Bronchoscopic cryotherapy is a relatively new addition to the bronchoscopic armamentarium. It is a type of therapeutic or diagnostic procedure done during bronchoscopy. In this method, cooling of the tissue is performed to destroy abnormal lung tissue (cryoablation), or remove lung tissue for biopsy (cryobiopsy)
To perform bronchoscopic cryotherapy, cryosurgery devices like cryoprobe, cooling agent, and a bronchoscope are required.
Bronchoscopic cryotherapy has several clinical applications. Some of them include:
- Transbronchial lung biopsy (Cryo lung biopsy)
- Removal of tumors in the airways and the lungs (Cryo recanalization)
- Removal of foreign body (cryoextraction)
- Endobronchial biopsy
A) Cryo lung biopsy
Cryo lung biopsy is a new diagnostic intervention to obtain tissue samples from the lungs. In this procedure, larger tissue samples can be obtained with fewer side effects than the surgical biopsy. It is performed during bronchoscopy. Cryo lung biopsy helps in identifying several subtypes of interstitial lung disease.
B) Cryo pleural biopsy
Cryo pleural biopsy is done to obtain pleural samples in pleural diseases such as pleural effusion. This procedure is done using pleuroscopy.
C) Cryo debulking of tumors
When large tumors obstruct the airways, cryotherapy can be used to reding the size of the tumors. Flexible cryoprobes are used for debulking of endobronchial tumors.
D) Cryo extraction of foreign bodies
Removal of foreign bodies, such as food particles, tablets, or any other obstacles in the airways can be achieved by using a cryoprobe during flexible bronchoscopy.
Before the procedure, your doctor will perform some diagnostic tests, such as:
- Computed tomography (CT) of the chest
- Blood tests for serum creatinine levels, complete blood count and coagulation profile
- Electrocardiogram and echocardiography
- Spirometry and pulse oximetry
- Arterial blood gases
- An anesthetic gel is applied on the outer surface of the bronchoscope to avoid so that the patient doesn’t experience pain during insertion.
- A rigis bronchoscope is then inserted in the direction of the long tracheal axis and moved gently to avoid tracheal injury.
- Once the bronchoscope is placed at the position, the optical telescope is removed, and a flexible video-bronchoscope is inserted through the bronchoscope barrel.
- Along with this bronchoscope, an occlusion balloon is inserted along the side of the flexible bronchoscope.
- The cryoprobe is inserted in the working channel of the bronchoscope and with the help of fluoroscopy, it is placed in an accurate position.
- Then the foot pedal of the cryostat is activated for 3-6 seconds.
- The cryoprobe along with the flexible bronchoscope is quickly pulled backward.
- Once the cryoprobe is removed, the occlusion balloon is inflated and kept for about 45 seconds.
- The biopsy pieces are collected in a vial and the bronchoscope is reinserted to check for any active bleeding.
- Nearly 2-4 biopsies are done in a similar way.
- You would be kept under observation in a recovery room
- After 2 hours of the procedure, a chest X-ray is done to check for pneumothorax.
- If the procedure is uncomplicated, you would be discharged on the same day.
- In some cases, you may have to stay at the hospital until the required duration as suggested by the doctor.
Cryo lung biopsy may lead to the following complications (<5% incidence):
- Pneumothorax (accumulation of air in the space between the lungs and the chest wall)
- Moderate-severe bleeding in the airways
- Aggravation of the underlying interstitial lung disease