A Near-Fatal Leak: Acute Cardiac Tamponade From Contrast Extravasation via a Thrombosed Port-a-Cath.

BACKGROUND Cardiac tamponade caused by intrapericardial contrast extravasation is a rare but life-threatening iatrogenic complication associated with central venous access devices (CVADs) during power injection. CVADs, including implanted ports (port-a-caths), are susceptible to fibrin sheath formation and mural thrombosis over time, which can tether the catheter tip against the vessel wall and predispose it to erosion or perforation. When high-pressure contrast is injected through a compromised device, contrast may bypass the vessel lumen entirely and accumulate within the pericardial sac, producing acute obstructive shock. CASE REPORT We report a 61-year-old woman with a history of diabetes mellitus, cerebrovascular accident, and an indwelling port-a-cath who underwent computed tomography (CT) angiography because of difficult peripheral venous access. Immediately after contrast administration, she developed sudden cardiovascular collapse and cardiac arrest. CT imaging demonstrated a large hyperdense pericardial effusion with superior vena cava thrombosis adjacent to the catheter tip, suggesting catheter-related vessel wall injury and direct contrast extravasation into the pericardial sac. Bedside echocardiography confirmed tamponade physiology with right ventricular diastolic collapse and chamber compression. Emergent pericardiocentesis drained 1 L of contrast-containing serosanguinous fluid and resulted in immediate hemodynamic recovery after cardiac arrest. CONCLUSIONS Contrast extravasation through a long-term indwelling port-a-cath is a rare but catastrophic cause of acute cardiac tamponade. Sudden cardiovascular collapse during or after contrast-enhanced CT in a patient with a long-term central venous device should prompt immediate suspicion for this diagnosis. Additionally, echocardiography enables rapid confirmation, and emergent pericardiocentesis is life-saving.