Bronchitis is one of the diseases that falls under the COPD umbrella. It is where the main airways become inflamed and irritated leading to shortness of breath, mucus build-up and severe coughing. The new treatment being tested on patients with chronic bronchitis targets the thickened airway tissue by freezing it via a technique known as cryotherapy.

The theory behind it is that the cycle of freezing and thawing destroys the damaged tissue in the lungs allowing healthy cells to develop in its place and helps to repair the lungs and improve breathing. This has already been used to successfully treat oesophageal cancer.
A catheter is inserted into the airway and navigated to where the airways are thickened via an MRI scan and then liquid nitrogen at -200C is sprayed onto that section. The section of lung tissue is then allowed to naturally thaw for a few minutes and then the area is repeatedly blasted until the target tissue has been destroyed. The flash-freeze and slow thaw of the tissue has been shown to destroy the targeted cells but does not affect the collagen, which provides the scaffold for healthy tissue to regrow into.
This is currently being trialled in several British Hospitals and appears to be successful. The treatment can be adapted according top the patients needs and the number of treatments will depend upon the severity of their condition and how much tissue needs to be frozen. Hopefully these trials are the start of a journey towards a new successful treatment for COPD.
The medical potential is vast as it could mean that damaged tissue anywhere in the body could be treated by cryotherapy in the same way and allow new tissue growth to come through, thereby allowing aided self-healing of a huge number of conditions.

References: www.dailymail.co.uk