Complications

Thus far, concluded studies and those still ongoing have shown a positive effect and minimal side effects. Several patients have developed a cough which was relieved quickly, and in some cases asthma symptoms were aggravated for up two 2 hours following surgery. Despite this, researchers remain optimistic that bronchial thermoplasty will not only reduce the severity and frequency of asthma exacerbations, but will also decrease medication dependency.

Listed below are the negative side effects encountered in one particular study involving 8 patients. It is, however, important to note that throughout the duration of the study there were no additional or unscheduled hospital visits made by any participant, nor was there any requirement for additional medications. Also, there were no instances of respiratory tract infection or the need for supplemental oxygen:

- 1 patient viewed at 5 days post-op had narrowing of 3 airways

(reduction in diameter of 25 to 50%) with retained mucus in

2 of the 3.

- 1 patient examined 13 days post-op had narrowing and

erythema in 1 treated airway.

Obtained from www.ctv.ca

To date, bronchial thermoplasty has been performed using two different treatment temperatures, 55°C and 65°C. Only subtle changes, including reduced amounts of smooth muscle (5%), some epithelial regeneration (<2%), and minor metaplasia of the mucus ducts/glands, have been observed as a result of treatment at 55°C. In contrast, histologic alterations have been more significant in airways treated at 65°C:

- On average, 50% of airway circumference experienced a

reduction in smooth muscle.

- While epithelium remained entirely normal in ½ the patients,

there was a variable amount (2-11%) of sloughing and

epithelial regeneration (14-65%) in the other ½.

- Airways showed mucus duct and gland necrosis at 5 day

follow-up and 17% of the treated sections exhibited new

cartilage growth along the pericardium.

- non-infectious pneumonitis ( inflammation) was observed in

17 of the 64 treated sections.

The procedure encompasses the application of controlled heat via conduction from a metal device, therefore epithelial injury, edema and mucus accumulation were to be expected. Since the temporary reduction in airway quality resolved quickly and produced no serious functional limitations, the procedure was determined to be effective. However, it is important to consider the studies limitations. Firstly, none of the participants who received surgery were diagnosed with asthma. It is very plausible that individuals with asthma may react to the procedure much differently than those discussed above. In addition, the subjects who underwent surgery were all scheduled to have the bronchial thermoplasty treated sections removed in the near future (within 20 days). Though positive hypotheses based upon animal studies seem plausible, evidence concerning the long term effects on human airways still remains relatively unknown.

Obtained from www.cvsurgery.com/bronch

Finally, there is one documented case whereby surgery was not performed due to an anatomical abnormality of the lungs. One patient, who volunteered to participate, was denied treatment based on the geometry of his right upper lobe. Researchers stated that the tissue’s structure compromised placement of the bronchoscope and catheter at their targeted sites and therfore opted to remove the subject from the study based on safety concerns.

Due to the limited availability of resources, the majority of information sited above was taken from a publication in Chest.

This site has been developed using various resourses for educational purposes only. It has been created by physiotherapy students in order to fullfill course requirements for PHYT 4173 at Dalhousie University. All information contained herein should not be used as a substitute for that given by a qualified professional.