Interventional pulmonology is a new and growing subspecialty of pulmonology. It focuses on the use of advanced therapeutic and diagnostic techniques for several conditions.
Tracheobronchial stenting is a procedure in which a stent is placed to widen the narrowed airways. It is a minimally invasive procedure to prevent or treat restricted airflow in the larger airways such as the trachea and the bronchi. This procedure is usually recommended when the larger airways get narrowed due to any cause. When the larger airways like the trachea or bronchi get narrowed, the air passage becomes difficult and this leads to difficulty in breathing and noisy breathing called as stridor.
Tracheobronchial stent: The stent is a cylindrical tube made of a biologically inert material that is inserted into the airways. Stents are made of silicone (Silicone stents), nitinol metal (Metal stents) or a combination of metal and polyurethane (Covered metal stents).
Patients who need this procedure
Airway obstruction caused by tumors is the most common airway disease that requires tracheobronchial stenting. Some other airway conditions that require tracheobronchial stenting include:
- Bronchial or tracheal-esophageal fistula
- Non-cancerous central airway obstruction (Post intubation tracheal stenosis, post tubercular tracheobronchial stenosis)
Procedure of tracheobronchial stenting
When a patient is under anesthesia, a rigid bronchoscope is inserted into the mouth. It is slowly moved down the throat and passed through the airways. The narrowed parts of the airway are initially dilated using specialized techniques like CRE balloons or rigid barrels. Once the airways are opened, a stent is deployed I the correct position. Fluoroscopy is used to place the metallic stent in position.
Bronchoscopy can be used to remove certain tumors of the airway and eliminate the need for surgery. During bronchoscopy, small surgical instruments are passed through the bronchoscope to remove the tumors. Different therapies can be administered with the help of a bronchoscope, such as:
- Laser therapy: In this therapy, a highly focused beam of light is targeted to the tumors, which resects or shrinks the tumor.
- Electrocautery: Electric current is passed through specialized accessories like a knife, snare or a probe. This is used to cut the tissue or to burn the tissue
- Argon beam coagulation: In this process, electricity and argon gas are used to kill tumor tissue and stop the bleeding.
- Cryotherapy: Specialized gases are used to freeze the tissues and destroy them after which they are removed.
All the above technologies are used in isolation or in combination to remove the tumors from the airways. Bronchoscopic tumor removal is indicated only for tumors which are entirely located within the airways of the patient.
Navigational bronchoscopy provides a virtual three-dimensional image of the lungs. In navigational bronchoscopy, a special bronchoscope is used to examine and treat the damaged tissues in the airways. It is mostly used in cases in which the lesion is present in the area in the lungs that is unreachable by normal bronchoscope.
Uses of navigational bronchoscopy
It is mostly done to diagnose and treat problems in the peripheral parts of the lungs. It is also performed for:
- Taking a biopsy of lung tissue (mainly peripheral lung lesion)
- Placing markers for radiation therapy
- Inserting internal radiation therapy catheters for cancerous lung tissues
- Helping in surgical removal of small peripheral lung lesion
First, a local anesthesia is administered to numb the throat. A computerized tomography scan is taken, and the scan images are saved in a special computer. The computer highlights the problem areas and the doctor uses these images to direct the scope. A bronchoscope is inserted in the mouth and gently moved down the throat to the lungs. After finishing the procedure, the tools and scope are removed. The tissue sample that is collected is sent to the lab and will be examined.
Bronchoscopic thermal vapor ablation is an endoscopic lung volume reduction technique. It is a quick, non-invasive procedure that is used to treat lung diseases like emphysema. The bronchoscopic thermal vapor ablation equipment consists of intervapor generator and intervapor catheter.
In this procedure, heated pure water in the form of steam is applied to the tissues. It is mostly used to treat patients with advanced upper lobe-predominant emphysema. Bronchoscopic thermal vapor ablation increases pulmonary function.
Steps of the procedure
Before starting the procedure, 3D images of the airway are taken. Mild sedation is given to make you relax. Then, a flexible bronchoscope is inserted through the mouth or nose and moved to the diseased area of the lungs. The catheter is placed at the location, and the balloon at the distal tip is inflated to occlude the bronchus. Then, hot steam (75°C) is sent within 3-10 seconds. After delivering the vapor, the balloon is deflated. The same procedure is repeated at another site with an interval of 3 minutes.