Substernal Thyroid Biopsy Using Endobronchial Ultrasound-guided Transbronchial Needle Aspiration

The overall goal of this procedure is to demonstrate the procedure for an endobronchial ultrasound guided transbronchial biopsy of a substernal thyroid gland. This is accomplished by first ruling out obvious endoluminal lesions using conventional bronchoscopy, and then deploying the endobronchial ultrasound guided bronchoscope. The second step is to use ultrasound to locate the lesion of interest and identify a point of entry for the biopsy needle.

Next, collect samples for analysis using transbronchial needle aspiration under real-time ultrasound guidance. The final step is to remove the ultrasound guided bronchoscope and undertake post-procedure surveillance. Ultimately, either rapid onsite cytopathology or in lab cytopathology studies are used for preliminary impression of whether the lesion is benign or malignant.

The main advantage of this technique over existing methods like mediastinoscopy or open thoracotomy, is that it is minimally invasive and extremely cost effective. Patients can go home the same day, and the complication rates for this procedure are extremely rare. This method can also obtain biopsies of retro and substernal thyroid masses that are notable to surgical biopsies because of comorbidities, especially in patients who are otherwise considered unfit for surgical biopsies because of comorbidities, knowing whether the these thyroid lesions are malignant or benign may be crucial to deciding whether to curatively operate or carefully watch these lesions with serial imaging Due to the rare occurrence of the substernal thyroid.

This video shows the procedure being performed on a mediastinal lymphadenopathy. The steps involved in biopsy of a substernal thyroid are exactly the same as shown in this video. Begin by becoming familiar with the equipment.

At the center of the procedure is the convex probe endobronchial ultrasound bronchoscope. This consists of a bronchoscope tube with a 6.3 millimeter diameter and a 6.9 millimeter diameter on the distal end with a scope camera that has a 35 degree forward. Oblique angle view at the tip of the bronchoscope is a 7.5 megahertz convex ultrasound probe that generates a 50 degree image.

The probe is inside a saline inflatable balloon. As with other bronchoscopies, the tip can undergo forward flexion, for example, to bring the probe in contact with the surface. It can also undergo backward flexion, for instance, to view more of the airway lumen biopsies are performed with a needle inserted through the working channel of the bronchoscope and fastened into place with a locking mechanism.

The needle comes out at 20 degrees relative to the endoscope axis and has an echogenic tip for use with the ultrasound probe. Inflate the balloon surrounding the probe with saline to provide a better medium for ultrasound studies. When inflated forward and backward flexion are still possible, this demonstration will begin after the patient has been appropriately prepared and anesthetized.

Begin by doing a pre-procedure surveillance bronchoscopy to clean the airways and rule out endobronchial lesions. Introduce the convex probe. Endo bronchial ultrasound bronchoscope through the vocal cords into the airway.

Advance the bronchoscope centrally in the airway. Use the 35 degree forward oblique angle view to observe the anterior wall and a small portion of the lumen. When passing through the vocal cords, ensure that only the anterior angle of the glottic opening is visible.

Continue to advance to the estimated position of the lesion. Stop and visualize the entire lumen using 35 degree backward flexion as needed. When advancing the probe, be certain that the entire lumen is not in sight, as this might mean the probe tip is scraping the airway wall.

After reaching the site of interest, introduce about two milliliters of normal saline to inflate the balloon. Flex the tip of the probe forward to bring it into contact with the airway. Next, turn on the ultrasound view and use the two screen display to see both the endoscopic view of the lumen and the corresponding ultrasound image with the bronchoscope in forward flexion.

To keep the probe in contact with the airway wall, move it both clockwise and counterclockwise by small angles. To identify the substernal thyroid gland, move the probe up and down so that its largest diameter is seen. Use the doppler mode to determine the lesion's position and identify adjacent vascular structures to avoid puncturing them.

Move to the level of the lesion and flex the bronchoscope forward. To bring the ultrasound probe in contact with the airway. Then obtain an ultrasound view of the lesion.

To obtain a full endoscopic view, flex the tip backward. Repeat these maneuvers to identify a point of entry between the tracheal rings for the trans bronchial needle aspiration needle. To perform the biopsy, have the dedicated needle for transbronchial needle aspiration ready.

Ensure the convex probe. Endo bronchial ultrasound probe tip is in the non flexed position, and introduce the needle into the working channel of the bronchoscope. Fasten the needle assembly onto the working channel using the locking mechanism.

Next, loosen the sheath adjuster knob and advance the sheath. Stop when the tip can be barely visualized on the endoscopic image. Fasten the sheath adjuster knob.

Continue by flexing the probe forward to bring it in contact with the airway wall. Use the ultrasound image to confirm that the longest diameter of the lesion is aligned with the projected path of the needle. Release the needle lock and remember, the needle exits the working channel at an angle of 20 degrees.

Use real-time ultrasound for feedback on the needle position. Use the needle to puncture through the airway wall into the lesion with the needle inside the lesion. Shake the internal stylet to clean out the needle tip, then remove the stylet.

Next, attach a 20 milliliter vacuum generating syringe and apply 20 milliliters of negative pressure. Move the needle back and forth inside the lesion, a total of at least 15 to 20 times. When done, turn the negative pressure knob off, then retrieve the needle from the working channel.

Recover the histological core by using the internal sheath to push it out. The sample is ready for review by onsite cytology services. Remove the ebus bronchoscope and continue with post-procedure surveillance conventional bronchoscopy to ensure hemostasis and remove remaining debris.

This benign follicular thyroid tissue was biopsied using endobronchial ultrasound with transbronchial needle aspiration, the tissue is stained using hematin, eoin and magnified 10 times. Once mastered, this technique can be performed in 30 minutes to an hour. The proceduralist should take adequate time to identify the lesion of interest using the ultrasound mode and confirm the absence of blood flow.

Using the color Doppler mode While attending this procedure, it's very important to identify the anatomical landmarks of the MidAm. This will ensure appropriate sampling of targeted lesion and decrease the risk of complications such as vascular punctures and mediastinitis.