Venous gas embolism during foam sclerotherapy of saphenous veins despite recommended treatment modifications

Objective: To investigate the effectiveness of methods proposed to prevent venous gas embolism during foam sclerotherapy. Methods: Transthoracic echocardiography was performed concurrent with ultrasound-guided sclerotherapy (UGS) of great or small saphenous veins. A volume of 2.5 mL of 3% sodium tetradecyl sulphate foam was prepared following the Tessari method and injected slowly 5-10 cm away from saphenous junctions. The procedure was repeated with modifications including using a 5 mu m filter to generate microfoam, carbon dioxide as the foaming gas, leg elevation before or after the injection and immobility post-treatment. Results: Bubbles entered the right heart in less than 60 seconds and continued for up to 50 minutes despite all treatment modifications. None of the patients had a patent foramen ovale and none developed any neurological or cardiac symptoms. Conclusion: Bubble emboli entered the heart during foam UGS of saphenous veins despite all treatment modifications and low volumes of foam used.