Paradoxical gas embolism by transpulmonary passage of venous emboli during hysteroscopic surgery: a case report and discussion.

After an episode of apparent venous gas embolism in a patient undergoing surgical hysteroscopy, transoesophageal echocardiography revealed air in the left but not in the right heart. Contrast echocardiography failed to demonstrate anatomical right-to-left shunts, making it likely that venous emboli overwhelmed the capacity of lungs to filter emboli, resulting in paradoxical embolization.