What you can expect

By Mayo Clinic Staff

You likely will be given medicine to help you relax.

During EUS your doctor passes a thin, flexible tube (endoscope) through your mouth and through your digestive tract. A small ultrasound device (transducer) in the tube produces sound waves that create a precise image of surrounding tissue, including lymph nodes in the chest. The endoscope is then gradually withdrawn.

If you have fine-needle aspiration with EUS, your doctor will pass a second, curved device into your digestive tract. That device can guide a very slender needle to your lymph nodes and tumors or other abnormalities. The needle extracts fluid and tissue for analysis.

EUS with fine-needle aspiration generally lasts about an hour.

Aug. 12, 2014