Using the Endoscope for Endobronchial Ultrasound in the Esophagus

Our scope is to identify new ways to perform biopsies from otherwise difficult-to-access areas in the most patient-friendly way, thus conclusive biopsies with few adverse events, low patients'discomfort, and low costs. EUS-B is a safe technique in the hands of respiratory physicians, despite that biopsies are taken not from the lungs or airways, but from the esophagus or stomach. It allows for more complete investigation of patients with possible lung cancer or other cancer.

We have contributed significantly to the field by exploring utility and safety of EUS-B, including identification of new targets that can be reached and sampled. The aspect of patient safety is of outmost importance, and EUS-B has no serious complications. EUS-B is an emerging technique, and there are still no simulators or phantoms that allows for safe learning of the technique.

This protocol provides a clear and stepwise instruction to support beginners and mentors to improve the learning curve. To begin, position the patient in a supine and apply monitoring equipment. Continuously monitor three-lead telemetry, oxygen saturation, pulse, and intermittent blood pressure.

While standing behind the patient's head, hold the handle of the echo endo bronchoscope with the left hand, thumb in the lever, and distal end in the right hand. Apply local anesthetic gel on the tip of the endoscope, then orally or through the nostril, introduce the endoscope into the oropharynx of the anesthetized patient. Advance the endoscope into the laryngeal pharynx while the epiglottis is in front of the scope.

Visualize the vocal cords using the bronchoscopic view. Next, turn the scope left or right to direct it lateral to the arytenoids. Ask the patient to swallow and slowly bend the endoscope posteriorly, introducing it into the esophagus following the patient's swallowing movement.

If required, spray two milliliters of topical lidocaine in the oropharynx. To identify six endoscopic ultrasound landmarks, shift to the ultrasonic image and introduce the endoscope into the stomach. At landmark one, turn the endoscope slightly counterclockwise to visualize the left liver lobe.

At landmark two, turn the scope clockwise to visualize the abdominal aorta with the celiac trunk and superior mesenteric artery. Turn the scope further clockwise at landmark three to visualize the left adrenal gland. At landmark four, retract the endoscope to the mediastinum to locate the mediastinal lymph node station seven.

Next, retract the endoscope a few centimeters and observe the reflections from the trachea. Now turn the endoscope counterclockwise, and at landmark five, find mediastinal lymph node station 4L between the aortic arch and the left pulmonary artery. At landmark six, turn the endoscope clockwise and pass the trachea to find the azygos vein and mediastinal lymph node station 4R.

Insert the sheath in the endoscope and adjust the length such that the tip is one millimeter outside the endoscope. Then lock the sheath in place. Move the FNA needle with the stylet forward and retract the stylet a few millimeters to sharpen the needle.

Under real-time ultra sonographic guidance, hit the target lesions, then retract the stylet and apply suction to the needle. Move the needle back and forth. Remove the suction and lock the needle in the upper position before removing the equipment from the endoscope.

The transesophageal ultrasound tissue sampling technique shows that diagnostic hit rates vary according to location, with slightly higher diagnostic success rates of intrathoracic lesions.