huisman MV, Kearon C, King CS, Knighton AJ, Lake E, Murin S, Vintch JRE, Wells PS, Moores LK.Antithrombotic Therapy for VTE Disease: Second Update of the CHEST Guideline and Expert Panel Report. Chest. 2021 Dec;160(6):e545-e608DISCLOSURES: No relevant relationships by Syed Hammad KazmiNo relevant relationships by Richa Nahar SESSION TITLE: Thrombosis Jamboree: Rare and Unique Cases SESSION TYPE: Rapid Fire Case Reports PRESENTED ON: 10/19/2022 12:45 pm - 1:45 pm INTRODUCTION: Paget Schroetter Syndrome is a primary spontaneous venous thrombosis of axillary-subclavian system that generally presents in the dominant arm of young individuals. It is a rare condition with an incidence of 1 to 2 per 100,000 individuals.1 Thrombosis is secondary to venous thoracic outlet compression through either anatomic predisposition or due to repetitive musculoskeletal motion. CASE PRESENTATION: 44-year-old female presented with 3 days of right upper extremity pain, swelling and limitation in ROM. She endorsed increased activity involving abducting arm while performing her tasks as a cook during the holiday season. She denied any respiratory symptoms, recent trauma, instrumentation, or immobilization of her right arm. She was up to date with cancer screening, had no prior thrombotic episodes and denied use of oral contraceptives. She was tachycardic with exam findings of a swollen, warm, tender right arm without skin changes. Doppler US showed occlusive acute thrombosis of right axillary and subclavian veins with non-occlusive extension into right innominate vein. CT PE revealed bilateral segmental pulmonary emboli without evidence of right heart strain. Her hypercoagulable lab work-up was unremarkable. Thrombolysis and follow up surgery were discussed with patient, however, she opted for conservative therapy with anticoagulation. A follow up CT venogram to assess for thoracic outlet obstruction was found to be negative. She was discharged with thoracic surgery follow up for elective first rib removal. DISCUSSION: In PSS vigorous physical activity can cause microtrauma to the blood vessels and subsequent thrombus formation. Prompt diagnosis and definitive treatment are necessary to prevent both acute and post-thrombotic neurovascular complications. Clinically apparent pulmonary embolism can concomitantly occur in 5-8% of patients with upper extremity DVT2. Immediate management of proximal upper extremity DVT involves systemic anticoagulation for 3-6 months. In patients with limb-threatening acute thrombosis, catheter-directed thrombolysis may be beneficial3. However, there is a lack of high-quality trials on the management of PSS without formed guidelines. Definitive surgical intervention is aimed at decompressing the thoracic outlet with first rib resection, but the timing of decompression is debatable without a prospective randomized comparison. In absence of definitive measures, these individuals are at high risk for post-thrombotic complications as well as recurrent thrombosis of proximal vasculature of the arm. If inadequately treated, Paget Schroetter syndrome could contribute to significant morbidity and disability as it affects the dominant arm of the high-functioning population. CONCLUSIONS: Paget Schroetter syndrome is thrombosis of proximal vessels of the arm in a young population for which further research is required to establish a standard of care treatment algorithm. Reference #1: Lindbald B, Tengborn L, Bergqvist D. Deep vein thrombosis of the axillary-subclavian veins: epidemiologic data, effects of different types of treatment and late sequelae. Eur J Vasc Surg 1988;2:161–5 Reference #2: Munoz FJ, Mismetti P, Poggio R, et al. Clinical outcome of patients with upper-extremity deep vein thrombosis: results from the RIETE Registry. Chest 2008;133:143-8 Reference #3: Stevens SM, Woller SC, Kreuziger LB, Bounameaux H, Doerschug K, Geersing GJ, Huisman MV, Kearon C, King CS, Knighton AJ, Lake E, Murin S, Vintch JRE, Wells PS, Moores LK. Antithrombotic Therapy for VTE Disease: Second Update of the CHEST Guideline and Expert Panel Report. Chest. 2021 Dec;160(6):e545-e608 DISCLOSURES: No relevant relationships by Syed Hammad Kazmi No relevant relationships by Richa Nahar