Development of Thrombus in a Systemic Vein after Balloon-Occluded Retrograde Transvenous Obliteration of Gastric Varices

Objective: To retrospectively evaluate the frequency and risk factors for developing thrombus in a systemic vein such as the infrarenal inferior vena cava or the iliac vein, in which a balloon-occluded retrograde transvenous obliteration (B-RTO) catheter was indwelled. Materials and Methods: Forty-nine patients who underwent B-RTO for gastric varices were included in this study. The B-RTO procedure was performed from the right femoral vein, and the B-RTO catheter was retained overnight in all patients. Pre- and post-procedural CT scans were retrospectively compared in order to evaluate the development of thrombus in the systemic vein in which the catheter was indwelled. Additionally, several variables were analyzed to assess risk factors for thrombus in a systemic vein. Results: In all 49 patients (100%), B-RTO was technically successful, and in 46 patients (94%), complete thrombosis of the gastric varices was achieved. In 6 patients (12%), thrombus developed in the infrarenal inferior vena cava or the right common-external iliac vein. All thrombi lay longitudinally on the right side of the inferior vena cava or the right iliac vein. One of the aforementioned 6 patients required anticoagulation therapy. No symptoms suggestive of pulmonary embolism were observed. Prothrombin time-international normalized ratio and the addition of 5% ethanolamine oleate iopamidol, on the second day, were related to the development of thrombus. Conclusion: Development of a thrombus in a systemic vein such as the inferior vena cava or iliac vein, caused by indwelling of the B-RTO catheter, is relatively frequent. Physicians should be aware of the possibility of pulmonary embolism due to iliocaval thrombosis.