# Refractory Antiphospholipid Syndrome With Thoracic Outlet and Superior Vena Cava Syndromes: A Complex Case of Recurrent Thrombosis

## TL;DR

A 39-year-old woman with multiple rare conditions, including antiphospholipid syndrome, faced severe and recurring blood clots due to overlapping disorders and mechanical venous blockages.

## Contribution

This case highlights the challenges of managing treatment-resistant APS with mechanical venous obstruction and complex comorbidities.

## Key findings

- The patient had multiple thrombotic events despite treatment with direct oral anticoagulants.
- Warfarin was the only effective anticoagulant for the patient's treatment-resistant APS.
- The case emphasizes the need for multidisciplinary approaches in managing overlapping rare disorders.

## Abstract

Thoracic outlet syndrome (TOS) and superior vena cava syndrome (SVCS) are rare and debilitating conditions that can cause vascular compression, hypercoagulable states, and central venous obstruction. This is the case of a 39-year-old female with treatment-resistant antiphospholipid syndrome (APS), hereditary angioedema (HAE), and mast cell activation syndrome (MCAS) complicated by SVCS and venous TOS. Her clinical course was further challenged by recurrent venous thromboembolism with treatment failure on multiple direct oral anticoagulants (DOACs), with warfarin being the only effective medication. Furthermore, the patient experienced several thrombotic events, which included: left subclavian vein thrombosis, recurrent deep vein thromboses (DVTs), and septic thrombophlebitis (methicillin-sensitive Staphylococcus epidermidis bacteremia) involving the left internal jugular vein. Her vascular history also included left lower lobectomy for pulmonary nodules and right cerebral stenting for reversible cerebral vasoconstriction syndrome (RCVS). The patient also had gastroparesis attributed to HAE-related visceral edema. This case illustrates the challenges posed by overlapping rare disorders, where the combination of APS and mechanical venous obstruction resulted in recurrent thromboses, complicated further by the patient’s complex past medical history. Our findings highlight the limitations of conventional anticoagulation strategies in treatment-resistant APS and emphasize the need for multidisciplinary approaches.