Acute SVC syndrome caused by extensive thrombosis requires prompt endovascular intervention. We report a 48-year-old female with colon cancer presenting with massive chemoport-related thrombosis involving the SVC, right atrium (RA), and bilateral brachiocephalic veins. Due to the lack of an embolic protection filter landing zone, we performed a novel plug-assisted thrombectomy (PAT) technique. A 20-mm vascular plug was positioned at the SVC-RA junction as a temporary tethered filter without detachment. Following mechanical thrombectomy, plug retrieval, and adjunctive balloon dilatation, the patient recovered and was discharged on day 12. This case demonstrates the technical feasibility of PAT as a proof-of-concept approach for embolic protection in patients with extensive SVC thrombosis where conventional filter placement is anatomically precluded.